Pre-polysomnographic assessment using the Pittsburgh Sleep Quality Index questionnaire is not useful in identifying people at higher risk for obstructive sleep apnea

BackgroundPolysomnography remains the diagnostic gold standard for obstructive sleep apnea syndrome (OSAS), but it is time consuming and requires dedicated personnel and setting. It may be more useful to plan a polysomnogram based on a preliminary screening.ObjectiveTo verify whether a questionnaire of general quality of sleep, the Pittsburgh Sleep Quality Index (PSQI), could outperform a dedicated questionnaire (Epworth Sleep Scale: ESS) in targeting OSAS patients in an at risk population.Methods254 consecutive subjects attending the outpatient clinic for respiratory diseases were clinically evaluated for sleep apnea and referred to a 12 channel night-time polysomnography. All patients were administered the ESS and the PSQI before the procedure. The correlation between the Apnoea/Hypopnoea Index (AHI) and the global score of the PSQI was calculated; Sensitivity, specificity, positive and negative predictive values (PPV and NPV, respectively), Diagnostic accuracy and the area under the receiver operating ...