U.S. congressional district cancer death rates

  • Yongping Hao1Email author,

    Affiliated with

    • Elizabeth M Ward1,

      Affiliated with

      • Ahmedin Jemal1,

        Affiliated with

        • Linda W Pickle2 and

          Affiliated with

          • Michael J Thun1

            Affiliated with

            International Journal of Health Geographics20065:28

            DOI: 10.1186/1476-072X-5-28

            Received: 11 May 2006

            Accepted: 23 June 2006

            Published: 23 June 2006

            Abstract

            Background

            Geographic patterns of cancer death rates in the U.S. have customarily been presented by county or aggregated into state economic or health service areas. Herein, we present the geographic patterns of cancer death rates in the U.S. by congressional district. Many congressional districts do not follow state or county boundaries. However, counties are the smallest geographical units for which death rates are available. Thus, a method based on the hierarchical relationship of census geographic units was developed to estimate age-adjusted death rates for congressional districts using data obtained at county level. These rates may be useful in communicating to legislators and policy makers about the cancer burden and potential impact of cancer control in their jurisdictions.

            Results

            Mortality data were obtained from the National Center for Health Statistics (NCHS) for 1990–2001 for 50 states, the District of Columbia, and all counties. We computed annual average age-adjusted death rates for all cancer sites combined, the four major cancers (lung and bronchus, prostate, female breast, and colorectal cancer) and cervical cancer. Cancer death rates varied widely across congressional districts for all cancer sites combined, for the four major cancers, and for cervical cancer. When examined at the national level, broad patterns of mortality by sex, race and region were generally similar with those previously observed based on county and state economic area.

            Conclusion

            We developed a method to generate cancer death rates by congressional district using county-level mortality data. Characterizing the cancer burden by congressional district may be useful in promoting cancer control and prevention programs, and persuading legislators to enact new cancer control programs and/or strengthening existing ones. The method can be applied to state legislative districts and other analyses that involve data aggregation from different geographic units.

            Background

            Cancer death rates presented by geographic boundaries such as state and county, state economic areas, and health service areas have been useful in monitoring temporal trends in allocating public health resources [1, 2], and in some instances, in generating etiological hypotheses. These rates are less useful for communicating to legislators and policy makers whose jurisdictions are not defined by state or county boundaries. There have been no published studies that attempted to measure cancer death rates within congressional districts.

            Public policy and legislation play a critically important role in efforts to reduce the burden of cancer. For example, the American Cancer Society estimates that in 2006 about 170,000 of the 564,830 cancer deaths are expected to be caused by tobacco use alone [3]. Policy measures that are proven to reduce smoking prevalence include excise taxes and funding for state comprehensive tobacco control programs [46]. Declines in smoking prevalence among men as a result of public health efforts have had a major influence on the declines in cancer mortality in the last decade.

            We present a method to calculate cancer death rates according to congressional district that may be useful in advocating for legislative initiatives and funding for cancer research and prevention programs.

            Results and discussion

            Maps of cancer death rates by congressional district were prepared for men and women, for all races combined, and for African Americans, non-Hispanic whites, and Hispanics (Figures 1, 2, 3, 4, 5); Hispanics are not mutually exclusive of whites and African Americans. Regional patterns of cancer mortality for African Americans and non-Hispanic whites were compared to previously published maps based on counties and state economic areas [1]. Although maps of cancer mortality by congressional district were also prepared for Hispanics, regional patterns are difficult to interpret because of insufficient data to calculate rates for most parts of the country. When examined at the national level, broad patterns of mortality for African Americans and non-Hispanic whites by sex and region were consistent with those previously observed [1]. Geographic variations in cancer death rates may reflect, in part, regional variations in risk factors such as smoking and obesity, early detection and screening, and access to and utilization of medical services.
            http://static-content.springer.com/image/art%3A10.1186%2F1476-072X-5-28/MediaObjects/12942_2006_Article_105_Fig1_HTML.jpg
            Figure 1

            All cancers combined death rates per 100,000 person-years by congressional district (age-adjusted 2000 US population), 1990–2001.

            http://static-content.springer.com/image/art%3A10.1186%2F1476-072X-5-28/MediaObjects/12942_2006_Article_105_Fig2_HTML.jpg
            Figure 2

            Lung cancer death rates per 100,000 person-years by congressional district (age-adjusted 2000 US population), 1990–2001.

            http://static-content.springer.com/image/art%3A10.1186%2F1476-072X-5-28/MediaObjects/12942_2006_Article_105_Fig3_HTML.jpg
            Figure 3

            Colorectal cancer death rates per 100,000 person-years by congressional district (age-adjusted 2000 US population), 1990–2001.

            http://static-content.springer.com/image/art%3A10.1186%2F1476-072X-5-28/MediaObjects/12942_2006_Article_105_Fig4_HTML.jpg
            Figure 4

            Prostate, female breast cancer death rates per 100,000 person-years by congressional district (age-adjusted 2000 US population), 1990–2001.

            http://static-content.springer.com/image/art%3A10.1186%2F1476-072X-5-28/MediaObjects/12942_2006_Article_105_Fig5_HTML.jpg
            Figure 5

            Cervical cancer death rates per 100,000 person-years by congressional district (age-adjusted 2000 US population), 1990–2001.

            Figure 1 shows geographic patterns of death rates for all cancer sites combined by congressional district in the United States. In men, rates range from 186.3 in Utah congressional district #3 to 343.7 in District of Columbia (Table 1) and in women, from 123.4 in Utah congressional district #1 to 217.4 in Pennsylvania congressional district #2 (Table 2). Generally, the patterns for all cancer sites combined are strikingly similar to those for lung cancer (Figure 2), reflecting the importance of lung cancer as a cause of cancer death, and the strong association of lung and cancers of several other sites with tobacco smoking. Lung cancer death rates in all races combined range from 35.7 in Utah congressional district #1 to 130.3 in Kentucky congressional district #5 for men and from 14.8 in Utah congressional district #3 to 57.9 in Kentucky congressional district #5 for women. Lung cancer death rates are the highest in congressional districts in Appalachia and the south among non-Hispanic white men and in the Midwest and the south among African American men. In contrast, among women, rates are the highest in congressional districts in the Midwest among African Americans and in the west, Appalachia, and the coastal south among non-Hispanic whites. Historically, smoking was more common in the south among men and in the west among women, especially among whites [7]. Although patterns of lung cancer mortality in the 1990's primarily reflect smoking patterns in the 1950's and 1960's, the burden of death from all cancers and lung cancer by congressional district can be used to illustrate the importance of tobacco control measures as well as to document local needs for cancer treatment and associated services.
            Table 1

            Age-adjusted death rates, all cancers combined, for US men by congressional district (CD), 1990–2001

            State

            CD

            Rate

            State

            CD

            Rate

            State

            CD

            Rate

            State

            CD

            Rate

            AL

            0101

            311.55

            FL

            1223

            233.18

            MN

            2705

            246.79

            OR

            4102

            245.13

            AL

            0102

            309.74

            FL

            1224

            262.08

            MN

            2706

            243.38

            OR

            4103

            270.72

            AL

            0103

            312.74

            FL

            1225

            231.74

            MN

            2707

            235.05

            OR

            4104

            246.92

            AL

            0104

            290.71

            GA

            1301

            306.92

            MN

            2708

            250.08

            OR

            4105

            246.09

            AL

            0105

            262.11

            GA

            1302

            318.36

            MS

            2801

            299.09

            PA

            4201

            341.70

            AL

            0106

            286.12

            GA

            1303

            310.67

            MS

            2802

            330.08

            PA

            4202

            343.25

            AL

            0107

            307.46

            GA

            1304

            256.56

            MS

            2803

            299.83

            PA

            4203

            262.65

            AK

            0299

            248.48

            GA

            1305

            283.68

            MS

            2804

            314.84

            PA

            4204

            279.79

            AZ

            0401

            205.84

            GA

            1306

            271.97

            MO

            2901

            282.13

            PA

            4205

            250.82

            AZ

            0402

            239.41

            GA

            1307

            253.45

            MO

            2902

            256.11

            PA

            4206

            251.69

            AZ

            0403

            229.35

            GA

            1308

            283.26

            MO

            2903

            298.52

            PA

            4207

            276.22

            AZ

            0404

            229.35

            GA

            1309

            276.76

            MO

            2904

            264.86

            PA

            4208

            272.61

            AZ

            0405

            229.35

            GA

            1310

            276.81

            MO

            2905

            277.15

            PA

            4209

            253.47

            AZ

            0406

            227.76

            GA

            1311

            290.20

            MO

            2906

            263.57

            PA

            4210

            260.76

            AZ

            0407

            211.10

            GA

            1312

            295.19

            MO

            2907

            272.91

            PA

            4211

            274.08

            AZ

            0408

            234.26

            GA

            1313

            267.16

            MO

            2908

            290.16

            PA

            4212

            268.01

            AR

            0501

            307.86

            HI

            1501

            202.59

            MO

            2909

            264.05

            PA

            4213

            295.64

            AR

            0502

            292.46

            HI

            1502

            202.59

            MT

            3099

            248.52

            PA

            4214

            288.08

            AR

            0503

            264.97

            ID

            1601

            234.87

            NE

            3101

            242.74

            PA

            4215

            253.36

            AR

            0504

            296.35

            ID

            1602

            221.35

            NE

            3102

            267.93

            PA

            4216

            244.42

            CA

            0601

            257.81

            IL

            1701

            287.98

            NE

            3103

            226.06

            PA

            4217

            266.93

            CA

            0602

            266.90

            IL

            1702

            287.63

            NV

            3201

            268.19

            PA

            4218

            277.63

            CA

            0603

            245.75

            IL

            1703

            287.98

            NV

            3202

            254.67

            PA

            4219

            252.99

            CA

            0604

            236.01

            IL

            1704

            287.98

            NV

            3203

            268.19

            RI

            4401

            276.83

            CA

            0605

            245.61

            IL

            1705

            287.98

            NH

            3301

            270.77

            RI

            4402

            278.12

            CA

            0606

            227.02

            IL

            1706

            256.03

            NH

            3302

            266.04

            SC

            4501

            293.71

            CA

            0607

            244.64

            IL

            1707

            287.98

            NJ

            3401

            292.38

            SC

            4502

            279.65

            CA

            0608

            244.76

            IL

            1708

            265.27

            NJ

            3402

            290.30

            SC

            4503

            283.26

            CA

            0609

            246.04

            IL

            1709

            287.98

            NJ

            3403

            277.44

            SC

            4504

            280.26

            CA

            0610

            242.33

            IL

            1710

            269.31

            NJ

            3404

            275.30

            SC

            4505

            311.21

            CA

            0611

            242.00

            IL

            1711

            272.33

            NJ

            3405

            259.29

            SC

            4506

            313.81

            CA

            0612

            232.65

            IL

            1712

            296.31

            NJ

            3406

            273.02

            SD

            4699

            246.34

            CA

            0613

            246.04

            IL

            1713

            257.26

            NJ

            3407

            260.46

            TN

            4701

            288.63

            CA

            0614

            216.61

            IL

            1714

            248.91

            NJ

            3408

            279.73

            TN

            4702

            281.01

            CA

            0615

            208.66

            IL

            1715

            267.45

            NJ

            3409

            260.33

            TN

            4703

            293.12

            CA

            0616

            208.66

            IL

            1716

            266.46

            NJ

            3410

            285.53

            TN

            4704

            299.25

            CA

            0617

            220.87

            IL

            1717

            273.62

            NJ

            3411

            253.50

            TN

            4705

            301.32

            CA

            0618

            248.61

            IL

            1718

            274.38

            NJ

            3412

            271.16

            TN

            4706

            282.64

            CA

            0619

            239.15

            IL

            1719

            275.28

            NJ

            3413

            283.59

            TN

            4707

            295.64

            CA

            0620

            235.22

            IN

            1801

            297.56

            NM

            3501

            224.30

            TN

            4708

            299.44

            CA

            0621

            231.25

            IN

            1802

            273.64

            NM

            3502

            227.97

            TN

            4709

            323.86

            CA

            0622

            241.10

            IN

            1803

            264.13

            NM

            3503

            205.63

            TX

            4801

            298.28

            CA

            0623

            216.41

            IN

            1804

            278.64

            NY

            3601

            272.33

            TX

            4802

            302.76

            CA

            0624

            218.17

            IN

            1805

            265.45

            NY

            3602

            269.70

            TX

            4803

            251.80

            CA

            0625

            234.12

            IN

            1806

            271.20

            NY

            3603

            245.27

            TX

            4804

            280.20

            CA

            0626

            239.12

            IN

            1807

            310.26

            NY

            3604

            236.48

            TX

            4805

            296.25

            CA

            0627

            229.74

            IN

            1808

            287.76

            NY

            3605

            225.59

            TX

            4806

            281.01

            CA

            0628

            229.74

            IN

            1809

            286.44

            NY

            3606

            222.78

            TX

            4807

            277.95

            CA

            0629

            229.74

            IA

            1901

            259.56

            NY

            3607

            247.39

            TX

            4808

            282.93

            CA

            0630

            229.74

            IA

            1902

            250.56

            NY

            3608

            247.21

            TX

            4809

            302.08

            CA

            0631

            229.74

            IA

            1903

            256.54

            NY

            3609

            229.07

            TX

            4810

            242.29

            CA

            0632

            229.74

            IA

            1904

            242.92

            NY

            3610

            242.88

            TX

            4811

            272.71

            CA

            0633

            229.74

            IA

            1905

            244.45

            NY

            3611

            242.94

            TX

            4812

            272.87

            CA

            0634

            229.74

            KS

            2001

            236.43

            NY

            3612

            240.42

            TX

            4813

            267.39

            CA

            0635

            229.74

            KS

            2002

            254.68

            NY

            3613

            263.79

            TX

            4814

            267.50

            CA

            0636

            229.74

            KS

            2003

            243.40

            NY

            3614

            241.66

            TX

            4815

            200.38

            CA

            0637

            229.74

            KS

            2004

            259.82

            NY

            3615

            251.70

            TX

            4816

            223.16

            CA

            0638

            229.74

            KY

            2101

            301.17

            NY

            3616

            267.24

            TX

            4817

            270.88

            CA

            0639

            229.74

            KY

            2102

            302.60

            NY

            3617

            255.21

            TX

            4818

            277.95

            CA

            0640

            224.83

            KY

            2103

            319.57

            NY

            3618

            245.32

            TX

            4819

            258.34

            CA

            0641

            248.53

            KY

            2104

            311.74

            NY

            3619

            263.83

            TX

            4820

            252.64

            CA

            0642

            232.32

            KY

            2105

            314.33

            NY

            3620

            266.28

            TX

            4821

            247.33

            CA

            0643

            253.34

            KY

            2106

            306.21

            NY

            3621

            267.14

            TX

            4822

            263.97

            CA

            0644

            225.41

            LA

            2201

            313.23

            NY

            3622

            270.59

            TX

            4823

            226.97

            CA

            0645

            225.51

            LA

            2202

            341.56

            NY

            3623

            278.23

            TX

            4824

            275.61

            CA

            0646

            226.08

            LA

            2203

            317.11

            NY

            3624

            257.38

            TX

            4825

            276.05

            CA

            0647

            224.82

            LA

            2204

            314.28

            NY

            3625

            266.60

            TX

            4826

            250.08

            CA

            0648

            224.82

            LA

            2205

            321.98

            NY

            3626

            270.45

            TX

            4827

            229.00

            CA

            0649

            232.00

            LA

            2206

            302.08

            NY

            3627

            271.37

            TX

            4828

            231.66

            CA

            0650

            235.70

            LA

            2207

            307.17

            NY

            3628

            268.37

            TX

            4829

            277.95

            CA

            0651

            235.62

            ME

            2301

            272.57

            NY

            3629

            268.26

            TX

            4830

            279.05

            CA

            0652

            235.70

            ME

            2302

            291.59

            NC

            3701

            325.75

            TX

            4831

            258.48

            CA

            0653

            235.70

            MD

            2401

            293.67

            NC

            3702

            307.11

            TX

            4832

            279.05

            CO

            0801

            247.17

            MD

            2402

            300.57

            NC

            3703

            312.42

            UT

            4901

            188.85

            CO

            0802

            216.40

            MD

            2403

            306.03

            NC

            3704

            276.61

            UT

            4902

            194.50

            CO

            0803

            218.01

            MD

            2404

            261.33

            NC

            3705

            270.43

            UT

            4903

            186.38

            CO

            0804

            217.45

            MD

            2405

            293.74

            NC

            3706

            269.53

            VT

            5099

            262.46

            CO

            0805

            230.10

            MD

            2406

            268.50

            NC

            3707

            303.46

            VA

            5101

            294.08

            CO

            0806

            205.15

            MD

            2407

            331.59

            NC

            3708

            295.65

            VA

            5102

            291.22

            CO

            0807

            223.10

            MD

            2408

            212.85

            NC

            3709

            280.84

            VA

            5103

            335.68

            CT

            0901

            252.15

            MA

            2501

            266.20

            NC

            3710

            283.71

            VA

            5104

            321.70

            CT

            0902

            255.68

            MA

            2502

            273.91

            NC

            3711

            251.18

            VA

            5105

            278.86

            CT

            0903

            253.05

            MA

            2503

            272.89

            NC

            3712

            273.38

            VA

            5106

            270.54

            CT

            0904

            237.15

            MA

            2504

            275.28

            NC

            3713

            274.86

            VA

            5107

            289.48

            CT

            0905

            246.80

            MA

            2505

            268.96

            ND

            3899

            243.02

            VA

            5108

            228.11

            DE

            1099

            289.44

            MA

            2506

            270.11

            OH

            3901

            295.76

            VA

            5109

            274.86

            DC

            1198

            343.78

            MA

            2507

            271.96

            OH

            3902

            293.68

            VA

            5110

            258.25

            FL

            1201

            287.59

            MA

            2508

            295.36

            OH

            3903

            284.95

            VA

            5111

            231.79

            FL

            1202

            287.22

            MA

            2509

            283.39

            OH

            3904

            274.64

            WA

            5301

            245.00

            FL

            1203

            285.46

            MA

            2510

            269.84

            OH

            3905

            262.93

            WA

            5302

            234.80

            FL

            1204

            316.89

            MI

            2601

            261.34

            OH

            3906

            287.57

            WA

            5303

            255.32

            FL

            1205

            256.17

            MI

            2602

            248.17

            OH

            3907

            276.90

            WA

            5304

            240.69

            FL

            1206

            281.19

            MI

            2603

            245.36

            OH

            3908

            271.26

            WA

            5305

            246.75

            FL

            1207

            262.33

            MI

            2604

            260.27

            OH

            3909

            287.34

            WA

            5306

            260.08

            FL

            1208

            262.72

            MI

            2605

            278.91

            OH

            3910

            293.92

            WA

            5307

            239.57

            FL

            1209

            265.45

            MI

            2606

            266.81

            OH

            3911

            293.92

            WA

            5308

            244.02

            FL

            1210

            249.68

            MI

            2607

            263.88

            OH

            3912

            281.32

            WA

            5309

            249.13

            FL

            1211

            277.62

            MI

            2608

            253.12

            OH

            3913

            277.94

            WV

            5401

            278.03

            FL

            1212

            265.00

            MI

            2609

            247.44

            OH

            3914

            266.04

            WV

            5402

            296.32

            FL

            1213

            225.69

            MI

            2610

            272.66

            OH

            3915

            293.41

            WV

            5403

            298.58

            FL

            1214

            215.92

            MI

            2611

            284.77

            OH

            3916

            259.50

            WI

            5501

            265.84

            FL

            1215

            252.94

            MI

            2612

            263.76

            OH

            3917

            272.68

            WI

            5502

            235.97

            FL

            1216

            236.00

            MI

            2613

            300.81

            OH

            3918

            280.22

            WI

            5503

            244.95

            FL

            1217

            238.61

            MI

            2614

            300.81

            OK

            4001

            270.44

            WI

            5504

            285.86

            FL

            1218

            239.87

            MI

            2615

            272.06

            OK

            4002

            295.23

            WI

            5505

            247.27

            FL

            1219

            225.47

            MN

            2701

            234.69

            OK

            4003

            252.79

            WI

            5506

            248.00

            FL

            1220

            241.08

            MN

            2702

            232.60

            OK

            4004

            263.30

            WI

            5507

            253.68

            FL

            1221

            237.96

            MN

            2703

            246.78

            OK

            4005

            273.49

            WI

            5508

            252.81

            FL

            1222

            228.26

            MN

            2704

            253.04

            OR

            4101

            239.29

            WY

            5699

            240.61

            Table 2

            Age-adjusted death rates, all cancers combined, for US women by congressional district (CD), 1990–2001

            State

            CD

            Rate

            State

            CD

            Rate

            State

            CD

            Rate

            State

            CD

            Rate

            AL

            0101

            178.15

            FL

            1223

            166.84

            MN

            2705

            167.95

            OR

            4102

            167.81

            AL

            0102

            169.16

            FL

            1224

            171.40

            MN

            2706

            159.96

            OR

            4103

            181.38

            AL

            0103

            173.01

            FL

            1225

            148.24

            MN

            2707

            149.49

            OR

            4104

            175.60

            AL

            0104

            160.11

            GA

            1301

            171.36

            MN

            2708

            167.49

            OR

            4105

            170.49

            AL

            0105

            158.39

            GA

            1302

            164.99

            MS

            2801

            163.41

            PA

            4201

            216.57

            AL

            0106

            166.72

            GA

            1303

            160.00

            MS

            2802

            178.71

            PA

            4202

            217.49

            AL

            0107

            173.12

            GA

            1304

            158.33

            MS

            2803

            162.39

            PA

            4203

            171.06

            AK

            0299

            177.59

            GA

            1305

            174.21

            MS

            2804

            173.19

            PA

            4204

            177.43

            AZ

            0401

            150.54

            GA

            1306

            168.46

            MO

            2901

            184.42

            PA

            4205

            167.87

            AZ

            0402

            160.42

            GA

            1307

            156.76

            MO

            2902

            172.86

            PA

            4206

            170.48

            AZ

            0403

            155.51

            GA

            1308

            166.01

            MO

            2903

            191.43

            PA

            4207

            185.30

            AZ

            0404

            155.51

            GA

            1309

            160.49

            MO

            2904

            167.09

            PA

            4208

            182.33

            AZ

            0405

            155.51

            GA

            1310

            158.41

            MO

            2905

            180.75

            PA

            4209

            162.09

            AZ

            0406

            154.84

            GA

            1311

            168.71

            MO

            2906

            167.65

            PA

            4210

            169.23

            AZ

            0407

            143.81

            GA

            1312

            169.92

            MO

            2907

            166.90

            PA

            4211

            175.65

            AZ

            0408

            155.45

            GA

            1313

            166.59

            MO

            2908

            173.10

            PA

            4212

            169.55

            AR

            0501

            176.39

            HI

            1501

            132.18

            MO

            2909

            168.23

            PA

            4213

            195.46

            AR

            0502

            167.22

            HI

            1502

            132.18

            MT

            3099

            164.72

            PA

            4214

            185.54

            AR

            0503

            159.68

            ID

            1601

            159.32

            NE

            3101

            154.37

            PA

            4215

            167.46

            AR

            0504

            171.75

            ID

            1602

            145.79

            NE

            3102

            172.54

            PA

            4216

            166.84

            CA

            0601

            180.93

            IL

            1701

            187.65

            NE

            3103

            148.99

            PA

            4217

            171.04

            CA

            0602

            179.84

            IL

            1702

            187.39

            NV

            3201

            185.55

            PA

            4218

            179.77

            CA

            0603

            173.30

            IL

            1703

            187.65

            NV

            3202

            178.47

            PA

            4219

            164.61

            CA

            0604

            171.91

            IL

            1704

            187.65

            NV

            3203

            185.55

            RI

            4401

            176.99

            CA

            0605

            174.43

            IL

            1705

            187.65

            NH

            3301

            184.05

            RI

            4402

            181.40

            CA

            0606

            174.68

            IL

            1706

            171.34

            NH

            3302

            177.78

            SC

            4501

            168.40

            CA

            0607

            172.79

            IL

            1707

            187.65

            NJ

            3401

            197.38

            SC

            4502

            169.68

            CA

            0608

            160.82

            IL

            1708

            183.94

            NJ

            3402

            194.20

            SC

            4503

            160.68

            CA

            0609

            171.62

            IL

            1709

            187.65

            NJ

            3403

            187.01

            SC

            4504

            163.56

            CA

            0610

            171.36

            IL

            1710

            184.25

            NJ

            3404

            189.04

            SC

            4505

            170.43

            CA

            0611

            166.00

            IL

            1711

            176.79

            NJ

            3405

            181.48

            SC

            4506

            170.50

            CA

            0612

            163.35

            IL

            1712

            182.42

            NJ

            3406

            189.45

            SD

            4699

            155.91

            CA

            0613

            171.63

            IL

            1713

            170.69

            NJ

            3407

            175.40

            TN

            4701

            163.70

            CA

            0614

            155.60

            IL

            1714

            173.48

            NJ

            3408

            186.04

            TN

            4702

            166.03

            CA

            0615

            150.41

            IL

            1715

            169.81

            NJ

            3409

            179.94

            TN

            4703

            170.24

            CA

            0616

            150.41

            IL

            1716

            173.31

            NJ

            3410

            190.31

            TN

            4704

            166.86

            CA

            0617

            159.08

            IL

            1717

            169.35

            NJ

            3411

            178.32

            TN

            4705

            181.74

            CA

            0618

            167.37

            IL

            1718

            175.46

            NJ

            3412

            185.32

            TN

            4706

            166.05

            CA

            0619

            160.90

            IL

            1719

            171.91

            NJ

            3413

            185.44

            TN

            4707

            171.72

            CA

            0620

            160.07

            IN

            1801

            187.73

            NM

            3501

            152.60

            TN

            4708

            172.99

            CA

            0621

            155.17

            IN

            1802

            174.13

            NM

            3502

            148.21

            TN

            4709

            191.57

            CA

            0622

            167.90

            IN

            1803

            171.04

            NM

            3503

            145.39

            TX

            4801

            170.48

            CA

            0623

            156.79

            IN

            1804

            175.19

            NY

            3601

            193.45

            TX

            4802

            179.62

            CA

            0624

            159.18

            IN

            1805

            174.37

            NY

            3602

            192.13

            TX

            4803

            158.43

            CA

            0625

            165.29

            IN

            1806

            173.27

            NY

            3603

            180.21

            TX

            4804

            171.21

            CA

            0626

            167.46

            IN

            1807

            195.50

            NY

            3604

            175.92

            TX

            4805

            174.87

            CA

            0627

            163.44

            IN

            1808

            174.00

            NY

            3605

            159.07

            TX

            4806

            173.74

            CA

            0628

            163.44

            IN

            1809

            174.32

            NY

            3606

            154.59

            TX

            4807

            174.78

            CA

            0629

            163.44

            IA

            1901

            167.19

            NY

            3607

            167.00

            TX

            4808

            175.14

            CA

            0630

            163.44

            IA

            1902

            160.01

            NY

            3608

            169.61

            TX

            4809

            184.12

            CA

            0631

            163.44

            IA

            1903

            166.60

            NY

            3609

            157.90

            TX

            4810

            161.79

            CA

            0632

            163.44

            IA

            1904

            155.81

            NY

            3610

            165.33

            TX

            4811

            162.37

            CA

            0633

            163.44

            IA

            1905

            158.63

            NY

            3611

            165.35

            TX

            4812

            173.24

            CA

            0634

            163.44

            KS

            2001

            150.79

            NY

            3612

            164.75

            TX

            4813

            166.63

            CA

            0635

            163.44

            KS

            2002

            164.11

            NY

            3613

            180.01

            TX

            4814

            161.32

            CA

            0636

            163.44

            KS

            2003

            162.29

            NY

            3614

            168.07

            TX

            4815

            130.06

            CA

            0637

            163.44

            KS

            2004

            167.47

            NY

            3615

            173.80

            TX

            4816

            150.47

            CA

            0638

            163.44

            KY

            2101

            169.41

            NY

            3616

            175.64

            TX

            4817

            163.78

            CA

            0639

            163.44

            KY

            2102

            175.24

            NY

            3617

            173.76

            TX

            4818

            174.78

            CA

            0640

            158.89

            KY

            2103

            193.34

            NY

            3618

            170.09

            TX

            4819

            158.33

            CA

            0641

            171.99

            KY

            2104

            188.93

            NY

            3619

            184.37

            TX

            4820

            159.07

            CA

            0642

            162.99

            KY

            2105

            194.13

            NY

            3620

            182.40

            TX

            4821

            156.84

            CA

            0643

            173.93

            KY

            2106

            182.99

            NY

            3621

            181.17

            TX

            4822

            163.94

            CA

            0644

            162.59

            LA

            2201

            185.99

            NY

            3622

            184.58

            TX

            4823

            145.28

            CA

            0645

            163.17

            LA

            2202

            195.03

            NY

            3623

            181.55

            TX

            4824

            173.40

            CA

            0646

            160.07

            LA

            2203

            183.13

            NY

            3624

            172.75

            TX

            4825

            173.48

            CA

            0647

            158.89

            LA

            2204

            181.02

            NY

            3625

            177.64

            TX

            4826

            166.78

            CA

            0648

            158.89

            LA

            2205

            178.98

            NY

            3626

            178.41

            TX

            4827

            145.93

            CA

            0649

            165.98

            LA

            2206

            180.49

            NY

            3627

            181.68

            TX

            4828

            145.40

            CA

            0650

            167.74

            LA

            2207

            187.87

            NY

            3628

            178.66

            TX

            4829

            174.78

            CA

            0651

            164.39

            ME

            2301

            184.93

            NY

            3629

            181.02

            TX

            4830

            173.69

            CA

            0652

            167.74

            ME

            2302

            183.09

            NC

            3701

            174.50

            TX

            4831

            160.07

            CA

            0653

            167.74

            MD

            2401

            188.54

            NC

            3702

            165.66

            TX

            4832

            173.69

            CO

            0801

            162.28

            MD

            2402

            192.89

            NC

            3703

            174.10

            UT

            4901

            123.40

            CO

            0802

            153.27

            MD

            2403

            196.95

            NC

            3704

            170.87

            UT

            4902

            131.73

            CO

            0803

            147.33

            MD

            2404

            174.28

            NC

            3705

            155.94

            UT

            4903

            127.35

            CO

            0804

            147.02

            MD

            2405

            189.44

            NC

            3706

            162.13

            VT

            5099

            172.62

            CO

            0805

            153.67

            MD

            2406

            169.34

            NC

            3707

            168.11

            VA

            5101

            180.85

            CO

            0806

            153.08

            MD

            2407

            205.58

            NC

            3708

            169.12

            VA

            5102

            184.69

            CO

            0807

            153.73

            MD

            2408

            150.96

            NC

            3709

            168.36

            VA

            5103

            197.48

            CT

            0901

            167.11

            MA

            2501

            174.47

            NC

            3710

            157.81

            VA

            5104

            186.12

            CT

            0902

            169.98

            MA

            2502

            178.16

            NC

            3711

            158.78

            VA

            5105

            163.70

            CT

            0903

            172.06

            MA

            2503

            178.00

            NC

            3712

            166.97

            VA

            5106

            163.67

            CT

            0904

            167.64

            MA

            2504

            179.23

            NC

            3713

            165.79

            VA

            5107

            176.21

            CT

            0905

            167.56

            MA

            2505

            179.67

            ND

            3899

            156.30

            VA

            5108

            165.17

            DE

            1099

            190.49

            MA

            2506

            179.61

            OH

            3901

            193.84

            VA

            5109

            166.02

            DC

            1198

            203.38

            MA

            2507

            181.29

            OH

            3902

            190.45

            VA

            5110

            170.94

            FL

            1201

            170.38

            MA

            2508

            190.60

            OH

            3903

            185.18

            VA

            5111

            168.97

            FL

            1202

            177.20

            MA

            2509

            188.59

            OH

            3904

            171.76

            WA

            5301

            171.78

            FL

            1203

            180.69

            MA

            2510

            184.62

            OH

            3905

            164.79

            WA

            5302

            169.26

            FL

            1204

            187.94

            MI

            2601

            170.39

            OH

            3906

            179.70

            WA

            5303

            176.09

            FL

            1205

            165.25

            MI

            2602

            161.41

            OH

            3907

            182.23

            WA

            5304

            163.04

            FL

            1206

            174.62

            MI

            2603

            163.09

            OH

            3908

            177.92

            WA

            5305

            166.08

            FL

            1207

            170.67

            MI

            2604

            164.71

            OH

            3909

            184.70

            WA

            5306

            180.48

            FL

            1208

            172.08

            MI

            2605

            177.98

            OH

            3910

            188.77

            WA

            5307

            166.68

            FL

            1209

            168.29

            MI

            2606

            172.69

            OH

            3911

            188.77

            WA

            5308

            169.06

            FL

            1210

            159.50

            MI

            2607

            173.30

            OH

            3912

            187.23

            WA

            5309

            171.64

            FL

            1211

            172.59

            MI

            2608

            169.43

            OH

            3913

            180.65

            WV

            5401

            178.91

            FL

            1212

            160.52

            MI

            2609

            171.89

            OH

            3914

            177.31

            WV

            5402

            186.23

            FL

            1213

            150.69

            MI

            2610

            175.35

            OH

            3915

            191.61

            WV

            5403

            191.78

            FL

            1214

            144.66

            MI

            2611

            185.66

            OH

            3916

            168.52

            WI

            5501

            173.85

            FL

            1215

            166.13

            MI

            2612

            173.14

            OH

            3917

            174.30

            WI

            5502

            160.12

            FL

            1216

            159.77

            MI

            2613

            191.34

            OH

            3918

            176.73

            WI

            5503

            156.93

            FL

            1217

            155.30

            MI

            2614

            191.34

            OK

            4001

            174.42

            WI

            5504

            183.35

            FL

            1218

            152.52

            MI

            2615

            181.41

            OK

            4002

            175.25

            WI

            5505

            164.99

            FL

            1219

            163.40

            MN

            2701

            150.21

            OK

            4003

            157.63

            WI

            5506

            163.77

            FL

            1220

            167.15

            MN

            2702

            161.35

            OK

            4004

            162.63

            WI

            5507

            158.81

            FL

            1221

            152.17

            MN

            2703

            167.91

            OK

            4005

            175.18

            WI

            5508

            157.81

            FL

            1222

            164.56

            MN

            2704

            172.77

            OR

            4101

            169.53

            WY

            5699

            164.81

            Historically, female breast cancer death rates have been elevated in the Northeastern and North Central regions; North-South differences have diminished over time as female breast cancer death rates decreased in the Northeast but increased in the South [8]. For all races combined, female breast cancer death rates vary from 20.6 in Hawaii to 39.4 in District of Columbia. Among African American women, breast cancer death rates are highest in congressional districts in the south, Midwest, and west coast, while among non-Hispanic whites, breast cancer mortality is highest in congressional districts in the Northeast and west coast (Figure 4, right panel). Patterns of breast cancer mortality partly reflect the influence of known risk factors as well as access to and utilization of cancer screening and treatment. Important cancer control measures include access to mammography for the uninsured and under-insured, and availability of Medicaid coverage for diagnosis and treatment.

            Colorectal cancer death rates are highest overall in the Northeast and parts of the South and Midwest. Generally, death rates range from 18.4 in Texas congressional district #15 to 37.1 in Pennsylvania congressional district #1 for men and from 11.3 in Texas congressional district #15 to 24.1 in District of Columbia for women (Figure 3). Although a strong geographic pattern for colorectal cancer mortality has existed since the 1950's, the reasons are not well-understood [1]. The current priority for colorectal cancer control is to increase the proportion of individuals over 50 who receive recommended screening tests. Illustrating colorectal cancer mortality by legislative district may be influential in encouraging legislative support for mandated insurance coverage of colorectal screening tests and for programs to provide testing for the uninsured and under-insured.

            For all races combined, prostate cancer death rates range from 23.8 in Texas congressional district #15 and Hawaii to 58.2 in District of Columbia. Generally, rates are highest in congressional districts in the mid-Atlantic and Southern coastal areas, reflecting in large part the higher proportion of the African American men in the population of these areas (Figure 4, left panel). Death rates for African American men are more than twice the rates for non-Hispanic white men, reflecting higher incidence, later stage at diagnosis and poorer survival among African American men. Among non-Hispanic whites, rates are highest in congressional districts in the Rocky Mountain region; high rate (40.2) is observed in Hispanics in Texas congressional district #13. A recent study suggested that 10% to 30% of the geographic variation in prostate cancer death rates might relate to variations in access to medical care [9]. Although cancer control measures for prostate cancer are less well-defined than measures for some other cancer sites, illustrating prostate cancer mortality by congressional district may be helpful in advocating for funding of research on the prevention, early detection and treatment of prostate cancer and highlighting the importance of access to medical care for African American men.

            Mortality from cervical cancer in all races combined is highest in congressional districts in Appalachia, in the South and parts of the Southwest, with rates ranging from 1.4 in Minnesota congressional district #2 to 5.7 in New York congressional district #16 (Figure 5). Among African American women, rates are highest in congressional districts in the south and southeast, among non-Hispanic whites, rates are highest in congressional districts in Appalachia, and in Hispanics rates are highest in congressional districts in the coastal parts of California and Texas and in Colorado congressional district #3. Important cancer control measures include access to Pap tests for the uninsured and under-insured, and availability of Medicaid coverage for diagnosis and treatment.

            Conclusion

            The cancer mortality patterns by congressional district are generally similar to the patterns seen using other geographic boundaries. However, the patterns by congressional district may be useful to cancer control advocates to illustrate the importance of cancer control measures (prevention, early detection, and treatment) for their constituents. The method can be applied to state legislative districts and other analyses that involve data aggregation from different geographic units. Further research is needed to validate the estimates using mortality data geocoded to the lower geographic level such as block.

            Methods

            Death rates for U.S. states and counties

            Mortality data were obtained from the National Center for Health Statistics (NCHS). We computed annual average age-adjusted death rates for all cancer sites combined, the four major cancers (lung and bronchus, prostate, female breast, and colorectal cancer) and cervical cancer from 1990–2001 for 50 states, District of Columbia, and all counties using SEER*Stat [10]. Death rates, counts (number of deaths), and populations for counties were directly obtained for men and women, for all races combined, and for African Americans, non-Hispanic whites, and Hispanics. Except for the years of 1990 and 2000, the intercensal populations computed by the Census Bureau were used to obtain the total populations for the study time period. Since county designation for Alaska and Hawaii was not available from NCHS, death rates for Alaska and Hawaii reflect state rates. Rates were standardized to the 2000 U.S. population and expressed per 100,000 person-years.

            Death rates for U.S. congressional districts

            There are 436 (excluding Puerto Rico) federal congressional districts in the U.S. [11]. Among these, eight congressional districts followed state boundaries or their equivalent (Alaska, District of Columbia, Delaware, Montana, North Dakota, South Dakota, Vermont, and Wyoming). Further, since county-specific mortality data were not provided for Hawaii in SEER*Stat, we assigned the state death rate to both congressional districts. For congressional districts whose boundaries did not follow state and county boundaries (n = 426), death rates were calculated by assigning county-level age-adjusted death rates to census block and then aggregating death rates over blocks by congressional district using GIS [12] and SAS [13]. By doing so, we assume that blocks within a county have same death rates.

            There are three major areal interpolation methods (area weighting, surface smoothing, and dasymetric technique) for generating estimates for target zones from data available for source zones when the two geographic units are not comparable. Areal weighting assumes that data are homogeneously distributed across geographic units, which is generally unrealistic; it also involves the direct superimposition of source zones and target zones [14], which often leads to a lot of geographic boundary-line discrepancies [15]. Surface smoothing models data available for source zones as a continuous surface across the adjacent zones, assuming that the density declines with distance, taking into account the proximity of neighboring centroids [16, 17]. Dasymetric technique uses ancillary information to refine uneven data distributions across geographic units. Land cover from remote sensing [18] and the street layer [15, 19] have been used as subzone ancillary information. A recent study uses parish level (the lowest administrative unit) population data to derive weights [20]. However, there is no universal rule to construct areal interpolation, and the best solution depends on various factors: the variables of interest, the spatial relationships between source zones and target zones, and the availability of ancillary information related to both.

            In this study, we constructed a dasymetric method based on the hierarchical spatial relationships between blocks and counties and between blocks and congressional districts. Generally, congressional district and county share census block as a common basic spatial unit (Table 3) [21, 22]. We used block level sex- and race- specific population to devise a dasymetric approach that assigns county-level measures such as cancer death rates to census block and then aggregates census blocks at the congressional district level, using block population as a weighting factor. We did not use area weighting because of its unrealistic homogeneity assumption and boundary-line discrepancies associated with direct superimposition of two incomparable geographic units. Surface smoothing gives reliable estimates when smoothness is the real property of the density. However, the occurrence of cancer rarely follows a smooth distance-decay surface because major risk factors that affect cancer occurrence do not have smooth paths from the centroid to its adjacent neighboring centroids.
            Table 3

            The hierarchical spatial relationships between blocks and counties and between blocks and congressional districts

            County

            Block

            Congressional district

            County A

            Block A1

             
             

            Block A2

             
             

            Block A3

             
              

            Congressional district #1

             

            ...

             

            County B

            Block B1

             
             

            Block B2

             
             

            Block B3

             
             

            ...

             

            County C

            Block C1

            Congressional district #2

             

            Block C2

             
             

            Block C3

             
             

            ...

             

            ...

            ...

            ...

            To make the calculations, the following steps were taken:

            1. The number of people living within each census block by sex and race was determined from the 2000 U.S. census (covering 42 states, 426 congressional districts). Therefore, block population is sex- and race- specific.

            2. Block population was spatially assigned to congressional districts by block centroids.

            3. The age-adjusted cancer death rates for counties by sex and race were assigned to block by county FIPS (Federal Information Processing Standards) codes; FIPS codes are a standardized set of numeric or alphabetic codes issued by the National Institute of Standards and Technology (NIST) to ensure uniform identification of geographic entities through all federal government agencies [23].

            4. Cancer death rate for each congressional district by sex and race was calculated by aggregating sex- and race- specific cancer death rates over blocks. Taking non-Hispanic white men as an example, suppose that r i was the age-adjusted cancer death rate for block i (obtained from the corresponding county rate calculated from SEER*Stat). Suppose that a ij was the population of block i within district j, and that the population for district j, http://static-content.springer.com/image/art%3A10.1186%2F1476-072X-5-28/MediaObjects/12942_2006_Article_105_IEq1_HTML.gif , were known. Then the aggregated cancer death rate for district j, p j , was the summation of r i , weighted by the proportion of block population within the district, http://static-content.springer.com/image/art%3A10.1186%2F1476-072X-5-28/MediaObjects/12942_2006_Article_105_IEq2_HTML.gif . Other sex- and race-specific cancer death rates were calculated similarly.

            5. The number of cancer deaths for each congressional district by sex and race was calculated by aggregating the sex- and race- specific number of cancer deaths over blocks. The number of cancer deaths for a block was the product of crude death rate for the block (inherited from the corresponding county, which is the number of deaths for the county divided by the county population) and the block population. Again, taking non-Hispanic white men as an example, suppose that n i and c i were the number of deaths and the population for the county to which block i belongs, the crude death rate for block i was http://static-content.springer.com/image/art%3A10.1186%2F1476-072X-5-28/MediaObjects/12942_2006_Article_105_IEq3_HTML.gif . Given a ij was the population of block i within district j, then the number of deaths for block i within district j was http://static-content.springer.com/image/art%3A10.1186%2F1476-072X-5-28/MediaObjects/12942_2006_Article_105_IEq3_HTML.gif a ij , and the aggregated number of deaths for district j was http://static-content.springer.com/image/art%3A10.1186%2F1476-072X-5-28/MediaObjects/12942_2006_Article_105_IEq4_HTML.gif . Other sex- and race- specific number of cancer deaths were calculated in a similar way.

            6. The aggregated cancer death rates and the number of cancer deaths for the congressional districts (n = 426) from step 4 & 5 were exported back to GIS and linked with the other ten congressional districts (Alaska, District of Columbia, Delaware, Montana, North Dakota, South Dakota, Vermont, Wyoming, and two Hawaii districts) for producing maps. The estimates of the number of deaths were not presented separately. Instead, they were used as the criteria when mapping death rates across congressional districts. Death rates based on the small number of deaths (< 20) for the study time period were considered not reliable and thus excluded.

            7. Maps were generated using ArcGIS [12]. For all cancer sites combined and for each cancer site, the maps for all races combined were created by categorizing the rates into five groups. Cut points for the lowest and highest groups are approximately the 10th and 90th percentiles, except for cervical cancer which are 20th and 80th percentiles. Intervening groups are set at equal length between the lower bound cut point of 90th or 80th and the upper bound of 10th or 20th. Thus each interval represents the same absolute change over the middle range of rates, while the most extreme rates fall into the first and fifth categories. For each cancer site, to allow comparison among ethnic subgroups, the cut points for all races combined are used for race specific maps if rates are in the same range as those for all races combined. When the race specific rates fall out of the range of rates for all races combined, cut points for the exceeded portion are equally set at the length of rates in the highest category for all races combined. Cancer death rates based on the small number of deaths (< 20) are considered unstable and congressional districts with such rates are marked with hatches.

            In describing the cancer burden by congressional district, we used direct age adjustment instead of indirect age adjustment because direct method is more statistically correct when the rates are being compared [24]. Direct age-adjusted death rates describe the cancer death rate each congressional district would have if it had the age-sex-race distribution of the U.S. in the year 2000. In so far as congressional districts have age-sex-race compositions different from the U.S. in 2000, the need for resources to eliminate disparities between districts might be more or less than that suggested by the results described in this paper.

            Disclaimer

            The views and opinions expressed in this article do not necessarily reflect those of the National Cancer Institute.

            Declarations

            Acknowledgements

            We gratefully acknowledge Dr. Lance A Waller from Rollins School of Public Health at Emory University for his comments and suggestions on the early version of the manuscript.

            Authors’ Affiliations

            (1)
            American Cancer Society,
            (2)
            NCI/DCCPS,

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            This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://​creativecommons.​org/​licenses/​by/​2.​0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.