The main purpose of this paper is to provide comprehensive direct cost estimates for type 2 diabetes-related treatment in patients who initiated insulin for the first time in five European countries, ie, France, Germany, Greece, Spain, and the UK. Our analysis indicates that health care diabetes-related resource utilization and direct costs for type 2 diabetes vary substantially between countries both before and after initiation of insulin. However, both mean and median direct costs per patient had increased in the 6-month follow-up period in all countries in our study, compared with the 6-month period prior to insulin initiation, in accordance with published data.21
The relatively high between-country variations in costs in our study might be due to differences in treatment patterns and care pathways, as well as to country-specific price level effects and purchasing power parities. For example, the frequency of reported macrovascular comorbidities at baseline was lowest in Greece,7
which may help to explain why mean direct costs per patient were lower than in other countries. Spain showed the highest increase in mean direct costs associated with adding insulin to therapy, with average resource consumption increasing across all resource components, except for oral antidiabetic drug use. Although it is possible that the relatively low cost increase we observed in France was a result of high preinsulin costs, the actual reasons for this finding are unknown and may be multifactorial, including variables such as self-monitoring or hospitalization rates.
Patterns of resource use and associated costs were not consistent across the five countries included in our study, nor were changes in usage or costs consistent across countries, either in terms of magnitude or direction of change in individual resources measured. Nevertheless, some changes in specific resources and their costs were almost universally observed. For example, although the proportion of patients using oral antidiabetic drugs increased by 3%–26% in all countries except the UK (where it decreased by 4%), both the absolute and proportion of mean total cost of oral antidiabetic drugs were lower during the 6 months after insulin initiation than in the baseline period in each of the five countries. Not unexpectedly, because of increased usage, blood glucose monitoring costs increased in all countries between the two periods. However, in Spain, the contribution of blood glucose monitoring to total costs tended to be lower in the 6 months after insulin initiation, possibly because the increase in hospitalization costs seen in this country affected the overall distribution of costs. In all other countries, hospitalization costs decreased. The mean cost of specialist care for glycemic control also increased in all countries, possibly because of the increase in visits and phone calls to specialist nurses that was consistently observed.
A limitation of this study is that the sample may not be representative of the population initiating insulin across all countries. Although diabetologists and primary care physicians were randomly selected from a database in France, making it likely that the French population was representative, in other countries physicians were not randomly selected, and in Germany, only diabetologists participated in the study. In this latter instance, the choice of diabetologists as the only participants may have influenced resource utilization, because they are likely to choose more complex insulin regimens that are associated with a higher training expenditure, a likelihood supported by our finding of a markedly different distribution of insulin regimens in Germany, compared with the other countries. Another possible limitation of our study is that, although most data were collected prospectively, the data before initiation of insulin therapy were collected retrospectively using reviews of patient records. However, this retrospective data collection has the advantage of reflecting real-world resource use in patients with type 2 diabetes.
According to results from the CODE-2 study, the largest study on diabetes-related resource use to date, mean yearly direct medical costs per patient with type 2 diabetes treated with insulin alone or in combination with oral antidiabetic drugs in 1999 were €5913 in France, €4997 in Germany, €2309 in Spain, and €2676 in the UK.10
These costs are higher than those reported in the INSTIGATE study, due perhaps to differences in study methodology (eg, retrospective design in the CODE-2 study versus retrospective and prospective data collection components in the INSTIGATE study), the time when the studies were conducted (CODE-2 in 1999 versus INSTIGATE in 2006), and the patients included (INSTIGATE involved a subpopulation of patients with type 2 diabetes initiating insulin, whereas CODE-2 included a broader sample of patients with type 2 diabetes). Therefore, some patients in the CODE-2 study may have had diabetes for longer and hence experienced more advanced complications, which are known to increase direct medical costs.
There is little available information regarding the current costs of diabetes in Europe, particularly at a level that is detailed enough to be useful for decision-makers, and data regarding the cost of initiation of insulin therapy are even more limited. However, it is expected that, at least initially, insulin therapy will increase resource utilization and direct costs because of both the cost of insulin itself and the need to teach patients how to manage such therapy optimally. The results of our study support this supposition in the five European countries of France, Germany, Greece, Spain, and the UK. Therefore, despite the limitations discussed, our study provides important health economic insight regarding direct cost estimates over the 6 months prior to and 6 months after insulin initiation in patients in five European countries in 2006, helping to meet the data gap identified by the International Diabetes Federation.1
It has been reported that health care costs for patients with type 2 diabetes initially increase when insulin therapy is initiated, but that this is followed by an overall decrease in long-term health care expenditure.20
Analysis of 2-year follow-up data on costs from the INSTIGATE study is planned and will be published in due course, helping to determine if the initial increase in costs is sustained in the longer term.