Referral to a sleep laboratory from primary care – are family doctors on the right track?

Abstract

Obstructive Sleep Apnea Syndrome (OSAS) is a highly prevalent disease, and screening mostly takes place on a primary care context. Several questionnaires have been validated as predictors of a high risk of OSAS, but a formal diagnosis is necessary, which requires a referral to a sleep laboratory for diagnostic testing.

The aim of this study was to assess the accuracy of primary care referral to a sleep lab for suspected OSAS.

421 patients, after referral from primary care, were evaluated on an early diagnosis screening program, which consisted of an appointment with a sleep physician and a domiciliary cardio-respiratory polygraphy. OSA was diagnosed as an AHI ≥5 events/hour.

The average body-mass index of the population was 30.7kg/m2 and patients scored an average of 9.7 points on the Epworth Sleepiness Scale. 72 patients (18%) had a negative test for OSA. Out of the 346 (82%) who tested positive, 123 (36%) had mild OSA, 104 (30%) had moderate OSA and 119 (34%) had severe OSA. According to the polygraphy result, along with the reported symptoms and medical history, treatment with positive pressure was initiated in 216 patients (51% of the total sample, 62% of those with OSA).

Our results show that while the high prevalence of OSAS can result in a great burden of referrals to sleep laboratories, in a vast majority of the referred patients the diagnosis of OSA is confirmed. The implementation of large-scale screening programs and standardized referral protocols are important tools to manage the high number of referrals and avoid long waiting lists.