Increasing childhood influenza vaccination: a cluster randomized trial

Abstract

Background: Since the 2008 inception of universal childhood influenza vaccination, national rates have risen more dramatically among younger children than older children and reported rates across racial/ethnic groups are inconsistent. Interventions may be needed to address age and racial disparities to achieve the recommended childhood influenza vaccination target of 70%.

Purpose: To evaluate an intervention to increase childhood influenza vaccination across age and racial groups.

Methods: In 2011-2012, a total of 20 primary care practices treating children were randomly assigned to the intervention and control arms of a cluster randomized controlled trial to increase childhood influenza vaccination uptake using a toolkit and other strategies including early delivery of donated vaccine, in-service staff meetings, and publicity.

Results: The average vaccination differences from pre-intervention to the intervention year were significantly larger in the intervention arm (n=10 practices) than the control arm (n=10 practices); for children aged 9-18 years (11.1 pct pts intervention vs 4.3 pct pts control, p<0.05); for non-white children (16.7 pct pts intervention vs 4.6 pct pts control, p<0.001); and overall (9.9 pct pts intervention vs 4.2 pct pts control, p<0.01). In multi-level modeling that accounted for person- and practice-level variables and the interactions among age, race, and intervention, the likelihood of vaccination increased with younger age group (6-23 months); white race; commercial insurance; the practice's pre-intervention vaccination rate; and being in the intervention arm. Estimates of the interaction terms indicated that the intervention increased the likelihood of vaccination for non-white children in all age groups and white children aged 9-18 years.

Conclusions: A multi-strategy intervention that includes a practice improvement toolkit can significantly improve influenza vaccination uptake across age and racial groups without targeting specific groups, especially in practices with large percentages of minority children.