Spielman · Sleep 1987 · uncontrolled before-after trial · n=35

Treatment of chronic insomnia by restriction of time in bed.

Cited 953 times in the scientific literature.

Level 4 - case-series / case-control

Uncontrolled before-and-after clinical intervention study (case series) with no control group.

PubMed 3563247 · record verified 2026-08-29

What was done

Thirty-five patients with chronic insomnia (mean age 46 years, mean insomnia history 15.4 years) completed an 8-week sleep restriction therapy protocol. Treatment started with marked restriction of time in bed, followed by gradual extension contingent on improved sleep efficiency. Sleep parameters and subjective insomnia were measured at post-treatment (8 weeks) and at a follow-up assessment averaging 36 weeks in 23 participants.

What was found

At 8 weeks, patients reported a statistically significant increase in total sleep time (p < 0.05) and improvements in sleep latency, total wake time, sleep efficiency, and subjective insomnia severity (all p < 0.0001). All sleep improvements remained statistically significant at the 36-week follow-up in the 23 evaluated patients. Absolute baseline, post-treatment, and follow-up values were not reported in the abstract.

Why it matters

This study introduced and provided early clinical evidence for sleep restriction therapy, demonstrating that limiting time in bed can improve sleep continuity in chronic insomnia.

Limits

The study lacked a control group, making it impossible to rule out placebo effects or spontaneous fluctuation. Sample size was small (n = 35), and attrition at the 36-week follow-up was 34% (12/35 lost). The abstract also notes that treatment compliance was difficult for some patients.

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