The first-night effect of sleep occurs over nonconsecutive nights in unfamiliar and familiar environments.
Level 3 - non-randomized controlled study
Non-randomized repeated-measures cohort study
PubMed 39126649 · doi:10.1093/sleep/zsae179
What was done
Polysomnography was used to assess sleep architecture and the first-night effect (FNE) over nonconsecutive nights and across different environments. In Study 1, 45 healthy participants spent two nights separated by one week in a sleep laboratory. In Study 2, 30 participants spent two nonconsecutive nights in the sleep laboratory and two nights at home. Measured outcomes included wake after sleep onset, sleep onset latency, total sleep time, and interhemispheric asymmetry during slow-wave sleep.
What was found
The abstract reports no exact numerical values or effect sizes. FNE-related sleep disruptions occurred across nonconsecutive nights, specifically altering wake after sleep onset, sleep onset latency, and total sleep time. These first-night disruptions occurred in both unfamiliar laboratory and familiar home environments. Slow-wave sleep hemispheric asymmetry did not correlate with the magnitude of the FNE and instead tended to fluctuate across multiple nights.
Why it matters
These findings validate the common research practice of scheduling adaptation nights nonconsecutively before experimental test nights to mitigate the first-night effect, while demonstrating that first-night disruption is not solely driven by an unfamiliar environment.
Limits
The abstract provides qualitative directions without point estimates, variance, or p-values. The combined sample size is modest (n = 75 across two sub-studies) and restricted to healthy individuals, limiting direct generalization to clinical sleep populations.
Cited by
- supports Sleeping in a new environment triggers the 'first night effect', which impairs sleep quality.