Outcome evaluation of long-term nasal continuous positive airway pressure therapy in obstructive sleep apnea.

A study was conducted at the Tri-State Sleep Disorders Center of Cincinnati, Ohio, to evaluate both quantitative and qualitative daily function and productivity outcomes of treating obstructive sleep apnea (OSA) with nasal continuous positive airway pressure (NCPAP). This was a prospective outcome study conducted in 316 patients with diagnosed and treated OSA. There were 234 men and 82 women, mean age, 48.79 +/- 0.67 years; weight averaged 250.39 +/- 3.55 pounds; mean pretreatment respiratory disturbance index was 42.9 +/- 1.7 episodes per hour and 2.8 +/- 0.2 episodes per hour with NCPAP treatment. Patients were surveyed by questionnaire, administered on polysomnographic confirmation of OSA and after 6 months of nightly treatment with NCPAP as to their perceptions of their level of daytime functioning and quality of life over the previous 6 months. Main outcome measures included number of incidents of excessive daytime sleepiness; number of headaches on awakening; number of automobile accidents and near-miss automobile accidents; number of days absent from work; number of physician visits; and a series of subjective scales, measuring job productivity, quality of life, general physical and mental condition, short-term memory, and changes in blood pressure. Significant decreases were found in the number of incidents of excessive daytime sleepiness, headaches on awakening, physician visits, days absent from work, and automobile accidents or near misses with NCPAP therapy. Patients also reported subjective increases in productivity, quality of life, physical and mental condition, and short-term memory and reduction in both diastolic and systolic blood pressure. Effective treatment of OSA results in improvement both in preexisting symptoms and in quality of life. Improvement in many of the major problems experienced by patients seeking treatment has important implications for preventive medicine as well as health care cost containment.