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Cost-effectiveness of pneumococcal vaccination for prevention of invasive pneumococcal disease in the elderly: an update for 10 Western European countries |
Evers S M, Ament A J, Colombo G L, Konradsen H B, Reinert R R, Sauerland D, Wittrup-Jensen K, Loiseau C, Fedson D S |
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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. Health technology The study compared pneumococcal vaccination in the elderly population versus no vaccination. The 14- and 23-valent pneumococcal polysaccharide vaccine (Aventis Pasteur MSD) was used. No further details of the vaccine were provided. Study population As this was a modelling study, the target population comprised two hypothetical cohorts of people older than 65 years of age. In addition, separate analyses were conducted for people aged 65 to 74 years, 75 to 84 years and above the age of 85. One cohort was assumed to receive vaccination and the other comprised the control (no vaccination). No further exclusion or inclusion criteria were provided. Setting The setting was primary care. The economic analysis was conducted separately for each of the countries included in the analysis: Belgium, Denmark, England and Wales, France, Germany, Italy, the Netherlands, Scotland, Spain and Sweden. Dates to which data relate The effectiveness and epidemiological data used to populate the model were obtained from a previous study (Ament et al. 2000) and from sources published between 1991 and 2005. The resource use data were also obtained from a previous study (Ament et al. 2000) and from national sources published between 1999 and 2004. The price year was 1999. Modelling A cohort model was used to extrapolate the progression of clinical outcomes. The model was based on one developed by Ament et al. (see 'Other Publications of Related Interest' below for bibliographic details). A life-long time horizon was used. Details of the model were given in the published study (Ament et al. 2000). Study designs and other criteria for inclusion in the review The clinical parameters associated with the vaccination included effectiveness of the pneumococcal vaccination. Further epidemiological parameters included the incidence of IPD and mortality rate due to IPD. Sources searched to identify primary studies The estimates of vaccination effectiveness were obtained from a case-control study. Country-specific estimates on the incidence of IPD were mainly derived from population-based studies based on laboratory reports and national official sources. Data for England, Wales and Germany were derived from two published studies, details of the design of which were not provided. The authors also made some assumptions about uncertain model inputs (i.e. incidence and mortality of IPD in Italy). Methods used to derive estimates of effectiveness It was unclear whether a review of the literature was undertaken to identify the primary studies. For further details the reader is referred to the previous study (Ament et al. 2000). Much of the data appear to have been obtained from national sources. No information on the methods used to pool the data was provided. Measure of benefits used in the economic analysis The measure of benefit used was the quality-adjusted-life-years (QALYs). Quality of life weights were derived from the published economic model on which this analysis was based (Ament et al. 1999). The benefits were discounted at a rate of 3%. Direct costs The analysis included the direct costs of vaccination (including the cost of the vaccine and its administration) and hospitalisation for IPD or pneumonia. Resource use and costs relating to hospitalisation were drawn from national sources. Vaccine costs reflected retail prices in each country, while vaccine administration costs were based on authors' assumptions and were set to be equal in all countries. It was reported that outpatient care costs for IPD and future costs of medical care were not accounted for in the analysis. The costs and the quantities were reported separately. All costs were reported for the price year 1999. Discounting was conducted at a rate of 3%. Statistical analysis of costs Cost estimates were treated deterministically. Indirect Costs Productivity costs were not accounted for in the analysis. Sensitivity analysis Parameter uncertainty was investigated using one- and two-way sensitivity analyses. The parameters investigated and the ranges over which the parameters were tested were all reported. The ranges over which the parameters were tested were either derived from published sources or based on authors' assumptions. Estimated benefits used in the economic analysis The estimated benefits were not reported separately. Cost results The cost results were not reported separately. Synthesis of costs and benefits For all people aged above 65 years, the cost per QALY gained ranged from EUR 9,239 in Denmark to EUR 23,657 in Sweden.
Sub-population analysis for age groups conducted in eight of the ten countries (Germany and Italy had no available data) demonstrated that the cost per QALY gained increased with age.
The one-way sensitivity analysis demonstrated that the results were sensitive to variation in the incidence and mortality of IPD, administration costs of the vaccine and vaccine effectiveness.
The two-way sensitivity analysis demonstrated that, when the incidence of IPD was set at 50 cases per 100,000, the results were most sensitive to variations in the mortality rate. When the mortality rate increased to 30%, the cost per QALY gained ranged from EUR 3,186 in Sweden to EUR 11,395 in Germany. Authors' conclusions The authors concluded that pneumococcal vaccination of the elderly population is a cost-effective strategy in the countries studied. CRD COMMENTARY - Selection of comparators The authors used no vaccination as the comparator as this would appear to represent current practice in their setting. You should decide if the comparator used represents current practice in your own setting. Validity of estimate of measure of effectiveness The parameters used in the model were derived from national official sources, from the published literature, and from authors' assumptions. However, no systematic search for the data was reported, and information on the primary studies was limited. Consequently, it is not possible to assess the validity of the clinical estimates from the information provided in this paper, . Validity of estimate of measure of benefit The authors used QALYs in the analysis, which represent a valid outcome of vaccination programmes. Discounting was performed appropriately. However, the methods used to estimate the utility weights were not described as they were taken from the original study (Ament et al. 2000). The authors did not report the disaggregated QALYs for the intervention and control groups. Validity of estimate of costs Although the authors reported that the study had been conducted from a societal perspective, productivity costs were not included. Thus, the perspective adopted appears to have been that of the health service. The authors excluded outpatient costs for IPD and future costs of medical care. You should consider if these are relevant to the analysis. Vaccine administration costs were based on authors' assumptions, and outpatient costs due to IPD were not omitted from the analysis. These factors are likely to have affected the authors' conclusions. The costs were reported separately from resource use, which will enhance the generalisability of the authors' results. However, the costs were not treated stochastically, and the robustness of the hospitalisation cost estimates was not investigated in sensitivity analyses. The price year was reported, thus simplifying reflation exercises in other time periods. Other issues The authors compared their findings with those from other studies and, in general, were found to be in agreement. In addition, a balanced discussion on methodological differences was provided. Variation in patient populations and cost data between different settings was addressed in the sensitivity analysis, and the authors also commented on the limitations of the transferability of the results to other settings not included in the current study. The authors do not appear to have presented their results selectively. The authors reported a number of limitations to their study, most of which related to the robustness of the estimates used in the analysis. Implications of the study The authors endorse the widespread use of pneumococcal vaccination in the elderly population. However, they recommend that the construction of a dynamic model would further assist economic evaluations, especially in countries where both the polysaccharide and the pneumococcal conjugate vaccine are being used. Source of funding Supported by an unrestricted grant from Aventis Pasteur MSD (now Sanofi Pasteur MSD). Bibliographic details Evers S M, Ament A J, Colombo G L, Konradsen H B, Reinert R R, Sauerland D, Wittrup-Jensen K, Loiseau C, Fedson D S. Cost-effectiveness of pneumococcal vaccination for prevention of invasive pneumococcal disease in the elderly: an update for 10 Western European countries. European Journal of Clinical Microbiology and Infectious Diseases 2007; 26(8): 531-540 Other publications of related interest Because readers are likely to encounter and assess individual publications, NHS EED abstracts reflect the original publication as it is written, as a stand-alone paper. Where NHS EED abstractors are able to identify positively that a publication is significantly linked to or informed by other publications, these will be referenced in the text of the abstract and their bibliographic details recorded here for information.
Ament A, Baltussen R, Duru G, Rigaud-Bully C, de Graeve D, Ortqvist A, et al. Cost-effectiveness of pneumococcal vaccination of older people: a study in 5 western European countries. Clin Infect Dis 2000;31:444-50. Indexing Status Subject indexing assigned by NLM MeSH Aged; Aged, 80 and over; Cost-Benefit Analysis; Europe /epidemiology; Health Care Costs /statistics & Humans; Pneumococcal Vaccines /economics; Pneumonia, Pneumococcal /economics /epidemiology /prevention & control; numerical data AccessionNumber 22007001709 Date bibliographic record published 06/09/2007 Date abstract record published 30/09/2008 |
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