Influencing Health Behaviors via Short Message Service

Text messaging, also known as short message services (SMS), is a burgeoning innovation area showing promise in eliciting health behavior changes. This dissertation details two intervention trials that each comparatively tests the efficacy of different text message sets intended to improve behaviors. In light of pervasive road traffic injuries amongst young men in Tanzania, the first intervention tested messaging strategies aimed at increasing helmet wearing amongst commercial motorcycle taxi drivers. Participants (N=391) were randomized to receive either: 1) social norming messages emphasizing society’s positive stance on helmets; 2) fear appeal messages emphasizing the dangers of riding without helmets, or 3) control messages. After 6-weeks, the odds of drivers reporting wearing their helmet “on every trip” was 1.58 times higher in the social norming group than amongst controls, though this difference was not significant after accounting for multiple hypothesis testing. There was little difference between fear appeal recipients and controls. In light of China’s excessive caesarean section rate of up to 54.9%, the second trial tested messaging strategies aimed at reducing unnecessa