Evidence map›Paper›PMID 30775014›Full record

ArticleBMJ global health2019

Synthesising quantitative evidence in systematic reviews of complex health interventions.

Julian P T Higgins, José A López-López, Betsy J Becker, Sarah R Davies, Sarah Dawson, Jeremy M Grimshaw, Luke A McGuinness, Theresa H M Moore, Eva A Rehfuess, James Thomas and 1 more

Abstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in BMJ global health, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 136 papers, 58 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
136citing papers in PubMed, 58 pooled it
–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

136 citing papers in PubMed, 58 syntheses or guidelines pooled it.

  1. Combined antithrombotic therapy vs. oral anticoagulation alone for ischemic stroke with concomitant atrial fibrillation and large artery atherosclerosis: a systematic review and meta-analysis.Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology · 2026
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76 more citing papers are in PubMed but not listed here.

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

11 authors.

Julian P T HigginsPopulation Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK.
José A López-LópezPopulation Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK.
Betsy J BeckerDepartment of Educational Psychology and Learning Systems, College of Education, Florida State University, Tallahassee, Florida, USA.
Sarah R DaviesPopulation Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK.
Sarah DawsonPopulation Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK.
Jeremy M GrimshawClinical Epidemiology Program, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, Ontario, Canada.
Luke A McGuinnessPopulation Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK.
Theresa H M MoorePopulation Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK.
Eva A RehfuessInstitute for Medical Information Processing, Biometry and Epidemiology, Pettenkofer School of Public Health, LMU Munich, Munich, Germany.
James ThomasEPPI-Centre, Department of Social Science, University College London, London, UK.
Deborah M CaldwellPopulation Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK.

Funding

Department of Health PHR/15/49/08Medical Research Council MC_UU_12013/9Medical Research Council MR/K025643/1Medical Research Council MR/M025209/1
6 · The paper itself

Abstract

Public health and health service interventions are typically complex: they are multifaceted, with impacts at multiple levels and on multiple stakeholders. Systematic reviews evaluating the effects of complex health interventions can be challenging to conduct. This paper is part of a special series of papers considering these challenges particularly in the context of WHO guideline development. We outline established and innovative methods for synthesising quantitative evidence within a systematic review of a complex intervention, including considerations of the complexity of the system into which the intervention is introduced. We describe methods in three broad areas: non-quantitative approaches, including tabulation, narrative and graphical approaches; standard meta-analysis methods, including meta-regression to investigate study-level moderators of effect; and advanced synthesis methods, in which models allow exploration of intervention components, investigation of both moderators and mediators, examination of mechanisms, and exploration of complexities of the system. We offer guidance on the choice of approach that might be taken by people collating evidence in support of guideline development, and emphasise that the appropriate methods will depend on the purpose of the synthesis, the similarity of the studies included in the review, the level of detail available from the studies, the nature of the results reported in the studies, the expertise of the synthesis team and the resources available.

Indexed as

complex interventionsguideline developmentmeta-analysissystematic reviews

Identifiers

PMID30775014
PMCPMC6350707

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC
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.