Practice funding and socioeconomic deprivation in English general practices: a longitudinal study 2013–2017

Background The NHS general practice payment formula has no specific measures of socio-economic deprivation, an important health determinant. Variables related to population health needs are poor predictors of cross-sectional variations in practice payments. Additional years of payments data allow longitudinal analyses. Aim Do deprivation scores predict variations in the slope over time of NHS practice payments, after adjusting for organisational and population factors? Method The sample was 6898 English practices with more than 500 patients, studied over 4 financial years, 2013–2014 to 2016–2017. The dependent variable was total NHS payments per registered patient (after deductions). The independent variable was the Index of Multiple Deprivation (IMD) 2015 score for each practice (range: 3.2 to 66.5). 17 Confounders were selected for conceptual plausibility and data availability at practice level, and included organisational variables and population variables A random intercepts and random slopes model was fitted to adjust for clustering of measurements within practices. The linear effects of independent variables on payments over time were modelled by fitting interaction terms (product of variable with year). Descriptive statistics and univariable analyses were undertaken. Results Practice IMD scores were very weak predictors of longitudinal variations in total payments’ slopes (4.9p/patient/1 unit increase in IMD). We also found that our confounders had very small predictive effects, and payments and IMD were not correlated in any year (Spearman correlation coefficients ranging from 0.01 to 0.06). The median of payments increased from £102.77 (2013–2014) to £115.43 (2016–2017). Conclusion Total payments increased very slightly more in practices with higher deprivation scores. This suggests that the NHS general practice payment formula may not adequately compensate practices whose populations have greater health needs.