Evidence map›Paper›PMID 23077528›Full record

ArticlePloS one2012

Which is more useful in predicting hospital mortality--dichotomised blood test results or actual test values? A retrospective study in two hospitals.

Mohammed A Mohammed, Gavin Rudge, Gordon Wood, Gary Smith, Vishal Nangalia, David Prytherch, Roger Holder, Jim Briggs

Abstract read
In one paragraph

Article in PloS one, 2012. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

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2 · The registry

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3 · Its place in the literature

Who cites it

3 citing papers in PubMed.

  1. Observational
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4 · The record

Corrections and comments

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5 · Who and what money

Authors and funding

8 authors.

Mohammed A MohammedPrimary Care Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, West Midlands, United Kingdom. M.A.Mohammed@Bham.ac.uk
Gavin Rudge
Gordon Wood
Gary Smith
Vishal Nangalia
David Prytherch
Roger Holder
Jim Briggs

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundRoutine blood tests are an integral part of clinical medicine and in interpreting blood test results clinicians have two broad options. (1) Dichotomise the blood tests into normal/abnormal or (2) use the actual values and overlook the reference values. We refer to these as the "binary" and the "non-binary" strategy respectively. We investigate which strategy is better at predicting the risk of death in hospital based on seven routinely undertaken blood tests (albumin, creatinine, haemoglobin, potassium, sodium, urea, and white blood cell count) using tree models to implement the two strategies. METHODOLOGY: A retrospective database study of emergency admissions to an acute hospital during April 2009 to March 2010, involving 10,050 emergency admissions with routine blood tests undertaken within 24 hours of admission. We compared the area under the Receiver Operating Characteristics (ROC) curve for predicting in-hospital mortality using the binary and non-binary strategy.

resultsThe mortality rate was 6.98% (701/10050). The mean predicted risk of death in those who died was significantly (p-value <0.0001) lower using the binary strategy (risk = 0.181 95%CI: 0.193 to 0.210) versus the non-binary strategy (risk = 0.222 95%CI: 0.194 to 0.251), representing a risk difference of 28.74 deaths in the deceased patients (n = 701). The binary strategy had a significantly (p-value <0.0001) lower area under the ROC curve of 0.832 (95% CI: 0.819 to 0.845) versus the non-binary strategy (0.853 95% CI: 0.840 to 0.867). Similar results were obtained using data from another hospital.

conclusionsDichotomising routine blood test results is less accurate in predicting in-hospital mortality than using actual test values because it underestimates the risk of death in patients who died. Further research into the use of actual blood test values in clinical decision making is required especially as the infrastructure to implement this potentially promising strategy already exists in most hospitals.

Indexed as

Hematologic TestsHospital MortalityAdultAgedAged, 80 and overFemaleHumansMaleMiddle AgedModels, StatisticalRetrospective StudiesRisk AssessmentROC Curve

Identifiers

PMID23077528
PMCPMC3471950

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LicenceCC BY
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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.