Sleep Condition Indicator: Read Your Score

The Sleep Condition Indicator (SCI) is an eight-question insomnia screener scored from 0 to 32, where a higher total means better sleep. Its authors suggested that a total of 16 or less may help pick out probable insomnia disorder, and they were clear that the cutoff still needs testing against a clinician's own assessment (Espie et al., 2014). It is free for non-commercial use, which is why you can take the full SCI here.

Who Made the SCI

The SCI was published in 2014 in BMJ Open by Colin Espie, Simon Kyle and colleagues at the University of Oxford and partner institutions (full paper, free on PubMed Central (opens in new tab)). Their aim was a short questionnaire a clinician could use in everyday practice to check sleep complaints against the then-new DSM-5 description of insomnia disorder.

The paper is open about its commercial links. Espie was Clinical and Scientific Director of Sleepio Ltd, a digital sleep program, and Sleepio Limited holds the copyright to the SCI. The paper also states that the SCI is "licensed free for non-commercial use" under a Creative Commons Attribution Non Commercial 4.0 license. That license is why CPAP Clarity can show the questions word for word, with the notice the license asks for.

What the Eight Questions Cover

The SCI asks about the past month. In plain terms, it covers:

• how long it usually takes you to fall asleep
• how long you are awake in total after waking in the night
• how many nights a week you have a sleep problem
• how you rate your sleep quality
• how much poor sleep has affected your mood, energy or relationships
• how much it has affected your concentration, productivity or ability to stay awake
• how much poor sleep troubles you in general
• how long you have had a sleep problem

That last question matters. Insomnia disorder is defined by persistence as well as severity, and many quick sleep questionnaires do not ask how long the problem has lasted.

How the SCI Is Scored

Each answer scores 0 to 4, with 4 the best answer (for example, falling asleep within 15 minutes, or sleep troubling you "not at all"). The eight scores add up to a total from 0 to 32. Higher is better sleep, which is the opposite direction to many symptom scales.

The authors also give a 0 to 10 version, which is the total divided by 3.2. A total of 16 is 5.0 on that scale.

On each question, the answers that score 2, 1 or 0 are shaded in the paper's table as meeting the threshold for insomnia disorder on that question. The SCI tool shows your answers against that shaded range, which is useful to bring to a doctor, because it shows where the trouble is as well as how much.

What the Cutoff of 16 Means

The authors tested a cutoff of 16 or less. They compared it with a different questionnaire, the Insomnia Severity Index (ISI), in 255 people from one of their samples. A total of 16 or less correctly picked out 89% of the 27 people scoring 15 or more on the ISI, and a total above 16 correctly identified 82% of the 228 people scoring 14 or less.

Two cautions come with that. First, it was checked against another questionnaire, not against a clinician's diagnosis, and the authors say studies against independent clinical evaluation "are essential before firm conclusions can be made." Second, any cutoff turns a sliding scale into a yes or no. A total of 17 is not meaningfully better than 16.

So a total of 16 or less is best read as "worth discussing with a doctor," and a total above 16 as "outside the range the authors linked to insomnia disorder." Neither is a diagnosis.

How Well It Holds Up

Across five samples totaling 30,941 people who took it online, the SCI's eight questions hung together well (internal consistency, Cronbach's alpha, of 0.86 or higher). Its totals tracked two established measures closely: a correlation of minus 0.79 with the ISI and minus 0.73 with the Pittsburgh Sleep Quality Index. The correlations are negative because a high SCI means good sleep while a high ISI or PSQI means poor sleep.

The authors also tested a two-question short form (SCI-02), using just the nights-per-week and troubled-in-general questions. Its total correlated with the full SCI at 0.90, which they suggested as lead questions a clinician could ask in a consultation.

Insomnia and Sleep Apnea Together

Insomnia and obstructive sleep apnea often occur together. A 2019 meta-analysis of 37 studies by Zhang and colleagues in Sleep Medicine Reviews found that 38% of people with obstructive sleep apnea met criteria for insomnia (abstract on PubMed (opens in new tab)), and a 2019 review by Sweetman, Lack and Bastien in Brain Sciences noted that insomnia symptoms tend to lower CPAP use (review on PubMed Central (opens in new tab)). Researchers call the combination COMISA, comorbid insomnia and sleep apnea.

That has two practical sides. If you use CPAP and your sleep still feels poor even though your machine's numbers look fine, insomnia is one possible reason to raise with your doctor; our guide to being still tired on CPAP walks through the others. And if you have insomnia but also snore or feel very sleepy in the day, sleep apnea is worth asking about too. The NoSAS score is a quick, free way to check that side.

What to Do With Your Score

If your total is 16 or less, it is worth discussing with your doctor. The American College of Physicians recommends cognitive behavioral therapy for insomnia (CBT-I) as the first treatment for chronic insomnia disorder in adults (Qaseem et al., 2016, Annals of Internal Medicine (opens in new tab)). CBT-I is a structured program that works on sleep habits, time in bed and the worry that keeps people awake. It is offered by trained therapists and through some digital programs.

If your total is above 16 but sleep still bothers you, it is still worth raising. A screener is a summary, and your own description of the problem counts.

Either way, retaking the SCI after a change (a new routine, a course of CBT-I, a new medication) shows whether things moved. Keep your totals with the date you took it.

When to Talk to Your Doctor

Talk to your doctor if poor sleep has lasted for months, if it is affecting your work, mood or safety, or if you have fallen asleep at the wheel or nearly so. Raise it too if you have started a new medication around the time sleep changed. Bring your SCI total and your answer profile; they make a vague complaint specific.

If You Already Use CPAP

Your CPAP machine records when you put the mask on and take it off every night. Short or broken usage can be a sign of trouble sleeping as much as trouble with the mask. You can import your SD card into CPAP Clarity to see that pattern in your browser, and bring it together with your SCI total to your sleep physician.

Frequently Asked Questions

What is a good Sleep Condition Indicator score?

The SCI runs from 0 to 32, and higher means better sleep. A total of 16 or less is the range the authors suggested may help detect probable insomnia disorder; a total above 16 is outside it.

How is the SCI different from the Insomnia Severity Index?

Both are short insomnia questionnaires, and their totals tracked each other closely in the SCI paper (a correlation of minus 0.79). The SCI scores in the opposite direction, so a high SCI means good sleep, and it asks how long the problem has lasted. The SCI is also free for non-commercial use, which is why CPAP Clarity can offer it in full.

Can I use the SCI to diagnose insomnia?

No. It is a screener. Its authors checked the cutoff against another questionnaire, not against a clinician's diagnosis. A total of 16 or less is a reason to talk to your doctor.

Primary Sources

• Espie CA, Kyle SD, Hames P, Gardani M, Fleming L, Cape J. The Sleep Condition Indicator: a clinical screening tool to evaluate insomnia disorder. BMJ Open. 2014;4(3):e004183. PubMed Central (opens in new tab)
• Zhang Y, Ren R, Lei F, et al. Worldwide and regional prevalence rates of co-occurrence of insomnia and insomnia symptoms with obstructive sleep apnea: a systematic review and meta-analysis. Sleep Med Rev. 2019;45:1-17. PubMed (opens in new tab)
• Sweetman A, Lack L, Bastien C. Co-Morbid Insomnia and Sleep Apnea (COMISA): Prevalence, Consequences, Methodological Considerations, and Recent Randomized Controlled Trials. Brain Sci. 2019;9(12):371. PubMed Central (opens in new tab)
• Qaseem A, Kansagara D, Forciea MA, Cooke M, Denberg TD. Management of Chronic Insomnia Disorder in Adults: A Clinical Practice Guideline From the American College of Physicians. Ann Intern Med. 2016;165(2):125-133. PubMed (opens in new tab)