Interventions to increase influenza vaccination rates in children with high-risk conditions—A systematic review

BackgroundInfluenza is a common cause of morbidity and mortality, especially among the elderly and those with certain chronic diseases. Annual influenza vaccination is recommended for individuals in at-risk groups, but rates of vaccination are particularly low in children with high-risk conditions (HRCs).ObjectiveTo conduct a systematic review of studies that have examined interventions aimed at improving influenza vaccination in children with HRCs.MethodsTwo databases – PubMed and SCOPUS – were searched (with no time or language restrictions) using a combination of keywords – Influenza AND vaccination OR immunization OR children AND asthma OR malignancy OR high-risk AND reminder. Duplicates were removed, and abstracts of relevant articles were screened using specific inclusion/exclusion criteria. Thirteen articles were selected, and five additional studies were identified following a review of the reference lists of the initial thirteen articles, bringing the total number to eighteen.ResultsMost studies were conducted in the United States. Among the 18 studies, there was one systematic review of a specific intervention in asthmatic children, seven randomized controlled trials (RCTs), six before-and-after studies, one non-randomized controlled trial, one retrospective cohort study, one quasi-experimental post-test study, and one letter to editors. Interventions reported include multi-component strategies, letter reminders, telephone recall, letters plus telephone calls, an asthma education tool and year-round scheduling for influenza vaccination, amongst others.ConclusionThere is good evidence that reminder letters will improve influenza vaccination uptake in children with HRCs, but the evidence that telephone recall or a combination of letter reminder and telephone recall will improve uptake is weak. It is not known if multiple reminder letters are more effective than single letters or if multi-component strategies are more effective than single or dual component strategies. There is a need for further research of these interventions, possibly outside the United States.