Low Specificity of Rapid Eye Movement Sleep Behavior Disorder Questionnaires: Need for Better Screening Methods

Correct diagnosis of rapid eye movement sleep behavior disorder (RBD) is critical due to its link to α-synucleinopathies and risk of injuries and requires video-polysomnography (V-PSG). Usefulness of screening questionnaires outside the context of validation studies is limited.

The aim was to assess the performance of three validated RBD screening questionnaires compared with gold-standard V-PSG.

In this bicentric prospective study, 400 consecutive subjects referred to a sleep center for the first time filled three RBD questionnaires (RBD Screening Questionnaire, RBD Single Question, and Innsbruck RBD Inventory) in random order before sleep experts' interview. Subjects positive for at least one questionnaire were invited to undergo V-PSG. Data from patients negative for all questionnaires undergoing V-PSG for other reasons were also evaluated. Questionnaire performances were compared to gold-standard V-PSG RBD diagnosis.

Three hundred ninety-nine patients (median age: 51 [interquartile range: 37-64] years, 54.9% men) participated. Two hundred thirty-eight (59.6%) were positive for at least one questionnaire, and RBD was diagnosed using V-PSG in 30 patients (7.5%). Questionnaire specificity was 48.1% to 67.4%, sensitivity 80% to 92%, accuracy 51% to 68.3%, negative predictive value 94.2% to 98%, and positive predictive value 14.1% to 20.7%, with no relevant differences in performances among the evaluated questionnaires.

RBD questionnaires have low specificity and low positive predictive value and should not be used as a standalone tool for the diagnosis of RBD. Further development of RBD screening methods is needed, particularly for upcoming neuroprotective trials. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.