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Economic impact of providing workplace influenza vaccination: a model and case study application at a Brazilian pharma-chemical company |
Burckel E, Ashraf T, Galvao de Sousa Filho J P, Neto E F, Guarino H, Yauti C, de Barros Barreto F, Champion L |
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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 Influenza vaccination for healthy adult workers.
Economic study type Cost-effectiveness analysis.
Study population 4,030 Brazilian pharmo-chemical company employees above the age of 18.
Setting Workplace, specifically a pharma-chemical conglomerate in Brazil. The economic analysis was conducted in Sao Paulo, Brazil.
Dates to which data relate Effectiveness data were taken from literature published between 1973 and 1998. No dates for resource data collection were reported, although most resource data were collected prospectively from the study company in 1997. 1997 price years were used.
Source of effectiveness data Effectiveness data were derived from a review of the literature, surveys and expert opinion.
Modelling A simulation model was constructed in which information on the incidence and morbidity of influenza and the efficacy of vaccination was combined prospectively with information supplied on costs and productivity levels within the case study firm in order to calculate both the costs of the vaccination programme and the potential costs of productivity losses avoided resulting from its implementation.
Outcomes assessed in the review The review assessed the incidence of influenza and associated morbidity as well as efficacy of influenza vaccine and incidence of the adverse reactions to vaccination.
Study designs and other criteria for inclusion in the review No study design or other inclusion criteria were specified.
Sources searched to identify primary studies Criteria used to ensure the validity of primary studies Methods used to judge relevance and validity, and for extracting data Number of primary studies included 12 publications were identified, some of which were reviews rather than primary studies. At least 8 primary studies were included in the review, but the study types are not clear.
Methods of combining primary studies Investigation of differences between primary studies Results of the review From the review a 10% overall incidence rate of influenza was assumed and this was broken down by age and disease severity as follows.
ages 18-24: low morbidity 8.4%, moderate morbidity 2.7%, and high morbidity 0.033%.
ages 25-44: 6.3%, 3.6% and 0.035%;
ages 45-64: 6.0%, 3.4% and 0.076%;
aged 65 and over: 5.2%, 4.6% and 0.294%.
Efficacy of influenza vaccination by age and morbidity was as follows:
ages 18-24: low morbidity 77.1%, moderate morbidity 83.1%, and high morbidity 89.0 %.
ages 25-44: 77.2%, 83.1%, and 89.0%.
ages 45-64: 73.6%, 78.3%, and 83.0%.
ages 65 and over: 70.0%, 73.6% and 77.1%.
Methods used to derive estimates of effectiveness Authors' opinion plus expert evidence from surveys and influenza networks were also used to derive estimates of effectiveness.
Estimates of effectiveness and key assumptions The authors made an assumption that incidence rates and other data from the general literature could be applied to Brazil, partly because of Brazilian survey data, and unpublished surveys and additionally because influenza surveillance networks isolated the same strain of influenza in both Europe and North America during two consecutive seasons.
Measure of benefits used in the economic analysis The benefit measure was the number of avoided cases of influenza.
Direct costs The direct costs of the vaccination programme and medical costs associated with the treatment of influenza and adverse reactions to vaccination were estimated. These direct costs were estimated using health insurance industry data, physician interviews and a survey of drug prices in pharmacies in Sao Paulo. Direct medical costs were assumed to include over the counter medication, and, if necessary, physician office visits and prescription medication. Direct medical costs averted were estimated as the product of the morbidity rate for employee categories and the typical cost of treatment in that category. Costs were estimated from the perspective of the employer. 1997 price years were used. Costs and benefits were not discounted, which was appropriate given the very short time frame of the model.
Indirect Costs Productivity losses and costs of vaccination were estimated based on interviews with the human resource manager at the pharma-chemical company and also on experience of local management consultants. Productivity losses were estimates as the marginal added value of each worker, i.e. the difference between total added value for each worker less their labour costs. The costs of lost working days were estimated using a previously published methodological framework which attributed a proportion of Gross National Product to each active adult. Added values to these costs were then estimated using a previously published rate of return on investment and applying this to a company rather than on a macro level. Estimated added values for workers in the four employment categories were determined using information from the management consultants and weightings were used to adjust added value for employees in each category. Costs of replacement workers or increased workload on existing staff were also estimated and used in adjusting estimates of lost productivity where such action had been taken. The cost of the vaccination programme was estimated as productivity time lost for vaccination plus lost productivity due to adverse effects of vaccination. Savings from productivity losses averted were estimated as the product of estimated morbidity avoided and estimated lost work days of employees in each category. Lost productivity costs were estimated from the perspective of the employer. 1997 prices were used and costs were not discounted, this was appropriate given the very short time frame of the model.
Currency US dollars ($). Converted from Brazilian reais at an average exchange rate from January to August 1997 ($1 = BRL 1.065). Sensitivity analysis One way and two way sensitivity analyses were conducted on a wide range of parameters in the model: incidence and efficacy rates, employee participation, vaccine costs, employee added value and the cost of labour. Parameter thresholds at which the vaccination programme broke even were identified.
Estimated benefits used in the economic analysis A vaccination programme would decrease the number of influenza cases by 267 (from 400.2 ("do-nothing") to 133.2) if 85% of the employees chose to be vaccinated.
Cost results Overall, as a result of the introduction of the vaccination programme, net costs would decrease by $121,441, or $35.45 per person vaccinated. The total costs of the vaccination programme for the 4,030 employees including administration costs were estimated to be $82,506 ($Brz 87,869). Specifically this included direct costs of vaccination administration and promotion $36,255, lost production time for vaccination $26,160, and $20,091 for adverse reactions to vaccination. Costs per vaccinated person were $24.09. Costs averted as a result of vaccination were estimated to be $203,947 ($Brz 217,203). These comprised direct medical treatment costs averted of $14,339, avoided loss of labour costs $77, 384, avoided loss of marginal added value $102,601 and avoided cost of replacement workers $9,623. Costs averted per person vaccinated were estimated to be $59.54
Synthesis of costs and benefits A synthesis was not carried out since the intervention was the dominant strategy.
Authors' conclusions The introduction of an employer sponsored influenza vaccination programme is in the interests of employers, as the costs of the programme are more than compensated for by averted costs of lost productivity due to influenza. The model used was robust in sensitivity analysis, with the vaccination programme generating cost savings for employers in most likely scenarios, and furthermore such vaccination programmes are likely to be most beneficial to employers who have to rely heavily on their existing workforce. Caution must be exercised however, as the model is sensitive to the estimated level of added value, and this may vary widely between different firms. Indirect costs averted accounted for 93% of total costs averted in this model and such costs are of particular importance when employers are responsible for the majority of both medical costs and consequences.
CRD COMMENTARY - Selection of comparators The employer sponsored vaccination programme was justifiably compared with the current practice of no general vaccination programme for working adults.
Validity of estimate of measure of benefit Incidence and efficacy rates were derived from published and non-published literature as well as from surveys and authors' assumptions. It would have been helpful, in addressing any potential bias, to have more information on the sources and criteria used to identify and combine information. However, estimates used in the analysis were subjected to sensitivity analysis in order to deal with uncertainty.
Validity of estimate of costs Sufficient details were provided on methods used in the analysis to determine both direct and indirect costs.
Other issues The results of the model may not be generalisable to other firms in different countries and with different labour force options. In addition, as noted by the authors, the model is sensitive to the level of added value and this may vary between firms. In determining productivity losses a future model may also wish to consider the possibility of replacing labour for additional capital inputs, and also consider that the existing labour force may not be producing at its most efficient level, and there may be sufficient slack within firms to allow current production levels to be maintained despite the loss of labour due to sickness.
Bibliographic details Burckel E, Ashraf T, Galvao de Sousa Filho J P, Neto E F, Guarino H, Yauti C, de Barros Barreto F, Champion L. Economic impact of providing workplace influenza vaccination: a model and case study application at a Brazilian pharma-chemical company. PharmacoEconomics 1999; 16(5 Part 2): 563-576 Indexing Status Subject indexing assigned by NLM MeSH Adolescent; Adult; Aged; Brazil; Chemical Industry; Cost-Benefit Analysis; Drug Industry; Female; Humans; Influenza Vaccines /economics; Influenza, Human /economics /prevention & Male; Middle Aged; Prospective Studies; Vaccination /economics; Workplace; control AccessionNumber 21999008334 Date bibliographic record published 29/02/2000 Date abstract record published 29/02/2000 |
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