Psychometric properties of the PROMIS sleep disturbance and sleep-related impairment scales short forms in the Iranian general population.

Sleep problems are common in the general population and are consistently associated with adverse health outcomes. The Patient-Reported Outcomes Measurement Information System (PROMIS) Sleep Disturbance (SD) and Sleep-Related Impairment (SRI) scales were developed to assess sleep disturbance and related Impairment. This study evaluated the validity and reliability of short forms of these scales in the general Iranian population. The questionnaires were completed by 440 participants via an online survey. Following confirmation of unidimensionality for the PROMIS SD and SRI by factor analysis, Item Response Theory (IRT) analysis was performed. Convergent and concurrent validity, internal consistency, marginal reliability, and test-retest reliability were subsequently evaluated. The original single-factor models, modified with correlated error terms for both scales and excluding PROMIS-SRI item 6, demonstrated excellent fit in the confirmatory factor analysis. The modified PROMIS-SD and PROMIS-SRI short forms demonstrated excellent internal consistency (α = 0.89, 0.93; ω = 0.86, 0.93), good convergent validity (AVE = 0.69, 0.67). In addition, these short forms exhibited satisfactory test-retest reliability (r = 0.69, 0.86) and excellent marginal reliability (α = 0.91, 0.92). Concurrent validity was supported by moderate to strong correlations of both PROMIS scales with established measures, including the Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), Epworth Sleepiness Scale (ESS), Sheehan Disability Scale (SDS), and Depression Anxiety Stress Scale - 21(DASS-21). Results suggest that Persian short forms of PROMIS-SD and PROMIS-SRI are reliable and valid psychometric instruments to assess sleep disturbance and related impairments in the Iranian general population.