Evidence map›Paper›PMID 35776749›Full record

Trial reportPloS one2022

Divergent confidence intervals among pre-specified analyses in the HiSTORIC stepped wedge trial: An exploratory post-hoc investigation.

Richard A Parker, Catriona Keerie, Christopher J Weir, Atul Anand, Nicholas L Mills

Abstract readRandomized Controlled Trial
In one paragraph

Trial report in PloS one, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
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

1 citing paper in PubMed.

  1. Article
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

5 authors.

Richard A ParkerEdinburgh Clinical Trials Unit, Usher Institute, The University of Edinburgh, Edinburgh, United Kingdom.ORCID 0000-0002-2658-5022
Catriona KeerieEdinburgh Clinical Trials Unit, Usher Institute, The University of Edinburgh, Edinburgh, United Kingdom.
Christopher J WeirEdinburgh Clinical Trials Unit, Usher Institute, The University of Edinburgh, Edinburgh, United Kingdom.
Atul AnandBritish Heart Foundation/University Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, United Kingdom.
Nicholas L MillsBritish Heart Foundation/University Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, United Kingdom.

Funding

British Heart Foundation CH/F/21/90010British Heart Foundation PG/15/51/31596British Heart Foundation RE/18/5/34216British Heart Foundation RE/18/6134217
6 · The paper itself

Abstract

backgroundThe high-sensitivity cardiac troponin on presentation to rule out myocardial infarction (HiSTORIC) study was a stepped-wedge cluster randomised trial with long before-and-after periods, involving seven hospitals across Scotland. Results were divergent for the binary safety endpoint (type 1 or type 4b myocardial infarction or cardiac death) across certain pre-specified analyses, which warranted further investigation. In particular, the calendar-matched analysis produced an odds ratio in the opposite direction to the primary logistic mixed-effects model analysis.

methodsSeveral post-hoc statistical models were fitted to each of the co-primary outcomes of length of hospital stay and safety events, which included adjusting for exposure time, incorporating splines, and fitting a random time effect. We improved control of patient characteristics over time by adjusting for multiple additional covariates using different methods: direct inclusion, regression adjustment for propensity score, and weighting. A data augmentation approach was also conducted aiming to reduce the effect of sparse data bias. Finally, the raw data was examined.

resultsThe new statistical models confirmed the results of the pre-specified trial analysis. In particular, the observed divergence between the calendar-matched and other analyses remained, even after performing the covariate adjustment methods, and after using data augmentation. Divergence was particularly acute for the safety endpoint, which had an event rate of 0.36% overall. Examining the raw data was particularly helpful to assess the sensitivity of the results to small changes in event rates and identify patterns in the data.

conclusionsOur experience reveals the importance of conducting multiple pre-specified sensitivity analyses and examining the raw data, particularly for stepped wedge trials with low event rates or with a small number of sites. Before-and-after analytical approaches that adjust for differences in patient populations but avoid direct modelling of the time trend should be considered in future stepped wedge trials with similar designs.

Indexed as

Myocardial InfarctionResearch DesignBiasConfidence IntervalsHumansSample Size

Identifiers

PMID35776749
PMCPMC9249209

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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.