Impact of Childhood Vaccine Discussion Format Over Time on Immunization Status

Abstract

Objective: Presumptive formats to initiate childhood vaccine discussions (eg, "Well, we have to do some shots") have been associated with increased vaccine acceptance after one visit compared to participatory formats (eg, "How do you feel about vaccines?"). We characterize discussion format patterns over time and the impact of their repeated use on vaccine acceptance.

Methods: We conducted a longitudinal prospective cohort study of children of vaccine-hesitant parents enrolled in a Seattle-based integrated health system. After the child's 2-, 4-, and 6-month visits, parents reported the format their child's provider used to begin the vaccine discussion (presumptive, participatory, or other). Our outcome was the percentage of days underimmunized of the child at 8 months old for 6 recommended vaccines. We used linear regression and generalized estimating equations to test the association of discussion format and immunization status.

Results: We enrolled 73 parent-child dyads and obtained data from 82%, 73%, and 53% after the 2-, 4-, and 6-month visits, respectively. Overall, 65% of parents received presumptive formats at ≥1 visit and 42% received participatory formats at ≥1 visit. Parental receipt of presumptive formats at 1 and ≥2 visits (vs no receipt) was associated with significantly less underimmunization of the child, while receipt of participatory formats at ≥2 visits was associated with significantly more underimmunization. Visit-specific use of participatory (vs presumptive) formats was associated with a child being 10.1% (95% confidence interval, 0.3, 19.8; P = .04) more days underimmunized (amounting to, on average, 98 more days underimmunized for all 6 vaccines combined).

Conclusions: Presumptive (vs participatory) discussion formats are associated with increased immunization.

Keywords: health communication; immunization; preventive health services.

Figure 1. Study Population

*Of these 152 total data points from the 2, 4 and 6 month visits, there were 19 instances (12%) in which no initiation format data was obtained because the parent reported that no shots were discussed (and therefore the initiation format questions were skipped). Of the remaining 133 data points, there were 2 instances (1%) in which the parent couldn’t remember the initiation format used or responded that shots were not needed (responses 4 and 5 in Appendix A). Therefore, 131 data points were included in analysis.

Figure 2

Discussion Format Over Time (N=131)

Figure 3

Immunization Status by Discussion Format