Evidence map›Paper›PMID 25869690›Full record

ArticleBMJ open2015

Can analyses of electronic patient records be independently and externally validated? Study 2--the effect of β-adrenoceptor blocker therapy on cancer survival: a retrospective cohort study.

David A Springate, Darren M Ashcroft, Evangelos Kontopantelis, Tim Doran, Ronan Ryan, David Reeves

Abstract readValidation Study
PubMed Full text at PMC Publisher
In one paragraph

Article in BMJ open, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 17 papers, 4 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
17citing papers in PubMed, 4 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

17 citing papers in PubMed, 4 syntheses or guidelines pooled it.

  1. Pooled it
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  12. The Secure Anonymised Information Linkage databank Dementia e-cohort (SAIL-DeC).International journal of population data science · 2020
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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.

David A SpringateNIHR School for Primary Care Research, Centre for Primary Care, Institute of Population, Health, University of Manchester, Manchester, UK Centre for Biostatistics, Institute of Population Health, University of Manchester, Manchester, UK.
Darren M AshcroftCentre for Pharmacoepidemiology and Drug Safety, Manchester Pharmacy School, University of Manchester, Manchester, UK.
Evangelos KontopantelisNIHR School for Primary Care Research, Centre for Primary Care, Institute of Population, Health, University of Manchester, Manchester, UK Centre for Health Informatics, Institute of Population Health, University of Manchester, Manchester, UK.
Tim DoranDepartment of Health Sciences, University of York, York, UK.
Ronan RyanPrimary Care Clinical Sciences, School of Health and Population Sciences, University of Birmingham, Edgbaston, UK.
David ReevesNIHR School for Primary Care Research, Centre for Primary Care, Institute of Population, Health, University of Manchester, Manchester, UK Centre for Biostatistics, Institute of Population Health, University of Manchester, Manchester, UK.

Funding

Medical Research Council MC_PC_13042Medical Research Council MR/K006665/1
6 · The paper itself

Abstract

objectivesTo conduct a fully independent, external validation of a research study based on one electronic health record database using a different database sampling from the same population.

designRetrospective cohort analysis of β-blocker therapy and all-cause mortality in patients with cancer.

settingTwo UK national primary care databases (PCDs): the Clinical Practice Research Datalink (CPRD) and Doctors' Independent Network (DIN).

participantsCPRD data for 11,302 patients with cancer compared with published results from DIN for 3462 patients; study period January 1997 to December 2006. PRIMARY AND SECONDARY OUTCOME MEASURES: All-cause mortality: overall; by treatment subgroup (β-blockers only, β-blockers plus other blood pressure lowering medicines (BPLM), other BPLMs only); and by cancer site.

resultsUsing CPRD, β-blocker use was not associated with mortality (HR=1.03, 95% CI 0.93 to 1.14, vs patients prescribed other BPLMs only), but DIN β-blocker users had significantly higher mortality (HR=1.18, 95% CI 1.04 to 1.33). However, these HRs were not statistically different (p=0.063), but did differ for patients on β-blockers alone (CPRD=0.94, 95% CI 0.82 to 1.07; DIN=1.37, 95% CI 1.16 to 1.61; p<0.001). Results for individual cancer sites differed by study, but only significantly for prostate and pancreas cancers. Results were robust under sensitivity analyses, but we could not be certain that mortality was identically defined in both databases.

conclusionsWe found a complex pattern of similarities and differences between databases. Overall treatment effect estimates were not statistically different, adding to a growing body of evidence that different UK PCDs produce comparable effect estimates. However, individually the two studies lead to different conclusions regarding the safety of β-blockers and some subgroup effects differed significantly. Single studies using even internally well-validated databases do not guarantee generalisable results, especially for subgroups, and confirmatory studies using at least one other independent data source are strongly recommended.

Indexed as

Electronic Health RecordsAdrenergic beta-AntagonistsAntihypertensive AgentsDatabases, FactualHumansNeoplasmsPrimary Health CareRetrospective StudiesUnited KingdomAdrenergic beta-AntagonistsAntihypertensive AgentsONCOLOGYPRIMARY CARESTATISTICS & RESEARCH METHODS

Identifiers

PMID25869690
PMCPMC4401857

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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.