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Economic analysis for evidence-based policy-making on a national immunization program: a case of rotavirus vaccine in Thailand |
Muangchana C, Riewpaiboon A, Jiamsiri S, Thamapornpilas P, Warinsatian P |
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Record Status This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn. CRD summary This study assessed the cost-effectiveness of incorporating rotavirus vaccination into a national immunisation programme. The study was requested by the Thai National Vaccine Committee. The authors concluded that rotavirus vaccination was not cost-effective, based on World Health Organization guidelines, due to the high cost of the vaccine. The methods were valid and transparent and most of the model assumptions were explicitly reported, especially for mortality, which could have affected the results. The authors’ conclusions appear to be robust. Type of economic evaluation Cost-effectiveness analysis, cost-utility analysis Study objective This study assessed the cost-effectiveness of incorporating rotavirus vaccination into a national immunisation programme. The study was requested by the Thai National Vaccine Committee. Interventions Two- and three-dose vaccines were considered for the rotavirus immunisation programme, with doses at two and four months, and the additional third dose at six months. The comparator was no rotavirus vaccination. Methods Analytical approach:The analysis was based on a decision tree, with a five-year time horizon. The authors stated that the perspectives of society and of the health care provider were adopted. Effectiveness data:Most of the data were from official Thai sources and surveillance databases, with some data from publications from other Asian countries. The efficacy of rotavirus vaccination was a key input for the model and was mainly from studies conducted in Thailand. Vaccine coverage was from a Thai study. Some assumptions and calculations were made. Monetary benefit and utility valuations:The disability weights for rotavirus-related conditions were from a Thai study on the burden of disease. Measure of benefit:Disability-adjusted life-years (DALYs) and lives saved were the summary benefit measures and they were discounted at an annual rate of 3%. Cost data:The societal analysis included the costs of vaccination, treatment of rotavirus (drugs and in-patient and out-patient care), and productivity losses. The payer’s analysis included only the direct medical costs. Vaccine costs included acquisition and logistics, while the costs of delivery, and travel and time for the children’s parents were assumed to be zero, as the vaccine was administered with routine infant vaccinations. The costs of side-effects were excluded. All costs were from official Thai sources, including published studies and provincial and regional hospitals. Charges were converted to costs, which were converted from Thai baht to US $. The price year was 2009 and a 3% annual discount rate was applied. Analysis of uncertainty:One-way sensitivity analyses were carried out, within the framework of a break-even analysis, as follows. The incremental cost-utility ratio (ICUR) was set at a threshold value based on the 2009 gross domestic product (GDP) per capita of $3,941, and the vaccine price was determined when varying the following parameters: discount rate, treatment cost, efficacy of vaccine, incidence, mortality, medical cost, duration of hospitalisation, and wastage rate. A probabilistic sensitivity analysis was performed, using conventional distributions for sets of inputs, and cost-effectiveness acceptability curves were generated. Results In the cost-utility analysis, indirect costs were not considered to avoid double-counting in the disability adjustments. In the societal analysis, with the two-dose schedule, the expected costs were $78,456,826 with vaccination and $21,023,007 with no vaccination. The deaths were 7.02 with vaccination and 20.52 without it. The DALYs were 263.33 with vaccination and 826.57 without it. The incremental cost-effectiveness with vaccination was $5,064,745 per life saved and $128,063 per DALY averted. With three doses it was $5,685,142 per life saved and $142,144 per DALY averted. From the payer's perspective it was $5,949,446 per life saved and $135,036 per DALY averted, with two doses, and $6,569,844 per life saved and $149,118 per DALY averted, with three doses. Vaccination had a negative net present value, as the cost of the programme was greater than the savings from reduced illness. At the GDP threshold, the vaccine break-even price was $4.98 with two doses and $3.32 with three doses, from the societal perspective, and $2.90 with two doses and $1.93 with three doses, from the payer's perspective. These prices were far lower than the actual vaccine price in Thailand. The deterministic analysis confirmed that large reductions in the vaccine price were required, when the model inputs were varied, to reach the cost-effectiveness threshold. The results of the probabilistic analysis were presented in graphs. Mortality due to diarrhoea was a key input for the analysis. Authors' conclusions The authors concluded that rotavirus vaccination was not cost-effective, based on World Health Organization guidelines, due to the high cost of the vaccine. CRD commentary Interventions:The selection of the comparators was clear as the proposed rotavirus vaccination programme was added to the conventional childhood immunisation programme in the authors’ setting. Effectiveness/benefits:Little information was provided on the sources for the clinical inputs and they appear to have been selected without a review of the literature. Most of the epidemiological data were from Thai sources, while the vaccine efficacy was from a mixture of Asian studies. It is difficult to fully judge the validity of these estimates, but the authors stated that they were from accurate sources. The disability weights were from a Thai study on the burden of disease, but the approach used to derive them was not described. Costs:Two perspectives were appropriately considered and the costs included for each viewpoint were clearly reported. The resource use and unit costs were presented for most items and the costs were appropriately from official Thai sources. A charge-to-cost ratio was used. The impact of variations in the cost estimates was assessed in the sensitivity analyses. The price year was explicitly stated, allowing reflation exercises. Analysis and results:The results were extensively presented, for all scenarios. The expected costs and benefits of the two strategies were synthesised, using an incremental approach, and the results were clearly illustrated and discussed. The uncertainty was investigated, using appropriate deterministic and probabilistic sensitivity analyses, which focused on variations in the vaccine price as the most important input. The authors stated that their results differed from those of a previous Thai study and some studies in similar countries, due to the assumption of a lower mortality from diarrhoea in this analysis. It appears that herd immunity was not considered. The findings were specific to the authors' setting, but might be transferable to countries with similar epidemiological estimates, vaccine costs, and GDP. Concluding remarks:The methods were valid and transparent and most of the model assumptions were explicitly reported, especially those for mortality, which are likely to have affected the results. The authors’ conclusions appear to be robust. Funding Supported by the Ministry of Public Health of Thailand. Bibliographic details 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): 2839-2847 Indexing Status Subject indexing assigned by NLM MeSH Child, Preschool; Costs and Cost Analysis; Diarrhea /economics /prevention & Health Policy; Humans; Immunization Programs /economics; Infant; Infant, Newborn; Policy Making; Rotavirus Infections /economics /prevention & Rotavirus Vaccines /administration & Thailand; control; control; dosage /economics AccessionNumber 22012014511 Date bibliographic record published 28/05/2012 Date abstract record published 05/12/2012 |
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