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

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). Prospective longitudinal cohort study. University sleep disorders center. 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. 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. 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). 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.