ISI-3: evaluation of a brief screening tool for insomnia

Area of Science:

• Gerontology
• Sleep Medicine
• Primary Care Research

Background:

• Insomnia is a prevalent sleep disorder in older adults, impacting overall health and quality of life.
• Accurate and efficient screening tools are crucial for timely diagnosis and intervention in primary care settings.
• The 7-item Insomnia Severity Index (ISI) is a validated measure, but shorter versions may improve usability.

Purpose of the Study:

• To evaluate the performance of the Insomnia Severity Index-3 (ISI-3) as a brief screening tool for clinically significant insomnia.
• To determine the diagnostic accuracy and optimal cut-points of the ISI-3 in an older primary care population.
• To assess the ISI-3's ability to identify individuals requiring further evaluation for insomnia.

Main Methods:

• Secondary analysis of data from two National Institute on Aging clinical trials involving individuals aged ≥60 years with osteoarthritis.
• Development of the ISI-3 using items from the 7-item ISI with the highest item-total correlations in Sample 1 (n=3197).
• Evaluation of ISI-3 diagnostic accuracy (sensitivity, specificity, AUC) against the 7-item ISI (score ≥15 as criterion) in Sample 1 and Sample 2 (n=247).

Main Results:

• The ISI-3, comprising sleep dissatisfaction, sleep interference with daily functioning, and worry about sleep problems, demonstrated high discriminant validity (AUC = 0.97-0.98).
• An ISI-3 score of ≥7 maximized sensitivity (0.94-0.97) and specificity (0.88-0.91), showing high agreement (89.1-91.5%).
• The selected items showed strong item-total correlations (r=0.78-0.81).

Conclusions:

• The ISI-3 serves as an effective and concise screening tool for insomnia in older adults within primary care.
• The ISI-3 can reliably identify individuals who may benefit from a more comprehensive insomnia assessment.
• Further validation in diverse community and clinical populations is recommended to broaden the applicability of the ISI-3.