The Half-Cycle Correction: Banish Rather Than Explain It

Abstract

The half-cycle correction is often used in discrete Markov models to estimate state membership. This article shows that the correction, in addition to being unintuitive, actually produces the wrong results in many circumstances. These include quality-adjusted life year (QALY) weights and unit costs that differ by cycle. The half-cycle correction is also incompatible with discounting of the obtained stream of state membership. It is furthermore shown that the life table method of estimating state membership obtains correct results under these circumstances and is also much more transparent. The article concludes that the half-cycle correction should be dropped in favor of the life table method.

Keywords

Markov Models mathematical models and decision analysis statistical methods.

Get full access to this article

View all access options for this article.

References

Naimark DM , Bott M. , Krahn M. The half-cycle correction explained: two alternative pedagogical approaches . Med Decis Making. 2008;28:706-12.

Kintner HJ The life table. In: Siegel JS , Swanson DA , eds. The Methods and Materials of Demography. 2nd ed. San Diego : Elsevier Academic Press; 2004.

Hunink M. , Glasziou P. , Siegel J. , et al. Decision Making in Health and Medicine: Integrating Evidence and Values. Cambridge, UK: Cambridge University Press; 2001.

Department of Health and Ageing. Guidelines for preparing submissions to the Pharmaceutical Benefits Advisory Committee. Canberra, Australia: Department of Health and Ageing; 2008.