Evidence map›Paper›PMID 24342421›Full record

Trial reportDrug and alcohol dependence2014

Regression to the mean and alcohol consumption: a cohort study exploring implications for the interpretation of change in control groups in brief intervention trials.

Jim McCambridge, Kypros Kypri, Patrick McElduff

Open access · hybridAbstract readRandomized Controlled Trial
PubMed Full text at PMC Publisher
In one paragraph

Trial report in Drug and alcohol dependence, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 24 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
24citing papers in PubMed, 1 pooled it
2.8field-weighted citation impact, top 9% of its field
1 · What the graph read from 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.

2 · The registry

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.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

24 citing papers in PubMed, 1 synthesis or guideline pooled it, 57 citations in OpenAlex.

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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

3 authors at 2 institutions in 2 countries.

Jim McCambridgeFaculty of Public Health and Policy London School of Hygiene and Tropical Medicine, 15-17 Tavistock Place, WC1H 9SH, London. Electronic address: Jim.McCambridge@lshtm.ac.uk.
Kypros KypriCentre for Clinical Epidemiology and Biostatistics School of Medicine and Public Health University of Newcastle, Australia.
Patrick McElduffCentre for Clinical Epidemiology and Biostatistics School of Medicine and Public Health University of Newcastle, Australia.
University of Newcastle Australia · AULondon School of Hygiene & Tropical Medicine · GB

Funding

Wellcome Trust WT086516MA
6 · The paper itself

Abstract

backgroundReductions in drinking among individuals randomised to control groups in brief alcohol intervention trials are common and suggest that asking study participants about their drinking may itself cause them to reduce their consumption. We sought to test the hypothesis that the statistical artefact regression to the mean (RTM) explains part of the reduction in such studies.

methods967 participants in a cohort study of alcohol consumption in New Zealand provided data at baseline and again six months later. We use graphical methods and apply thresholds of 8, 12, 16 and 20 in AUDIT scores to explore RTM.

resultsThere was a negative association between baseline AUDIT scores and change in AUDIT scores from baseline to six months, which in the absence of bias and confounding, is RTM. Students with lower baseline scores tended to have higher follow-up scores and conversely, those with higher baseline scores tended to have lower follow-up scores. When a threshold score of 8 was used to select a subgroup, the observed mean change was approximately half of that observed without a threshold. The application of higher thresholds produced greater apparent reductions in alcohol consumption.

conclusionsPart of the reduction seen in the control groups of brief alcohol intervention trials is likely to be due to RTM and the amount of change is likely to be greater as the threshold for entry to the trial increases. Quantification of RTM warrants further study and should assist understanding assessment and other research participation effects.

Indexed as

Control GroupsAdolescentAlcohol DrinkingCohort StudiesEarly Medical InterventionFemaleHumansLongitudinal StudiesMaleNew ZealandRegression AnalysisStudentsSurveys and QuestionnairesYoung AdultAlcoholBrief interventionRegression to the meanResearch participationStudent

Identifiers

PMID24342421
PMCPMC3929002
OpenAlexW2104367365

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

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.