The Treatment Self-Regulation Questionnaire (TSRQ) assesses perceived autonomy, treatment-related motivation, and health behavior change. A 15-item questionnaire measures motivation and regulation styles that individuals employ to manage their health-related treatments or behaviors. Scale: 1=Not at all true to 7=Very true. Score 1-7 for each of the following components: TSRQ Autonomous motivation, TSRQ Introjected regulation, TSRQ External regulation, and TSRQ Amotivation. The subscales are averaged to report the mean TSRQ score. Higher numbers indicate higher autonomous motivation, controlled motivation, or amotivation. 6-month change in perceived autonomy among M system users versus E system users.