Evaluation of a $10 vs. $20 Incentive Promise on the National Immunization Survey-Child (NIS-Child)
Erik Amonson
NORC at the University of Chicago
Amie E. Conley
NORC at the University of Chicago
Laurie D. Elam-Evans
National Center for Immunization and Respiratory Diseases
Qiao Ma
NORC at the University of Chicago
Chalanda Smith
National Center for Immunization and Respiratory Diseases
The National Immunization Survey-Child (NIS-Child) is a random-digit-dial (RDD) telephone survey used to monitor vaccination coverage among children age 19-35 months in the United States. The protocol includes a household telephone survey of parents/guardians followed by a mail survey to the child's vaccination providers. Each year, over 60,000 household interviews are completed and over 60,000 questionnaires are mailed to vaccination providers. In 2018, the NIS transitioned from a dual-frame landline and cell phone sample design to a single-frame cell phone sample design. As response rates continue to be lower for cell phones than for landlines, it is important to identify methods for increasing response rates for the NIS. The NIS-Child incentive protocol for cell phones previously consisted of an $11 promise upon re-contact, for potential respondents with incomplete interviews after reporting at least one possibly-eligible child in the household. In Quarters 3 and 4 of 2018, NORC conducted an experiment to assess the impact of a $20 incentive promise compared to $10.