Equity in institutional Pay-for-Performance: Investigating the Reverse Robin Hood effect in England’s Maternity Incentive Scheme using logistic modelling

Background: The reverse Robin Hood effect (RRH) describes an unintended consequence wherein advantaged groups tend to benefit from policy interventions, while disadvantaged groups tend to be further disadvantaged. The RRH could pose a challenge to equity in institutional Pay-for-Performance (P4P) programs such as England’s Maternity Incentive Scheme (MIS), which incentivizes NHS trusts to improve the quality and efficiency of maternity services. Whether the RRH occurs in P4P remains uninvestigated.

Objective: To investigate whether the RRH can be empirically demonstrated in in the MIS.

Methods: Using publicly available data on MIS, we used logistic models to investigate whether trusts that receive funding, and those with higher scores, have a higher probability of success in subsequent years. Additional characteristics, namely trusts’ Index of Multiple Deprivation (IMD) scores, staff and number of births were considered as potential predictors.

Results: The probability of funding is higher in previously successful trusts (0.83, 95% CI 0.80, 0.87) than in previously unsuccessful trusts (0.54, 95% CI 0.48, 0.61). Trusts with higher scores are likelier to be funded in the subsequent year. Trust characteristics such as staff, births and IMD score do not influence the funding probability.

Conclusions: Previous score and funding status are the main predictors of subsequent funding, suggesting that unsuccessful and low-scoring trusts are likely to be significantly disadvantaged. To address this, future P4P programs should consider rewarding improvement rather than absolute attainment. While these findings could suggest a reverse Robin Hood effect, further discussion is needed on how best to test this phenomenon empirically.