Figure 4.

The association between ambient temperature (every 1˚C increase in daily mean temperature) and hospitalization for renal diseases [Relative risk with 95% confidence intervals (CIs)] over 0–7 lag days. The relative risk represents the cumulative association over lag 0–7 days and came from a time-stratified case-crossover design with conditional logistic regression. A cross-basis function for mean temperature was used in the model with adjustment for daily mean relative humidity and public holidays. P for difference was estimated by meta-regression to test the difference in associations between subgroups.