Table 3. Adjusted odds ratios (OR) and 95% confidence intervals (CI) of association with 90^th percentile precipitation and hospitalizations for gastrointestinal illness by season and water source.

	Groundwater				Surface water				Other
	WarmN = 16284		ColdN = 12584		WarmN = 52254		ColdN = 39658		WarmN = 12587		ColdN = 9214
	OR	95% CI	OR	95% CI	OR	95% CI	OR	95% CI	OR	95% CI	OR	95% CI
No lag	1.05	0.93–1.18	0.93	0.80–1.08	1.12	1.05–1.19*	0.90	0.83–0.97*	1.06	0.93–1.20	0.98	0.83–1.15
1-day lag	1.02	0.91–1.14	0.88	0.76–1.02	1.05	1.00–1.11	0.85	0.79–0.91*	1.01	0.89–1.14	0.94	0.80–1.10
2-day lag	1.08	0.96–1.20	0.98	0.85–1.12	1.09	1.03–1.16*	0.89	0.83–0.96*	1.07	0.95–1.20	1.01	0.86–1.19
3-day lag	1.00	0.90–1.12	0.89	0.76–1.03	1.02	0.96–1.07	0.83	0.77–0.89*	1.11	0.99–1.25	0.89	0.75–1.04
4-day lag	1.06	0.95–1.19	0.97	0.84–1.12	1.06	1.00–1.12	0.95	0.88–1.02	1.16	1.03–1.31*	1.02	0.87–1.19
5-day lag	1.06	0.95–1.19	1.05	0.92–1.21	1.03	0.98–1.09	0.98	0.91–1.05	1.10	0.97–1.24	0.97	0.83–1.13
6-day lag	1.01	0.90–1.13	1.05	0.92–1.21	1.02	0.96–1.08	0.95	0.88–1.02	1.02	0.91–1.15	0.89	0.76–1.06
7-day lag	1.00	0.90–1.12	0.86	0.75–1.00*	0.97	0.92–1.03	1.01	0.94–1.09	1.05	0.93–1.19	1.01	0.86–1.19
3-day avg (no lag)	1.00	0.90–1.13	0.82	0.70–0.96*	1.03	0.97–1.10	0.86	0.80–0.93*	1.04	0.92–1.17	0.91	0.77–1.08
3-day avg (3-d lag)	0.99	0.88–1.11	1.02	0.88–1.19	1.03	0.97–1.09	0.91	0.85–0.98*	1.06	0.94–1.20	0.98	0.83–1.15
3-day avg (5-d lag)	0.98	0.87–1.10	1.10	0.96–1.28	0.97	0.91–1.02	0.98	0.92–1.05	0.97	0.86–1.09	1.19	1.02–1.39*
3-day avg (7-d lag)	1.01	0.91–1.13	1.02	0.87–1.18	1.01	0.95–1.07	1.07	0.99–1.15	1.07	0.95–1.21	1.07	0.90–1.26

ORs adjusted for temperature and humidity; Warm season (April–October), Cold Season (November-March); N is number of case and control days.

*Statistically significant (p-value < 0.05).