Objectives: To assess the frequency and characteristics of missed opportunities for influenza immunization in children with chronic medical conditions and, among unimmunized children in that group, to explore parent-reported reasons for not vaccinating their child.
Design: Prospective cohort study. Data were obtained from billing and immunization registry databases and telephone interviews of parents.
Setting: Four pediatric practices in metropolitan Denver, Colo, during the 2002-2003 influenza season.
Participants: Children aged 6 to 72 months with 1 or more chronic medical conditions. Main Outcome Measure A missed opportunity for influenza immunization, defined as having a billed encounter, being eligible for immunization, and not receiving vaccine. Subjects with asthma were analyzed separately from those with other conditions.
Results: We identified 926 children with chronic conditions: 820 (89%) with asthma only and 106 (11%) with other conditions. Missed opportunities occurred at 78% of all vaccine-eligible visits for children with asthma and 74% of all visits for children with other conditions. For children with asthma, 92% of vaccine-eligible visits in December and January resulted in a missed opportunity vs 69% in October and November; for children with other conditions, corresponding frequencies were 86% vs 68%, respectively. For children with asthma, 86% of non-well-child visits resulted in a missed opportunity, compared with 62% of well-child visits; similar frequencies were seen among children with other chronic conditions. Parents of unimmunized children reported lack of a physician recommendation and low perceived susceptibility to influenza as the primary reasons for not immunizing their child.
Conclusion: Missed opportunities contribute significantly to low influenza immunization rates among children with chronic medical conditions.