Abstract
Background : Although seasonal variations in CPAP-usage are often attributed to changes in temperature, no real- world study has evaluated the influence of temperature on long-term CPAP-usage.Methods : The TempCPAP study is a retrospective real-life cohort study. Adult patients newly treated and undergoing at least 1 month of CPAP were included. Daily 12-PM temperature data from the nearest weather station was assigned to each patient and CPAP-usage was collected using telemonitoring data. The primary objective of the study was to investigate the relationship between temperature and CPAP-usage.Results : 8151 patients (37.2 % women) with a median age of 61 (IQ25-75: 51–71) years, initial AHI of 36 (29–49.6) events/h, treated for a median duration of 1.6 years (0.7–3.0), and with a CPAP-usage of 5.4 (3.0–6.9) h/day were included. The relationship between CPAP-usage and temperature was non-linear. The best model found two breakpoints at 18°C and 29°C. CPAP-usage dropped drastically when the temperature exceeded 29°C, as each 1°C increase was associated with a 3.6-min reduction in CPAP-usage. Compared to temperatures of less than 5°C, temperatures above 30°C resulted in a mean reduction in CPAP-usage of 30.3 (confidence interval (CI95 %): 29.3–31.4) minutes/day, achieving the minimal clinically important difference of 30 min in 46.6 % of patients.Conclusion : In patients undergoing long-term CPAP therapy, temperatures over 29°C at 12-PM were associated with reduced CPAP-usage.