Re: Saunders R, Lian J, Karolicki B, Valentine W. The cost-effectiveness and budget impact of stepwise addition of bolus insulin in the treatment of type 2 diabetes: evaluation of the FullSTEP trial. J Med Econ 2014;17(12):827-36

Dear Editor,

The article by Saunders et al.1 provides pharmacoeconomic assessment of the stepwise addition of bolus insulin in the treatment of type 2 diabetes. Economic data were determined using the FullSTEP study which was a 32-week, randomized, open-label, non-inferiority study with 401 participants. It demonstrated that stepwise addition (SWA) of bolus insulin aspart (rapid acting) was non-inferior to full basal-bolus (FBB) and reduced the rates of hypoglycemia. The budget impact analysis focuses on how a health plan’s cost would be affected by these two methods of insulin escalation. Drummond et al.’s2 points for economic evaluation of healthcare programs are used to assess the quality of the methodology, the accuracy of reporting, and whether the results can be generalized to other populations. The article could be clearer if it included clinical event rates which were kept on file with Novo Nordisk since they were a significant component of the cost analysis.

First, the budget impact analysis included costs associated with clinical outcomes (e.g. office visits, emergency department visits, and hypoglycemic events) which affected the first-year cost savings. While these condition-related costs were determined for the companion cost-effectiveness analysis, the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) principles for good practice when performing a budget impact analysis state that results should be presented both with and without these costs included3. Since the SWA group had reported fewer hypoglycemic events, there was an advantage given to this arm over the FBB by including these clinical outcomes.

The differences in reported costs of bolus insulin (NOVOLOG and NOVOLOG FlexPen) could lead to a misinterpretation of the findings of the budget impact analysis. Using RED BOOK Online4 near the time of initial publication of this analysis article, there were significant differences in prices for each of the insulin aspart products used in the study. The price used in the study is $0.19/unit (USD2013) assuming 80% pen usage and the price listed is $0.0945/unit (AWP, USD2014) with the same assumption. These prices are lower than the reported prices so the costs may be over-estimated. One of the cost-savings for SWA is the reduction in bolus insulin needed, so this could lead to an increase in the interpretation of cost savings in the budget impact analysis.

Last, it was assumed that all eligible patients made the switch from full basal-bolus to stepwise addition of insulin for the analysis. The estimated usage should be based on market share and penetration of the protocol. This would greatly reduce the estimated total saving, mean saving per intensifying patient and per member per month saving.

Transparency

Declaration of financial/other relationships

DT has disclosed that he has no significant relationships with or financial interests in any commercial companies related to this study or article.