Cost–Effectiveness of Angiotensin-converting Enzyme Inhibitors in Nondiabetic Advanced Renal Disease

Charles Christian Adarkwah; Afschin Gandjour

Disclosures

Expert Rev Pharmacoeconomics Outcomes Res. 2011;11(2):215-223. 

In This Article

Sensitivity Analysis

To address uncertainty around mean incremental costs and effectiveness, we conducted univariate sensitivity analyses, where we varied one variable at a time while keeping all other variables constant at their mean or base-case value. We ran analyses using the upper and lower limit of the 95% confidence intervals (CIs) of the mean. For transplantation costs, we did not have information on the 95% CI and thus varied costs by 20% (see Table 2 for uncertainty ranges).

In order to assess how a simultaneous change of several variables affects the incremental cost–effectiveness ratio, we performed a Monte Carlo simulation, a type of multivariate sensitivity analysis. This technique runs a large number of simulations (in this case 1000) by repeatedly drawing samples from probability distributions of input variables. Thus, it provides a probability distribution for the output variables (incremental costs, incremental effectiveness and incremental cost–effectiveness ratios). Probabilities were assumed to follow a β distribution β(α, β) because they are normally distributed but restricted to take on values between 0 and 1. The standard error of a probability or proportion was calculated according to the following formula:[32]

where p = probability and n = sample size. Cost data were assumed to follow a γ distribution γ(a, b), which reflects the long right tail and restriction to positive values. Relative risks and odds ratios were assumed to follow a lognormal distribution.

Based on the Monte Carlo simulation, we generated a cost–effectiveness acceptability curve. A cost–effectiveness acceptability curve allows a decision-maker to consider whether a prevention strategy is cost effective in relation to the maximum amount a decision-maker is willing to pay for a QALY. At each willingness-to-pay threshold, the cost–effectiveness acceptability curve shows the probability that treatment is cost effective.

Comments

3090D553-9492-4563-8681-AD288FA52ACE
Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.

processing....