Insomnia Severity Index (ISI)

What is the "Insomnia Severity Index (ISI)"

The Insomnia Severity Index (ISI) is a widely used clinical tool designed to assess the severity and impact of insomnia. It consists of a self-report questionnaire that measures different dimensions of insomnia, including the severity of sleep onset, sleep maintenance, and early morning awakening problems, as well as the satisfaction with current sleep patterns, the extent to which these sleep difficulties interfere with daily functioning, noticeable distress caused by the sleep problem, and the concern of bed partners or others about the individual's sleep.

Overview

• Structure: The ISI is composed of seven items, each rated on a five-point scale (ranging from 0 to 4), with a total score ranging from 0 to 28.
• Scoring: Scores are interpreted as follows:
  • 0-7: No clinically significant insomnia
  • 8-14: Subthreshold insomnia
  • 15-21: Clinical insomnia (moderate severity)
  • 22-28: Clinical insomnia (severe)
• Purpose: The index is used both in clinical settings to guide treatment decisions and in research to evaluate the efficacy of insomnia treatments. It helps in identifying the severity and impact of insomnia on a person's life.
• Application: It is suitable for adults and can be used to track changes in insomnia symptoms over time, such as in response to treatment interventions.

Overall, the ISI provides a reliable and valid measure of perceived insomnia severity, making it an important tool for both clinicians and researchers.