The effect of patient neighbourhood income level on the purchase of continuous positive airway pressure treatment among patients with sleep apnea

Rationale/Objectives — Using a large historical cohort of patients with obstructive sleep apnea (OSA), we evaluated an association between patient neighbourhood income level and the acceptance (purchase) of a CPAP device under a co-payment healthcare system.

Methods/Measurements — All adults who underwent a first diagnostic sleep study at St Michael's Hospital (Toronto, Canada) between 2004 and 2010 were included. Severity of OSA was determined by the apnea-hypopnea index (AHI); level of daytime sleepiness – by the Epworth Sleepiness Scale (ESS). Patient data were linked to provincial health administrative data from 1991 to 2013 to determine the purchase of CPAP equipment, comorbidities, neighbourhood income and rural status at baseline. Neighbourhood income was categorized into quintiles, ranked from poorest (Q1) to wealthiest (Q5). Assuming that the majority of participants with severe OSA (AHI > 30 events/hr) and excessive daytime sleepiness (ESS≥10) would have been strongly recommended CPAP, we evaluated the association between patient neighbourhood income and purchase of a CPAP device in this group via multivariable Cox regressions.

Main Results — Of the 695 participants with severe OSA and excessive daytime sleepiness, 400 (58%) purchased a CPAP. Patients who accepted CPAP were more likely to live in a higher income neighbourhood. Cumulative incidence of CPAP acceptance at 6 months was 43% (95%CI: 35%-51%) for individuals in a low income neighbourhood (Q1) and 52% (95%CI: 48%-56%) in combined higher income neighbourhoods (Q2-5) (p=0.05). Controlling for sex and age, living in higher income neighbourhoods was associated with a 27% increased chance of accepting CPAP compared to the lowest income neighbourhood (HR Q2-5 vs. Q1 = 1.27, 95%CI: 0.98-1.64, p = 0.07).

Conclusions — Thus, living in an unfavourable neighbourhood is not an obstacle to CPAP treatment among symptomatic patients with severe OSA under a co-payment healthcare system. However, a potential 27% improvement in CPAP acceptance associated with higher neighbourhood income is not ignorable. Regulatory agencies should review available data, including findings from our study, prior increasing a co-payment amount for CPAP treatment. Also the overall CPAP acceptance rate was relatively low, suggesting that obstacles other than financial are primarily responsible.