Treatment of OSA with either PAP or OAs significantly improves ESS scores, with PAP being more effective.13 The difference appears to widen in patients with greater daytime sleepiness; in other words, patients with greater daytime sleepiness will gain even greater benefit from PAP, both overall and when compared with OAs.15
Patients with OSA who have excessive daytime sleepiness can gain substantial symptomatic benefit from treatment with positive airway pressure or oral appliances.
One randomized trial of an intensive lifestyle modification program for patients with OSA failed to show improvement in the ESS in the intention-to-treat analysis, but did demonstrate a 2.4-point greater reduction in ESS scores in those patients who successfully followed the program (achieving weight loss).16 Surgical treatments for OSA, such as uvulopalatopharyngoplasty or maxillary advancement, have been shown in some (but not all) studies to improve ESS scores; the different types of surgical treatment and the heterogeneity of studies prevents estimation of effect size.17 A meta-analysis of case series studies of hypoglossal nerve stimulation reported a mean improvement of 4.5 points on the ESS;18 comparison with other interventions is lacking.
Improved quality of life
Both PAP and OAs have been shown to improve sleep-related quality of life in patients with OSA. However, while the improvement is statistically significant, the effect size is small.14
That could be said of a study by Lewis et al.19 These researchers randomized patients with moderate-to-severe OSA and known coronary artery disease (CAD) or at least 3 risk factors for CAD to receive PAP, nocturnal oxygen, or lifestyle education.19 The patients randomized to receive PAP improved vitality scores by only 3.6 points on a 100-point scale; this was significantly better statistically than the improvement achieved by those randomized to lifestyle education. Smaller improvements were noted in depression, social function, and general health. Patients who had more daytime sleepiness at baseline had greater improvements in function.19
Cognitive function findings are mixed
In a systematic review published in 2004, Aloia et al4 found measurable impairments on neuropsychological tests of global cognitive functioning, attention/vigilance, executive functioning, memory, psychomotor function, and constructional abilities in patients with OSA. The results of treatment studies (all but 1 using PAP) were mixed. No studies showed improvement in psychomotor speed or language, and studies disagreed on whether treatment produced benefits in global cognition, attention, or executive functions.4
