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Cross-sectional study evaluating data quality of the National Cancer Registration and Analysis Service (NCRAS) prostate cancer registry data using the Cluster randomised trial of PSA testing for Prostate cancer (CAP)


Objectives To compare the completeness and agreement of prostate cancer data recorded by the National Cancer Registration and Analysis Service (NCRAS) with research-level data specifically abstracted from medical records from the Cluster randomised triAl of prostate specific antigen (PSA) testing for Prostate cancer (CAP) trial.

Design Cross-sectional comparison study.

Participants We included 1356 men from the CAP trial cohort who were linked to the NCRAS registry.

Primary and secondary outcome measures Completeness of prostate cancer data in NCRAS and CAP and agreement for tumour, node, metastases (TNM) stage (T1/T2; T3; T4/N1/M1) and Gleason grade (4–6; 7; 8–10), measured by differences in proportions and Cohen’s kappa statistic. Data were also stratified by year and pre-2010 versus post-2010, when NCRAS reporting standards changed.

Results Compared with CAP, completeness was lower in NCRAS for Gleason grade (41.2% vs 76.7%, difference 35.5, 95% CI 32.1 to 39.0) and TNM stage (29.9% vs 67.6%, difference 37.6, 95% CI 34.1 to 41.1). NCRAS completeness for Gleason grade (pre-2010 vs post-2010 31.69% vs 64%; difference 32.31, 95% CI 26.76 to 37.87) and TNM stage (19.31% vs 55.50%; difference 36.19, 95% CI 30.72 to 41.67) improved over time. Agreement for Gleason grade was high (Cohen’s kappa, κ=0.90, 95% CI 0.88 to 0.93), but lower for TNM stage (κ=0.41, 95% CI 0.37 to 0.51) overall. There was a trend towards improved agreement on Gleason grade, but not TNM stage, when comparing pre-2010 and post-2010 data.

Conclusion NCRAS case identification was very high; however, data on prostate cancer grade was less complete than CAP, and agreement for TNM stage was modest. Although the completeness of NCRAS data has improved since 2010, the higher completeness rate in CAP demonstrates that gains could potentially be achieved in routine registry data. This study’s findings highlight a need for improved recording of stage and grade data in the source medical records.

  • prostate disease
  • epidemiology
  • urological tumours

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  • Contributors The Cluster randomised triAl of PSA testing for Prostate cancer (CAP) trial was performed by RMM, JD, FH, DN, ELT, CM, GJY and EW, amongst others. ELT and EW extracted the relevant CAP trial data for this study. LH and IT extracted the relevant National Cancer Registration and Analysis Service registry data for this study. SWDM, EW and GJY performed the data analysis. SWDM drafted this manuscript, to which all authors made amendments and approved the finalversion.

  • Funding The CAP trial was supported by Cancer Research UK and the UK Department of Health (C11043/A4286, C18281/A8145, C18281/A11326 and C18281/A15064).

  • Competing interests RM,ET, JOD, and CM have received grants from Cancer Research UK in the previous three years.

  • Ethics approval Ethical approval to access information about all those in the CAP study was obtained from UK Trent Multi-Centre Research Ethics Committee (MREC/03/4/093). The CAP study was exempt from gaining individual consent to participant having obtained Section 251 approval from the UK Patient Information Advisory Group (PIAG) (now the Confidentiality Advisory Group, CAG), under Section 251 of the NHS Act 2006 [PIAG 4-09 (k)/2003]. The CAP study is sponsored by the University of Bristol and is registered at Current Controlled Trials (ISRCTN92187251).

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement The dataset supporting the conclusions of this article cannot be shared with third parties due to conditions within the Section 251 approval that governs this research.

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