Association between ambient temperature and hospitalization for renal diseases in Brazil during 2000–2015: A nationwide case-crossover study

BACKGROUND: Climate change is increasing the risks of injuries, diseases, and deaths globally. However, the association between ambient temperature and renal diseases has not been fully characterized. This study aimed to quantify the risk and attributable burden for hospitalizations of renal diseases related to ambient temperature. METHODS: Daily hospital admission data from 1816 cities in Brazil were collected during 2000 and 2015. A time-stratified case-crossover design was applied to evaluate the association between temperature and renal diseases. Relative risks (RRs), attributable fractions (AFs), and their confidence intervals (CIs) were calculated to estimate the associations and attributable burden. FINDINGS: A total of 2,726,886 hospitalizations for renal diseases were recorded during the study period. For every 1°C increase in daily mean temperature, the estimated risk of hospitalization for renal diseases over lag 0–7 days increased by 0·9% (RR = 1·009, 95% CI: 1·008–1·010) at the national level. The associations between temperature and renal diseases were largest at lag 0 days but remained for lag 1–2 days. The risk was more prominent in females, children aged 0–4 years, and the elderly ≥ 80 years. 7·4% (95% CI: 5·2–9·6%) of hospitalizations for renal diseases could be attributable to the increase of temperature, equating to 202,093 (95% CI: 141,554–260,594) cases. INTERPRETATION: This nationwide study provides robust evidence that more policies should be developed to prevent heat-related hospitalizations and mitigate climate change. FUNDING: China Scholarship Council, and the Australian National Health and Medical Research Council