Using a Geographical Information System to investigate the relationship between reported cryptosporidiosis and water supply

Table 1 Health authority of reported cases, including reasons for exclusion from analysis

				Reasons for excluding post codes
Health Authority	Total records	Included in analysis	Excluded	Incorrect	Duplicate	Incomplete	Missing	% excluded
Bro Taf	2		2	2				100
Bury and Rochdale	51	43	8	4	2	1	1	15.7
Dyfed Powys	49	44	5	5				10.2
East Lancashire	47	45	2	2				4.3
Gwent	12	12	0					0
Iechyd Morgannwg	6		6	6				100
Morecambe Bay	13	10	3			3		23.1
Manchester	69	48	21	3		10	8	30.4
N Cheshire	6	6	0					0
North Wales	121	111	10	9		1		8.3
North West Lancashire	74	59	15	3	2		10	20.3
South Cheshire	63	63	0					0
South Lancashire	20	20	0					0
Salford	34	28	6			4	2	17.6
St Helens & Knowsley	8	8	0					0
Stockport	66	60	6	1	1		4	9.1
West Pennine	32	29	3		1	1	1	9.4
Wigan and Bolton	46	35	11	2	4	4	1	23.9
Wirral	28	28	0					0
TOTAL	747	649	98	37	10	24	27	13.1

ISSN: 1476-072X