An Evaluation of the Impact of Using an Alternate Caller ID Display in the National Immunization Survey.

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.