Behavioral Insights for Public Health Engagement: A Four-Arm School-Level Comparative Study on Parental Registration in FAST Heroes

FAST Heroes is a school-based education programme that teaches kindergarten-aged children and their families to recognize stroke symptoms (using the FAST acronym: Face, Arms, Speech, Time) and to call emergency services promptly. A key component of the programme requires parents to complete online registration, but registration rates have historically been low. This study was conducted to identify communication strategies that could improve parental registration.

Eligible schools were those that had implemented the FAST Heroes programme during the prior school year (2023-2024) with zero parental registrations recorded. From the pool of eligible schools, participating schools were allocated at the school level to one of four conditions using a pre-specified, non-random balanced allocation procedure intended to achieve comparability across conditions in pupil numbers and school settlement category (urban versus non-urban, per the 2021 Greek Census classification): (1) a printed letter sent home with pupils; (2) an email sent directly to parents; (3) an email combined with weekly teacher-delivered reminders to parents for five weeks; and (4) an email combined with weekly teacher reminders plus an automated chatbot (delivered via a messaging app chatbot) sending parents reminders over the same five-week period.

The primary outcome was the proportion of parents who completed online registration within eight weeks of the initial prompt in their assigned condition. Because schools (not individual pupils) were the unit of allocation while registration was assessed at the level of individual pupils/families, the primary analysis used mixed-effects logistic regression with a random intercept for school to account for clustering within schools. Exploratory analyses examined whether the effect of condition varied by school settlement category (urban vs. non-urban) and by class size.