Journal of Community Health, Vol. 25, No. 1, February 2000 PREDICTING COST-BENEFITS BEFORE PROGRAMS ARE STARTED: LOOKING AT CONJUGATE VACCINE FOR INVASIVE PNEUMOCOCCAL INFECTIONS William J. Hueston, MD; Arch G. Mainous III, PhD; Nicole Brauer ABSTRACT: This analysis uses existing data to examine how an analysis to predict the net financial impact for an emerging medical program, namely a conjugate vaccine against Streptococcus pneumoniae, and to identify which key variables will have the greatest impact on the program’s costs and benefits. Using data available on the prevalence and case fatality rates for invasive diseases caused by S pneumoniae, we examined the theoretical economic impact of vaccinating all newborns versus not vaccinating. Effec- tiveness estimates for conjugated pneumococcal vaccines and disease inci- dence and fatality rates were obtained from published sources. Because of scanty or inconclusive data for otitis media and pneumonia, the analysis was limited to cases of meningitis and bacteremia due to S pneumoniae. Based on these two diseases alone, immunization with conjugate pneumo- coccal vaccine could save an estimated 222 lives per million children vaccinated per year. Analysis of direct costs (projected immunization costs minus savings from reduced illness) show that a pneumococcal vaccine program will result in net direct costs between $0.08 and $2.42 per child. When indirect costs are included in the analysis, the vaccine is cost savings for all cases except when the two year incidence of disease and death rates are lowest and the cost of the vaccine series is $150. Further research should focus on these key issues as the vaccine is introduced into use, as expected in the next few years. INTRODUCTION Decision analysis has become a useful tool for evaluating on-going programs. These analyses allow policy makers to evaluate the impact of programs including determination of the net impact of programs on illness prevalence and lives lost, and the relative costs of programs versus not having a program in place. These analyses all blend reliable data gathered William J. Hueston, MD, and Arch G. Mainous, PhD, are from the Department of Family Medicine, Medical University of South Carolina, Charleston. Nicole Brauer is a medical students at the Medical College of Wisconsin, Milwaukee. Requests for reprints should be addressed to: William J. Hueston, MD; Department of Family Medicine, Medical University of South Carolina, 295 Calhoun Street, PO Box 250192, Charleston, SC 29401. This work was partially supported through a Robert Wood Johnson Generalist Scholar Award to Dr. Hueston.  2000 Human Sciences Press, Inc. 23