Predictors of Obstructive Sleep Apnea on Polysomnography after a Technically Inadequate or Normal Home Sleep Test

Home sleep testing (HST) is an accepted alternative to polysomnography (PSG) for diagnosing obstructive sleep apnea (OSA) in high-risk populations. Clinical guidelines recommend PSG in cases where the HST is technically inadequate (TI) or fails to establish the diagnosis of OSA in patients with high pretest probability. This retrospective study evaluated predictors of OSA on PSG within patients who had a TI or normal HST.

Electronic medical records were reviewed on 1,157 patients referred for HST at our sleep center. Two hundred thirty-eight patients had a TI or normal HST with subsequent PSG. Age, BMI, Epworth score, HST result, and PSG-based apnea-hypopnea index (AHI) were abstracted.

Two hundred thirty-eight consecutive patients with either a normal HST (n = 127) or TI HST (n = 111) underwent subsequent PSG. Of 127 who had a normal HST, 76% had a normal PSG and 24% had OSA (23 mild, 6 moderate, 1 severe). Of 111 who had a TI HST, 29% had a normal PSG and 71% had OSA (43 mild, 19 moderate, 17 severe). Individuals younger than 50 years old with a normal HST were more likely to have a normal PSG. Older age predicted diagnosis of OSA on PSG among individuals with a TI HST.

In this retrospective analysis of a clinical sample, when the HST is interpreted as normal in a younger patient population, the subsequent PSG is likewise normal in majority of the patients, although significant OSA is sometimes discovered. When a HST is read as TI, the majority of patients have OSA.