Evidence map›Paper›PMID 34430755›Full record

ArticleContemporary clinical trials communications2021

Effect sizes and intra-cluster correlation coefficients measured from the Green Dot High School study for guiding sample size calculations when designing future violence prevention cluster randomized trials in school settings.

Md Tofial Azam, Heather M Bush, Ann L Coker, Philip M Westgate

Open access · goldAbstract read
In one paragraph

Article in Contemporary clinical trials communications, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
0.2field-weighted citation impact, top 38% 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

0 citing papers in PubMed, 5 citations in OpenAlex.

No citing paper in PubMed yet.

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

4 authors at 1 institution in 1 country.

Md Tofial AzamUniversity of Kentucky, Department of Biostatistics, College of Public Health, Lexington, KY, USA.
Heather M BushUniversity of Kentucky, Department of Biostatistics, College of Public Health, Lexington, KY, USA.
Ann L CokerUniversity of Kentucky, College of Medicine, 800 Rose St., Pavilion H, Room C361, Lexington, KY, 40536, USA.
Philip M WestgateUniversity of Kentucky, Department of Biostatistics, College of Public Health, Lexington, KY, USA.
University of Kentucky · US

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeCluster randomized controlled trials (cRCTs) are popular in school-based research designs where schools are randomized to different trial arms. To help guide future study planning, we provide information on anticipated effect sizes and intra-cluster correlation coefficients (ICCs), as well as school sizes, for dating violence (DV) and interpersonal violence outcomes based on data from a cRCT which evaluated the bystander-based violence intervention

methodsWe utilized data from 25 schools from the Green Dot High School study. Effect size and ICC values corresponding to dating and interpersonal violence outcomes are obtained from linear mixed effect models. We also calculated the required number of schools needed for future studies utilizing available methods that do and do not consider variation in school size.

resultsObserved effect sizes for DV outcomes range from 0.06 to 0.11. Observed ICC values for DV outcomes range from 0.0006 to 0.0032. The upper limit of 95% CIs for the true ICCs range from 0.0023 to 0.0070.

conclusionSchool-based evaluations with violence outcomes are expected to have small effect sizes. Observed ICCs are less than 0.005 and upper limit of of 95% CIs for the true ICCs are less than 0.01. Designing school-based cRCTs should account for the ICC, even if its value is assumed to be negligible. Furthermore, variation in school sizes should also be accounted for to avoid having too few schools to achieve the desired power.

Indexed as

Cluster randomized controlled trialcRCT, Cluster randomized controlled trialDating violenceDV, Dating violenceEffect sizeGDHS, Green dot high schoolICC, Intra-cluster correlation coefficientIntra-cluster correlation coefficientSample size calculationSexual violenceSV, Sexual violence

Identifiers

PMID34430755
PMCPMC8367849
OpenAlexW3192638149

What OpenQuestion holds

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LicenceCC BY-NC-ND
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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.