Review: interventions to increase influenza vaccination among healthcare workers in hospitals.

Annual influenza vaccination rates among hospital healthcare workers (HCW) are almost universally low despite recommendations from WHO and public health authorities in many countries. To assist in the development of successful vaccination programmes, we reviewed studies where interventions aimed to increase the uptake of influenza vaccination among hospital HCW. We searched PUBMED from 1990 up to December 2011 for publications with predetermined search strategies and of pre-defined criteria for inclusion or exclusion. We evaluated a large number of 'intervention programmes' each employing one or more 'intervention components' or strategies, such as easy access to vaccine or educational activities, with the goal to raise influenza vaccine uptake rates in hospital HCW during one influenza season. Included studies reported results of intervention programmes and compared the uptake with the season prior to the intervention (historical control) or to another intervention programme within the same season that started from the same set of baseline activities. Twenty-five studies performed in eight countries met our selection criteria and described 45 distinct intervention programmes. Most studies used their own facility as historical control and evaluated only one season. The following elements were used in intervention programmes that increased vaccine uptake: provision of free vaccine, easy access to the vaccine (e.g. through mobile carts or on-site vaccination), knowledge and behaviour modification through educational activities and/or reminders and/or incentives, management or organizational changes, such as the assignment of personnel dedicated to the intervention programme, long-term implementation of the strategy, requiring active declination and mandatory immunization policies. The number of these components applied appeared to be proportional to the increase in uptake. If influenza uptake in hospital HCW is to be increased on sustained basis, hospital managers need to be committed to conduct a well-designed long-term intervention programme that includes a variety of co-ordinated managerial and organizational elements.