ASPO Abstracts
Missed Opportunities for HPV Vaccination among Childhood Cancer Survivors
Category: Survivorship & Health Outcomes/Comparative Effectiveness Research
Conference Year: 2021
Abstract Body:
Purpose: Childhood cancer survivors are at higher risk of human papillomavirus (HPV)-related cancers than
adolescents without cancer, yet their HPV vaccination uptake is lower. We evaluated whether adolescent survivors
of childhood cancer are at higher risk of missed opportunities for HPV vaccination than adolescents without a
cancer history.
Methods: Using electronic health records from two major health care systems, a statewide insurance claims
database, data from an immunization information system, and cancer registry records, we identified vaccination
events for childhood cancer survivors. Eligible survivors were diagnosed 2000-2016 at ages 0-9 (n=337) and were
matched by birth year and sex to a sample without cancer from the general population (n=803). Follow-up was
bounded by the dates claims data were available: 2013-2016. Individuals were aged 9-12 years at start of follow-
up. Missed opportunities were defined as health care encounters where the HPV vaccine was not administered
but another vaccine was received. Mixed effects Poisson regression estimated the rate of missed opportunities per
person-year of follow-up and 95% confidence intervals by vaccine encounter type (adolescent/catch-up or flu shot
only).
Results: Survivors had more HPV vaccine missed opportunities than the population sample: 70.2% vs 62.1% of
vaccine encounters (p<0.001). Survivors were 24% more likely to have missed opportunities at an encounter
where they received other adolescent vaccines (incidence rate ratio [IRR]=1.24, 95% CI: 1.06-1.44) and 19%
more likely to have missed opportunities at flu shot encounters (IRR=1.19, 95% CI: 1.10-1.28). Significantly more
missed opportunities were observed at both adolescent/catch-up and flu shot encounters for survivors who were
female, Non-Hispanic White, Other Race/Ethnicity, resided in urban areas, privately insured, and whose first
vaccine during study follow-up was at age 9-10 years. Among survivors, those treated with chemotherapy had
more missed opportunities than those who did not receive chemotherapy (IRR=1.28, 95% CI: 1.01-1.62).
Conclusions: Childhood cancer survivors are at significantly higher risk of HPV vaccine missed opportunities than
adolescents who have never had cancer at both adolescent/catch-up and flu shot encounter
Keywords: HPV, Immunizations, Childhood Cancer Survivors, Missed Opportunities