Seasonal influenza vaccination campaigns for health care personnel: systematic review

Background

In Canada, vaccination coverage for seasonal influenza among health care personnel remains below 50%. The objective of this review was to determine which seasonal influenza vaccination campaign or campaign components in health care settings were significantly associated with increases in influenza vaccination among staff.

Methods

We identified articles in eight electronic databases and included randomized controlled trials, controlled before-and-after studies and studies with interrupted time series designs in our review. Two reviewers independently abstracted the data and assessed the risk of biases. We calculated risk ratios and 95% confidence intervals for randomized controlled trials and controlled before-and-after studies and described interrupted time series studies.

Results

We identified 99 studies evaluating influenza vaccination campaigns for health care workers, but only 12 of the studies were eligible for review. In nonhospital health care settings, including long-term care facilities, campaigns with a greater variety of components (including education or promotion, better access to vaccines, legislation or regulation and/or role models) were associated with higher risk ratios (i.e, favouring the intervention group). Within hospital settings, the results reported for various types of campaigns were mixed. Many of the criteria for assessing risk of bias were not reported.

Interpretation

Campaigns involving only education or promotion resulted in minimal changes in vaccination rates. Further studies are needed to determine the appropriate components and combinations of components in influenza vaccination campaigns for health care personnel.Health care personnel can act as vectors of influenza and may transmit the disease to patients who are at risk for influenza-related complications or death.¹ A Cochrane review² of three studies showed that vaccination of health care personnel, combined with vaccination of patients, was 86% efficacious (95% confidence interval [CI] 40%–97%) in preventing influenza-like illnesses among elderly patients. It is recommended that all health care personnel (i.e., minimum 90% coverage) receive the seasonal influenza vaccine for protection from the virus.³Rates of vaccination against seasonal influenza among health care personnel are often below targeted levels and vary across health care organizations in Canada and internationally. In 2003, vaccination coverage was 46% among Canadians employed in ambulatory care settings, hospitals and long-term care facilities.⁴ In a survey of Canadian long-term care facilities, the average vaccination rate among workers was 35%.⁵ Similarly, in the United States, vaccination coverage for health care personnel was about 40%,⁶ and in European countries, reported vaccine uptake has ranged from 14% to 48%.⁷The Canadian National Advisory Committee on Immunization encourages all organizations to actively promote the influenza vaccine and to provide education aimed at health care personnel.³ The US Healthcare Infection Control Practices Advisory Committee and the Advisory Committee on Immunization Practices have recommended that all organizations employing health care personnel use evidence-based approaches that may overcome barriers to vaccine uptake as part of their influenza vaccination campaigns.⁶ These two committees identified five categories of components of influenza vaccination campaigns aimed at improving immunization rates among health care personnel (6

Component	Operational definition	Examples
Education or promotion	Organized effort to raise awareness and/or increase knowledge about influenza and influenza vaccination	Educational sessions and materials, material or events promoting vaccine, incentives
Improved access to vaccine	Strategies to allow for easier access to vaccination for health care personnel	Mobile vaccine carts, peer-to-peer vaccination, additional or extended vaccine clinics
Legislation or regulation	Interventions involving changes in vaccination policy for health care personnel	Staff vaccination policy, mandatory vaccination programs, declination forms
Measurement and feedback	Tracking of vaccination rates of health care personnel and dissemination of results	Regular monitoring of vaccination coverage rates, reporting of coverage rates to administrators and health care personnel
Role models	Activities that involve leaders and/or senior staff to encourage vaccination	Vaccination advocates and champions, public support from leaders, visible vaccination of senior staff

Open in a separate windowNo systematic reviews have been conducted on interventions aimed at increasing influenza vaccination coverage among staff of health care organizations. Previous relevant reviews included a Cochrane review for improving vaccination rates among patient groups,⁸ a summary of 32 studies examining staff perceptions of the influenza vaccine and vaccination coverage⁹ and a systematic review of interventions to improve influenza vaccination coverage among high-risk adults.¹⁰ A narrative review on use of declination forms concluded that the intervention might lead to modest increases in vaccination rates, depending on the content and language of the forms.¹¹ The primary objective of the current review was to determine which influenza vaccination campaign or campaign components in health care settings were significantly associated with higher rates of influenza vaccination among staff. The focus of our systematic review was seasonal influenza vaccination campaigns; we did not consider pandemic influenza vaccination programs.