Validation of the Insomnia Severity Index as a Web-Based Measure

October 20, 2017 by School of Medicine Webmaster

Although the Insomnia Severity Index (ISI) is already administered online, this frequently used instrument has not been validated for Web delivery. This study compares online and paper-and-pencil ISI versions completed by participants in a randomized controlled trial testing an Internet-delivered intervention for insomnia. Forty-three adults with insomnia completed both ISI versions during pre- (Assessment 1) and post-intervention (Assessment 2). Correlations between total scores of both versions were significant (rs ≥ .98, ps < .001). For both ISI versions, internal consistency was acceptable (Assessment 1, α = .61; Assessment 2, α ≥ .88). Among participants not receiving the parent study intervention, correlations between 1 format at Assessment 1 and the alternative format at Assessment 2 were generally significant (rs = .26–.82). Together, findings suggest the ISI can be delivered online.