Table 2.
Number of wells within 2 kilometres | # Cases | Population | Attack rate per 1,000 | Ratio |
---|---|---|---|---|
0 | 636 | 35,063 | 18 | Reference |
1 | 1,511 | 25,792 | 59 | 3 |
2 | 4,010 | 22,245 | 180 | 10 |
3 | 552 | 670 | 824 | 45 |
Overall | 6,709 | 83,770 | 80 | - |
a Chi Square for linear trend = 6769; p value = < 0.0000