Long-term use of CPAP therapy for sleep apnea/hypopnea syndrome

Patients with the sleep apnea/hypopnea syndrome (SAHS) treated by nasal continuous positive airway pressure (CPAP) need to use CPAP long-term to prevent recurrence of symptoms. It is thus important to clarify the level of long-term CPAP use and the factors influencing long-term use. We examined determinants of objective CPAP use in 1, 211 consecutive patients with SAHS who were prescribed a CPAP trial between 1986 and 1997. Prospective CPAP use data were available in 1, 155 (95.4%), with a median follow-up of 22 mo (interquartile range [IQR], 12 to 36 mo). Fifty-two (4.5%) patients refused CPAP treatment (these were more often female and current smokers); 1,103 patients took CPAP home, and during follow-up 20% stopped treatment, primarily because of a lack of benefit. Methods of survival analysis showed that 68% of patients continued treatment at 5 yr. Independent predictors of long-term CPAP use were snoring history, apnea/hypopnea index (AHI), and Epworth score; 86% of patients with Epworth > 10 and an AHI >/= 30 were still using CPAP at 3 yr. Average nightly CPAP use within the first 3 mo was strongly predictive of long-term use. We conclude that long-term CPAP use is related to disease severity and subjective sleepiness and can be predicted within 3 mo.