A health professional motivational interviewing intervention is an acceptable and feasible weight gain prevention treatment for mid-age women: process evaluation results from the 40-Something RCT. (#159)
The parallel group 40-Something RCT (ACTRN12611000064909) aimed to determine whether a 12-month health professional-led intervention, based on motivational interviewing principles, would affect diet and physical activity behaviour change for obesity prevention, in non-obese (BMI=18.5-29.9kg/m2) 44-50 year old premenopausal women. Fifty-four women were randomly allocated to either a motivational interviewing intervention group (MI) (n=28) (4 Dietitian consultations and 1 Exercise Physiologist consultation) or a self-directed intervention (SDI) group (n=26) (written, tailored information), with 40 completing a satisfaction and process evaluation questionnaire (adapted from an existing instrument) at 12 months. Participants were asked to complete rating scales for intervention components and open-ended questions on the program strengths and weaknesses, with suggestions for improvement. Almost all women (n=39) felt motivated to control their weight in the future due to study participation. Ninety-five per cent of MI women (n=21/22) were satisfied with the program compared to 50% (n=9/18) of SDI women. Sixty-eight per cent of MI women agreed or strongly agreed that their weight was successfully controlled due to participation (n=15/22) and that the study had provided them with enough support (91%, n=20/22), in comparison to 16% (n=3/18) and 28% (n=5/18) of SDI women respectively. Of those who received the MI intervention, 82% felt that four sessions with the Dietitian was sufficient, while 73% felt that one session with the Exercise Physiologist was not sufficient. Despite evidence highlighting the importance of self-monitoring in weight management, only half of the women agreed or strongly agreed that they regularly recorded their weight (MI=55%, SDI=39%) and intended to record their weight in the future (MI=68%, SDI=56%). The findings demonstrate the acceptability and feasibility of the 40-Something MI intervention for weight gain prevention. However, more attention should be placed on methods to enhance self-monitoring and support for physical activity in future versions of the intervention.