vaxSMS: A randomised controlled trial of text messaging and calendar reminders for improving immunisation timeliness in areas of low immunisation coverage

We are evaluating the effectiveness of a tablet computer application (app) in encouraging on time immunisation. The app is designed to be used by immunisation service providers (ISP) staff. It provides parents or carers with automatic SMS reminders 2 weeks and 2 days before upcoming immunisation dates and personalised calendars with each child's photograph and routine childhood immunisation dates up until the age of 4 years. Parents of children less than 16 months will be recruited at participating ISPs and randomly allocated to one of 4 groups: 1) SMS reminder messages, 2) calendar, 3) SMS reminder messages and calendar, and 4) no intervention. Timeliness of vaccine receipt, as recorded in the Australian Childhood Immunisation Register (ACIR), will be compared in the four groups. We will be recruiting from a range of immunisation service providers nationwide, including Aboriginal Medical Services and culturally and linguistically diverse group practices. This will have important implications for strategies to improve vaccination uptake, particularly in communities where vaccine coverage is low.