Obstructive sleep apnea is a common disorder that affects about 6 percent of the adult population and close to 20 percent of the elderly population. Patients with obstructive sleep apnea have excess daytime sleepiness and decreased health-related quality of life. The treatment for obstructive sleep apnea is continuous positive airway pressure (CPAP). This treatment can substantially reduce symptoms and reduce the risk for cardiovascular morbidity and mortality related to obstructive sleep apnea. Despite the positive aspects of the therapy, compliance can be difficult to achieve. CPAP can cause nasal congestion, claustrophobic sensations, and other side effects. Sin and colleagues studied patients with sleep apnea to determine short-term and long-term compliance with this treatment, baseline predictors for long-term CPAP compliance, and whether CPAP use provides sustained improvement in daytime sleepiness in these patients.
The design was a prospective cohort longitudinal study of patients referred to a university sleep disorders center. Patients with moderate to severe obstructive sleep apnea, as defined by an apnea-hypopnea index of 20 or more events per hour on polysomnography, were enrolled. Participants were provided with a CPAP device that contained a computer chip for monitoring compliance. Participants agreed to use the CPAP and were instructed on its use. They were informed that noncompliance would result in the loss of the machine. Within the first week of the study, patients began making daily telephone contact with a CPAP clinic nurse and were followed up in the office at two weeks, four weeks, three months, and six months. During each follow-up visit, patients were asked to complete a questionnaire regarding their degree of daytime sleepiness.
The study was completed by 296 patients. Compliance rates (defined as use of the CPAP machine for 3.5 hours or longer per day) was in the high 80 percent range at each of the follow-up visits. The daytime sleepiness score improved over the entire follow-up period, with the lowest score occurring at six months. Three variables that correlated with increased use of CPAP were female gender, increased age, and reduction of daytime sleepiness scores.
The authors conclude that a population-based CPAP program for the treatment of obstructive sleep apnea consisting of free CPAP devices, extensive education, and follow-up with regular feedback to both patients and physicians can achieve a substantial compliance rate. Utilizing this program can result in a significant decrease in daytime sleepiness and may reduce cardiovascular morbidity and mortality related to obstructive sleep apnea.