Long-term adherence to nasal continuous positive airway pressure therapy by hypertensive patients with preexisting sleep apnea

Abstract

Background and objective: Although positive screening for and treatment of obstructive sleep apnea (OSA) have been recommended for patients with cardiovascular problems, patient adherence to nasal continuous positive airway pressure (CPAP) therapy primarily for a cardiovascular concern is unknown. Therefore, this study aimed to determine the adherence to CPAP therapy by hypertensive patients with OSA after a screening test performed regardless of OSA-related symptoms.

Subjects and methods: CPAP therapy was administered to 194 of the 1365 hypertensive patients who underwent the screening. The monthly dropout from CPAP therapy and the adequate use level (4h every night, 70% days in a month) were assessed using the Kaplan-Meier analysis over a 3-year follow-up period.

Results: Of the patients, 106 (55%) refused or abandoned the therapy by the end of the follow-up period (adherence, 45%). An adequate use level was maintained by 76 patients (39%). Most of the patients' background characteristics, including age, sex, Epworth sleepiness scale scores, and parameters obtained on polysomnography, were not related to adherence or adequate use level. The good-compliance level on the first visit after CPAP therapy introduction was most strongly related to adherence (95% CI, 0.05-0.32; p<0.001) and adequate use level (95% CI, 0.06-0.33; p<0.05). Fourth quartile of apnea hypopnea index value (greater than 67/h) was also related to adherence (95% CI, 0.21-0.98; p<0.02) and adequate use level (95% CI, 0.19-0.88; p<0.05).

Conclusions: The adherence and use level in this population may not be satisfactory but are comparable with those in previous sleep center reports treating symptomatic OSA patients. Thus, the present results would encourage hypertensive patients to undergo positive screening for OSA, regardless of OSA-related symptoms. However, an outcomes study with the same cohort is needed.

Keywords: Adherence; CPAP therapy; Compliance; Hypertension; Obstructive sleep apnea.