Reliability and Validity of the Brief Insomnia Questionnaire in the America Insomnia Survey

Abstract

in the America Insomnia Survey (AIS), a large (n = 10,094) epidemiologic survey of the prevalence and correlates of insomnia in a sample of subscribers to a large, national, managed healthcare plan in the United States.This Brief Insomnia Questionnaire (BIQ) was designed to be administered by an interviewer.It generates insomnia diagnoses according to the inclusion criteria of the Diagnostic and Statistical Manual, Fourth Edition, Text Revision 1 (DSM-IV-TR), International Classification of Diseases-10 2 (ICD-10), and research diagnostic criteria 3 (RDC), and International Classification of Sleep Disorders-2 4 (ICSD-2), and systems but without operationalizing the diagnostic hierarchy rules or organic exclusion rules in these systems.One important aim of the AIS is to compare the prevalence and correlates of insomnia across these diagnostic systems to determine the implications of using one system rather than another.Although a number of self-report scales or fully structured interviews have shown good concordance with clinical diagnoses either in patient samples [5][6][7][8][9] or community samples comparing insomniacs with good sleepers, 10-12 none of those scales or interviews available generates insomnia diagnoses according to the definitions and general criteria of all the systems of interest to the AIS: DSM-IV-TR, ICD-10, and RDC/ ICSD-2.Rather than use multiple existing measures for this purpose, we developed the BIQ to assess insomnia according to all of these diagnostic systems.This was done by developing a set of questions similar to those in other brief screening measures that were judged by an advisory group of experts in sleep medicine to have good face validity in operationalizing each of the relevant criteria in each of the 3 diagnostic systems.Analysis of the psychometric properties of the BIQ proceeded in 4 steps.First, we investigated short-term test-retest reliability of each questionnaire component in a small (n = 59) probability subsample of AIS respondents, oversampling BIQ positives who were readministered the BIQ 2 days after the AIS interview.The retest interval was purposefully kept short to guarantee that there was very little change in the recall pe-