Diagnostic accuracy of level 3 portable sleep tests versus level 1 polysomnography for sleep-disordered breathing: a systematic review and meta-analysis.

BACKGROUND: Greater awareness of sleep-disordered breathing and rising obesity rates have fueled demand for sleep studies. Sleep testing using level 3 portable devices may expedite diagnosis and reduce the costs associated with level 1 in-laboratory polysomnography. We sought to assess the diagnostic accuracy of level 3 testing compared with level 1 testing and to identify the appropriate patient population for each test. METHODS: We conducted a systematic review and meta-analysis of comparative studies of level 3 versus level 1 sleep tests in adults with suspected sleep-disordered breathing. We searched 3 research databases and grey literature sources for studies that reported on diagnostic accuracy parameters or disease management after diagnosis. Two reviewers screened the search results, selected potentially relevant studies and extracted data. We used a bivariate mixed-effects binary regression model to estimate summary diagnostic accuracy parameters. RESULTS: We included 59 studies involving a total of 5026 evaluable patients (mostly patients suspected of having obstructive sleep apnea). Of these, 19 studies were included in the meta-analysis. The estimated area under the receiver operating characteristics curve was high, ranging between 0.85 and 0.99 across different levels of disease severity. Summary sensitivity ranged between 0.79 and 0.97, and summary specificity ranged between 0.60 and 0.93 across different apnea-hypopnea cut-offs. We saw no significant difference in the clinical management parameters between patients who underwent either test to receive their diagnosis. INTERPRETATION: Level 3 portable devices showed good diagnostic performance compared with level 1 sleep tests in adult patients with a high pretest probability of moderate to severe obstructive sleep apnea and no unstable comorbidities. For patients suspected of having other types of sleep-disordered breathing or sleep disorders not related to breathing, level 1 testing remains the reference standard.

Can continuous positive airway pressure therapy improve the general health status of patients with obstructive sleep apnea?: a clinical effectiveness study.

STUDY OBJECTIVES: To determine the short-term and long-term impacts of continuous positive airway pressure (CPAP) therapy on health-related quality of life (HRQL) in patients with obstructive sleep apnea (OSA). DESIGN: Prospective longitudinal cohort study. SETTING: University sleep disorders center. PATIENTS: Three hundred sixty-five patients with an apnea-hypopnea index (AHI) > or = 20 per hour of sleep and 358 patients with an AHI of < 20. INTERVENTIONS: All patients with AHIs > or = 20 received CPAP therapy; those with AHIs < 20 did not. The HRQL of all study participants was measured using the 36-item medical outcomes study short form (SF-36) questionnaire at baseline and then at 3 and 12 months of follow-up. RESULTS: Although the SF-36 scores were similar at baseline, after 3 months of therapy, the CPAP group had higher adjusted emotional summary scores than did those who did not receive CPAP therapy (score increase, 1.72; 95% confidence interval [CI], 0.08 to 3.37). These improvements were maintained for 12 months. The gains in the SF-36 scores were most striking in the vitality domain (score increase, 10.52; 95% CI, 7.04 to 14.00 U increment). The severe OSA group (ie, AHIs > or = 40) experienced the largest benefit. Their adjusted vitality scores were 12.3 U higher (95% CI, 8.0 to 16.6) than those persons without OSA (ie, AHIs < 5). CONCLUSIONS: CPAP therapy was associated with marked short-term and long-term improvements in the vitality of patients with moderate-to-severe OSA in the community. These findings suggest that CPAP therapy is effective in improving the long-term HRQL of patients with OSA.