Using observational data to investigate cognitive outcomes of obstructive sleep apnea treatment: a scoping review

Prior research indicates a connection between obstructive sleep apnea (OSA) and cognitive deficits, prompting interest in whether OSA treatment can prevent or slow cognitive decline. Past clinical trials on OSA treatment and cognitive impairment have shown inconsistent results. However, observational data might help by examining more diverse populations and larger sample sizes, increasing the ability to detect subtle effects. Therefore, we reviewed literature to characterize studies evaluating cognitive outcomes from OSA treatment using observational study data.

We conducted a scoping review of studies retrieved on PubMed and Embase. Studies were screened by title/abstract, and then full text, for inclusion. We extracted data characterizing data source, study design, population, sample size, follow-up time, treatments assessed, cognitive outcome variables, and key associations.

Of 3655 unique articles obtained from PubMed and Embase, 13 met eligibility criteria. All were retrospective cohort studies. Ten studies evaluated positive airway pressure (PAP) therapies, one examined uvulopalatopharyngoplasty, and 2 evaluated any type of OSA treatment. No studies evaluated mandibular advancement devices. Cognitive outcomes assessed included dementia diagnosis (8 studies), and changes in cognitive performance (5 studies). Results from studies for the most part found OSA treatment was associated with better cognitive outcomes, although effects varied in magnitude and statistical significance based on the data source, outcomes, and sample size.

Observational data has the potential to help evaluate cognitive outcomes from OSA treatment, but more studies are needed, especially for OSA therapies beyond PAP alone.