The measurement of influenza vaccine coverage among health care workers

Department of Community Health Sciences, Faculty of Medicine, University of Calgary, Alberta, Canada.
American Journal of Infection Control (Impact Factor: 2.21). 01/2004; 31(8):457-61. DOI: 10.1016/S0196-6553(03)00085-3
Source: PubMed


Annual influenza vaccination is recommended for health care workers in both the United States and Canada. Estimations of vaccine coverage are commonly used to evaluate these vaccination programs.
We identify, discuss, and illustrate challenges including definitions of health care worker (HCW), selection of indicators, and data sources in the estimation of staff influenza vaccination coverage rates.
To illustrate the impact of the factors we discuss, we created a database of a simulated pool of HCWs that included varying proportions of permanent, casual, and contract staff under differing scenarios of staff turnover and differing probabilities of individuals being vaccinated. The Excel 97 random number generator (Microsoft) was used to randomly allocate the HCW to different strata under differing staff turnover rates and to designate individuals as being vaccinated.
The nature of the staff targeted in the program policy has a large impact on the estimations of vaccine coverage. Different indicators provide data that might be useful for different purposes. The counts in the numerator and denominator of a period prevalence may be useful for estimation of the total workload required of the vaccination program. An incidence density might be useful as an indicator of the efficiency of the program in "capturing" staff for vaccination. The indicator that may be easiest is the point prevalence.
Program evaluators must think carefully when planning to estimate staff vaccination coverage to avoid invalid comparisons of estimates over time and place. State or province-wide targets for health care worker (HCW) vaccination may be meaningless unless appropriate criteria for the calculation of influenza vaccination rates are developed and specified.

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    • "The World Health Organization (WHO), US Centers for Disease Control and Prevention (CDC) and immunization guidelines of many countries recommend yearly influenza vaccination of HCP to prevent transmission of influenza from HCP to patients [11] [12]. However, despite longstanding recommendations, and unlike HBV vaccine, vaccination coverage rates for influenza remain suboptimal among HCP [13] [14] [15] [16] [17] [18] [19] [20] [21] [22]. "
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    ABSTRACT: Healthcare personnel (HCP) are at risk from occupational exposure to airborne and bloodborne pathogens, and the risk of infection among HCP is greater than among the general population. The aim of the study was to characterize attitudes toward occupational recommended vaccines as well as the perception of risks of occupationally acquired infections. We surveyed 650 medical students to assess their perception of influenza and hepatitis B and their opinions and beliefs about influenza and hepatitis B vaccines. We found differences between pre-clinical and clinical students regarding the uptake of influenza and hepatitis B vaccines, about the chances of being occupationally infected with influenza or hepatitis B, and about the likelihood of suffering from severe side-effects following immunization. Interestingly, the risk perception varied drastically between the two vaccine-preventable diseases hepatitis B and influenza. Medical students rated the probability of contracting hepatitis B due to a work-related exposure and the severity of disease significantly higher than for influenza, and this may be an explanation for the greater acceptance of the hepatitis B vaccine. Furthermore, our findings suggest that medical students are frequently inaccurate in assessing their own risk level, and their specific knowledge about both diseases and the severity of these diseases proved to be unsatisfactory.
    Full-text · Article · Sep 2013 · Vaccine
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    • "Measurement of the coverage achieved allows estimates of the protection obtained in all HCW, monitoring of trends between seasons and measurement of the impact of the intervention. Russell et al [1] stress the importance of using the same target population for spatiotemporal comparisons between coverage. When making comparisons, reported coverage numerators are acquired from two sources: a) self-reported surveys of HCW [2]–[4] and, b) vaccination records [5]–[8]. "
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    ABSTRACT: Published influenza vaccination coverage in health care workers (HCW) are calculated using two sources: self-report and vaccination records. The objective of this study was to determine whether self-report is a good proxy for recorded vaccination in HCW, as the degree of the relationship is not known, and whether vaccine behaviour influences self-reporting. A cross-sectional study was conducted using a self-administered survey during September 2010. Considering the vaccination record as the gold standard of vaccination, the properties of self-report as a proxy of the record (sensitivity, specificity, positive predictive value, negative predictive value) were calculated. Concordance between the vaccination campaigns studied (2007-2010) was made using the Kappa index, and discordance was analyzed using McNemar's test. 248 HCW responded. The 95% confidence intervals of coverage according to the vaccination record and to self-report overlapped, except for 2007, and the Kappa index showed a substantial concordance, except for 2007. McNemar's test suggested that differences between discordant cases were not due to chance and it was found that the proportion of unvaccinated discordant cases was higher than that of vaccinated discordant cases. In our study population, self-reported influenza vaccination coverage in HCW in the previous two years is a good proxy of the vaccination record. However, vaccination behaviour influences the self-report and explains a trend to overestimate coverage in self-reporting compared to the vaccination record. The sources of coverage should be taken into account whenever comparisons are made.
    Full-text · Article · Jul 2012 · PLoS ONE
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    • "Most of the data concerning the use of influenza vaccine and attitudes toward it have been collected from HCWs in United States [8] [9] [10] [11]. Annually, more than 2 million Muslims from over 140 countries embark on the Hajj. "
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    ABSTRACT: Annual influenza vaccination is recommended for healthcare workers (HCWs) in order to reduce the morbidity associated with influenza in healthcare settings. The objectives of the study were to determine the rate of influenza vaccination, knowledge, attitudes and beliefs toward influenza immunization among healthcare workers at our hospital, and to identify reasons for electing or declining the immunization. Between January and February 2009, we carried out a cross-sectional study of influenza vaccination coverage among HCWs at King Abdul-Aziz Hospital, Saudi Arabia. After receiving a brief description of the aim of the study, 512 of 902 HCWs self-completed an anonymous questionnaire. Influenza vaccination coverage was low at a rate of 34.4% in 2008-9. The knowledge of influenza disease and prevention was low, with a mean knowledge score of 5.8+/-2.1. The most common reason for being vaccinated was self-protection from illness (95%), and the most common reason for not being vaccinated was a belief that vaccine is not effective in disease prevention (51%). We found that being female, awareness of effectiveness of vaccine in disease prevention, feeling at risk of influenza, self-protection, to protect the patients, previous influenza vaccination were statistically significant factors for influenza vaccination. Despite the recommendations, influenza vaccination coverage is low among HCWs at our hospital. Misconceptions about influenza vaccination were prevalent among the healthcare workers. Specific continuous educational and vaccination programs for different targets should be organized to reduce morbidity and mortality in high-risk patients.
    Full-text · Article · Jun 2010 · Vaccine
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