Reporting of harms associated with CPAP use in randomised controlled trials: a systematic review

Obstructive sleep apnea (OSA) is a common sleep-related breathing disorder. Many people with OSA use a continuous positive airway pressure (CPAP) device as part of their treatment, although treatment tolerance and adherence may be affected by adverse events. We performed a systematic review of randomized controlled trials (RCTs) published from 2009 through 2023 evaluating the reporting of harms and adverse events (AEs) associated with CPAP therapy. This review was undertaken following concerns regarding polyurethane foam degradation in certain CPAP devices, which highlighted uncertainties surrounding the characterization and reporting of CPAP-related harms in the existing literature. We sought to evaluate how AEs associated with CPAP therapy were defined, characterized, and reported in RCTs, including the types and severity of reported AEs. We included 28 manuscripts reporting AEs, representing 8232 participants. Study populations, protocols and harms reported were highly heterogeneous, limiting reliable comparison and synthesis of AE frequencies across studies and precluding quantitative meta-analysis. Reporting of the AE followed four patterns: (i) explicit reporting of no AEs (3 studies N = 293); (ii) reporting of study-specific events unrelated to CPAP therapy (6 studies, N = 873); (iii) reporting of common CPAP-related AEs as occurring more frequently with CPAP use (4 studies, N = 480); (iv) comprehensive AE reporting (2 studies, N = 3942) and (v) study specific AE (17 studies, N = 3124). Respiratory and device-related harms were not reported by 20 studies and indirectly reported by 2 others. Overall, adverse event reporting in CPAP randomized controlled trials lacked standardization and completeness, limiting interpretation of the safety profile of CPAP therapy and reducing the ability of clinicians and patients to anticipate, contextualize, and mitigate potential harms.