A Population-Based Cohort Study of Undervaccination in 8 Managed Care Organizations Across the United States

JAMA pediatrics 01/2013; 167(3):1-8. DOI: 10.1001/jamapediatrics.2013.502
Source: PubMed


OBJECTIVES To examine patterns and trends of undervaccination in children aged 2 to 24 months and to compare health care utilization rates between undervaccinated and age-appropriately vaccinated children. DESIGN Retrospective matched cohort study. SETTING Eight managed care organizations of the Vaccine Safety Datalink. PARTICIPANTS Children born between 2004 and 2008. MAIN EXPOSURE Immunization records were used to calculate the average number of days undervaccinated. Two matched cohorts were created: 1 with children who were undervaccinated for any reason and 1 with children who were undervaccinated because of parental choice. For both cohorts, undervaccinated children were matched to age-appropriately vaccinated children by birth date, managed care organization, and sex. MAIN OUTCOME MEASURES Rates of undervaccination, specific patterns of undervaccination, and health care utilization rates. RESULTS Of 323 247 children born between 2004 and 2008, 48.7% were undervaccinated for at least 1 day before age 24 months. The prevalence of undervaccination and specific patterns of undervaccination increased over time (P < .001). In a matched cohort analysis, undervaccinated children had lower outpatient visit rates compared with children who were age-appropriately vaccinated (incidence rate ratio [IRR], 0.89; 95% CI, 0.89- 0.90). In contrast, undervaccinated children had increased inpatient admission rates compared with age-appropriately vaccinated children (IRR, 1.21; 95% CI, 1.18-1.23). In a second matched cohort analysis, children who were undervaccinated because of parental choice had lower rates of outpatient visits (IRR, 0.94; 95% CI, 0.93-0.95) and emergency department encounters (IRR, 0.91; 95% CI, 0.88-0.94) than age-appropriately vaccinated children. CONCLUSIONS Undervaccination appears to be an increasing trend. Undervaccinated children appear to have different health care utilization patterns compared with age-appropriately vaccinated children.

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    • "Parents in the United States, Australia, and the United Kingdom (among other countries) are increasingly refusing routine childhood vaccines (Omer et al. 2009; Omer et al. 2012; Nicholson and Ramet 2013; Konner 2011; Glanz et al. 2013). Many of these 'vaccine refusers' invoke ideas about sanctity. "
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    ABSTRACT: Vaccine refusers often seem motivated by disgust, and they invoke ideas of purity, contamination and sanctity. Unfortunately, the emotion of disgust and its companion ideas are not directly responsive to the probabilistic and statistical evidence of research science. It follows that increased efforts to promulgate the results of vaccine science are not likely to contribute to increased rates of vaccination among persons who refuse vaccines because of (what has been called) the ‘ethics of sanctity’. Furthermore, the fact that disgust-based vaccine refusal is not monolithic – vaccine refusers manifest disgust at different objects and invoke different ideas about purity and contamination – further complicates public health efforts to increase vaccination rates.
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    • "An obvious way around this problem is to include unvaccinated children in the study population. However, unvaccinated persons may differ in important ways from vaccinated persons in terms of factors including socioeconomic status, parental education, likelihood that a parent will bring a child in for evaluation of events or illnesses, and other sociodemographic factors [18] [20]. Controlling for confounding in studies including unvaccinated persons may be more difficult then when samples are restricted to vaccinated persons. "
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    Vaccine 03/2013; 31(17). DOI:10.1016/j.vaccine.2013.02.054 · 3.62 Impact Factor
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    Academic pediatrics 09/2013; 13(5):475-80. DOI:10.1016/j.acap.2013.03.011 · 2.01 Impact Factor
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