Cost Effectiveness of Ambulatory Management for Veterans With Sleep Apnea

Objective: The overall goal of the project is to improve access to care for veterans with suspected obstructive sleep apnea (OSA), a breathing disorder during sleep characterized by repetitive closure of the pharyngeal airway. Portable monitors are commercially available to diagnose participants with suspected OSA and establish the continuous positive airway pressure (CPAP) setting needed for treatment. Their application to home testing is not widely accepted because it is not known whether home testing, when compared to conventional in-lab polysomnograms, is cost effective and produces similar outcomes with regard to participant adherence to CPAP treatment and improvements in functional impairment. The specific goals of the proposed research are to address these barriers by comparing the functional impact, cost, and cost-effectiveness of evaluating veterans with suspected OSA using home versus in-lab testing.

Research Design: In this prospective randomized control trial of equivalency, participants referred to the Philadelphia and Pittsburgh VA Medical Centers for evaluation for OSA will be randomized to either exclusively in-lab or home testing following baseline assessment.

Methodology: In-lab polysomnograms will be performed to diagnose OSA and titrate the pressure setting for subsequent CPAP therapy. Self-administered home testing will consist of an overnight unattended sleep study followed by a 1-week autoCPAP titration trial. Objectively assessed CPAP adherence and its consequent effects on subjective and objective daytime sleepiness, disease specific and general functional impairment, and participant preference will be obtained at 1- and 3-months after starting CPAP treatment and 3-monthly thereafter to the end of study follow-up. Medical service use and cost will be collected for the entire observation period.

Aim 1 will determine if participants with suspected OSA who receive home testing have the same adherence to subsequent CPAP treatment and the same functional outcomes as participants receiving in-lab testing. Primary outcome measures will be 1) objectively measured adherence to CPAP treatment and 2) the global score on the Functional Outcomes of Sleep Questionnaire (FOSQ) to assess the consequent effects of adherence on disease specific functional impairment. Secondary functional outcome measures will assess subjective (Epworth Sleepiness Scale) and objective (Psychomotor Vigilance Test) daytime sleepiness, and general quality of life (SF-12). Hypothesis 1: Despite differences between in-lab versus home testing in terms of technology, time participants interact with health care professionals, and environment, there is no clinically significant decline in mean CPAP adherence and no clinically significant reduction in functional outcomes in participants receiving home versus in-lab testing.

Aim 2 will compare the differences in cost and quality-adjusted life years saved (QALYS) between home versus in-lab testing to estimate a cost-effectiveness ratio. Participant preference will be assessed with the EuroQol (EQ-5D) and Health Utilities Index 2 (HUI). Hypothesis 2a: Average total health-care delivery cost is lower for veterans receiving home testing relative to those receiving in-lab testing. Hypothesis 2b: Because we believe that at-home testing will have lower costs and equivalent outcomes, we will be 90% confident that the cost per QALY ratio comparing at-home testing with in-lab testing will be less than $100,000.

Clinical Relationship: We need to determine the most cost effective way to diagnose veterans with OSA and initiate them on CPAP treatment. If the results show that home testing produces clinical outcomes that are not significantly clinically inferior and similar or reduced costs compared with in-lab testing, decision makers can be confident that home monitors can be used to diagnose and treat OSA and that improving veterans' access to care for OSA need not require construction of additional, costly sleep labs.

Findings: We anticipate that the results of Aim 1 will demonstrate that participants receiving in-lab versus home testing have similar clinical outcomes. We further anticipate that Aim 2 will demonstrate that home testing is more cost effective than in-lab testing. If confirmed, these findings will lead to wide acceptance of home portable monitor testing and increase veteran access to care.

Inclusion criteria

Individuals willing to participate must meet the following eligibility criteria prior to enrollment:

• Patients referred for a sleep evaluation for suspected sleep apnea.
• Age 18 years or older
• Living within 90 miles of the Sleep Center.

Exclusion criteria

Individuals will be excluded from the study for the following reasons:

• Unable or unwilling to provide informed written consent.
• Lack of telephone access or inability to return for follow-up testing.
• A history of prior sleep evaluations, OSA treatment, or sleep disorder in addition to OSA.
• A clinically unstable chronic medical condition as defined by a new diagnosis or change in medical management in the previous 3 months of cardiac disease, thyroid disease, diabetes, depression or psychosis, cirrhosis, or recently diagnosed cancer.
• Individuals already on long term oxygen therapy or requiring bilevel positive airway pressure.
• Individuals with rotating shift work or irregular work schedules over the last 6 months.
• Suspected or confirmed to be pregnant. A pregnancy test will be performed using the urine sample obtained at the initial visit.
• Inability to complete the Assessment Battery - e.g. less than a 5th grade reading level