Criterion validity of the Pittsburgh Sleep Quality Index and Epworth Sleepiness Scale for the diagnosis of sleep disorders

• The ESS and PSQI do not predict the diagnosis of OSA, PLMD, RBD, and narcolepsy.
• The meta-analysis confirmed that the ESS has no value in identifying OSA.
• The PSQI and ESS are more influenced by subjective rather than objective measures.

Objectives(1) To examine criterion validity of the Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS) using obstructive sleep apnea (OSA), periodic limb movement disorder (PLMD), rapid eye movement sleep behavior disorder (RBD), and narcolepsy as criterion standard. (2) To summarize the evidence for criterion validity of the ESS for the diagnosis of OSA by a meta-analysis that combines the current and previous studies. (3) To investigate the determinants of the PSQI and ESS scores.MethodsThe PSQI and ESS as well as the Hospital Anxiety and Depression Scale (HADS), which measures anxiety and depression levels, were administered to 367 patients consecutively referred to a sleep clinic. They underwent overnight polysomnography (PSG) and the multiple sleep latency test if narcolepsy was suspected.ResultsThe area under the receiver operating characteristic curves for the ESS and PSQI (and its subscale) were <0.9, meaning that these questionnaires were not highly accurate for predicting the four sleep disorders. The meta-analysis found that the ESS had no value in identifying OSA. The variable that most strongly influenced PSQI or ESS scores was the HADS score.ConclusionThe PSQI and ESS should no longer be used as a screening or diagnostic instrument for the four PSG-defined sleep disorders, especially in a low-risk population.