Investigación original / Original research Economic impact of a rotavirus vaccination program in Mexico Dagna Constenla,1 F. Raúl Velázquez,2 Richard D. Rheingans,1 Lynn Antil,1 and Yolanda Cervantes 3 Suggested citation Constenla D, Velázquez FR, Rheingans RD, Antil L, Cervantes Y. Economic impact of a rotavirus vac- cination program in Mexico. Rev Panam Salud Publica. 2009;25(6):481–90. ABSTRACT Objectives. To evaluate the cost and benefits of a national rotavirus childhood vaccination program in Mexico. Methods. A decision-analysis model was designed to take the Mexican health care system’s perspective on a comparison of two alternatives: to vaccinate against rotavirus or not. Us- ing published, national data, estimations were calculated for the rotavirus illnesses, deaths, and disability-adjusted life years (DALYs) that would be averted and the incremental cost- effectiveness ratios (US$/DALY) of a hypothetical annual birth cohort of 2 285 000 children, with certain assumptions made for cost, coverage, and efficacy rates. Results. With 93% coverage and a vaccine price of US$ 16 per course (2 doses), a rotavirus vaccination program in Mexico would prevent an estimated 651 deaths (or 0.28 deaths per 1 000 children); 13 833 hospitalizations (6.05 hospitalizations per 1 000 children); and 414 927 outpatient visits (182 outpatient visits per 1 000 children) for rotavirus-related acute gastro- enteritis (AGE). Vaccination is likely to reduce the economic burden of rotavirus AGE in Mex- ico by averting US$ 14 million (71% of the overall health care burden). At a vaccine price of US$ 16 per course, the cost-effectiveness ratio would be US$ 1 139 per DALY averted. A re- duction in the price of the rotavirus vaccination program (US$ 8 per course) would yield a lower incremental cost-effectiveness ratio of US$ 303 per DALY averted. Conclusions. A national rotavirus vaccination program in Mexico is projected to reduce childhood incidence and mortality and to be highly cost-effective based on the World Health Organization’s thresholds for cost-effective interventions. Key words Rotavirus, rotavirus vaccines, cost-benefit analysis, mass immunization, gastroenteri- tis, Mexico. Rotavirus is a virus that infects the various factors, including limited access 1 Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, small intestine and can lead to life- to health care facilities, lower mean age United States of America. Send correspondence to: threatening acute gastroenteritis (AGE) at contraction, and malnutrition. Due to Dagna Constenla, Ph.D., Department of Global in infants and young children world- the widespread nature of rotavirus, its Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA; telephone/fax: +01- wide. Unlike many other enteropatho- high concentration in the feces, and its 970-266-1153; e-mail: [email protected] gens, rotavirus affects children in both ability to survive in the environment, the 2 Unidad de Investigación Médica en Enfermedades developed and developing countries, prevention of rotavirus spread is virtu- Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexi- regardless of socioeconomic status (1, ally impossible, even where the highest cano del Seguro Social, Ciudad de México, DF, 2). However, the risk of dying from hygiene standards are followed (2). México. 3 GlaxoSmithKline Biologicals S.A., Mexico City, rotavirus-related gastroenteritis (GE) is In Mexico, rotavirus is one of the prin- Mexico. greater in lower-income countries due to cipal causes of GE and occurs mainly Rev Panam Salud Publica/Pan Am J Public Health 25(6), 2009 481 Original research Constenla et al. • Cost-effectiveness of rotavirus vaccination in Mexico during the fall and winter months. It is of FIGURE 1. Model framework depicting rotavirus (RV) vaccine introduction and subse- particular concern in pediatric hospitals, quent events that may be experienced by each child, including life-years gained (LYG) emergency rooms, and outpatients clin- and disability-adjusted life years (DALYs) ics. However, improved availability of Epidemiology potable water, access to oral rehydration Health Benefits therapy, and enhanced surveillance of • RV rates • RV proportion • Events all diarrheal episodes have reduced the • Healthcare utilization • Deaths overall burden of GE in young children • LYG Vaccine • DALYs (3). Morbidity rates associated with all • Coverage diarrheal diseases decreased from 4 588 • Efficacy per 100 000 children under 5 years of age • Cost in 1999 to 3 383 by 2002, with the great- est reduction observed among those under 1 year. There has also been a sig- Cost- nificant decrease in severe diarrheal Economic Burden Effectiveness episodes among children under 5 years • $ per cohort • $/DALY averted of age, from 24.8 per 100 hospitalizations • Medical cost • $/deaths averted • $/LYG in 1990 to 9.2 in 1995. This represents a • Patient cost 63% reduction (3) and is the most accu- Economics Net Cost rate information to date. Overall mortal- • Hospital per diem Savings • Visit costs • $ per cohort ity due to AGE in children under 5 years • Direct costs also decreased from 125.3 per 100 000 in • Parent expenses 1990 to 19.7 by 2002, an 84% reduction (3). From 1990–2002, a significant reduc- tion in mortality was observed in April– August, from 13.4 per 100 000 children effectiveness of rotavirus vaccination is DALY estimates were discounted at a under 5 years in 1990 to 1.6 in 2002 (3). shown in Figure 1. The boxes identify the 3% rate, as recommended by the U.S. While overall GE morbidity and mor- primary inputs needed for the model Panel of Cost-Effectiveness in Health tality have declined, the proportion at- (epidemiological, economic, and vaccine and Medicine (7) and the World Bank tributable to rotavirus appears to be data). The circles represent the intermedi- Global Burden of Disease Project (8). increasing (3, 4). The highest mortality ary outputs (health benefit, economic The annual birth cohort considered rates for children under 1 year coincided burden, and net cost savings). The pri- was 2 285 000 children (9). The age dis- precisely with the fall and winter season. mary outputs of the model are displayed tribution of rotavirus illness was esti- A retrospective, cross-sectional study of in hexagons as cost-effectiveness ratios. In mated for each one of the disease out- 15 large cities in Mexico reported that, this study, these ratios are expressed as comes (deaths, hospitalizations, and annually, 42% of the children seeking the cost per death averted, per disability- outpatient visits) using published stud- AGE treatment at pediatric hospitals adjusted life years (DALYs) averted, or ies from Mexico and Latin America (10– were rotavirus positive (3). per life year gained (LYG). This diagram 20). The estimated number of outcomes This paper presents detailed analyses provides only a broad representation of for an annual birth cohort was distrib- of the disease burden and costs of the inputs and outputs of the model. uted as follows: 0–2 months of age, 3–5, rotavirus disease among Mexican chil- A decision-analysis model was devel- 6–8, 9–11, 12–23, 24–35, 36–47, and 48–59. dren, and the expected cost-effectiveness oped in Microsoft Excel® to estimate the of introducing a national rotavirus vacci- health and economic outcomes of a na- Model inputs nation program. These results are part of tional rotavirus vaccination program in a a larger study being carried out in Latin hypothetical annual birth cohort of chil- Rotavirus disease burden. Disease bur- America and the Caribbean, specifically dren for a 5-year period. The net, med- den was estimated as the expected num- Argentina, Brazil, Chile, Dominican Re- ical, direct-cost of the vaccination pro- ber of rotavirus-associated outcomes public, Honduras, Mexico, Panama, and gram was determined to be the cost of for a single birth cohort. The risk of Venezuela (5, 6). In contrast to this Re- the vaccination program, minus the ex- rotavirus-related outpatient visit, hospi- gional study, in which estimates were pected averted medical costs (the sav- talization, and death were based on the derived from extrapolated data, this ings from reduced use of health care cumulative risk of each AGE event dur- paper focuses solely on Mexico and uses resources). ing the first 5 years of life and the pro- country-level epidemiological data and The primary perspective for this portion of these events attributed to ro- cost estimates. analysis was that of the health care sys- tavirus. The cumulative risk of each tem. Costs such as non-medical direct event in Mexico was estimated from na- MATERIALS AND METHODS costs or productivity losses to caregivers tional administrative data for the year were not included in these cost-effective- 2002 (21, 22), and refers to the proportion Analytic overview ness calculations due to paucity of data. of children in a defined population in- All cost estimates collected in local fected with rotavirus at least once before A diagram of the model used to esti- currency were converted to 2007 United reaching their 5th year of life. Risk refers mate the economic burden and cost- States dollars (US$). Future costs and to the proportion of a population for an 482 Rev Panam Salud Publica/Pan Am J Public Health 25(6), 2009 Constenla et al. • Cost-effectiveness of rotavirus vaccination in Mexico Original research event and cumulative is the risk for each The cumulative risk of a rotavirus- 2004 and made available to the private year of age multiplied together. related death was based on 2002 national sector in January 2005. In March 2007, In brief, the cumulative risk of a rota- data from the Instituto Nacional de Es- the vaccine was incorporated into the virus outpatient visit was calculated tadística Geografía e Informática (Na- routine immunization schedule, first by using data provided by the epidemiol- tional Institute of Statistics, Geography, the IMSS and later, in August 2007, by ogy unit of the Instituto Mexicano del and Informatics, INEGI) (4).