Impacto da campanha de vacinação para influenza em uma empresa

Abstract

Influenza is one of the most prevalent acute respiratory diseases and it is an important cause of absenteeism and presenteeism. However, the influenza vaccine efficacy can reach 80% when there is a high correspondence between vaccinal and circulating strains. For that reason, the company has promoved vaccination campaigns for several years, although without measuring its effectiveness (efficacy on reducing the disease´s load) and the economic impact (productivity) to improve occupational health policy. The campaign effectiveness would be determined by the the vaccinal efficacy that had been shown previously in randomized studies, by the degree of diagnostic accuracy or screening of cases, by the levels on health records and by the patient´s information and vaccination coverage achieved. Aiming at assessing the effectiveness and the economic impact of the vaccination campaign, we opted for an observational historic cohort study design with features of study design based in historical data from the 2008 campaign and individual information on the frequency of respiratory symptoms and absenteeism, age, gender, function (administrative and operational) and income, relevant co morbidities and smoking, obtained through a revision of medical records of the following twelve months, compared to vaccinated and non-vaccinated group (Chi square and t-test) and analyzed by logistic regression, and estimated the preventable fraction (proportion of potential influenza episodes avoided by vaccination). Medical records of 2.425 workers were analyzed (1.651 non-vaccinated and 754 vaccinated) corresponding to 31,1% coverage. The prevalence of influenza observed was 10,4% and vaccination has been effective between workers (RR = 0,51; IC95% 39-67), when considering symptoms of high probability of influenza. The preventable fraction was 0,09 (9 avoided cases for every 100 workers vaccinated). The vaccination campaign was more effective and sparked greater economic impact among workers in the operating system.