The success rate of split-night polysomnography and its impact on continuous positive airway pressure compliance

With the increased volume of referrals of patients with obstructive sleep apnea (OSA) for sleep studies, there is a great need for alternatives of the standard two-night polysomnography (PSG) like split-night PSG. Therefore, we conducted this study to determine the success rate of continuous positive airway pressure (CPAP) titration during split-night PSG, and to determine the predictors of titration success and the impact on subsequent CPAP compliance in Saudi patients with OSA.

This is a prospective cohort study that included consecutive patients who were diagnosed with OSA and underwent a split-night PSG (n = 454). A subgroup of patients who used CPAP therapy, agreed to come for follow-up after 4 and 10 months (n = 130). This subgroup was compared with a matched group of OSA patients who underwent a two-night sleep study protocol (n = 80).

The study group had a mean age of 48.7 ± 13.3 years, body mass index (BMI) of 37.5 ± 10.1 kg/m(2) and apnea hypopnea index of 58.4 ± 35.0 events/h. Successful CPAP titration was achieved in 350 (77%) patients. In a full adjusted model, "BMI >35 kg/m(2)" and "known cardiac disease" remained significant predictors of a lower success rate of CPAP titration. After 10 months, 88% of the patients in the split-night protocol met the set criteria for good compliance versus 85% in the two-night protocol.

Split-night protocol is an effective protocol for diagnosing OSA and titrating CPAP. CPAP compliance rate showed no difference between the split-night and the two-night protocols.