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Insomnia Severity Index (ISI) Calculator

Score the Insomnia Severity Index (ISI) — 7 questions on falling asleep, staying asleep, early waking, satisfaction, noticeability, worry and daytime impact — 0 to 28 with insomnia severity.

1. Difficulty falling asleep (last 2 weeks)

2. Difficulty staying asleep

3. Problems waking up too early

4. How satisfied are you with your current sleep?

5. How noticeable to others is the impact on your quality of life?

6. How worried or distressed are you about your sleep problem?

7. How much does it interfere with daily functioning (fatigue, mood, concentration, work)?

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How it works

ISI = sum of 7 items, each 0–4 (range 0–28). 0–7 no clinically significant insomnia · 8–14 subthreshold insomnia · 15–21 clinical insomnia (moderate) · 22–28 clinical insomnia (severe).

The Insomnia Severity Index (Morin, 1993; validated by Bastien, Vallières and Morin, Sleep Medicine 2001) is a brief self-report questionnaire about the past two weeks. It covers night-time symptoms and how much the sleep problem bothers you and affects daytime life. In community samples a cut-off of 10 detects insomnia well, and in treatment studies a fall of 8 points or more is a meaningful improvement. Insomnia that lasts three months or more usually responds best to cognitive behavioural therapy for insomnia (CBT-I).

Worked example

Answers of 2 (falling asleep), 2 (staying asleep), 1 (waking early), 3 (dissatisfied), 1 (noticeable), 2 (worried) and 2 (interference) give ISI = 2 + 2 + 1 + 3 + 1 + 2 + 2 = 13 / 28 — subthreshold insomnia (8–14).

Sources: Bastien CH, Vallières A, Morin CM. Validation of the Insomnia Severity Index as an outcome measure for insomnia research. Sleep Med 2001 · Morin CM et al. The Insomnia Severity Index: psychometric indicators to detect insomnia cases and evaluate treatment response. Sleep 2011

Frequently asked questions

What is a normal ISI score?

0–7 means no clinically significant insomnia. 8–14 is subthreshold, 15–21 moderate clinical insomnia and 22–28 severe clinical insomnia.

What period do the questions cover?

The last two weeks. Answer for a typical night and day in that time, not just last night.

What ISI change means improvement?

A drop of about 8 points or more is a clinically meaningful improvement, and a score under 8 is often used to define remission after treatment.

What should I do with a high score?

Talk to a doctor — they can check for causes such as sleep apnoea, pain, mood problems or medicines, and recommend CBT-I, the first-line treatment for chronic insomnia.

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A rating scale or questionnaire, not a diagnosis — only a qualified clinician can diagnose. If you or someone you care for is in crisis or having thoughts of self-harm, contact emergency services or a crisis line now.