Table 1 Methods use to assess spatial variability of legionellosis, classification criteria for high-risk census tracts, and corresponding number of census tracts, cases, and estimated population captured by each method
Method of spatial variability | “High-risk” classification | # of census tracts identified as “high-risk” | # of cases residing in “high-risk” census tract | Estimated population within “high-risk” census tract |
|---|---|---|---|---|
Unadjusted IR | IR ≥ 2 per 100,000 | 744 | 1407 | 3,126,058 |
Standardized IR | IR ≥ 2 per 100,000 | 724 | 1376 | 3,151,260 |
1% cluster detection | Detected within a cluster | 93 | 243 | 327,824 |
50% cluster detection | Detected within a cluster | 259 | 412 | 981,983 |
Reliable cluster detection | RS ≥ 0.5 and a RR ≥ 2 | 136 | 397 | 507,694 |