Thiazolidinediones for Diabetes Mellitus Considerations for Reimbursements by Third-Party Payors

摘要

Thiazolidinediones (TZDs), including pioglitazone and rosiglitazone, have been prescribed for a number of years as monotherapy or combination therapy for glycemic control of type 2 diabetes mellitus. It has been hypothesized that the clinical advantages offered by TZDs compared with other commonly used oral hypoglyce-mic agents (OHAs) [i.e. improved glycemic control, improved lipid profiles, and low rates of hypoglycemic events] should lead to improvements in long-term outcomes, such as decreased incidence of micro- and macrovascular disease, leading in turn to improvements in life expectancy and quality-adjusted life expectancy. While the acquisition costs of TZDs are generally higher than other alternatives, such as metformin or sulfonylureas, it has been postulated that the higher initial acquisition costs of the medications should be offset by decreased costs of treating complications. As such, TZDs could represent an efficient form of treatment for type 2 diabetes.In order to provide an overview of studies performed to date, we have reviewed the available literature on the cost effectiveness of TZDs as a treatment in type 2 diabetes. An extensive literature search of major databases of indexed studies and proceedings of diabetes and health economics-related international conferences was performed to identify studies reporting health-economic outcomes for pioglitazone or rosiglitazone. Very few health-economics studies of TZDs have been published in peer-reviewed journals to date. A total of 16 studies (3 peer-reviewed international journal publications, 13 abstracts) were identified. These studies used various economic-simulation models to estimate the cost effectiveness of rosiglitazone or pioglitazone compared with other commonly prescribed OHAs, such as metformin, sulfonylureas, or acarbose, used either as monotherapy or in combination therapy for the treatment of type 2 diabetes. The studies demonstrated that the short-term clinical advantages of using TZDs translated into decreased incidence and progression of micro- and macrovascular complications, leading to improvements in life expectancy and quality-adjusted life expectancy. The short-term increase in costs due to the higher acquisition prices of the TZDs were partially offset by the long-term avoidance of complication costs. In Japan, pioglitazone was shown to lead to overall cost savings compared with other commonly used OHAs. While bearing in mind the issues of publication bias and other limitations outlined, the cost-effectiveness analyses identified and discussed in this paper lend support to the hypothesis that TZDs can be cost-effective therapies when compared with other commonly prescribed OHAs. Future clinical and health-economics studies must make direct head-to-head comparisons between pioglitazone and rosiglitazone to identify which TZD offers the best value for money. Furthermore, the more recently discovered renoprotective properties of TZDs must be factored into future analyses and are likely to have an important impact on their long-term cost effectiveness.