Trial reportPloS one2014
Hawthorne effect with transient behavioral and biochemical changes in a randomized controlled sleep extension trial of chronically short-sleeping obese adults: implications for the design and interpretation of clinical studies.
Trial report in PloS one, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT00261898 (Chronic Sleep Deprivation as a Risk Factor for Metabolic Syndrome and Obesity), which is not on this map. Cited by 32 papers, 4 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Chronic Sleep Deprivation as a Risk Factor for Metabolic Syndrome and Obesity
Who cites it
32 citing papers in PubMed, 4 syntheses or guidelines pooled it.
- The Effect of Behavioral Sleep Interventions on Measures of Obesity, Dietary Intake and Physical Activity in Adults With Poor Sleep Health: A Systematic Review, Meta-Analysis and Meta-Regression Analysis.Obesity reviews : an official journal of the International Association for the Study of Obesity · 2026Pooled it
- Defining and evaluating the Hawthorne effect in primary care, a systematic review and meta-analysis.Frontiers in medicine · 2022Pooled it
- Experimental sleep restriction effect on adult body weight: a meta-analysis.Sleep & breathing = Schlaf & Atmung · 2019Pooled it
- The effect of non-pharmacological sleep interventions on glycaemic measures in adults with sleep disturbances and behaviours: A systematic review and meta-analysis.Diabetes & vascular disease researchPooled it
- Evaluating the efficacy of I-fiber pearl on reducing body fat accumulation in obese females: A randomized, double-blind, and placebo-controlled trial.Journal of food and drug analysis · 2026Trial
- Randomised feasibility trial of a remotely delivered holistic UK employee programme combining tailored sleep hygiene, diet, and physical activity counselling for weight management: a mixed-methods evaluation.Journal of nutritional science · 2026Trial
- Effects of Two-Week Sleep Extension on Glucose Metabolism in Chronically Sleep-Deprived Individuals.Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine · 2019Trial
- Sleep extension is a feasible lifestyle intervention in free-living adults who are habitually short sleepers: a potential strategy for decreasing intake of free sugars? A randomized controlled pilot study.The American journal of clinical nutrition · 2018Trial
- Improved sleep quality in older adults with insomnia reduces biomarkers of disease risk: pilot results from a randomized controlled comparative efficacy trial.Psychoneuroendocrinology · 2015Trial
- Awareness of Prediabetes Status and Subsequent Health Behavior, Body Weight, and Blood Glucose Levels.Journal of the American Board of Family Medicine : JABFMTrial
- No evidence of reactivity in accelerometry-based measurement of physical activity and sleep.British journal of health psychology · 2026Article
- From yawn to dawn: the effects of a sleep extension intervention on objective and subjective dimensions of sleep health in adults with habitual short sleep duration.Sleep advances : a journal of the Sleep Research Society · 2026Article
- Effect of behavioural sleep interventions on blood pressure, heart rate, and heart rate variability in adults with poor sleep health: a systematic review, meta-analysis, and meta-regression analysis.European heart journal open · 2026Review
- A temperature-controlled mattress cover is associated with improved subjective sleep in elite male Australian-rules football athletes: A 14-night parallel-group field study.Temperature (Austin, Tex.) · 2026Article
- Learning from missteps: Potential of transcranial electrical stimulation in neuropsychological rehabilitation.Journal of neuropsychology · 2025Review
- Adherence to unilateral hypoglossal nerve stimulation and changes in Epworth Sleepiness Scale scores.Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine · 2025Article
- Second Edition of the Scientists of Tomorrow/Cientistas do Amanhã Project: advancing scientific thinking, methodology, and equitable education.Einstein (Sao Paulo, Brazil) · 2025Article
- Associations Among Cardiometabolic Risk Factors, Sleep Duration, and Obstructive Sleep Apnea in a Southeastern US Rural Community: Cross-Sectional Analysis From the SLUMBRx-PONS Study.JMIR formative research · 2024Observational
- Associations Between Sleep and Metabolic Outcomes in Preadolescent Children.Journal of the Endocrine Society · 2022Article
- Anxiety in anesthesia providers during coronavirus disease 19 pandemic: Insights into perception of harm a cross-sectional study.Annals of medicine and surgery (2012) · 2022Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors.
Funding
Abstract
objectiveTo evaluate the effects of study participation per se at the beginning of a sleep extension trial between screening, randomization, and the run-in visit.
designSubjects were screened, returned for randomization (Comparison vs. Intervention) after 81 days (median), and attended run-in visit 121 days later.
settingOutpatient. PATIENTS: Obese (N = 125; M/F, 30/95; Blacks/Whites/Other, N = 73/44/8), mean weight 107.6±19.7 kg, <6.5 h sleep/night.
interventionNon-pharmacological sleep extension. MEASUREMENTS: Sleep duration (diaries and actigraphy watch), sleep quality (Pittsburgh Sleep Quality Index), daily sleepiness (Epworth Sleepiness Scale), fasting glucose, insulin and lipids.
resultsPrior to any intervention, marked improvements occurred between screening and randomization. Sleep duration increased (diaries: 357.4 ±51.2 vs. 388.1±48.6 min/night; mean±SD; P<0.001 screening vs. randomization; actigraphy: 344.3 ±41.9 vs. 358.6±48.2 min/night; P<0.001) sleep quality improved (9.1±3.2 vs. 8.2±3.0 PSQI score; P<0.001), sleepiness tended to improve (8.9±4.6 vs. 8.3±4.5 ESS score; P = 0.06), insulin resistance decreased (0.327±0.038 vs. 0.351±0.045; Quicki index; P<0.001), and lipids improved, except for HDL-C. Abnormal fasting glucose (25% vs. 11%; P = 0.007), and metabolic syndrome (42% vs. 29%; P = 0.007) both decreased. In absence of intervention, the earlier metabolic improvements disappeared at the run-in visit. LIMITATIONS: Relatively small sample size.
conclusionsImprovements in biochemical and behavioral parameters between screening and randomization changed the "true" study baseline, thereby potentially affecting outcome. While regression to the mean and placebo effect were considered, these findings are most consistent with the "Hawthorne effect", according to which behavior measured in the setting of an experimental study changes in response to the attention received from study investigators. This is the first time that biochemical changes were documented with respect to the Hawthorne effect. The findings have implications for the design and conduct of clinical research.
trial registrationClinicalTrials.gov NCT00261898.
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.