A direct method and ICER tables for the estimation of the cost-effectiveness of smoking cessation interventions in general populations: application to a new cytisine trial and other examples.

INTRODUCTION: The popularity of smoking cost-effectiveness (CE) analysis has grown rapidly. Differences in models and inputs mean results may not be comparable, and researchers may have to take them on trust because the methods are beyond their expertise and not always transparent. We describe a direct method and tables of results for researchers without specialist knowledge.
METHODS: We estimate the health benefit to an individual attributed to an intervention and compute tables of incremental cost-effectiveness ratios (ICERs) for interventions with varying incremental intervention effects and costs. Estimates of life years gained come from the longest epidemiological study. After discounting, adjustments are made for future cessation and relapse. The method is described in simple steps, and conservative inputs are used throughout.
RESULTS: To look up an ICER, the user needs only to know the cost of the intervention per smoker and the effect as measured by the percentage of ex-smokers attributable to the intervention at either 6- or 12-month follow-up. Reanalysis of authoritative reports indicates that these ICERs are comparable to those from decision-analytic simulation models.
CONCLUSIONS: Researchers can now obtain immediate estimates of the CE of interventions in general populations. The method is easily programmed in a spreadsheet. ICERs are from the payer perspective and exclude offset and societal costs. Interventions in subpopulations will require inputs specific to those populations. Readers who wish to include an adjustment for quality of life can easily do so. The tables might promote a standard approach, with interventions compared on a consistent and transparent basis.