Evidence map›Paper›PMID 30635048›Full record

ArticleSystematic reviews2019

The impact of different inclusion decisions on the comprehensiveness and complexity of overviews of reviews of healthcare interventions.

Michelle Pollock, Ricardo M Fernandes, Amanda S Newton, Shannon D Scott, Lisa Hartling

Abstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in Systematic reviews, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 24 papers, 9 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
24citing papers in PubMed, 9 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

24 citing papers in PubMed, 9 syntheses or guidelines pooled it.

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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

5 authors.

Michelle PollockDepartment of Pediatrics, Alberta Research Centre for Health Evidence, University of Alberta, Edmonton, Canada.
Ricardo M FernandesClinical Pharmacology Unit, Instituto de Medicina Molecular, University of Lisbon, Lisbon, Portugal.
Amanda S NewtonDepartment of Pediatrics, University of Alberta, Edmonton, Canada.
Shannon D ScottFaculty of Nursing, University of Alberta, Edmonton, Canada.
Lisa HartlingDepartment of Pediatrics, Alberta Research Centre for Health Evidence, University of Alberta, Edmonton, Canada. hartling@ualberta.ca.ORCID 0000-0001-8341-3991

Funding

CIHR 119373
6 · The paper itself

Abstract

backgroundOverviews of reviews (overviews) compile information from multiple systematic reviews (SRs) to provide a single synthesis of relevant evidence for decision-making. Overviews may identify multiple SRs that examine the same intervention for the same condition and include some, but not all, of the same primary studies. There is currently limited guidance on whether and how to include these overlapping SRs in overviews. Our objectives were to assess how different inclusion decisions in overviews of healthcare interventions affect their comprehensiveness and results, and document challenges encountered when making different inclusion decisions in overviews.

methodsWe used five inclusion decisions to conduct overviews across seven topic areas, resulting in 35 overviews. The inclusion decisions were (1) include all Cochrane and non-Cochrane SRs, (2) include only Cochrane SRs, or consider all Cochrane and non-Cochrane SRs but include only non-overlapping SRs, and in the case of overlapping SRs, select (3) the Cochrane SR, (4) the most recent SR (by publication or search date), or (5) the highest quality SR (assessed using AMSTAR). For each topic area and inclusion scenario, we documented the amount of outcome data lost and changed and the challenges involved.

resultsWhen conducting overviews, including only Cochrane SRs, instead of all SRs, often led to loss/change of outcome data (median 31% of outcomes lost/changed; range 0-100%). Considering all Cochrane and non-Cochrane SRs but including only non-overlapping SRs and selecting the Cochrane SR for groups of overlapping SRs (instead of the most recent or highest quality SRs) allowed the most outcome data to be recaptured (median 42% of lost/changed outcome recaptured; range 28-86%). Across all inclusion scenarios, challenges were encountered when extracting data from overlapping SRs.

conclusionsOverlapping SRs present a methodological challenge for overview authors. This study demonstrates that different inclusion decisions affect the comprehensiveness and results of overviews in different ways, depending in part on whether Cochrane SRs examine all intervention comparisons relevant to the overview. Study results were used to develop an evidence-based decision tool that provides practical guidance for overview authors.

Indexed as

Decision MakingResearch DesignSystematic Reviews as TopicEvidence-Based MedicineHumansCase seriesKnowledge synthesisOverview of reviewsSystematic review

Identifiers

PMID30635048
PMCPMC6329144

What OpenQuestion holds

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LicenceCC BY
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Registered trials

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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.