Background: The healthy adherer effect (HAE) has gained increasing attention as potential source of bias in observational studies examining the association of positive airway pressure (PAP) adherence with health outcomes in obstructive sleep apnea (OSA). Research question: Is adherence to PAP associated with healthy behaviors and healthcare resource use prior to device prescription? Methods: Data from the IRSR Pays de la Loire Sleep Cohort were linked to health administrative data to identify proxies of heathy behaviors (HB) including adherence to cardiovascular (CV) drugs (medication possession ratio, [MPR]), cancer screening tests, influenza vaccination, alcohol and smoking consumption, and drowsiness-related road accidents during the two years preceding PAP onset in OSA patients. Multivariable regression analyses were conducted to evaluate the association of HB with subsequent PAP adherence. Healthcare resource use was evaluated according to subsequent PAP adherence. Findings: We included 2,836 patients who had started PAP therapy between 2012 and 2018 (65% of whom were PAP adherent with mean daily use ≥4h/night). Being adherent to CV active drugs (MPR≥80%) and non-smoker were associated with a higher likelihood of PAP adherence (odds ratio, OR [95% confidence interval]: 1.43 [1.15; 1.77] and 1.37 [1.10; 1.71] respectively). Patients with no history of drowsiness-related road accidents were more likely to continue PAP (OR: 1.39 [1.04; 1.87]). PAP adherent patients used less healthcare resources 2 years before PAP initiation, than non-adherents (mean number of outpatient consultations: 19.0 vs 17.2, P=.003; hospitalization days: 5.7 vs 5.0, P=.04; emergency room visit: 30.7 vs 24.0% P=.0002). Interpretation: Patients who adhere to PAP therapy of OSA were more health seeking and less healthcare users prior to device initiation than non-adherent patients. Until the HAE associated with PAP adherence is better understood, caution is warranted when interpreting the association of PAP adherence with CV health outcomes and healthcare resource use in non-randomized cohorts.