Elsevier

Vaccine

Volume 33, Issue 6, 4 February 2015, Pages 759-770
Vaccine

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

https://doi.org/10.1016/j.vaccine.2014.12.013Get rights and content

Highlights

  • Influenza is a common cause of morbidity and mortality, and children with high-risk conditions (HRCs) are more likely to be hospitalized with influenza than previously healthy children.

  • Despite recommendations by the World Health Organization (WHO), annual influenza vaccination rates in children with HRCs have remained low, especially when compared to rates in other risk groups such as the elderly and pregnant women.

  • This systematic review identifies, describes and compares studies of interventions to improve influenza vaccination rates in children with HRCs – we found good evidence that reminder letters are effective, but weak evidence of effectiveness of other strategies or combination of strategies.

  • There is a need for further research of these interventions, possibly outside the United States, as almost all of the studies included in this review originated from there.

Abstract

Background

Influenza 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).

Objective

To conduct a systematic review of studies that have examined interventions aimed at improving influenza vaccination in children with HRCs.

Methods

Two 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.

Results

Most 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.

Conclusion

There 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.

Introduction

Influenza is a common cause of morbidity and mortality across the world. Severe morbidity and mortality are more common among elderly people and those with certain chronic diseases [1]. For example, in the United States, the average excess hospitalization associated with influenza in previously healthy children under 4 years of age was 100 per 100,000 and in the age group 5–15 years, 40 per 100,000. For children at particular risk of serious infection, these annual rates were about 5 times higher than in those that were previously healthy. The World Health Organization consequently recommends that influenza vaccination should be offered to all individuals over 6 months of age with chronic heart or lung disease (including asthma), metabolic or renal disease or immunodeficiency [1]. Similar recommendations have been adopted in the United States [2] and the large majority of European countries [3].

In the UK, the vaccine is offered without cost to at-risk groups [4]. Despite these recommendations, Influenza vaccination rates in children with High-Risk Conditions (HRCs) have traditionally been low. In England and Wales in 2003–04, uptake was only 8% overall in children aged 0–19 with HRCs [5]. A more recent study, utilizing data from the UK General Practice Research Database (GPRD) collected during the 2009/10 influenza season, found that uptake for the seasonal influenza vaccine was 26% for children with HRCs aged 6 months to 4 years, and 34.5% for those aged 5–19 years. Older age groups with HRCs had higher rates, from 37.1% in those aged 20–39 to 74.8% in the 65–79 age group [6].

Several studies examining how to improve influenza vaccination rates in susceptible groups have been published, including a systematic review on improving influenza vaccination rates in the elderly [7] and a systematic review on improving influenza vaccination rates through reminder/recall systems in children with one particular HRC (asthma), with data published up to 2009 [8]. However, no systematic review on improving influenza vaccination rates in children with high-risk conditions other than asthma (such as chronic airway disease, chronic kidney disease, heart disease, liver disease and immunosuppression, e.g. from malignancy or medication) has been identified.

The aim of this review was to identify, describe and compare studies that have examined interventions aimed at improving influenza vaccination in children with HRCs.

Section snippets

Method

Two databases (PubMed and SCOPUS) were searched using the following combination of keywords – Influenza AND vaccination OR immunization OR children AND asthma OR malignancy OR high-risk AND reminder (asthma is the commonest chronic condition in children, and malignancy is a common indication for influenza vaccination). There were no time or language restrictions in the search. The search was last conducted on 18/03/2014.

Results

The 18 studies included one systematic review of a specific intervention in asthmatic children [8], 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. Most of the studies (nine) were carried out on children with asthma, four were on children with HRCs, one covered children with onco-haematological malignancies, one was on children with

Discussion

This review does not include a meta-analysis because the heterogeneity caused by the different study methods, study populations and intervention programmes made it impossible to meaningfully combine the data.

Most of the studies were undertaken in the United States, except two studies that were conducted in Italy. There were no reported studies from other parts of the world, including the UK, where the extensive primary care system managed by general practitioners and funded from general

Conclusion/implications for practice

We would suggest that the evidence found in this review supports the following conclusions:

  • There is good evidence that reminder letters can improve influenza immunization uptake in children with HRCs, although it would be helpful to test this in countries other than the United States.

  • There is a lack of evidence that multiple reminder letters are more effective than single letters.

  • There is weak evidence that telephone recall improves uptake and good evidence that a known clinician making the

Acknowledgement

Thanks to the Health Protection Agency/Public Health England for funding the research.Contributors: All authors participated in defining the research question and devising the protocol. NA led on the identification and analysis of papers and all authors contributed to their assessment and interpretation. NA prepared the first draft of the paper and all authors contributed to its revision and preparation of the final document. Conflict of interest statement: All authors have no conflict of

References (41)

  • R.E. Thomas et al.

    Interventions to increase influenza vaccination rates of those 60 years and older in the community

    Cochrane Database Syst Rev

    (2010)
  • S.N. Jones Cooper et al.

    Using reminder/recall systems to improve influenza immunization rates in children with asthma

    J Pediatr Health Care

    (2012)
  • Critical Appraisal Skills Programme. 11 questions to help you make sense of a trial. Available from:...
  • S.H. Halpern et al.

    Appendix: Jadad scale for reporting randomized controlled trials

    Evidence-based obstetric anaesthesia

    (2005)
  • R.K. Zimmerman et al.

    Improving influenza vaccination rates of high-risk inner-city children over 2 intervention years

    Ann Fam Med

    (2006)
  • M.T. Britto et al.

    Improving influenza immunisation for high-risk children and adolescents

    Qual Saf Health Care

    (2007)
  • P.G. Szilagyi et al.

    Improving influenza vaccination rates in children with asthma: a test of a computerized reminder system and an analysis of factors predicting vaccination compliance

    Pediatrics

    (1992)
  • K.J. Kemper et al.

    Do computer-generated reminder letters improve the rate of influenza immunization in an urban pediatric clinic?

    Am J Dis Child

    (1993)
  • M.F. Daley et al.

    Identification and recall of children with chronic medical conditions for influenza vaccination

    Pediatrics

    (2004)
  • M.L. Moore et al.

    Influenza vaccine compliance among pediatric asthma patients: what is the better method of notification?

    Pediatr Asthma Allergy Immunol

    (2006)
  • Cited by (32)

    • Short Message Service Reminders to Parents for Increasing Adolescent Human Papillomavirus Vaccination Rates in a Secondary School Vaccine Program: A Randomized Control Trial

      2019, Journal of Adolescent Health
      Citation Excerpt :

      The benefits of sending a reminder also appear to be restricted to individuals who had missed an earlier dose, as those students who were up-to-date with the vaccine (i.e., completed dose 2 before the third school visit) almost always completed the three-dose schedule even without the intervention. The findings of this randomized control trial are consistent with several published systematic reviews in this field, which have found that overall, interventions using reminder strategies positively impact vaccination rates [34–37] and with studies specifically investigating SMS reminders to increase adolescent HPV vaccination rates [17,18]. However, there are two important differences between these and the present trial.

    • Communication-based interventions for increasing influenza vaccination rates among Aboriginal children: A randomised controlled trial

      2018, Vaccine
      Citation Excerpt :

      This means that children may be at risk from other vaccine-preventable diseases such as influenza. Influenza is a common cause of morbidity and mortality around the world, particularly among vulnerable populations like the elderly and young children [5]. Additionally, “a substantial proportion of the Indigenous population [report] a current medical condition that increases their risk of severe influenza” [6].

    • Effects of Phone and Text Message Reminders on Completion of the Human Papillomavirus Vaccine Series

      2017, Journal of Adolescent Health
      Citation Excerpt :

      Just over half of parents chose a text reminder, and we found that text reminders resulted in an 18% increase in patients achieving full vaccination for HPV. Several studies and systematic reviews have found telephone reminders to be effective for increasing early childhood immunization rates [8,30,31], for influenza vaccine [32], and adult pneumococcal vaccine [33]. Yet our study found a nonsignificant 8% increase in patients being fully vaccinated for HPV vaccine after telephone reminders, perhaps because of sample size limitations.

    • Randomized controlled trial of text message reminders for increasing influenza vaccination

      2017, Annals of Family Medicine
      Citation Excerpt :

      To limit the message length (ie, cost) we did not include educational content in the messages used in the current study. Considering that previous research has shown patient education activities to be associated with improved vaccine uptake, however, it is possible that our intervention would have been more successful had we incorporated some patient education.13,14 For example, patients with no history of influenza vaccination may have responded better if we had provided educational content on vaccination benefits.

    View all citing articles on Scopus
    View full text