Evidence map›Paper›PMID 25867772›Full record

ArticlePloS one2015

The method quality of cross-over studies involved in Cochrane Systematic Reviews.

Hong Ding, Guang Li Hu, Xue Yan Zheng, Qing Chen, Diane Erin Threapleton, Zeng Huan Zhou

Abstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in PloS one, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 53 papers, 35 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
53citing papers in PubMed, 35 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

53 citing papers in PubMed, 35 syntheses or guidelines pooled it.

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  4. Effect of online hemodiafiltration on quality of life, fatigue and recovery time: a systematic review and meta-analysis.Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs · 2025
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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

6 authors.

Hong DingDepartment of Epidemiology, School of Public Health and Tropical Medicine, Southern Medical University, Guangdong, China.
Guang Li HuDepartment of Epidemiology, School of Public Health and Tropical Medicine, Southern Medical University, Guangdong, China.
Xue Yan ZhengDepartment of Epidemiology, School of Public Health and Tropical Medicine, Southern Medical University, Guangdong, China.
Qing ChenDepartment of Epidemiology, School of Public Health and Tropical Medicine, Southern Medical University, Guangdong, China.
Diane Erin ThreapletonDivision of Epidemiology, School of Public Health and Primary Care, the Chinese University of Hong Kong, Hong Kong, China.
Zeng Huan ZhouDepartment of Epidemiology, School of Public Health and Tropical Medicine, Southern Medical University, Guangdong, China.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundIt is possible that cross-over studies included in current systematic reviews are being inadequately assessed, because the current risk of bias tools do not consider possible biases specific to cross-over design. We performed this study to evaluate whether this was being done in cross-over studies included in Cochrane Systematic Reviews (CSRs).

methodsWe searched the Cochrane Library (up to 2013 issue 5) for CSRs that included at least one cross-over trial. Two authors independently undertook the study selection and data extraction. A random sample of the CSRs was selected and we evaluated whether the cross-over trials in these CSRs were assessed according to criteria suggested by the Cochrane handbook. In addition we reassessed the risk of bias of these cross-over trials by a checklist developed form the Cochrane handbook.

resultsWe identified 688 CSRs that included one or more cross-over studies. We chose a random sample of 60 CSRs and these included 139 cross-over studies. None of these CSRs undertook a risk of bias assessment specific for cross-over studies. In fact items specific for cross-over studies were seldom considered anywhere in quality assessment of these CSRs. When we reassessed the risk of bias, including the 3 items specific to cross-over trials, of these 139 studies, a low risk of bias was judged for appropriate cross-over design in 110(79%), carry-over effects in 48(34%) and for reporting data in all stages of the trial in 114(82%).Assessment of biases in cross-over trials could affect the GRADE assessment of a review's findings.

conclusionThe current Cochrane risk of bias tool is not adequate to assess cross-over studies. Items specific to cross-over trials leading to potential risk of bias are generally neglected in CSRs. A proposed check list for the evaluation of cross-over trials is provided.

Indexed as

Cross-Over StudiesReview Literature as TopicResearch Design

Identifiers

PMID25867772
PMCPMC4395015

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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.