A Baseline Prediction Model for First-Year CPAP Treatment Disengagement in Adults with Obstructive Sleep Apnea: A Secondary Analysis of a Danish Cohort.

Purpose: To estimate and internally evaluate a fixed baseline model for recorded first-year continuous positive airway pressure (CPAP) treatment disengagement before device-use data are available and compare it with more complex alternatives. Patients and Methods: We conducted a secondary analysis of a Danish single-center cohort that initiated CPAP in 2012-2013. The outcome was the recorded 52-week treatment-status event, which did not distinguish active discontinuation from loss to follow-up. Of 695 participants, 662 had determinate status and 94 events. The fixed logistic model included current smoking, Epworth Sleepiness Scale (ESS) score, and apnea-hypopnea index (AHI), with coefficients estimated in 632 complete cases (85 events). Performance was evaluated by repeated 10-fold cross-validation with bootstrap confidence intervals (CIs). Results: Current smoking was associated with higher odds of the recorded outcome (odds ratio [OR] 2.45, 95% CI 1.47-4.07). Higher ESS (OR per 5-point increase, 0.68; 95% CI, 0.53-0.87) and AHI (OR per 10 events/hour increase, 0.56; 95% CI, 0.45-0.68) were associated with lower odds. The cross-validated area under the curve was 0.762 (95% CI, 0.709-0.812), the Brier score was 0.103 (0.087-0.119), the calibration intercept was -0.001 (-0.259 to 0.226), and the calibration slope was 0.927 (0.624-1.298). In 662 participants, extended and full models did not consistently improve prediction error. The 94 events could not be separated into active discontinuation and loss to follow-up. Conclusion: Three routinely available baseline measures provided moderate predictive information, while broader and penalized models offered no consistent improvement. These findings provide a fixed-horizon benchmark for external validation in contemporary CPAP cohorts that directly assess device use, treatment preferences, and treatment burden.