A novel postal-based approach to diagnosing obstructive sleep apnoea in a high-risk population

More than 50% of patients with diabetic macular oedema (DMO) have obstructive sleep apnoea (OSA), but the majority remain undiagnosed. We used a four-channel device (ApneaLink [AL], ResMed, UK) to establish a remote postal-based diagnostic service for patients with DMO. Here we describe our experience.

Patients with DMO were invited to participate. Interested patients returned a free-post reply slip to the study team, who posted an AL with pictorial and written instructions to them. Following a single night study, the AL was returned by a freepost service.

Responses from 733 patients meeting the inclusion criteria were received, comprising 469 males and 264 females, mean age 64 years (standard deviation 10.4 years). ALs were issued to 718 patients, of whom 606 completed a diagnostic study. A total of 71 patients (12%) required a repeat study due to inadequacy of the first attempt. Completed sleep studies showed that 75% of respondents had sleep disordered breathing: 4% ODI 0-4/h, 24%; 5-9/h, 19%; 10-19/h, 23%; ≥20/h, 34%; and AHI 0-4/h, 25%; 5-14/h, 38%; 15-29/h, 20%; ≥30/h, 17%. Among 1592 postal events through the national post service, 20 ALs were lost.

We have demonstrated that a remote postal-based diagnostic service for populations with a high risk of OSA can be successfully performed. This novel approach, which avoids clinic attendance, may be useful in clinical practice.