848 Use of health action process approach & propensity score to evaluate a social marketing campaign

BackgroundBicycle injuries represent an important proportion of injuries among Canadian children. Since helmet use was mandated in 1996 in BC, Canada, use has increased and head injuries have decreased. Despite the law, many child cyclists don’t wear a helmet. This study determines additional factors that may influence child helmet use by studying caregiver attitudes and behaviours. We study whether intention to wear a bicycle helmet is moderated by planning skills of the individual, and whether individuals exposed to a social marketing campaign have higher scores in risk awareness, intention and behaviour as compared to propensity score (PS) matches without exposure to the campaign.MethodsWe use the Health Action Process Approach to identify single traits that lead to helmet use. PS is applied to address the lack of a control group: the social marketing campaign is a population-wide campaign. PS allows a matched group to be drawn, enabling comparative analysis of the impact of the social marketing campaign on bicycle helmet use. A survey collects detailed bicycle helmet use information from 25–55 yr olds (n = 300) in BC, as part of the continual monitoring and evaluation of a social marketing campaign. Data is examined using multiple regression to identify factors and moderating effects that influence bicycle helmet use. PS is calculated using socio-economic data and injury history over the past 12-months. PS is used to match pairs of individuals with equal PS but different levels of campaign exposure: exposed vs. not exposed. The matched groups are analysed using tests for independent groups.ResultsData will be collected by Dec 2015. Data cleaning and analysis will be completed by Mar 2016, and final results will be presented at Safety 2016.ConclusionsAn important step to increasing bicycle helmet use is to determine additional factors, beyond laws, that may influence helmet use, such that social marketing campaigns can deliver targeted messages.