- Research article
- Open Access
- Open Peer Review
Cost of rotavirus diarrhea for programmatic evaluation of vaccination in Vietnam
© The Author(s). 2016
- Received: 12 October 2015
- Accepted: 5 August 2016
- Published: 11 August 2016
Rotavirus is the most common etiology of diarrhea-associated hospitalizations and clinic visits in Vietnamese children < 5 years old. To estimate the economic burden of rotavirus-associated formal healthcare encounters, an economic study was conducted.
A cost-of-illness study was performed from a societal perspective. Data were collected from children below the age of five years who presented to a clinic or hospital with symptoms of acute gastroenteritis (AGE). Patient-specific information on resource use and cost was obtained through caregiver interviews and medical chart review. Costs are presented in 2014 US dollar ($).
A total of 557 children with symptoms of AGE were enrolled from March through June 2009, with mean age of 16.5 months. Of the 340 outpatients and 217 admitted patients enrolled, 41 % tested rotavirus positive. It was found that, from a societal perspective, the mean total cost of AGE was $175. Costs of patients with and without rotavirus were $217 and $158, respectively. From multiple regression analysis, it was found that rotavirus infection, patient age and receiving oral rehydration solution before visiting health facility had significant effect on the costs.
This study clearly demonstrated substantial economic burden of AGE including rotavirus disease. They were significantly greater than the previously reported cost estimates in Vietnam. These updated costs of illness result in more favorable vaccine cost-effectiveness than in previous economic evaluations.
- Rotavirus burden
- Acute gastroenteritis
- Cost of illness
Rotavirus infection is a major reason for hospitalization and clinic visits among children under five years of age, with a significant impact on utilization of health care resources and costs, both in developed and developing countries [1–3]. Recently, two rotavirus vaccines have been licensed globally but neither has been adopted in the routine immunization program in the majority of developing countries. Decisions concerning the addition of new vaccines to national immunization program are driven by scientific, political, economic, and logistic considerations . Key factors influencing such a policy decision include the economic burden of disease on health care system and society and the cost-effectiveness of a new immunization program. The cost-effectiveness of rotavirus vaccines has been evaluated more widely over the past decade . In Vietnam, several groups have published the cost effectiveness of rotavirus vaccine [3, 6–8]. All the previous studies on the cost-effectiveness of rotavirus vaccine were based on the same cost estimates of rotavirus disease from the earliest study by Fischer et al.  which, as its authors acknowledged, had limitation in its assumptions and methodologies . First, patient-specific data were obtained retrospectively by interviewing families of historical patients, in which recall bias could not be excluded. Second, per bed-day and per-visit costs were estimated based on the opinions of regional health experts rather than a properly designed institutional costing study. Third, costs were estimated for historical diarrheal patients without confirmed rotavirus etiology. Last, data were collected from the patients recruited in one province, making it problematic, as it is not representative of nationally. Aiming to update knowledge of the country’s burden of rotavirus disease, we performed a cost-of-illness study in three provinces of Vietnam, based on prospective study of rotavirus patients. In addition, we demonstrated how to use the costs in economic evaluation of vaccination program.
This study was designed as an incidence-based, cost-of-illness study from a societal perspective. An incidence-based approach considers only the newly occurring cases within a study period and follows them during the entire course of each episode. Costs were measured based on a micro-costing approach [9, 10]. This study was nested in a rotavirus surveillance project, which was performed in three provinces of Vietnam during 2009.
Study population and sites
Vietnam is a developing country in Southeast Asia with a long coastline on the South China Sea, stretching more than 2400 km from a temperate climatic zone in the north to a subtropical climate in the South. The population of 89.71 million (according to the census in April 2012) includes an annual birth cohort of 1.7 million with an infant mortality rate of 15.3 per 1000 live births in 2013 . The study was carried out in three provinces representing the Northern, Northeastern and Southeastern regions. Vinh Phuc in the Red River delta of Northern Vietnam, population 1.0 million; Hai Phong in the Northeastern coastal area, population ~1.9 million; and Khanh Hoa in the Southeastern coastal area, population 1.1 million. For both the rotavirus surveillance and the cost-of-illness studies, cases with symptoms of acute gastroenteritis (AGE) were enrolled among children aged less than 5 years and living in one of the five catchment areas of three provinces in Vietnam: Nha Trang city in Khanh Hoa Province, Vinh Yen city and Bin Xuyen district in Vinh Phuc province, and Kien An and Le Chan districts in Hai Phong. Catchment areas were selected considering the balance of geographic location and economic level in order to make data more representative of the whole country. It was also considered whether a population could easily be defined in terms of health care utilization pattern and was relatively stable. We invited all hospitals and major outpatient clinics that were known to serve pediatric diarrheal patients in each of the five catchment areas.
In order to obtain more accurate and representative cost estimates, patients were divided into groups based on the suspected cost predictors, including geographical location (province), type of patient care (inpatient, outpatient), type of facilities (private clinic, polyclinic, hospital), rotavirus in stool, patients receiving oral rehydration solution prior to institutional treatment, patients receiving breastfeeding, and child’s age. Stratified by a combination of predictor variables, at least 30 cases are needed for each patient-group . Thus, we targeted at least 330 AGE episodes to be enrolled for this economic study.
In this study, total cost of illness is defined as the sum of direct cost and indirect cost (the cost of productivity loss) starting from the onset of illness through the end of each episode. Thus, information was collected on all resource uses incurred at any health care provider/service before and after presentation to a study site, together with the resources used at the study facility. Direct costs are defined as direct medical and direct non-medical costs. Direct medical cost is the sum of treatment costs. Direct non-medical costs are for travel and meals. Indirect cost is defined as time lost by caregivers due to the child’s illness, because patients in this study are not of working age [13, 14]. Hence, caregiving time was calculated as the number of person-days that parents and/or family members spent on providing care for the sick child.
Data and stool collection
Treatment costs prior to and after the presentation to a study site were based on the expenditure information obtained from caregiver interviews. The treatment costs at a study site (except for private clinics) were the sum of the cost of routine services at OPD/IPD, costs of medicines, and laboratory investigation costs.
Dedicated staff reviewed the address and age of each AGE patient upon presentation in order to check eligibility. Once written informed consent was obtained from parents/guardians, information was collected through caregiver interview and medical chart reviews. A pre-structured questionnaire was used in interviewing caregivers to collect demographic information and history of healthcare utilization (e.g. type of facilities where admitted or treated, and duration of stay or frequency of visit). Any out-of-pocket expenses that incurred during the course of each episode were ascertained by asking caregivers, and included treatment cost, transportation fee, and cost of meal and/or accommodation. The total time spent for caring for the sick child by all caregivers was collected to calculate time cost (or productivity loss). Trained staff reviewed medical records to extract the relevant data on medical resource uses, then recorded them on a standardized case report form. Information collected included the list and quantity of medicines, laboratory tests, and the number of days hospitalized. Family members were followed up every three days after discharge until the recovery of each episode was confirmed.
A bulk stool specimen was collected from each patient in a standardized stool container. Within 48 h of collection, stool specimens were transported to the referral location. Once a week, specimens were sent to the National Institute for Hygiene and Epidemiology (NIHE) in Hanoi and tested for rotavirus antigen by enzyme immunoassay (EIA) test using a commercial kit (DAKO, UK) under the standard operating procedure .
Unit costs of laboratory tests and routine services were extracted from a facility-based institutional costing study performed in Khanh Hoa province . The costs included material, labor and capital costs. Unit prices were adjusted by the ratio of cost to charge, resulting in unit costs for this study. These ratios were 1.18 and 1.17 for polyclinics (public clinics) and hospitals, respectively . Treatment costs at a private clinic were based on the charged prices. Caregivers’ time costs were calculated according to the reference wage: 88,380 Vietnamese Dong (VND) per day . The cost of rotavirus antigen testing was not included because it was a part of surveillance project (not routine practice).
Costs were estimated under the assumptions of two models: Model A classified the time loss of caregivers as indirect cost (base case) and Model B classified it as direct non-medical cost [9, 10]. All costs were originally calculated in 2009 Vietnamese Dong (VND). They were converted to 2014 values by the consumer price index of medicine and health care (2009 = 100, 2014 = 195.08) . Finally, they were converted to US dollars ($) using the exchange rate of $1.00 = 21,130.5 VND .
Data management and analysis
Data were double entered into a custom-made database, using Microsoft Visual FoxPro Software 9.0 platform and then exported into Microsoft Excel for verification and further analyses. IBM SPSS Statistics version 21 was used for statistical analysis . Descriptive statistics were used to summarize study variables. The costs were log-transformed to meet the assumption of normal distribution. Model checks included linearity, normal distribution, multi-collinearity, influential observations, and outliers .
To obtain adjusted estimates of the effect of rotavirus on costs, stepwise multiple regression analysis was employed . Independent variables with probability values of F statistics ≤ 0.05 were entered. Sensitivity analysis was conducted to measure the effect of cost classification; Models A and B, classifying costs of caregiver time (informal care) as indirect and direct, respectively. In addition, the costs were measured based on different economic evaluation methods.
Characteristics of patients
Rotavirus in stool
Child primarily breastfed; yes
Receiving oral rehydration solution before visiting the study facilitya; yes
Health facility typea
Type of patienta
Resource utilization and costs (2014 USD)
Rotavirus in stool
No (n = 329, 59.1 %)
Yes (n = 228, 40.9 %)
Total (n = 557)
Length of stay of inpatients (days)
Total direct cost (not including informal care)a,b
Total direct medical costa,b
Direct nonmedical cost (not including informal care)
Indirect cost (with informal care)a,b
Total cost of illnessa,b
Average cost of illness (2014 USD) classified by age, rotavirus infection and cost component
Rotavirus in stool
Number of cases
Total direct medical cost
Total direct cost
Total cost of illness
Potential predictor variables for multiple regression analysis
Natural log of direct medical cost
Natural log of direct cost (not include informal care)
Natural log of cost of illness
Potential predictor variables
Receiving oral rehydration solution before visiting the study facility
Receiving = 1 (30 %), no = 0 (70 %)
Rotavirus in stool
Positive = 1 (41 %), negative =0 (59 %)
Child age (months)
Mean age in months (16.27)
Child receiving primarily breastfed
Receiving = 1 (94 %), no = 0 (6 %)
Regression models investigating effect of rotavirus infection on the costs
Direct medical cost
Total cost of illness
Rotavirus in stool
Child age (months)
Receiving oral rehydration solution before visiting the study facility
Cost of rotavirus diarrhea classified by economic evaluation methods from societal perspective (2014 USD)
Cost by evaluation methods
Model A: Cost of informal care as a part of indirect cost.
1. Direct cost
1.1 Direct medical cost
1.2 Direct nonmedical cost
2. Indirect cost
Model B: Cost of informal care as a part of direct nonmedical cost.
1. Direct cost
1.1 Direct medical cost
1.2 Direct nonmedical cost
2. Indirect cost
Focusing on the cost of rotavirus diarrhea in Southeast Asia, studies in Indonesia, Malaysia and Vietnam have been published in international journals [3, 22–24]. In a study conducted in Indonesia in 2007 , parents of 1349 patients were interviewed during outpatient visits, while inpatients were interviewed on discharge and again two weeks later. The study covered direct medical costs, direct non-medical costs and indirect costs (time taking care of sick children). Direct medical costs were based on actual payments made by the patients. In Malaysia, Lee et al. (2002) measured the cost of inpatients from a hospital perspective. Three hundred and ninety-three patients were included in the study. The costs included were treatment costs or direct medical costs, covering only patient service departments. Costs of supporting departments (e.g. administration) were not included . Another study conducted in Malaysia during August 2006 and July 2007 measured out-of-pocket costs . The study covered 260 patients and included expenses for medical consultations, medication prior to hospitalization, hospital bills, any special food or diet, transportation, extra diapers, productivity loss for caregivers, and other costs incurred by family members. In Vietnam, a 2003 study enrolled 90 patients  and included direct medical costs, direct non-medical costs, and indirect costs (time taking care of sick children). Direct medical costs were estimated per day and per visit, by interviewing government officials. For direct non-medical costs and indirect costs, parents were interviewed.
Due to the different study designs and data limitations, it was not feasible to directly compare costs between studies. For direct medical or treatment costs, none of the previous studies used direct measurement of the actual costs over the whole hospital (service and supporting departments). This could be a limitation in terms of economic evaluation from a societal perspective. Therefore, our study covered both actual and complete cost of the hospitals with considerable sample size.
In terms of cost drivers, in addition to rotavirus infection, it is interesting to notice a similarity between the study in Canada and our one, namely that age was significant predictor variable . The history of receiving ORS was an additional significant predictor variable in our analysis (Table 5). In these models, coefficients of determination indicating power of explanation were small (0.068–0.129). In the exploration, we fitted a model by adding health facility types (private clinic, polyclinic and hospital) and found an increase of the coefficient to 0.885. However, with significant effect of the facilities, rotavirus infection did not show the effect. Our interpretation is that rotavirus infection has effects on the cost but much less than the types of services at different levels of health facilities. In real-life practice, rotavirus infection is not investigated by laboratory test: laboratory investigations reported here were done as part of the research project. Therefore, in day-to-day practice, physicians provide treatment based on clinical symptoms, patient and health system factors.
In terms of cost driver analysis, we used stepwise multiple regression analysis. We had limited ability to validate the model using out-of sample data. Costs are a major concern in economic evaluation. Reduction in cost of illness increases net cost and raises the cost-effectiveness ratio, making the intervention less attractive economically . As shown in Table 6, we found a substantially larger cost burden of rotavirus disease in Vietnam than Fischer et al. in 2004 . The 2014 values of the 2004 study were USD88, USD18, USD16 and USD21 for in-patients, outpatients at hospitals, polyclinics and private clinics, respectively. Several factors might have contributed to this. First, costs were estimated based on the data collected from patients with rotavirus infection in a prospective manner, whereas the earlier study was based on historical patients. Second, we followed up each patient during the entire period of an episode starting from the onset of disease until the recovery. Nearly one half of the patients enrolled in our study reported that they had sought health care prior to presentation to a study health facility. Relevant costs associated with any health care utilization prior to or after presentation to a study health facility were traced, identified, and included in our cost estimation. Such an intensive follow-up could not have been made in the previous study since data were obtained from historical episodes. Third, we calculated unit costs per clinic visit and per bed day based on an actual study from Vietnam , whereas the previous study was based on the opinions of local health officials. Last, our study was based on the data from multiple study sites throughout three provinces in different regions of Vietnam whereas the earlier cost estimates were based on the data from one province . However, a limitation of our study was the absence of patients with mild symptoms who self-treated and did not come to the study sites. This limits the generalizability in terms of economic burden. Information on the economic burden of an illness is important in setting priorities, financial and budgeting management, and efficiency management . Cost of illness is a measurement of an illness’ economic burden on society. Hurdles in conducting cost-of-illness studies include the absence of reliable local data, and conceptual or methodological issues in costing . The latter include controversies in including productivity cost , costing methods (e.g., human capital approach versus friction cost method ), and reference values (e.g. discount rate ). Whether to classify caregivers’ time as direct non-medical or indirect cost has also been controversial . The point at issue is double counting because time cost can be included as either monetary value or health state (e.g., quality adjusted life year) . In a review of cost-utility analysis published during 1976 and 1997, 5.7 % of the papers included caregiver costs . In a similar economic evaluation, a study in Thailand classified caregiver costs as direct-nonmedical , while another in Indonesia classified them as indirect costs . One study omitted mortality costs, to avoid double counting, but did not mention the costs of caregiver time loss . Another included them as indirect costs without identifying their components . Hodgson concluded that cost-utility analysis from a societal perspective should exclude indirect costs of morbidity and mortality (but not that of caregivers) . In summary, previous studies varied in terms of inclusion and classification of indirect costs in their cost-utility analysis. This could affect their results in terms of the incremental cost-effectiveness ratio (ICER). If the ICER is less than the threshold of willingness-to-pay (for instance, 1 per capita gross domestic product) for the health intervention evaluated, the intervention is accepted, and conversely. For instance, in a study on economic evaluation of varicella vaccination, the vaccine was not acceptable for a base-case analysis (not including the indirect cost). However, when the indirect cost was included, the vaccine is acceptable .
WHO guideline recommends that time costs should be reported separately from other cost estimates in cost of illness studies. The guideline also recommends that cost-effectiveness or cost-utility analysis should be conducted both with and without these time costs . Thus, in our analysis, the cost of rotavirus disease was based on the two different models of cost classification that caregiver’s time was included as indirect cost versus non-medical direct costs (Table 6).
This study clearly demonstrated a substantial cost burden of rotavirus disease to society in Vietnam. This burden was significantly greater than found previously , implying a more favorable cost effectiveness outcome of rotavirus vaccination in the country. As the first step, for Vietnam government’s policy decision on whether to implement rotavirus vaccination, an economic evaluation of the vaccine should be repeated in the Vietnamese context based on this updated cost information of rotavirus disease.
AGE, acute gastroenteritis; CEA, cost-effectiveness analysis; CUA, cost-utility analysis; DALY, disability-adjusted life year; EIA, enzyme immunoassay; NIHE, National institute for hygiene and epidemiology; ORS, oral rehydration salt; QALY, quality-adjusted life year; VND, Vietnamese Dong
The research team would like to acknowledge the funding from Shin Han Bank (Seoul, Korea) through International Vaccine Institute. Neal Alexander receives support from the United Kingdom Medical Research Council (MRC) and Department for International Development (MR/K012126/1). We are grateful to children and parents who participated in this study. We thank all technical staff and research assistants involved in data collection at the Khanh Hoa Health Service, Hai Phong Children’s hospital, and Provincial Preventive Medicine Center.
Rotavirus Economic Study Group: Le Huu Tho5, Vu Thi Thuy6, Ta Van Chan7, Phu Quoc Viet5, Nguyen Minh Nguyet7, Le Thi Hoa6
5Khanh Hoa Health Service, Nha Trang, Khanh Hoa Province, Vietnam
6Hai Phong Children’s Hospital, Hai Phong, Vietnam
7Vinh Phuc Center for Preventive Medicine, Vinh Phuc, Vietnam
This work was supported by a grant awarded from Shin Han Bank (Seoul, Korea) through International Vaccine Institute, the United Kingdom Medical Research Council (MRC) and Department for International Development (DFID) (MR/K012126/1).
Availability of data and materials
The raw data can be made available on request to the corresponding author.
AR was responsible for all facets of this study and preparing the manuscript. SS, NA and DDA contributed to the study design and analysis. LPM, VDT and NTA contributed to data collection and data management. The Rotavirus Economic Study Group involved the data collection. All authors read and approved the final manuscript.
The authors declare that they have no competing interests.
Consent for publication
Ethics approval and consent to participate
This study was approved by the Institutional Review Boards of the International Vaccine Institute (Seoul, Korea) and National Institute of Hygiene and Epidemiology (Hanoi, Vietnam). Written informed consent was obtained from a parent or guardian of each child subject enrolled.
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
- Koopmans M, Brown D. Seasonality and diversity of Group A rotaviruses in Europe. Acta Paediatr Suppl. 1999;88(426):14–9.View ArticlePubMedGoogle Scholar
- Van Damme P, Giaquinto C, Huet F, Gothefors L, Maxwell M, Van der Wielen M, Group RS. Multicenter prospective study of the burden of rotavirus acute gastroenteritis in Europe, 2004–2005: the REVEAL study. J Infect Dis. 2007;195 Suppl 1:S4–S16.View ArticlePubMedGoogle Scholar
- Fischer TK, Anh DD, Antil L, Cat ND, Kilgore PE, Thiem VD, Rheingans R, le Tho H, Glass RI, Bresee JS. Health care costs of diarrheal disease and estimates of the cost-effectiveness of rotavirus vaccination in Vietnam. J Infect Dis. 2005;192(10):1720–6.View ArticlePubMedGoogle Scholar
- Bresee JS, Hummelman E, Nelson EA, Glass RI. Rotavirus in Asia: the value of surveillance for informing decisions about the introduction of new vaccines. J Infect Dis. 2005;192 Suppl 1:S1–5.View ArticlePubMedGoogle Scholar
- Postma MJ, Jit M, Rozenbaum MH, Standaert B, Tu HA, Hutubessy RC. Comparative review of three cost-effectiveness models for rotavirus vaccines in national immunization programs; a generic approach applied to various regions in the world. BMC Med. 2011;9:84.View ArticlePubMedPubMed CentralGoogle Scholar
- Kim SY, Goldie SJ, Salomon JA. Cost-effectiveness of Rotavirus vaccination in Vietnam. BMC Public Health. 2009;9:29.View ArticlePubMedPubMed CentralGoogle Scholar
- Kim SY, Goldie SJ, Salomon JA. Exploring model uncertainty in economic evaluation of health interventions: the example of rotavirus vaccination in Vietnam. Med Decis Making. 2010;30(5):E1–E28.View ArticlePubMedGoogle Scholar
- Tu HA, Rozenbaum MH, Coyte PC, Li SC, Woerdenbag HJ, Postma MJ. Health economics of rotavirus immunization in Vietnam: potentials for favorable cost-effectiveness in developing countries. Vaccine. 2012;30(8):1521–8.View ArticlePubMedGoogle Scholar
- Luce BR, Manning WG, Siegel JE, Lipscomb J. Estimating costs in cost-effectiveness analysis. In: Gold MR, Sigel JE, Russell LB, Weinstein MC, editors. Cost-effectiveness in health and medicine. Oxford: Oxford University Press; 1996.Google Scholar
- Kobelt G. Health economics: an introduction to economic evaluation. 2nd ed. London: Office of Health Economics; 2002.Google Scholar
- General Statistics Office of Vietnam. Statistical data. 2015. http://www.gso.gov.vn/Default_en.aspx?tabid=766 Accessed 10 Apr 2015.
- Lwanga SK, Lemeshow S. Sample size determination in health studies: a practical manual. Geneva: World Health Organization; 1991.Google Scholar
- Assessment V, Team M. Guidelines for estimating the economic burden of diarrhoeal disease with focus on assessing the costs of rotavirus diarrhoea. Geneva: Department of Immunization, Vaccines and Biologicals, World Health Organization; 2005.Google Scholar
- Department of Immunization Vaccines and Biologicals. WHO guide for standardization of economic evaluations of immunization programmes. Geneva: World Health Organization; 2008.Google Scholar
- Immunization Vaccines and Biologicals. Manual of rotavirus detection and characterization methods. Geneva: World Health Organization; 2009.Google Scholar
- Anh DD, Yen NTB, Riewpaiboon A. Institutional cost of shigellosis at Khanh Hoa Hospital and lower health facilities in Vietnam. Hanoi: National Institute of Hygiene and Epidemiology; 2008.Google Scholar
- General Statistics Office of Vietnam. Consumer price index. 2015. http://gso.gov.vn/default_en.aspx?tabid=780 Accessed 5 Mar 2015.
- Ministry of Finance. Announcement monthly exchange rate. http://www.mof.gov.vn/webcenter/portal/mof/r/o/tght?centerWidth=670px&leftWidth=286px&rightWidth=0&showFooter=false&showHeader=false&_adf.ctrlstate=jdly515al_219&_afrLoop=26667069091110052#! Accessed 5 Mar 2015.
- IBM Corp. Released 2012. IBM SPSS Statistics for Windows, Version 21.0. Armonk, NY: IBM Corp; 2012.Google Scholar
- Cohen J, Cohen P, West SG, Aiken LS. Applied multiple regression/ correlation analysis for the behavioral sciences. 3rd ed. Mahwah: Lawrence Erlbaum Associates, Inc; 2003.Google Scholar
- Weinstein MC, Siegel JE, Gold MR, Kamlet MS, Russell LB. Recommendations of the Panel on Cost-effectiveness in Health and Medicine. JAMA. 1996;276(15):1253–8.View ArticlePubMedGoogle Scholar
- Wilopo SA, Kilgore P, Kosen S, Soenarto Y, Aminah S, Cahyono A, Ulfa M, Tholib A. Economic evaluation of a routine rotavirus vaccination programme in Indonesia. Vaccine. 2009;27 Suppl 5:F67–74.View ArticlePubMedGoogle Scholar
- Lee WS, Poo MI, Nagaraj S. Estimates of economic burden of providing inpatient care in childhood rotavirus gastroenteritis from Malaysia. J Paediatr Child Health. 2007;43(12):818–25. Epub 2007 Jun 2029.View ArticlePubMedGoogle Scholar
- Chai PF, Lee WS. Out-of-pocket costs associated with rotavirus gastroenteritis requiring hospitalization in Malaysia. Vaccine. 2009;27 Suppl 5:F112–115.View ArticlePubMedGoogle Scholar
- Jacobs P, Shane L, Fassbender K, Wang E, Moineddin R, Ford-Jones E. Economic analysis of rotavirus-associated diarrhea in the metropolitan Toronto and Peel regions of Ontario. Can J Infect Dis. 2002;13(3):167–74.View ArticlePubMedPubMed CentralGoogle Scholar
- Hodgson TA. Costs of illness in cost-effectiveness analysis. A review of the methodology. Pharmacoeconomics. 1994;6(6):536–52.View ArticlePubMedGoogle Scholar
- Rizzo JD, Powe NR. Methodological hurdles in conducting pharmacoeconomic analyses. Pharmacoeconomics. 1999;15(4):339–55.View ArticlePubMedGoogle Scholar
- Pritchard C, Sculpher M. Productivity costs: principles and practice in economic evaluation. London: Office of Health Economics; 2000.Google Scholar
- Koopmanschap MA. A practical guide for calculating indirect costs of disease. PharmacoEcon. 1996;10(5):460–6.View ArticleGoogle Scholar
- Cairns J. Discounting in economic evaluation. In: Drummond M, McGuire A, editors. Economic evaluation in health care; merging theory with practice. Oxford: Oxford University Press; 2001.Google Scholar
- Neumann PJ. Costing and perspective in published cost-effectiveness analysis. Med Care. 2009;47(7 Suppl 1):S28–32.View ArticlePubMedGoogle Scholar
- Muangchana C, Riewpaiboon A, Jiamsiri S, Thamapornpilas P, Warinsatian P. Economic analysis for evidence-based policy-making on a national immunization program: A case of rotavirus vaccine in Thailand. Vaccine. 2012;30(18):2839–47.View ArticlePubMedGoogle Scholar
- Suwantika AA, Tu HA, Postma MJ. Cost-effectiveness of rotavirus immunization in Indonesia: taking breastfeeding patterns into account. Vaccine. 2013;31(32):3300–7.View ArticlePubMedGoogle Scholar
- Suwantika AA, Postma MJ. Effect of breastfeeding promotion interventions on cost-effectiveness of rotavirus immunization in Indonesia. BMC Public Health. 2013;13:1106.View ArticlePubMedPubMed CentralGoogle Scholar
- Soarez PC, Novaes HM, Sartori AM. Impact of methodology on the results of economic evaluations of varicella vaccination programs: is it important for decision-making? Cad Saude Publica. 2009;25 Suppl 3:S401–414.View ArticlePubMedGoogle Scholar