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 2.8 kg(−9.7, 0.6) and BMI 1.2 kg/m²(−3.1, 0.4) more compared to less frequent planners. Frequent goal setters increase their BMI(3.6 kg/m², 1.5, 5.7) and weight (9.5 kg, 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.