The Impact of Voicemail Message Content on RDD Cell Phone Response Rates in the National Immunization Surveys
Erik Amonson
NORC at the University of Chicago
Megha Ravanam
NORC at the University of Chicago
Benjamin Skalland
NORC at the University of Chicago, Chicago, IL
Emily Myers
NORC at the University of Chicago
Holly A. Hill
National Center for Immunization and Respiratory Diseases
Laurie D. Elam-Evans
National Center for Immunization and Respiratory Diseases
Chalanda Smith
National Center for Immunization and Respiratory Diseases
S. Cassandra Pingali
National Center for Immunization and Respiratory Diseases
The National Immunization Survey-Child (NIS-Child) is a cell phone random-digit-dial (RDD) survey used to assess vaccination coverage in the United States among children age 19-35 months. Among working telephone numbers in the cell phone RDD sample, the most common NIS-Child call outcome is reaching a potential respondent's voicemail. Under current procedures, the voicemail message is delivered pre-recorded by an automated system rather than left by an interviewer. Beginning in Quarter 1 of 2019, NORC conducted an operational evaluation of the content of the pre-recorded message. In Quarters 1 and 2 of 2019, telephone numbers in the sample were randomly assigned to one of four groups: 1) the standard NIS pre-recorded voicemail message serving as the control, 2) a pre-recorded version using informal language and mentioning criteria for household eligibility, 3) a pre-recorded version using informal language without mentioning eligibility, and 4) a pre-recorded version emphasizing the importance of the study and without mentioning eligibility. Respondent contact and cooperation rates in the NIS-Child were compared across groups for the first dial following the voicemail message.