Objectives: Sleep disorder is a growing public health concern that requires attentive assessment and treatment. However, the length of assessment tools for sleep disorders, including insomnia, hinders their use in both research and clinical settings. Brief assessment measures expedite assessment time, reducing respondent burden, and save resources, especially in resource-limited settings.
Methods: This study investigated the validity and reliability of a short three-item insomnia scale, the Insomnia Severity Index-3 (ISI-3) and established two cutoff scores in a sample of 238 healthcare providers in Oman (45.8% physicians and 54.2% nurses).
Results: The ISI-3 demonstrated good convergent and divergent validity. The receiver operator characteristic recommended two cutoff scores of > 4 (a sensitivity of 0.87.3 and a specificity of 0.96.4) and > 6 (a sensitivity of 0.96.9 and a specificity of 0.97.1).
Conclusions: The ISI-3 is a good assessment index of insomnia, especially when the utilization of the full insomnia index is unfeasible.