ISI

Overview

The Insomnia Severity Index (ISI) is a 7-item self-report questionnaire designed to assess the severity of insomnia and its impact on daily functioning. The ISI aims to provide information on various aspects of insomnia, including its frequency, severity, and effects on daytime functioning.

Purpose

The main purposes of the ISI are:

• Assessing Insomnia Severity: Determining the level of insomnia severity and its impact on sleep quality and daily activities.
• Monitoring Symptoms: Evaluating changes in insomnia symptoms to track treatment effectiveness and adjust therapeutic approaches.

Structure

The questionnaire consists of 7 items, each evaluating different aspects of insomnia, including its frequency, duration, impact on daily activities, and overall perception of sleep quality. Respondents rate each item on a scale from 0 to 4.

Application

• Clinical Use: The ISI is used by doctors, psychiatrists, and sleep specialists for diagnosing and managing insomnia, as well as for assessing treatment effectiveness.
• Research Use: In scientific research, the ISI is employed to study the prevalence of insomnia and its impact on various aspects of life, as well as to evaluate new therapeutic methods.

Psychometric Properties

The ISI demonstrates strong psychometric properties:

• Reliability: The scale shows high internal consistency, with a Cronbach’s alpha coefficient above 0.70, indicating reliable measurement of insomnia symptoms. Test-retest reliability also confirms the stability of results over time.
• Validity: The ISI exhibits good construct validity, correlating with other measures of sleep quality and sleep disorders. Discriminant validity effectively distinguishes between different levels of insomnia severity.

Translation and Adaptation

The ISI has been translated into multiple languages and adapted to various cultural contexts, ensuring its relevance and accuracy across different populations. These translations and adaptations contribute to its widespread use in international research and clinical practice.

Conclusion

The Insomnia Severity Index (ISI) is a reliable and valid tool for assessing the severity of insomnia and its impact on daily functioning. Its robust psychometric properties and versatility make it an important instrument for clinicians and researchers, aiding in the identification and management of insomnia.