The development of a coding system to code planning talk within motivational interviewing.

OBJECTIVE: Understanding mechanisms of motivational interviewing (MI) could improve practice. Planning is important for behavior change, and a component of MI. We aimed to develop a scale to measure planning talk within MI and explore the potential association between planning and weight loss maintenance (WLM).

METHODS: A literature review and thematic analysis was used to develop the coding system. Reliability was tested using MI examples and a transcript. It was applied to 50 sessions and associations between planning and WLM were analyzed using logistic and linear regression.

RESULTS: The coding system included: past, continuing, future and hypothetical plans and goal setting, varying on specificity and commitment. The percentage agreement was 86% and 75% for examples and transcript reliability respectively. Frequent planners, potentially decrease their weight 2.8kg(-9.7, 0.6) and BMI 1.2kg/m2 (-3.1, 0.4) more compared to less frequent planners. Frequent goal setters increase their BMI(3.6kg/m2 , 1.5, 5.7) and weight (9.5kg, 3.4, 15.6) compared to non-goal setters.

CONCLUSION: It is feasible to measure planning, with acceptable agreement. Limited conclusions for the potential associations were demonstrated.

PRACTICE IMPLICATIONS: This is the first scale to measure planning, an important aspect of MI which has received less attention.