Effectiveness calculation in economic analysis: the case of statins for cardiovascular disease prevention
- 1Department of Public Health, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, Netherlands
- 2Department of Epidemiology and Preventive Medicine, Monash University Central and Eastern Clinical School, Melbourne, Australia
- 3Belgian Health Care Knowledge Centre (KCE), Brussels, Belgium
- Correspondence to: Dr O H Franco Unilever Corporate Research, Colworth House, Sharnbrook, Bedfordshire MK44 1LQ, UK; oscar.franco{at}unilever.com
- Accepted 15 March 2006
Abstract
Objectives: This report aimed to evaluate the calculation of estimates of effectiveness in cost effectiveness analyses of statins for cardiovascular disease prevention.
Methods: Methodological aspects were reviewed of seven primary studies (based on trial results) and 12 secondary modelling studies (extrapolated) on the cost effectiveness of statin treatment, published between 1995 and 2002. Estimates of life years gained were extracted and compared with estimates calculated using the Dutch male life table of 1996–2000.
Results: Of the seven primary modelling analyses, six showed all the essential data. They estimated that 3 to 5.6 years (average 4.6 years) of statin treatment resulted in 0.15 to 0.41 years (average 0.3 years) saved over a lifetime time horizon. In contrast none of the 12 secondary modelling studies provided transparent results. They assumed lifelong treatment, leading to life table estimations of 2.4 and 2.0 (undiscounted) years saved for 40 and 60 year olds, with peak savings at around the mean age of death: 75–80 years. With 5% discounting, these effects reduced to 0.4 and 0.8 years respectively.
Conclusion: Reporting of essential data and assumptions on statin treatment was poor for secondary modelling analyses and satisfactory for primary modelling studies. Secondary modeling studies made assumptions on long term effectiveness that were hard to justify with the available evidence, and that led to the majority of life years saved at high ages. Further standardisation in economic analyses is important to guarantee transparency and reproducibility of results.
- CHD, coronary heart disease
- YLS, years of life saved
- CEA, cost effective analysis
- LE, life expectancy
Footnotes
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Funding: this study was supported by a grant from Netherlands Organisation for Scientific Research (ZON-MW). OHF, ES, AP, and LB were partly funded by the Netherlands Organisation for Scientific Research ZonMw (grant number 904-66-093). AP was also partly funded by VicHealth (fellowship grant number 2002-0191). All authors declare to have acted independently from the funders of this project.
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Ethical approval was not needed, as this was a secondary data analysis.
