Instrument reference
Insomnia Severity Index (ISI)
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- Construct measured
- Perceived severity and impact of insomnia symptoms.
- Category
- Sleep and functioning
- Intended population
- Adults with sleep complaints.
- Number of items
- Not stated here — check the official source.
- Administration format
- Self-report questionnaire.
- Scoring approach
- Follow the rights holder's materials. This catalogue does not reproduce items or scoring tables.
- Language and population validation
- Translations are distributed through the rights holder; check availability and validation.
Reliability and validity evidence
- Validated as an outcome measure for insomnia research. — Bastien et al. (2001)
Interpretation cautions
- Insomnia complaints can reflect medical conditions, medications, depression, anxiety or sleep disorders such as sleep apnoea; screening does not distinguish these.
Copyright and licence
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Distributed through Mapi Research Trust's ePROVIDE platform. Terms were not confirmed for this catalogue; request access through the distributor.
Reuse terms could not be confirmed from an official source for this catalogue. Only factual metadata is published. Check with the rights holder before any use.
Official source
ePROVIDE — ISI (opens in a new tab)
Rights and evidence last verified: 2026-10-19.