The principal finding of this research is that there is no obvious relationship between the size of the financial incentive and health gain for indicators with available data on health gain in the 2004 or 2006 QOF for an average general practice. This is the case for both a marginal improvement in performance of 1% and also for maximum levels of performance. Some interventions (such as beta blockers in heart disease) receive a relatively low incentive compared with their expected health gain, whereas others (such as interventions for smoking cessation) receive a relatively high incentive compared with their expected health gain. Although the incentives were intended to reward general practice for both the volume and quality of the work done , our findings suggest that the incentives are not aligned with maximising health outcomes, which is an explicit aim of the Department of Health . Many practices exceeded the threshold for maximum incentive payments in clinical indicators, and in these situations the GMS contract does not reward further improvement in the quality of care.
Strengths and limitations
Strengths of this study include that robust and up-to-date measures of health gain were used which were computed specifically for the clinical indicators in the general practice contract, and included two different measures of health gain. The estimates of health gain are quite robust to measurement error, since all that is required for Spearman correlation tests in is that the estimates reflect the rankings of interventions by size of health gain. Sensitivity analyses excluding trials with lower levels of evidence and using maximum achievable health gain instead of incentivised health gain, show similar results.
Limitations include that we were only able to identify measures of health gain for a subset of 28 out of a total of 98 indicators in the 2004 and 2006 QOF including an additional area of cervical screening. However, these 28 are important indicators with measurable health outcomes and are all considered clinically important interventions, which account for an achievable 1,085 QALYs gained and 22 lives saved in one year for an average sized practice, and yield 41% of the maximum possible payment for clinical interventions. Of the clinical indicators that were not included in this study, a further 27 were processes which were related to achievement of these 28 indicators (additional file 1).
Not all QOF indicators may be mutually independent. For example a practice which has a successful influenza management system may be more likely to target all eligible patients for immunisation irrespective of which chronic disease they have. Furthermore if a patient has co morbidities such as diabetes and heart disease which include the same intervention, for example influenza immunisation (CHD 12 and DM 18) or hypertension control (CHD 6 and DM12), then there will be an inter dependency between these indicators in different disease domains. QOF interventions are selected by the NHS in agreement with the BMA and in consultation with stakeholder groups. The actions of these agencies at the primary care level may influence the priority that primary care gives to certain medical conditions in a number of ways in addition to inclusion in the QOF.
This research does not capture baseline performance, so our analysis is limited to examining pay for the level of performance, rather than for performance improvement. Our estimates of marginal incentive for a one percent point improvement in health gain are not affected by this problem, so long as baseline performance is below the target for maximum payment. We only considered the health benefits of the interventions in relation to the size of the QOF payments made. The costs of the interventions themselves and their effect on other health service costs have not been considered. Such costs would have to be considered if we were to evaluate the cost-effectiveness of the QOF. For example in another study it was found that two of the indicators considered actually reduced overall costs to the NHS (CHD 10- aspirin in heart disease and DM 15- ACE inhibitor drugs in diabetic renal disease) . The net health impact of cost saving interventions could be higher than the average health impact we have estimated, since the resources saved can be used elsewhere for treating patients and delivering health gains. There will be a small number of individual practices with atypical populations where a closer national alignment of QOF incentives and expected health gain does not fit the health need for those particular practices. We have made the assumption that health gains are distributed evenly across all percentage increases in performance, which may not be the case.
Comparison with previous research
Several studies have examined the expected health gain, effectiveness and cost effectiveness of QOF, and one examined the relationship between financial incentives and health gain [12, 14, 18, 21]. The findings of this small study were similar to our study, finding no association between the size of the financial incentive and expected health gain .
The main implication for policy makers is that the lack of an association between the size of the incentive and the expected health gain may risk skewing activity towards areas with high workload but relatively low benefit to health . Other areas which receive little or no incentive may be relatively ignored [17, 18]. Indications for further research include a systematic review of interventions across the spectrum of primary care to identify the evidence base in terms of QALYs to inform both the selection of new indicators and the relative size of financial incentives.