Economic Evaluation of Insulin Lispro versus Neutral (Regular) Insulin Therapy Using a Willingness-To-Pay Approach

Abstract

This willingness-to-pay (WTP) analysis is the first study of its kind undertaken in Australia to support an application for listing of a new drug on the Australian national formulary. The technique offers the advantage of being able to summarise diverse outcomes of therapy in a single unit of measure. Willingness to pay is used to value benefits in cost-benefit analysis (CBA), and CBA represents an absolute decision rule. An open-ended question with a bid-up approach was used to minimise bias and elicit the maximum amount patients would be willing to pay for insulin lispro. The WTP study incorporated scenarios describing the outcomes from insulin lispro and neutral (regular) insulin, the results from a formal metaanalysis and a description of the injection characteristics of the therapies. A sample of 83 patients with type I or II diabetes mellitus were surveyed using an open questionnaire to determine their maximum willingness to pay for the therapy they preferred. Overall, 92% of patients preferred insulin lispro (referred to as insulin A) and 8% preferred neutral insulin (referred to as insulin B). The incremental benefit per patient was calculated as 452.16 Australian dollars ($A) per year. Insulin lispro was listed on the Australian national formulary at a 36% premium over neutral insulin, so the additional cost per patient would be $A70.32 per year. Therefore, costs were exceeded by the benefits and insulin lispro was deemed to offer a net benefit. A multivariate analysis indicated that those patients who were middle-aged had the strongest preference for insulin lispro.

A United States cost–benefit comparison of an apodized, diffractive, presbyopia-correcting, multifocal intraocular lens and a conventional monofocal lens

“…[10][11][12] However, this study is the first to report patients' WTP for multifocal IOLs. Most economic analyses in the ophthalmic literature are dominated by cost-utility analyses.…”

“…10,11 In the cataract literature, CBAs have been used to assess WTP for cataract surgery or, in countries practicing socialized medicine, to assess WTP (in the form of increased taxes) for reducing waiting times for cataract surgery. 12,13 In the multifocal IOL literature, Javitt et al 14 were the first to evaluate WTP in a retrospective case-control study of first-generation multifocal IOLs.…”

Management of Diabetes Mellitus with Insulin Lispro

“…106,107 The former analysis evaluated insulin lispro in relation to RHI, 105 and the latter evaluated lispro mixture-25 in relation to biphasic human insulin 70/30. 106 In these studies, significantly higher preference for lispro and mixture-25 than for RHI and biphasic human insulin 70/30 was demonstrated.…”

Comparison of Costs and Utilization Between Users of Insulin Lispro Versus Users of Regular Insulin in a Managed Care Setting

“…It may well be that physicians reserve the use of insulin lispro for select patients, which affects the outcomes of direct cost comparisons. A few economic studies of insulin lispro exist, 16,17 but only one study has been conducted that adequately addresses treatment selection bias and compares cost and utilization between insulin lispro patients and regular insulin patients. 18 The objective of our study was to examine diabetes-related and nondiabetes-related cost and resource utilization among insulin lispro and regular insulin patients using a propensity score approach that controls for treatment selection bias.…”