Skip to main content
The ISI is the brief sleep measure that matters most for tracking treatment response. Seven items, two-week window, summed 0–28. It’s the dominant outcome instrument for Cognitive Behavioural Therapy for Insomnia (CBT-I) and is short enough to administer every two to four weeks during active treatment.

​
What it measures

Insomnia severity along three dimensions:
  • Difficulty falling asleep, staying asleep, and waking too early
  • Satisfaction with current sleep pattern
  • Functional impairment during the day (interference with daily functioning, noticeability to others, distress)
Each item is rated 0–4 over the past two weeks. The sum is the total ISI score.

​
When to send it

  • Intake whenever insomnia is a presenting concern
  • Every 2–4 weeks during CBT-I or any sleep-focused work
  • Pre/post for psychoeducation + sleep-hygiene interventions
  • As a follow-up after a high PSQI Global score — ISI gives you the severity band on a tighter timeframe
The seven items take 2–3 minutes. Most clients fill it in async between sessions.

​
How Rivet scores it

Simple sum of all seven items, range 0–28. Severity bands surface in the live-scoring pill the moment your client submits:
TotalBand
0–7No clinically significant insomnia
8–14Subthreshold insomnia
15–21Clinical insomnia (moderate)
22–28Clinical insomnia (severe)
The ≥15 cutoff is the standard threshold for clinical insomnia and the common gate for CBT-I or sleep-clinic referral. Morin (2011) suggests a ≥10 cutoff for community-screening sensitivity if you’re using ISI as the first pass before a more detailed assessment.

​
Tracking change

A 6-point drop in the total is the published minimal clinically important difference for CBT-I response (Morin et al. 2011). Rivet’s longitudinal view shows the score trajectory across administrations so the change is visible at a glance.

​
Citation

Bastien, C. H., Vallières, A., & Morin, C. M. (2001). Validation of the Insomnia Severity Index as an outcome measure for insomnia research. Sleep Medicine, 2(4), 297–307. Original instrument: Morin, C. M. (1993). Insomnia: Psychological Assessment and Management. New York: Guilford Press. Free clinical use.

​
When not to use it

ISI is severity-focused, not diagnostic — it tells you how bad the insomnia is, not what’s driving it. For sleep-disorder differential screening (apnea, restless legs, circadian rhythm disorders), use the PSQI or refer to a sleep-medicine workup. For acute insomnia in the context of a recent crisis, the 2-week window may not yet reflect the current picture — re-administer once two weeks of the current pattern have passed.

PSQI — Pittsburgh Sleep Quality Index

19-item, 1-month window. Broader sleep-quality screen.

Tracking change over time

The longitudinal view for repeated measures.