Impact Of Extreme Temperatures On Primary Care Requirement In France: The Chaufos Study (2010-2018)

Introduction: The health impact of cold and hot waves is major. Nevertheless, the respective impact of extreme high and low temperatures remains controversial.Method: The daily number of (1) patients managed by SAMU 93 dispatching centre - primary care requirement indicator, (2) Mobile Intensive care Unit (MICU) interventions - patient severity indicator and (3) number of deaths have been recorded. Daily minimum and maximum temperatures were recorded from 2010 to 2018. The analysis covered the 10 warmest and coldest days of each year (2 x 70 days), and the 30 warmest and coldest days of the total period (2 x 30 days).Results: Over 2,702 days, 1,513,070 patients, 89,478 MICU interventions and 7,350 deaths were analysed. Median temperature: 16.0[10.4-21.6]degrees C.The coldest days were associated with a significant increase in patients managed (665[609-764] vs 538[474-619]; p < 0.001), MICU interventions (35[32-39] vs 33 [28-38]; P = 0.006) and deaths (3[2-5] vs 2[1-4]; P = 0.0008) considering the 10 days of extreme temperatures in each year and a significant increase in patients managed 615[580-698] vs 542[475-627]; P < 0.001) considering the 30-day extreme of the period.The hottest days were associated with a significant decrease in patients managed (484[443-549] vs 538[474-619]; P < 0.001), MIcU interventions (31[25-37] vs 33[28-38]; P = 0.006) and deaths (2[1-3] vs 2[1-4]; P = 0.0008) considering the 10 extreme days of each year and a significant decrease in patients managed (536[479-576] vs 542[475-627]; P < 0.001) considering the 30 extreme days of the period.Conclusion: primary care requirement, number of severe patients and mortality increased significantly with extreme low of temperature.