Use of quality-based funding, in which data on survival are included in the quality indicators, may encourage the hospitals to treat patients wherever good results may be expected. If no control for underlying variables is made, this may give rise to misallocation of resources. Absence of risk adjustment may thus be a disadvantage, for patients with serious diseases that are hard to treat, as well as for the hospitals that provide care to these patients. For example, it has been shown that the introduction of quality indicators for heart surgery in New York and Pennsylvania gave rise to patient selection among the hospitals (18).
The model used for quality-based funding in Norway does not clarify how the risk adjustment has been undertaken (3). The objective of this study was thus to investigate how various forms of risk adjustment affected the predicted mortality, using patients discharged with a diagnosis of acute myocardial infarction as an example.
The main conclusions from the analysis are that gender, age, comorbidity, disability and travel time are candidate variables that should be considered for inclusion in the adjustment. Other variables to which we have had no access, for example information on genetic factors (19), may also be relevant. The socioeconomic variables made a smaller contribution to the risk adjustment once the former variables had been included.
Even though this analysis has a limited statistical strength and there were few confidence intervals that did not overlap with the national average for 30-day mortality, the changes that occurred as a result of the risk adjustments are important in terms of how resources are allocated in a quality-based funding system. Estimated mortality changed significantly for patients in the catchment areas for the Asker og Bærum, Stavanger, Sunnmøre, and Nordmøre og Romsdal hospital trusts, and also for Førde when further variables were included. Therefore, the main conclusion from the analysis is that controls for a broad range of underlying variables should be made, both when quality information is published and when quality indicators are used as a basis for the funding system.
In the normative debate on how quality-based funding systems should be designed, questions are raised regarding whether the use of procedures should be included as a quality indicator (20). The only variable included in our analysis that can be linked to the treatment provided by the hospital trust was percutaneous coronary intervention.
Two issues render it obvious that rewards for this type of treatment may not be a good solution. It may give rise to overtreatment and result in a geographically skewed distribution of resources due to the current structure of PCI centres, since this method is more common in hospital trusts that have a PCI centre when compared to those that have none. This applies also to percutaneous coronary interventions after 14 days and reflects the opportunities for emergency treatment with the aid of this method as well as the expected effectiveness of such treatment after the acute phase. The list of procedures that could be included in the analysis may be expanded, however. With regard to myocardial-infarction patients, rehabilitation, check-ups and medication use may provide relevant procedure variables.
While the decision to perform percutaneous coronary intervention is made at the clinical level in the hospital, a number of other variables may be influenced at the local or regional level within the health-enterprise system. Travel time to the PCI centre is one example. Seen in isolation, if long distances give rise to higher mortality and a decision is made to adjust for distances in the allocation model, this may entail a premium on centralisation of the activities. The size of the hospital trusts is another example of issues that can be influenced and may have an effect on the results of the type of analyses that we have undertaken. If the analyses are undertaken on the basis of the hospital trusts’ catchment areas, large hospital trusts will, seen in isolation, demonstrate less inter-trust variation when compared to a greater number of small hospital trusts.
Our analysis represents an example of how risk adjustment may be undertaken to provide a basis for quality-based funding. The analysis has its limitations, however. To increase the strength of the analysis we should ideally have used data for more than one year. For some hospital trusts, however, the results reveal confidence intervals that do not overlap with the national average if their mortality rates lie 3 – 4 % above or below this level. One key question that remains unclarified concerns how much the mortality rate for each hospital trust should be permitted to deviate from the national average before this will have an effect on the budget allocations to the regional hospital trusts.
The data need to be as updated as possible, to permit the hospital staff to see the financial effects of quality changes in the course of one or two years. For practical reasons, especially because of the time it takes to process applications for data access and retrieve the data, we have used data for 2009. Improvements to contingency planning have been made in recent years, and the analysis may therefore have yielded different results today. The travel-time variable that we have used could also be improved by including patient-level data from the database that registers information on ambulance call-outs (Akuttmedisinsk informasjonssystem, AMIS).
We have based this study on the responsibility of the hospital trusts to provide care, meaning that the patient’s residential address decides his or her affiliation to a particular hospital trust. The Norwegian Knowledge Centre for the Health Services base their analyses of survival and readmissions to Norwegian hospitals on the actual place of treatment, weighted by hospitalisation time if multiple locations are involved.
These two different perspectives entail consequences in terms of who will be held responsible for the patient’s treatment outcome. While we hold responsible the hospital trust that in practice is charged with providing care to the patient, the Knowledge Centre places this responsibility with the hospital trust that actually provides treatment. In a system of quality-based funding it is essential to have a well-considered opinion regarding the choice of one perspective or the other. We see no reason why the funding in this respect should deviate from the principles that have been chosen for funding of the hospital trusts in general.