Brief screening measure for insomnia severity and outcomes. ≈ 2 min to complete. Free with attribution.
ISI (Insomnia Severity Index) is a validated clinical instrument used to assess brief screening measure for insomnia severity and outcomes.. It is most often used for brief screening measure for insomnia severity and outcomes.. The instrument contains 7 items. Typical administration time is ≈ 2 min.
Source / attribution: Free to use with citation
Brief screening measure for insomnia severity and outcomes. ISI is part of standard practice in this setting because it provides a structured, replicable assessment that can be tracked over time and compared across patients or visits.
Like all screening or assessment instruments, ISI is a structured aid — not a diagnostic test in isolation. Results should be interpreted alongside history, examination, and clinical context. Where a score crosses an actionable threshold, the next step is typically a more detailed clinical evaluation rather than a definitive diagnosis.
Answer all 7 items below to see your ISI score and interpretation.
Each item is scored on a 5-point scale (0–4). Your score updates live as you answer.
All scoring runs in your browser. No data is sent anywhere — close the tab and the answers are gone.
Sum all 7 items scored 0-4. Total range 0-28.
Scoring notes: Sum all 7 items scored 0-4. Total range 0-28.
The cutoffs below are drawn from the published validation literature. Always interpret in clinical context.
| Score range | Band | Interpretation |
|---|---|---|
| 0–7 | No clinically significant insomnia | None |
| 8–14 | Subthreshold insomnia | Sleep hygiene education |
| 15–21 | Moderate insomnia | Consider treatment |
| 22–28 | Severe insomnia | Active treatment |
This is an illustrative walkthrough, not a real patient. Follow the same four steps with your own answers — or use the live calculator at the top of this page.
Read each question and choose the response that best fits. Each response has a number next to it — that number is the item's score. The example below uses illustrative answers.
| # | Item | Example response | Score |
|---|---|---|---|
| 1 | Difficulty falling asleep | Severe | 3 |
| 2 | Difficulty staying asleep | Moderate | 2 |
| 3 | Problem waking up too early | Severe | 3 |
| 4 | How satisfied/dissatisfied are you with your current sleep pattern | Moderately satisfied | 2 |
| 5 | How noticeable to others do you think your sleep problem is in terms of impairing the quality of your life | Much | 3 |
| 6 | How worried/distressed are you about your current sleep problem | Somewhat | 2 |
| 7 | To what extent do you consider your sleep problem to interfere with your daily functioning | Much | 3 |
Add up all the item scores you noted in Step 1.
3 + 2 + 3 + 2 + 3 + 2 + 3 = 18
Find the row in the interpretation table whose range contains your total:
Total = 18 falls between 15 and 21 → Moderate insomnia
Moderate insomnia. Consider treatment
A score is one input alongside history and examination. ISI supports clinical judgment — it does not replace it.
Psychometric figures are drawn from the validation literature and may vary across clinical populations and translations.
If ISI doesn't fit your context, related instruments in sleep include:
| Scale | Measures | Items | Time |
|---|---|---|---|
| PSQI | 19-item measure assessing sleep quality and disturbances over one month. | 7 | ≈ 5 min |
| ESS | 8-item questionnaire measuring daytime sleepiness in everyday situations. | 8 | ≈ 2 min |
| AIS | 8-item scale based on ICD-10 insomnia criteria for clinical assessment. | 8 | ≈ 2 min |
| PHQ-9 | Severity of depression | 9 | ≈ 3 minutes |
| GAD-7 | Severity of generalized anxiety | 7 | ≈ 2 minutes |
| AUDIT | 10-item WHO screening tool for hazardous alcohol consumption and dependence. | 10 | ≈ 3 min |
| CHA2DS2-VASc | Annual stroke risk in non-valvular atrial fibrillation | 8 | — |
| Glasgow Coma Scale | Level of consciousness after head injury | 3 | — |
ISI (Insomnia Severity Index) is a validated instrument that assesses brief screening measure for insomnia severity and outcomes. It is designed for clinicians, medical students, evidence-synthesis researchers. It takes about 2 min to complete, and the 7 items are summed to produce a total score.
ISI typically takes about 2 min to administer. The exact duration varies a little depending on whether it is self-administered or completed with a clinician. Its brief format is part of what makes it practical for routine clinical use and for repeat administration when tracking change over time.
ISI contains 7 items. Item scores are summed to produce the total. Scores run from 0 to 28, grouped into 4 interpretation bands from ‘No clinically significant insomnia’ up to ‘Severe insomnia’.
On the ISI (total score 0–28), scores of 22–28 fall in the ‘Severe insomnia’ band — interpreted as: Active treatment. The full ladder is: 0–7 — No clinically significant insomnia: None.; 8–14 — Subthreshold insomnia: Sleep hygiene education.; 15–21 — Moderate insomnia: Consider treatment.; 22–28 — Severe insomnia: Active treatment. A higher score reflects a more severe presentation, and crossing a cutoff is a prompt to step up assessment or care — but these bands are screening thresholds, not diagnoses.
Scores of 0–7 fall in the ‘No clinically significant insomnia’ band: None. A low score is reassuring but does not by itself rule out the underlying condition — if symptoms or clinical suspicion persist, reassess over time or use a complementary evaluation rather than relying on the number alone.
ISI has reported Cronbach's α of 0.9 in validation samples and test–retest reliability of 0.87. Correlates with sleep diaries and polysomnography. In practical terms, a Cronbach’s α around 0.9 indicates excellent internal consistency (the items hang together well), and a test–retest reliability of 0.87 means scores are strongly stable when the scale is repeated without real clinical change.
ISI is free to use with attribution — clinical, educational, and research use is permitted provided the original source is credited. If you publish results or reproduce the scale, include the citation to the source paper.
Bastien, C. H., Vallieres, A., & Morin, C. M. (2001). Validation of the Insomnia Severity Index. Sleep, 24(2), 297-298. This is the original publication for the ISI — the reference to cite when reporting results.
No. ISI is a structured assessment aid, not a diagnostic test. Its proper role is clinical assessment of brief screening measure for insomnia severity and outcomes — it standardizes assessment and flags who needs closer evaluation, but the result must be weighed alongside history, examination, and clinical context. When a score conflicts with your clinical impression, clinical judgment takes precedence; treatment decisions should never rest on a screening score alone.
ISI is supported by the following peer-reviewed sources: