Dynamic Modeling of Cost-effectiveness of Rotavirus Vaccination, Kazakhstan - Volume 20, Number 1—January 2014 - Emerging Infectious Disease journal - CDC
Volume 20, Number 1—January 2014
Dynamic Modeling of Cost-effectiveness of Rotavirus Vaccination, Kazakhstan
Birgitte Freiesleben de Blasio , Elmira Flem, Renat Latipov, Ajnagul Kuatbaeva, and Ivar Sønbø Kristiansen
Author affiliations: Norwegian Institute of Public Health, Oslo, Norway (B. Freiesleben de Blasio, E. Flem); University of Oslo, Norway (B. Freiesleben de Blasio, I.S. Kristiansen); Research Institute of Virology, Tashkent, Republic of Uzbekistan (R. Latipov); Scientific-Practical Centre of Epidemiologic Surveillance, Almaty, Republic of Kazakhstan (A. Kuatbaeva)
Rotavirus is the leading cause of severe acute gastroenteritis in children worldwide (1). Rotavirus vaccines Rotarix (GlaxoSmithKline Biologicals, Rixensart, Belgium) and Rotateq (Merck & Co., Whitehouse Station, NJ, USA) are in use in the national immunization programs in Australia, the United States, Latin America, and a few European countries. In these high- and middle-income countries, rotavirus effects have decreased markedly after introduction of the vaccine (2–4). Universal rotavirus vaccination has not been widely implemented in Asia, and the health effects of rotavirus differ considerably across the continent, with the highest mortality rates concentrated in developing areas. In Central Asia, there are also large variations in the reported rotavirus effects by country (5), emphasizing the need for local data to guide the decision on the introduction of the vaccine.
Kazakhstan is the most prosperous country in Central Asia. It has a population of 16 million (6) and a land mass equal to approximately half of the continental United States. Kazakhstan has large reservoirs of oil and natural gas and is classified as an upper-middle income economy; its gross national income was US $8,220 per capita in 2011 (7), making the country ineligible for international funds to introduce new vaccines. Vaccines included in the national childhood immunization program are fully funded by the government. The health effects of rotavirus in Kazakhstan were estimated at 68 deaths, 4,007 hospitalizations, and 32,500 outpatient visits during 2009 (5); another study estimated the total annual cost of rotavirus disease to be US $37.5 million (8). No current cost-effectiveness analyses of rotavirus vaccines were available for Kazakhstan.
Recently, 2 economic evaluations of the rotavirus vaccination were conducted in low-income countries in Central Asia (9,10), but because of differences in rotavirus epidemiology, health care costs, and economy, the results are not generalizable to Kazakhstan. These studies were performed on the basis of static models, which implicitly assume that the probability for disease exposure is constant in time. In contrast, immunization will not only reduce the probability of a vaccinated child to become ill but will also lower the exposure of the virus to others (i.e., herd protection).
Models that account for changes in transmission over time are referred to as dynamic models. Cost-effectiveness studies of rotavirus vaccination performed on the basis of dynamic transmission modeling were recently used in the United States (11), England, and Wales (12). To the best of our knowledge, this approach has not been applied in middle-income countries or in settings with a transitional economy. These countries face particular challenges because they are not eligible for international financing of vaccines, and their resources for new health interventions are limited. Rotavirus vaccine effectiveness has been shown to correlate with income level within a country (13). It is possible that rotavirus vaccines may perform worse in middle-income settings than in upper-income countries. Hence, scientifically sound estimates of the effect of rotavirus vaccination are in demand.
We present a cost-effectiveness study of rotavirus vaccination in a middle-income country using dynamic modeling. We incorporated direct effects such as death rates and indirect effects such as herd protection of a nationwide vaccination program. Our purpose for the study is twofold: to inform the impending decision on the introduction of rotavirus vaccination into the national immunization program in Kazakhstan, and to compare the cost-effectiveness of a rotavirus vaccination program in a middle-income country with that reported for high-income settings.
Materials and Methods
We adapted our previously published dynamic model for rotavirus (14,15) to Kazakhstan. The model is presented in the Technical Appendix [PDF - 783 KB - 13 pages].
- Table 1. Natural history and vaccine-related parameters used in dynamic modeling of cost-effectiveness of rotavirus vaccination, Kazakhstan
- Table 2. Description of scenarios for the economic evaluation of rotavirus vaccination, Kazakhstan
- Table 3. Estimates of projected direct and indirect costs associated with rotavirus disease and rotavirus vaccination, Kazakhstan
- Table 4. Estimated projected costs and avoided health outcomes of rotavirus vaccination program in Kazakhstan, 2012–2031
- Table 5. Estimated projected costs in US dollars and avoided health outcomes from rotavirus vaccination with 2-year protection, Kazakhstan, 2012–2031
Suggested citation for this article: de Blasio B F, Flem E, Latipov R, Kuatbaeva A, Kristiansen IS. Dynamic modeling of cost-effectiveness of rotavirus vaccination, Kazakhstan. Emerg Infect Dis. 2013 Jan [date cited]. http://dx.doi.org/10.3201/eid2001.130019