Transparency in positive airway pressure therapy trials: an evaluation of reporting quality

Aim: Accurate and detailed reporting of nonpharmacological interventions such as positive airway pressure (PAP) therapy is essential for reproducibility, yet previous research shows frequent reporting deficiencies. Due to the complexity of PAP therapy, we evaluated the quality of PAP intervention reporting in ClinicalTrials.gov and publications, and assessed consistency between them. Materials & methods: ClinicalTrials.gov was searched on 16 May 2023, for adult obstructive sleep apnea trials involving PAP therapy. Trials were evaluated for registration completeness (21 WHO Trial Registration DataSet items) and intervention reporting (adapted 12-item Template for Intervention Description and Replication checklist). Publications identified on 3 September 2025, following a 2-year publication period, were compared with registered data for participant characteristics, outcomes and intervention reporting. Results: Among 299 included trials, 178 corresponding publications were identified. Reporting of PAP therapy was frequently incomplete in registry and publications, with key procedural details - such as mask fitting, device acclimatization and adherence strategies - missing in the majority of records. Substantial discrepancies were also found between the registered and published data. Sample size calculation was reported in 56.1% of publications but in none of the trial registrations, with participant numbers differing in 29.3% of articles. Inconsistencies were most common for secondary outcomes (43.3%), while primary outcomes differed from those registered in 24.2% of publications. Conclusion: Incomplete and inconsistent reporting of PAP therapy across registry and corresponding publications may be compatible with selective reporting. Rather than pointing to individual misconduct, these discrepancies indicate that key information on protocol changes, outcomes and adherence is fragmented across sources, limiting the ability of clinicians and researchers to appraise trial findings in full. Strengthening adherence to trial registration requirements and structured intervention-reporting frameworks is therefore essential to improve transparency and reinforce confidence in the evidence base for obstructive sleep apnea management.