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)

ObjectivesTo 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 PSA testing for Prostate cancer (CAP) trial.DesignCross-sectional comparison studyParticipantsWe included 1,356 men from the CAP trial cohort who were linked to the NCRASregistry.Primary and secondary outcome measuresCompleteness of prostate cancer data in NCRAS and CAP and agreement for TNMstage (T1/T2; T3; T4/N1/M1) and Gleason grade (4-6; 7; 8-10), measured bydifferences in proportions and Cohen’s Kappa statistic. Data were also stratified by year and pre- versus post-2010, when NCRAS reporting standards changed.ResultsCompared to CAP, completeness was lower in NCRAS for Gleason grade (41.2% vs 76.7%, difference 35.5 95% CI 32.1, 39.0) and TNM stage (29.9% vs 67.6%, difference 37.6 95% CI 34.1, 41.1). NCRAS completeness for Gleason grade (pre- versus post-2010 31.69% vs 64%; difference 32.31 95% CI 26.76, 37.87) and TNM stage (19.31% vs 55.50%; difference 36.19 95% CI 30.72, 41.67) improved over time. Agreement for Gleason grade was high (Cohen’s Kappa, κ=0.90 95% CI 0.88, 0.93), but lower for TNM stage (κ=0.41 95% CI 0.37, 0.51) overall. There was a trend towards improved agreement on Gleason grade, but not TNM stage, when comparing pre- and post-2010.ConclusionNCRAS 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 demonstrate 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.