Table 2. Summary of empirical studies examining the impact of OSA treatments on monetized economic outcomes.

Ref	Sample	Design	OSA treatment	Economic outcome	Key findings
28	N = 34, M age = 48y, 100% men in Canada	Retrospective cohort study	CPAP	Outpatient visits, physician costs	Vs. 1y prediagnosis, CPAP reduced outpatient visits (1.03 visits) and physician costs by $14.23 over 5y
29	N = 344, M age = 49y, 100% men in Canada	Prospective cohort study	CPAP or BPAP	Physician costs, hospitalizations	Vs. 2y prediagnosis and among adherers, CPAP reduced physician costs and hospitalizations over 2y
30	N = 414, M age = 49y in Canada	Retrospective cohort study	CPAP or BPAP	Outpatient visits, physician costs	Vs. 1y prediagnosis, CPAP reduced outpatient visits and physician costs by $37.26 over 2y
31	N = 15,424, M age = 48y, 70% men in USA	Retrospective cohort study	CPAP	Total costs, all-cause and OSA-related hospitalizations	Vs. 1y prediagnosis, CPAP reduced total costs ($792 vs. $883) and rates of all-cause (19% vs. 24.2%) and OSA-related (8% vs. 11.3%) hospitalizations over 2y
32	N = 22,361 w/OSA, M age = 67.2y, 53% men in US	Retrospective cohort study	CPAP	Total costs	Vs. 1y prediagnosis, CPAP adherence reduced total costs
33	N = 86, M age = 50.7y, 82.3% men in US	Multicenter RCT	CPAP, OA	QALY, total costs	CPAP was more clinically effective, but based on cost per QALY, OA was more cost-effective at 12 months (€33.701 [−€191.106 to €562.271] per QALY gained)
34	N = 248, M age = 44y, 99% men commercial drivers in USA	Retrospective cohort study	CPAP or BPAP	Total costs	Vs. 1y prediagnosis, CPAP reduced HCU costs over 2y (y1: $3,062; y2: $3,465)
35	N = 30,719, M age = 67.1y, 43% men in USA	Retrospective cohort study	CPAP	Costs	Vs. those not tested, clinically diagnosed, and not treated ($12,080/quarter [$10,759 in 2010]), costs were lowest for those tested, diagnosed, and treated ($6,465/quarter [$5,758 in 2010])
36	N = 19,438, 78% men in Denmark	Retrospective cohort study	CPAP, UPPP	Total costs	Vs. 2y prediagnosis, neither CPAP nor UPPP reduced HCU costs over 2y
37	N = 1,098, M age = 55.7y, 63% men in US	Retrospective cohort study	CPAP	Acute care HCU and costs	CPAP adherence reduced inpatient (RR = 0.92, 95% CI: 0.86–0.98) and overall acute care visits (RR = 0.96, 95% CI: 0.92–0.99). Among CPAP adherers, fewer ED visits and inpatient stays were observed.
37	N = 278, M age = 71y, 79% men in UK	Multi-center RCT	APAP	CEA HrQOL: EQ-5D and SF-6D	Vs. untreated OSA, APAP was associated with 0.018 QALYs gained per SF-6D, but no gains per EQ-5D. APAP reduced costs (–$61 [–£35 in 2014 GBP]) over 1y and was marginally cost-effective.
38	N = 82, M age = 55y, 82% men in Sweden	Retrospective cohort study	CPAP	Hospital costs	Vs. 2y prediagnosis, CPAP reduced CVPD-related hospitalization costs ($80,680 vs. $11,134) over 2y
39	N = 740 children <18y, M age = 5.6y, 37% boys in Israel	Prospective, longitudinal case- control study	T&A	Total costs	Vs. 1y prediagnosis, CPAP reduced total costs (32.5%; P <0.0004) over 1y

APAP, automatic positive airway pressure; BPAP, bilevel positive airway pressure; CEA, cost-effectiveness analysis; CPAP, continuous positive airway pressure; CVPD, cardiovascular and pulmonary disease; ED, emergency department; EQ-5D, European Quality of Life 5 Dimension; HCU, healthcare utilization; HrQOL, health-related quality of life; OA, oral appliance; OSA, obstructive sleep apnea; QALY, quality adjusted life year; RCT, randomized controlled trial; RR, rate ratio; SF-6D, Short Form questionnaire-6 Dimensions; T&A, adenotonsillectomy; UPPP, uvulopalatopharyngoplasty