There is considerable evidence that things like post cards and phone calls likely help boost influenza vaccine coverage in elderly people, but not much is known about how to improve coverage in most other high-risk groups such as pregnant women, according to a lengthy review released today by the European Centre for Disease Prevention and Control (ECDC).
ECDC officials scoured the medical literature for evidence-based strategies that lift vaccine coverage in target groups, including the elderly, those with chronic illnesses, healthcare workers, pregnant women, and children. Coverage for these groups in most European countries still falls short of a 75% target set by the European Council of Ministers in 2013.
The findings are presented in a 39-page report titled "Review of the Scientific Literature on Drivers and Barriers of Seasonal Influenza Vaccination Coverage in the EU/EEA."
The authors sorted through 4,981 articles and came up with 26 that contained data they deemed worth including in the review.
Personal reminders
For elderly people, the reviewers found "ample, although low quality" evidence that reminder post cards and phone calls are effective in increasing vaccine uptake. Ten randomized controlled trials (RCTs) supported the use of post cards or letters, and 11 RCTs supported "personalized post cards or phone calls."
There is also some evidence that home visits and facilitators in clinics are effective, but reminders to physicians alone are not effective, the reviewers concluded. Also, one "good quality" RCT in Japan showed that personal advocacy by community pharmacists boosted vaccine uptake in the elderly.
In other findings about the elderly, the report says, "Observational studies suggest that individuals who are older than 85 or married, who use medical services more frequently or who suffer from a chronic disease are more likely to get vaccinated." On the negative side, "barriers to vaccination include social disadvantage, smoking, and lack of social support."
For people with chronic conditions, the evidence for interventions was limited. One study indicated that reminder/recall systems increase vaccine uptake in children with asthma, but another report suggested that adding an educational message to the reminder doesn't help.
The reviewers found that barriers to vaccination of those with chronic conditions, as revealed in US studies, include worries about side effects and the belief that the vaccine can cause the disease.
Vaccination of healthcare workers
The authors found "plenty of evidence" about steps to improve vaccine coverage in healthcare workers. In non-hospital settings, multi-pronged campaigns, such as those including education and more access to the vaccine, significantly boosted coverage. In hospitals, such campaigns were commonly used but never raised coverage above 90%, the report says.
Two observational studies from the United States suggest that vaccine mandates work better than voluntary approaches if the aim is to lift coverage above the 95% mark, the reviewers say.
As for pregnant women, the report says, "There was no good quality evidence on interventions in this group." Low-grade evidence suggests that standing orders, role models, HCW education, and electronic reminders might improve coverage. On the downside, even weaker evidence indicates that inconsistent advice from HCWs may be a barrier to vaccine uptake.
The reviewers found no systematic reviews or RCTs on strategies for raising vaccine coverage in children, leaving the evidence "scarce and weak."
They did find two US studies and one UK study on barriers to flu vaccination in kids, which were found to include parents' low perception of the risk of catching flu, concern about vaccine safety and efficacy, and concern about thimerosal in the vaccine. (Flu vaccines sold in multi-dose vials still may contain thimerosal as a preservative, whereas vaccine sold in single-dose formulations does not.)
See also:
Nov 4 ECDC report landing page
