Real world characteristics of central sleep apnea: a review of 29,000 consecutive patients undergoing polysomnography.

Purpose: The characteristics of central sleep apnea (CSA) in real-world sleep referral populations remain poorly understood. We used the electronic health record of a large health system to understand the prevalence and risk factors for CSA among patients referred for sleep evaluation.

Methods: We reviewed the records of 29,803 patients who underwent diagnostic polysomnography at six sleep laboratories over 14 years. A validated algorithm was used to extract polysomnographic results. CSA was defined as having an apnea hypopnea index (AHI) ≥ 5, a central apnea index ≥ 5, and a central apnea index > obstructive apnea index, while obstructive sleep apnea (OSA) was defined as AHI ≥ 5, obstructive apnea index ≥ 5, and obstructive apnea index > central apnea index.

Results: A total of 583 patients had CSA (2.0% of overall cohort and 5.5% of those with AHI ≥ 5). Compared to those with OSA, older age and male sex were strong risk factors for CSA. The comorbidities most strongly associated with CSA included prior myocardial infarction and atrial fibrillation with adjusted odds ratios of 1.88 (95% confidence interval 1.28-2.74), and 1.85 (1.43-2.38). The prevalence of CSA in these groups was 7.1%, and 5.8% respectively. Of note, the importance of risk factors varied by sex.

Conclusion: CSA was identified in 2.0% of patients undergoing diagnostic polysomnography in routine clinical practice, with risk varying substantially by demographics and comorbidities. Greater recognition of CSA risk can lead to more thoughtful evaluation to ensure accurate diagnosis and appropriate treatment.