Accounting for morbidity in capitation payments: A person-based workload formula for primary medical care in England

Background

Accurate needs-based capitation is key to effective and equitable primary care funding. Most capitation schemes use only basic demographic and area characteristics.

Objective

We developed capitation weights for general practices in England using morbidity indicators recorded in primary and secondary care.

Methods

We used primary care records from the Clinical Practice Research Datalink (CPRD) linked with Hospital Episode Statistics (HES) for 12,667,755 patients registered with 1397 general practices on 1 April 2018. Using linear regression models, we estimated the effects on cost-weighted clinical appointments of patient age and gender, ethnicity, area-level deprivation, new registration, and morbidity (four sets of indicators covering 20 to 209 conditions). We included practice fixed-effects to adjust for differences in capacity and productivity. We applied the coefficients on patient characteristics as need-weights to data available nationally and we calculated weighted-patients for all 6892 practices in England.

Results

Most patients (71 %) had at least one appointment per-year. The average annual workload per-patient was £110, with large variations across patients (range £0-£882) and practices (£47-£179). Workload increased with age and with deprivation, but their direct effects halved when including morbidity in the model. Including morbidity widened the range of weighted-patient between practices at the 5th and 95th percentiles (from 0.84–1.14 to 0.79–1.16) and in the least and most deprived deciles (from 0.96–1.04 to 0.95–1.06).

Conclusion

Needs-based capitation weights accounting for morbidity and adjusting for unexplained variations in practice capacity and productivity increase workload differentiation and direct resources toward practices in more deprived areas.