Annals of internal medicine 2017 01 10166(5) 332-340 doi 10.7326/M16-1301
The clinical utility of limited-channel sleep studies (which are increasingly conducted at home) versus laboratory polysomnography (PSG) for diagnosing obstructive sleep apnea (OSA) is unclear.
To compare patient outcomes after PSG versus limited-channel studies.
Multicenter, randomized, noninferiority study. (Australian New Zealand Clinical Trials Registry: ACTRN12611000926932).
7 academic sleep centers.
Patients (n = 406) aged 25 to 80 years with suspected OSA.
Sleep study information disclosed to sleep physicians comprised level 1 (L1) PSG data (n = 135); level 3 (L3), which included airflow, thoracoabdominal bands, body position, electrocardiography, and oxygen saturation (n = 136); or level 4 (L4), which included oxygen saturation and heart rate (n = 135).
The primary outcome was change in Functional Outcomes of Sleep Questionnaire (FOSQ) score at 4 months. Secondary outcomes included the Epworth Sleepiness Scale (ESS), the Sleep Apnea Symptoms Questionnaire (SASQ), continuous positive airway pressure (CPAP) compliance, and physician decision making.
Change in FOSQ score was not inferior for L3 (mean difference [MD], 0.01 [95% CI, -0.47 to 0.49; P = 0.96]) or L4 (MD, -0.46 [CI, -0.94 to 0.02; P = 0.058]) versus L1 (noninferiority margin [NIM], -1.0). Compared with L1, change in ESS score was not inferior for L3 (MD, 0.08 [CI, -0.98 to 1.13; P = 0.89]) but was inconclusive for L4 (MD, 1.30 [CI, 0.26 to 2.35; P = 0.015]) (NIM, 2.0). For L4 versus L1, there was less improvement in SASQ score (-17.8 vs. -24.7; P = 0.018), less CPAP use (4.5 vs. 5.3 hours per night; P = 0.04), and lower physician diagnostic confidence (P = 0.003).
Limited-channel studies were simulated by extracting laboratory PSG data and were not done in the home.
The results support manually scored L3 testing in routine practice. Poorer outcomes with L4 testing may relate, in part, to reduced physician confidence.
Primary Funding Source
National Health and Medical Research Council and Repat Foundation.