|Modeling Age Differences in Cost-Effectiveness Analysis:
A Review of the Literature
Louise B. Russell, Ph.D., Rutgers University, and Jane E. Sisk, Ph.D.,
Mount Sinai School of Medicine
International Journal of Technology Assessment in Health Care
|Objectives: Cost-effectiveness analysts often present cost-effectiveness
results by age to help inform decisions about the use of an intervention.
Yet it is not known how well studies model the risks and costs associated
with age. We reviewed published studies to examine their modeling of age
Methods: Medline searches identified all cost-effectiveness analyses
published between 1985 and 1997 that included adults 50 and older, were
based on data for developed countries, and compared cost-effectiveness
ratios for adults of different ages or for initiation of an intervention at
different ages; 36 articles met these criteria. They were reviewed to
determine the extent to which they incorporated age-specific data. Studies
that justified using the same data for all ages were counted as having
varied the data element by age.
Results: All studies varied life expectancy by age. Most also varied the
incidence/prevalence of the target condition and the case fatality rate.
Only 36% varied the effectiveness rate of the intervention by age. Costs
were usually assumed constant: 42% of studies varied the cost of treating
adverse effects and 17% varied the cost of treating the target condition.
Whether a data element was varied or not did not appear to be related to the
pattern of cost-effectiveness ratios by age.
Conclusions: Many studies have not modeled age differences in sufficient
detail to ensure that differences in cost-effectiveness ratios by age are
accurate and a sound basis for decisions. As cost-effectiveness analysis
becomes more widespread, analysts should strive to incorporate more complete
age-specific data.Louise B. Russell and Jane E. Sisk. "Modeling age differences in cost-effectiveness analysis: A review of the literature." International Journal of Technology Assessment in Health Care. 16(4):1158-67, 2000 Autumn.|