Uncertainty about the effort-performance relationship in threshold-based payment schemes

Examining organisational responses to performance-based financial incentive systems: a case study using NHS staff influenza vaccination rates from 2012/2013 to 2019/2020

Objective

Financial incentives are often applied to motivate desirable performance across organisations in healthcare systems. In the 2016/2017 financial year, the National Health Service (NHS) in England set a national performance-based incentive to increase uptake of the influenza vaccination among frontline staff. Since then, the threshold levels needed for hospital trusts to achieve the incentive (ie, the targets) have ranged from 70% to 80%. The present study examines the impact of this financial incentive across eight vaccination seasons.

Design

A retrospective observational study examining routinely recorded rates of influenza vaccination among staff in all acute NHS hospital trusts across eight vaccination seasons (2012/2013–2019/2020). The number of trusts included varied per year, from 127 to 137, due to organisational changes. McCrary’s density test is conducted to determine if the number of hospital trusts narrowly achieving the target by the end of each season is higher than would be expected in the absence of any responsiveness to the target. We refer to this bunching above the target threshold as a ‘threshold effect’.

Results

In the years before a national incentive was set, 9%–31% of NHS Trusts reported achieving the target, compared with 43%–74% in the 4 years after. Threshold effects did not emerge before the national incentive for payment was set; however, since then, threshold effects have appeared every year. Some trusts report narrowly achieving the target each year, both as the target rises and falls. Threshold effects were not apparent at targets for partial payments.

Conclusions

We provide compelling evidence that performance-based financial incentives produced threshold effects. Policymakers who set such incentives are encouraged to track threshold effects since they contain information on how organisations are responding to an incentive, what enquiries they may wish to make, how the incentive may be improved and what unintended effects it may be having.

Allocation of health care under pay for performance: Winners and losers

Many physicians receive a payment for their performance (P4P). This performance is often linked to a health target that triggers a bonus when met. For some patients the target is easily met, while others require a significant amount of care to reach the target (if ever). This study contributes to the literature by providing evidence of how P4P affects allocation of care across patients with low and high responsiveness to treatment compared to a fixed payment, such as capitation and salary, under different degrees of resource constraint. Our evidence is based on a controlled laboratory experiment involving 143 medical students in Denmark in 2019. We find that patients who have the potential to reach the health target, gain care under P4P, whereas patients with no potential to reach it, may receive less care. Redistribution of care between patients under P4P arises when physicians are resource constrained. As many physicians are currently operating under tight resource constraints, policymakers should be careful to avoid unintended inequalities in patients' access to health care when introducing P4P. Risk-adjusting the performance target may potentially solve this issue.