ObjectiveGP list inflation occurs when the number of patients registered at a GP practice exceeds the number of residents. It may be associated with out-of-date patient contact data, affecting invitations for cancer screening. We examined whether bowel, breast and cervical screening coverage was associated with list inflation after adjusting for deprivation and ethnicity.MethodsWe used ecological data, with GP practice the unit of analysis. Outcomes were NHS Fingertips 2019-2020 screening programme performance data. List inflation/deflation was calculated as the difference between GP-registered patients in July 2021 and Office for National Statistics population estimates in their Lower Super Output Areas (LSOA). Percentage White population was calculated using census (2021) data. Index of multiple deprivation (IMD) score was available from NHS Fingertips. Linear regression models were used to examine correlations between outcomes and list inflation before and after adjustment for deprivation and ethnicity.ResultsThe study included 6085 GP practices covering the whole of England. Median list inflation was 8.6% (interquartile range (IQR) 4.7%-16.9%). List inflation was a significant independent predictor of screening coverage. For each 10 percentage points increase in list inflation, coverage declined as follows: -1.96% (95% CI: -2.19, -1.73), -2.20% (95% CI: -2.39, -2.02), -0.99% (95% CI: -1.15, -0.84) and -1.59% (95% CI: -1.75, -1.43) for breast, cervical (aged 25-49), cervical (aged 50-64) and bowel cancer screening, respectively.ConclusionsIt is important to control for variations in list inflation as well as population demographics when comparing screening programme coverage. Uptake improvement initiatives should include strategies for overcoming issues with out-of-date registration data.
Keywords: Breast cancer screening; bowel cancer screening; cervical cancer screening; coverage; population counts.