Send to

Choose Destination
Cancer Epidemiol. 2012 Oct;36(5):425-9. doi: 10.1016/j.canep.2012.05.013. Epub 2012 Jun 21.

Validity of cancer diagnosis in a primary care database compared with linked cancer registrations in England. Population-based cohort study.

Author information

King's College London, Department of Primary Care and Public Health, 42 Weston Street, London SE1 3QD, United Kingdom.



The present study aimed to evaluate the validity of cancer diagnoses and death recording in a primary care database compared with cancer registry (CR) data in England.


The eligible cohort comprised 42,556 participants, registered with English general practices in the General Practice Research Database (GPRD) that consented to CR linkage. CR and primary care records were compared for cancer diagnosis, date of cancer diagnosis and death. Read and ICD cancer code sets were reviewed and agreed by two authors.


There were 5216 (91% of CR total) cancer events diagnosed in both sources. There were 494 (9%) diagnosed in CR only and 213 (4%) that were diagnosed in GPRD only. The predictive value of a GPRD cancer diagnosis was 96% for lung cancer, 92% for urinary tract cancer, 96% for gastro-oesophageal cancer and 98% for colorectal cancer. 'False negative' primary care records were sometimes accounted for by registration end dates being shortly before cancer diagnosis dates. The date of cancer diagnosis was median 11 (interquartile range -6 to 30) days later in GPRD compared with CR. Death records were consistent for the two sources for 3337/3397 (99%) of cases.


Recording of cancer diagnosis and mortality in primary care electronic records is generally consistent with CR in England. Linkage studies must pay careful attention to selection of codes to define eligibility and timing of diagnoses in relation to beginning and end of record.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center