Completeness and diagnostic validity of recording acute myocardial infarction events in primary care, hospital care, disease registry, and national mortality records: cohort studyBMJ 2013; 346 doi: https://doi.org/10.1136/bmj.f2350 (Published 21 May 2013) Cite this as: BMJ 2013;346:f2350
- Emily Herrett, research fellow1,
- Anoop Dinesh Shah, clinical research fellow2,
- Rachael Boggon, research statistician34,
- Spiros Denaxas, senior research associate2,
- Liam Smeeth, professor of clinical epidemiology and general practitioner1,
- Tjeerd van Staa, professor of pharmacoepidemiology134,
- Adam Timmis, professor of clinical cardiology5,
- Harry Hemingway, professor of clinical epidemiology2
- 1London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
- 2Department of Epidemiology and Public Health, Clinical Epidemiology Group, University College London, UK
- 3Clinical Practice Research Datalink Group, Medicines and Healthcare products Regulatory Agency, London, UK
- 4Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, Netherlands
- 5Barts and the London School of Medicine and Dentistry, London, UK
- Correspondence to: E Herrett
- Accepted 26 March 2013
Objective To determine the completeness and diagnostic validity of myocardial infarction recording across four national health record sources in primary care, hospital care, a disease registry, and mortality register.
Design Cohort study.
Participants 21 482 patients with acute myocardial infarction in England between January 2003 and March 2009, identified in four prospectively collected, linked electronic health record sources: Clinical Practice Research Datalink (primary care data), Hospital Episode Statistics (hospital admissions), the disease registry MINAP (Myocardial Ischaemia National Audit Project), and the Office for National Statistics mortality register (cause specific mortality data).
Setting One country (England) with one health system (the National Health Service).
Main outcome measures Recording of acute myocardial infarction, incidence, all cause mortality within one year of acute myocardial infarction, and diagnostic validity of acute myocardial infarction compared with electrocardiographic and troponin findings in the disease registry (gold standard).
Results Risk factors and non-cardiovascular coexisting conditions were similar across patients identified in primary care, hospital admission, and registry sources. Immediate all cause mortality was highest among patients with acute myocardial infarction recorded in primary care, which (unlike hospital admission and disease registry sources) included patients who did not reach hospital, but at one year mortality rates in cohorts from each source were similar. 5561 (31.0%) patients with non-fatal acute myocardial infarction were recorded in all three sources and 11 482 (63.9%) in at least two sources. The crude incidence of acute myocardial infarction was underestimated by 25-50% using one source compared with using all three sources. Compared with acute myocardial infarction defined in the disease registry, the positive predictive value of acute myocardial infarction recorded in primary care was 92.2% (95% confidence interval 91.6% to 92.8%) and in hospital admissions was 91.5% (90.8% to 92.1%).
Conclusion Each data source missed a substantial proportion (25-50%) of myocardial infarction events. Failure to use linked electronic health records from primary care, hospital care, disease registry, and death certificates may lead to biased estimates of the incidence and outcome of myocardial infarction.
Trial registration NCT01569139 clinicaltrials.gov.
We acknowledge the support of Barts and the London Cardiovascular Biomedical Research Unit, which is funded by the National Institute for Health Research. The views expressed in this paper are those of the authors and do not reflect the official policy or position of the Medicines and Healthcare products Regulatory Agency.
Contributors: EH and ADS contributed equally to the design and analysis of the study and writing the manuscript. All authors were involved in study design and reviewing draft manuscripts. HH is guarantor.
Funding: This work was supported by grants from the UK National Institute for Health Research (grant No RP-PG-0407-10314), the Wellcome Trust (086091/Z/08/Z), and UK Biobank. LS is supported by a senior clinical fellowship from the Wellcome Trust (098504). EH is supported by a Medical Research Council studentship. AS is supported by a clinical research training fellowship from the Wellcome Trust (0938/30/Z/10/Z). Clinical Practice Research Datalink is owned by the UK Department of Health and operates within the Medicines and Healthcare products Regulatory Agency. Clinical Practice Research Datalink has received funding from the Healthcare products Regulatory Agency, Wellcome Trust, Medical Research Council, National Institute for Health Research health technology assessment programme, Innovative Medicine Initiative, UK Department of Health, Technology Strategy Board, Seventh Framework Programme EU, various universities, contract research organisations, and pharmaceutical companies. The department of Pharmacoepidemiology and Pharmacotherapy, Utrecht Institute for Pharmaceutical Sciences has received unrestricted funding for pharmacoepidemiological research from GlaxoSmithKline, Novo Nordisk, the private-public funded Top Institute Pharma (www.tipharma.nl, includes co-funding from universities, government, and industry), the Dutch Medicines Evaluation Board, and the Dutch Ministry of Health. The funding sources had no role in the design and conduct of the study, analysis, interpretation, preparation, review, and approval of the manuscript; or the decision to submit the paper for publication. The views expressed in this paper are those of the authors and not necessarily those of the NHS, the National Institute for Health Research, or the Department of Health.
Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare: financial support for the submitted work from the Wellcome Trust, National Institute for Health Research, Medicines and Healthcare products Regulatory Agency, Medical Research Council, and UK Biobank for the submitted work; no relationships that might have an interest in the submitted work in the previous three years; their spouses, partners, or children have no financial relationships that may be relevant to the submitted work; and no non-financial interests that may be relevant to the submitted work.
Ethical approval: This study was approved by the Medicines and Healthcare products Regulatory Agency’s independent scientific advisory committee (protocol 11 088), the MINAP Academic Group, and the CALIBER Scientific Oversight Committee.
Data sharing: No additional data available.
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