RESUMEN
The National Immunization Surveys (NIS) include dual frame random-digit-dial telephone surveys used to monitor vaccination coverage in the United States among children age 19-35 months (NIS-Child) and adolescents age 13-17 years (NIS-Teen), and to assess influenza vaccination for children age 6 months-17 years (NIS-Flu). The surveys collect household-reported demographic and access-to-care data during telephone interviews with the survey-eligible child's parent or guardian. The parent or guardian is then asked for consent to contact the child's vaccination provider(s) to obtain a provider-reported immunization history using a mailed questionnaire. The success of the NIS relies heavily on getting a respondent to answer the telephone, and the caller ID display is the earliest opportunity to convey information to a respondent about the identity of the caller. An evaluation was conducted in Quarter 4 of 2017 to determine the impact on contact rates of using an alternate caller ID display. The caller ID for the NIS surveys was previously set to display "NORC UCHICAGO", identifying the contractor administering the surveys, with a Chicago-based telephone number. It was hypothesized that having the caller ID display the name of the more recognizable survey sponsor instead of the contractor would increase contact rates. Half of the sample was randomly flagged to display the "NORC UCHICAGO" caller ID text as a control, and the other half was flagged to display "CDC NATL IMMUN" as a treatment. This paper presents the study design, results, conclusions, limitations, and recommendations for future research.
RESUMEN
Adaptive design principles are applied to the National Immunization Survey-Teen (NIS-Teen), sponsored by Centers for Disease Control and Prevention, which monitors vaccination coverage of U.S. adolescents age 13-17 years. Data collection is ongoing in two phases: (1) a random-digit-dial telephone survey to interview parents/guardians with age-eligible adolescents, followed by (2) a mail survey to vaccination providers, called the provider record check (PRC), to obtain vaccination histories for the adolescents. A logistic regression model relating the probability that an Immunization History Questionnaire (IHQ) is returned for a teen-provider pair to characteristics of the adolescent, mother, household, and providers was fit. R-indicators and partial R-indicators for the PRC phase of the 2015 NIS-Teen are presented to evaluate the representativeness of response in the PRC. The indicators are visualized using interactive graphics embodied in an R Shiny application to track the real time changes. Programmatic interventions to improve representativeness are discussed, which include strategies for prompting providers and special treatment of certain subgroups.
RESUMEN
BACKGROUND: Vaccination requirements for kindergarten entry vary by state, but all states require 2 doses of measles containing vaccine (MCV) at kindergarten entry. OBJECTIVE: To assess (i) national MCV vaccination coverage for children who had attended kindergarten; (ii) the extent to which undervaccination after kindergarten entry is attributable to parents' requests for an exemption; (iii) the extent to which undervaccinated children had missed opportunities to be administered missing vaccine doses among children whose parent did not request an exemption; and (iv) the vaccination coverage gap between the "highest achievable" MCV coverage and actual MCV coverage among children who had attended kindergarten. METHODS: A national survey of 1465 parents of 5-7year-old children was conducted during October 2013 through March 2014. Vaccination coverage estimates are based provider-reported vaccination histories. Children have a "missed opportunity" for MCV if they were not up-to-date and if there were dates on which other vaccines were administered but not MCV. The "highest achievable" MCV vaccination coverage rate is 100% minus the sum of the percentages of (i) undervaccinated children with parents who requested an exemption; and (ii) undervaccinated children with parents who did not request an exemption and whose vaccination statuses were assessed during a kindergarten grace period or period when they were provisionally enrolled in kindergarten. RESULTS: Among all children undervaccinated for MCV, 2.7% were attributable to having a parent who requested an exemption. Among children who were undervaccinated for MCV and whose parent did not request an exemption, 41.6% had a missed opportunity for MCV. The highest achievable MCV coverage was 98.6%, actual MCV coverage was 90.9%, and the kindergarten vaccination gap was 7.7%. CONCLUSION: Vaccination coverage may be increased by schools fully implementing state kindergarten vaccination laws, and by providers assessing children's vaccination status at every clinic visit, and administering missed vaccine doses.