Does environmental message framing impact proportional reach and sample representativeness related to motivational characteristics?

Physical activity (PA) promotion messages are commonly used to engage target populations in PA programs. However, little is known about how recruitment messages impact program reach. Evidence suggests that framing messages to be congruent with individuals' motivational orientation can maximize effectiveness. This congruency effect has not been tested in the context of brief PA promotion messages used in a recruitment environment. It is plausible that framed messages attract certain individuals, while deterring others. The purpose of this study was to determine whether message framing influences representativeness of a sample recruited for a PA program with regards to motivational factors. Three messaging conditions (gain-framed, neutral, loss-framed) were counterbalanced across days of data collection in a primary care waiting room. Patients were asked to complete a questionnaire including surveys on personality and PA, and basic demographic questions. Respondents were offered the chance to participate in a low-burden PA program. Interested respondents were instructed to provide contact information. The proportion and representativeness, with respect to motivational orientation, of individuals volunteering for program participation was assessed using chi-squared tests, and two-way (condition × group) ANOVAs, respectively. After controlling for demographic and behavioral covariates, there was no effect of message framing on the motivational orientation of the resultant samples. Results did not support a congruency effect of a covert message-framing manipulation. More work should aim to understand how recruitment materials and strategies influence motivational characteristics of the resulting sample to maximize intervention outcomes, and target individuals who are more likely to engage in risky health behaviors.