Evidence map›Paper›PMID 27177885›Full record

ArticleStatistical methods in medical research2017

Missing continuous outcomes under covariate dependent missingness in cluster randomised trials.

Anower Hossain, Karla Diaz-Ordaz, Jonathan W Bartlett

Abstract read
In one paragraph

Article in Statistical methods in medical research, 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 18 papers.

0numbers the graph read from it
0cells of the map it votes in
18citing 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

18 citing papers in PubMed.

  1. Trial
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  5. Review
  6. Article
  7. Article
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  9. Observational
  10. Article
  11. How should a cluster randomized trial be analyzed?Journal of epidemiology and population health · 2024
    Article
  12. Article
  13. Article
  14. Article
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  16. Article
  17. Article
  18. Review
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.

Anower Hossain1 Department of Medical Statistics, London School of Hygiene & Tropical Medicine (LSHTM), London, UK.
Karla Diaz-Ordaz1 Department of Medical Statistics, London School of Hygiene & Tropical Medicine (LSHTM), London, UK.
Jonathan W Bartlett2 Statistical Innovation Group, AstraZeneca, Cambridge, UK.

Funding

Medical Research Council MR/L011964/1
6 · The paper itself

Abstract

Attrition is a common occurrence in cluster randomised trials which leads to missing outcome data. Two approaches for analysing such trials are cluster-level analysis and individual-level analysis. This paper compares the performance of unadjusted cluster-level analysis, baseline covariate adjusted cluster-level analysis and linear mixed model analysis, under baseline covariate dependent missingness in continuous outcomes, in terms of bias, average estimated standard error and coverage probability. The methods of complete records analysis and multiple imputation are used to handle the missing outcome data. We considered four scenarios, with the missingness mechanism and baseline covariate effect on outcome either the same or different between intervention groups. We show that both unadjusted cluster-level analysis and baseline covariate adjusted cluster-level analysis give unbiased estimates of the intervention effect only if both intervention groups have the same missingness mechanisms and there is no interaction between baseline covariate and intervention group. Linear mixed model and multiple imputation give unbiased estimates under all four considered scenarios, provided that an interaction of intervention and baseline covariate is included in the model when appropriate. Cluster mean imputation has been proposed as a valid approach for handling missing outcomes in cluster randomised trials. We show that cluster mean imputation only gives unbiased estimates when missingness mechanism is the same between the intervention groups and there is no interaction between baseline covariate and intervention group. Multiple imputation shows overcoverage for small number of clusters in each intervention group.

Indexed as

Data Interpretation, StatisticalBiasCluster AnalysisHumansLinear ModelsProbabilityRandomized Controlled Trials as TopicReproducibility of ResultsCluster randomised trialscomplete records analysiscovariate dependent missingnessmissing outcome datamultiple imputation

Identifiers

PMID27177885
PMCPMC5467798

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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.