RESUMO
<p><b>OBJECTIVE</b>This study aimed to assess the association between emergency-room visits for respiratory tract infection (RTI) with diurnal temperature range (DTR), a weather parameter closely associated with urbanization and global climate change.</p><p><b>METHODS</b>We conducted a semiparametric time-series analysis to estimate the percentage increase in emergency-room visits for RTI associated with changes in DTR after adjustment for daily weather conditions (temperature and relative humidity) and outdoor air pollution.</p><p><b>RESULTS</b>DTR was significantly associated with daily emergency-room visits for RTI. An increase of 1 °C in the current-day (L0) and in the 2-day moving average (L01) DTR corresponded to a 0.94% [95% confidence interval (CI), 0.34%-1.55%] and 2.08% (95% CI, 1.24%-2.93%) increase in emergency-room visits for RTI, respectively.</p><p><b>CONCLUSION</b>DTR was associated with increased risk of RTI. More studies are needed to understand the impact of DTR on respiratory health.</p>