Per cent increase in hospital admissions for GI illness among the elderly of Philadelphia associated with an interquartile range increase in turbidity, 1992–1993
| Lag of turbidity | Per cent increase | 95% Confidence intervals | |
|---|---|---|---|
| Entire city By water plant | 9–11 days | 9.0 | (5.3, 12.7) |
| Belmont plant | 4–6 days | 9.1 | (5.2, 13.3) |
| 11 days | 15.1 | (7.8, 12.3) | |
| Queen Lane Plant | 10 days | 8.2 | (0.6, 16.4) |
| Baxter Plant | 9 days | 5.3 | (0.4, 10.4) |
| By age | |||
| age 65–74 | 9–11 days | 2.5 | (−3.8, 9.1) |
| age 75+ | 9–11 days | 9.1 | (5.2, 13.3) |