Performance measures in three rounds of the English bowel cancer screening pilot

Abstract

Objectives: To compare performance measures across all three rounds of the English bowel cancer screening faecal occult blood test pilot and their relation to social deprivation and ethnicity.

Methods: In each round in three primary care trusts, data for a restricted population of over 48,500 aged 60-69 years were analysed. Individual-based data included postcode linked to area-based data on the Index of Multiple Deprivation (IMD) 2004, and ethnicity. Outcomes were the rates of screening and colonoscopy uptake, positivity and detection of neoplasia (adenomas or bowel cancer) and bowel cancer, and the positive predictive values (PPVs) of a positive test for neoplasia and bowel cancer. Sensitivity was calculated by the proportional incidence method using data on interval cancers identified from cancer registrations.

Results: The overall uptake rate was 61.8%, 57.0% and 58.7% in the first, second and third rounds, respectively. Although the PPV for cancer decreased over the course of the three rounds (10.9% in the 1st round, 6.5% in 3rd round), the PPV for all neoplasia remained relatively constant (42.6% in 1st round, 36.9% in 3rd round). Deprivation and non-white ethnic background (principally Indian subcontinent in the pilot region) were associated with low screening and colonoscopy uptake rates, and this changed little over the three screening rounds. Uptake was lower in men, although differences in uptake between men and women decreased over time. Non-participation in previous rounds was a strong predictor of low uptake.

Conclusions: Performance measures are commensurate with expectations in a screening programme reaching its third round of screening, but a substantial ongoing effort is needed, particularly to address the effects of deprivation and ethnicity in relation to uptake.

Figure 1

Screening process to give test result.