Protocol
Sleep restriction treatment (CBT-I)
Meta-analysis A study that pools the numbers from several trials into one combined estimate. of 20 randomized trials against inactive comparators: sleep onset latency improved by 19.0 minutes, wake after sleep onset by 26.0 minutes, and sleep efficiency by 9.9 percent, with changes sustained at follow-up.
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How this letter has changedLatest: October 2026 · Corrected.
The record carried a not-replicated flag while its B rested on a 20-trial meta-analysis (Trauer et al., Ann Intern Med, 2015; PMID PubMed ID: the permanent number the US National Library of Medicine gives a published paper. Each one links to that paper's record on PubMed. 26054060). The flag describes a single trial nobody has repeated; a meta-analysis of independent randomized trials is replication The same finding reproduced by a separate research group. A result seen once can be chance or bias; a replicated one is harder to explain away. by definition, and what caps this letter at B is the endpoint The outcome a trial measures to decide whether the treatment worked, such as heart attacks, blood pressure or a symptom score., not the absence of a second trial. Flag removed, letter unchanged. Applied the written grade definition under the editor's standing instruction of October 2026 (Arnold Sandlow, D.C.).PMID 26054060
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Sleep restriction is a core part of a structured talk treatment for insomnia, known as CBT-I. It sets a fixed window of time for sleep each night. A review of 20 studies compared it with no active treatment. People fell asleep about 19 minutes faster, spent 26 fewer minutes awake at night, and slept more of their time in bed. The gains lasted. These results come from sleep diaries people kept themselves. No study here compared it head to head with sleeping pills.
Meta-analysis of 20 randomized trials against inactive comparators: sleep onset latency improved by 19.0 minutes, wake after sleep onset by 26.0 minutes, and sleep efficiency by 9.9 percent, with changes sustained at follow-up. Capped at B because the outcomes are diary-based self-report. No head-to-head comparison against sleep medication is cited.
Why this gradeThe reasoning, and what the grade does not cover.
Grade B on insomnia. A meta-analysis of 20 randomized trials against inactive comparators found sleep onset 19 minutes faster, wake after sleep onset 26 minutes shorter and sleep efficiency 9.9 percent higher, sustained at follow-up (Trauer et al., 2015; PMID 26054060).
WHY NOT Athe outcomes are diary-based self-report.
WHAT THIS GRADE DOES NOT COVERsuperiority over sleep medication, which no cited trial tested head to head, and mortality. The link between sleep duration and mortality (Cappuccio et al., 2010; PMID 20469800) is observational Research that watches what people already do rather than assigning a treatment. It can show that two things travel together, not that one causes the other. and carries no letter.
A grade describes the human evidence for a named use. It is not advice, and it is not a judgment on any individual prescription. How the letters are decided →
The evidence, in fullTwo papers, each linked to its PubMed record.
Trauer et al. meta-analysis (Annals of Internal Medicine, 2015; PMID 26054060): CBT-I improves chronic insomnia. Capped at B because the primary outcomes are self-reported sleep measures. Cappuccio et al. (Sleep, 2010; PMID 20469800) is a meta-analysis of PROSPECTIVE OBSERVATIONAL studies linking short and long sleep duration to all-cause mortality. It is not randomized and does not carry a grade; it is the epidemiology that motivates the intervention, not evidence for it.
Total sleep time, sleep onset latency, and wake-after-sleep-onset using a sleep diary for two weeks at baseline; repeated at weeks 6 and 12. The Insomnia Severity Index (ISI) at baseline and end of the CBT-I program. Sleep restriction is the most effective component: adherence to the assigned sleep window is the primary process measure and should be logged nightly.
Evidence notes: meta-analysis
Endpoint graded: Insomnia: sleep onset, time awake after sleep onset and sleep efficiency, from sleep diaries (self_report)
Last reviewed: July 2026
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