Cancer recording and mortality in the General Practice Research Database and linked cancer registries

Authors

  • Rachael Boggon,

    1. Clinical Practice Research Datalink, Medicines and Healthcare products Regulatory Agency, London, UK
    2. Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, the Netherlands
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  • Tjeerd P. van Staa,

    Corresponding author
    1. Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, the Netherlands
    2. London School of Hygiene & Tropical Medicine, London, UK
    • Clinical Practice Research Datalink, Medicines and Healthcare products Regulatory Agency, London, UK
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  • Michael Chapman,

    1. National Cancer Intelligence Network, London, UK
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  • Arlene M. Gallagher,

    1. Clinical Practice Research Datalink, Medicines and Healthcare products Regulatory Agency, London, UK
    2. Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, the Netherlands
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  • Tarek A. Hammad,

    1. Office of Surveillance and Epidemiology, Food and Drug Administration, Silver Spring, MD, USA
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  • Mike A. Richards

    1. National Cancer Action Team, London, UK
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  • This article is published with the permission of the Controller of HMSO and the Queen's Printer for Scotland.

Correspondence to: T.P. van Staa, General Practice Research Database, Medicines and Healthcare Products Regulatory Agency, 151 Buckingham Palace Road, London SW1W 9SZ. E-mail: Tjeerd.vanstaa@CPRD.com

ABSTRACT

Purpose

Large electronic datasets are increasingly being used to evaluate healthcare delivery. The aim of this study was to compare information held by cancer registries with that of the General Practice Research Database (GPRD).

Methods

A convenience sample of 101 020 patients aged 40+ years drawn from GPRD formed the primary data source. This cohort was derived from a larger sample originally established for a cohort study of diabetes. GPRD records were linked with those from cancer registries in the National Cancer Data Repository (NCDR). Concordance between the two datasets was then evaluated. For cases recorded only on one dataset, validation was sought from other datasets (Hospital Episode Statistics and death registration) and by detailed analysis of a subset of GPRD records.

Results

A total of 5797 cancers (excluding non-melanomatous skin cancer) were recorded on GPRD. Of these cases, 4830 were also recorded on NCDR (concordance rate of 83.3%). Of the 976 cases recorded on GPRD but not on NCDR, 528 were present also in the hospital records or death certificates. Of the 341 cases recorded on NCDR but not on GPRD, 307 were recorded in these other two datasets. Rates of concordance varied by cancer type. Cancer registries recorded larger numbers of patients with lung, colorectal, and pancreatic cancers, whereas GPRD recorded more haematological cancers and melanomas. As expected, GPRD recorded significantly more non-melanomatous skin cancer. Concordance decreased with increasing age.

Conclusion

Although concordance levels were reasonably high, the findings from this study can be used to direct efforts for better recording in both datasets. Copyright © 2012 Crown copyright.

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