TABLE VIII.B. 11.

Positive airway pressure (PAP) therapy and clinical outcomes in overlap syndrome

Study	Year	LOE	Study design	Study groups	Clinical endpoint	Conclusion
Marin et al.1356	2010	2b	Prospective cohort	228 patients with Overlap on CPAP 213 patients with Overlap not on CPAP 210 patients with COPD only	1. Mortality and first-time hospitalization from COPD exacerbation in Overlap Syndrome 2. Effect of CPAP on mortality and first-time hospitalization	Overlap syndrome patients had higher incidence of hospitalization from COPD exacerbations; (RR 1.70; 1.21–2.38). Overlap syndrome is associated with increased mortality compared with COPD alone; (RR 1.79; 1.16–2.77). CPAP improves mortality in overlap syndrome patients compared to overlap patients without CPAP.
Machado et al.1355	2010	2b	Prospective cohort	Overlap syndrome patients with moderate-severe OSAS and severe COPD on LTOT (N = 95) Treatment with CPAP No CPAP	Effect of CPAP on survival	Significant 5-year survival advantage with CPAP (71%) treatment compared to no CPAP (26%); (p < 0.01).
Singh et al.1358	2019	2b	Retrospective cohort	5% national sample of Medicare beneficiaries with COPD and on CPAP therapy Pre-CPAP Post-CPAP	Effect of CPAP on emergency room visits and hospitalizations for all-cause and COPD related conditions in 1-year pre- and post-CPAP initiation	Hospitalization rates for COPD related conditions were lowered in 1-year post-CPAP treatment compared to 1-year pre-CPAP. Hazard ratio for death due to respiratory failure or cardiovascular disease between groups was 0.19 (95% CI 0.08–0.48). No change in ER visits for COPD related conditions or for any cause. CPAP was more beneficial in older adults, higher COPD complexity, and three or more medical comorbidities.
Stanchina et al.1357	2013	4	Retrospective cohort (post hoc analysis)	Overlap syndrome patients identified from large outpatient database analyzed for CPAP adherence	Mortality	Greater hours on CPAP were associated with reduction in mortality; (HR 0.71, p < 0.001).
Kuklisova et al.1363	2018	2b	Retrospective cohort (post hoc analysis)	Post hoc analysis of large database with overlap patients using CPAP versus bilevel PAP	Determinants of CPAP failure	PCO2 awake and CT90% predicted failure, bilevel PAP was well tolerated and effective.

COPD, chronic obstructive pulmonary disease; CPAP, continuous positive airway pressure; CT90%, sleep time with SpO₂ < 90%; ER, emergency room; HR, hazard ratio; LTOT, long-term oxygen therapy; PCO₂, partial pressure arterial carbon dioxide.