The impact of split-night polysomnography for diagnosis and positive pressure therapy titration on treatment acceptance and adherence in sleep apnea/hypopnea

Abstract

Study objectives: The time and resource intensive nature of the traditional two-night paradigm for diagnosing and titrating positive pressure therapy for Obstructive Sleep Apnea/Hypopnea (OSA/H) contributes to patient care cost and limitation of service availability. Although split night polysomography (PSG(SN)) algorithms can establish a diagnosis of OSA/H and establish a positive pressure prescription for many patients, there has been only limited evidence that this strategy does not impair acceptance and adherence to treatment. The objective of this study was to test the null hypothesis that PSG(SN) does not adversely impact acceptance and adherence to positive pressure therapy for OSA/H compared with a standard two-night PSG strategy (PSG(TN)).

Design: Retrospective case-controlled study.

Setting: University-based sleep disorders program

Patients: Both PSG(SN) and PSG(TN) (control) patients were selected on the basis of having an initial medical/sleep evaluation by a full-time physician member of the University of Pittsburgh Sleep Disorders Program, must not have had prior diagnostic PSG or treatment for sleep-disordered breathing, and must have been followed by the Sleep Program team. Selection of PSG(SN) patients required the ability to be matched with a control patient. Both groups underwent evaluation during the same time period. Of 146 patients who underwent PSG(SN) between October 1995 and September 1997, 51 had their initial evaluation and subsequent follow-up by physician-staff members of our Program. Of these, 15 were excluded from analysis because of a previous diagnostic PSG's or prior OSA/H therapy. Also, matches were unavailable for 5 patients. Seven patients refusal to use positive pressure at home and were not available for assessment of adherence, but were included in analysis of therapeutic acceptance. Thus, analysis of the impact of PSG(SN) on adherence to positive pressure therapy was based on a data set of 24 patients in whom a PSG(SN) was performed and 24 patients who had PSG(TN). The two groups were matched for age, Apnea+Hypopnea Index (AHI) and gender.

Measurement and results: There were no significant differences between the PSG(SN) and PSG(TN) groups with respect to age, body mass index (BMI), Desaturation Event Frequency (DEF), Arousal Index (ArI) or the Epworth Sleepiness Score (ESS). The nadir of oxyhemoglobin saturation (SpO2) during sleep was lower in the PSG(TN) than PSG(SN) group (69.3+/-15 vs. 79.8+/-9, mean+/-SD, p=0.012). During positive pressure titration, the time spent at the final pressure which was prescribed for the patients were comparable in both groups (123.4+/-64 vs. 161+/-96 minutes, PSG(SN) and PSG(TN), respectively, p=0.17). Adherence to therapy was objectively assessed by the average daily run-time of the positive pressure device at the first meter-read following initiation of treatment (55.1+/-44 vs. 40.8+/-16 days following home set-up, PSG(SN) and PSG(TN), respectively, p=0.14). Depending whether or not patients with previous exposure to positive pressure therapy were included in the analysis, 84-86% of patients undergoing PSG(SN) accepted therapy. There was no difference between the groups with respect to adherence (5.1+/-4 vs. 4.6+/-3 hours, PSG(SN) and PSG(TN), respectively, p=0.64).

Conclusions: In a population of predominantly moderate-to-severe OSA/H patients, PSG(SN) strategy does not adversely impact on adherence to positive pressure therapy over the first six weeks of treatment. Acceptance of therapy is comparable to that reported in the literature following PSG(TN).