Development and Pilot Testing of Text Reminders for Immunization Compliance In Kids (TRICKs)

Theoretical Background and research questions/hypothesis: Cellular phones have penetrated at-risk populations, such as low-income families, at a much higher rate than computers and internet. Text messaging may be an ideal avenue to provide immunization reminders to promote vaccination among children in order to reduce the incidence of vaccine-preventable diseases. The purpose of these studies were to 1) identify whether parents were interested in and capable of receiving Text Reminders for Immunization Compliance in Kids (TRICKs); 2) employ Human Factors assessments to identify ideal content within the 160-character limit; 3) pilot test TRICKs in a randomized controlled trial (RCT); and 4) survey providers regarding implementing such a system.

Methods: Paper surveys were administered to English-speaking parents. Next, face-to-face structured interviews (including User-Centered Design activities) were completed with both English- and Spanish-speaking parents to determine whether parents were interested in receiving TRICKs, to evaluate capability of sending and receiving text messages and to identify preferred content. This information was assembled into a pilot RCT to assess text messaging software, ability to recruit parents and parent feedback post-intervention. We also used a multi-method survey of local providers regarding interest in implementing TRICKs. Two IRBs approved all studies; studies were funded by KUSM-W Dean’s Level I or Kansas Bioscience Authority/Wichita Center for Graduate Medical Education Level II and III grants.

Results: The majority of participants in each study were low income and their children were on Medicaid. Parents were highly likely to own a cell phone with text messaging capability (88%; 167/190) and support receiving text message immunization reminders from their child’s physician (survey 93%, 156/167; interviews 99%, 103/104). Content was preferred that used short, personalized statements and included attention-grabbers and courtesy (i.e. please and thank you). Differences in preferred content were identified between English- and Spanish-speakers. Parents were willing to participate in an RCT on TRICKs; 72% of parents approached agreed to participate (n=90). Immunization rates at 2, 4 and 6 months of age were higher in the group that received TRICKs as was timeliness of immunizations, although none reached statistical significance. Limitations included a 40% loss of cellular phone service at 7-months for intervention group members (19/48). However, follow-up with parents completing the study suggest parents found the text reminders very (83%; 15/18) or somewhat helpful (17%; 3/18). The survey of physicians found of 102 respondents, 86% felt technology makes it easier to care for their patients and 92% had moderate to high comfort with technology. However, only 27% were willing to use text message immunization reminders, 43% were unsure and 31% unwilling.  

Conclusions: Parents appear to want text message immunization reminders; however physicians are hesitant to employ them. Such reminders appear to increase immunization rates and timeliness of immunizations; although a fully powered RCT is needed to reach statistical significance.

Implications for research and/or practice: Current studies include a demonstration project using TRICKs and structured interviews with immunization providers state-wide regarding barriers to implementing technology-based communication systems. Including feedback from patients and physicians during the development process will be key to creating a system that can be successfully implemented.