Development and evaluation of an instrument for assessing brief behavioral change interventions

To develop an observational coding instrument for evaluating the fidelity and quality of brief behavioral change interventions based on the behavioral theories of the 5 A's, Stages of Change and Motivational Interviewing.

Content and face validity were assessed prior to an intervention where psychometric properties were evaluated with a prospective cohort of 116 medical students. Properties assessed included the inter-rater reliability of the instrument, internal consistency of the full scale and sub-scales and descriptive statistics of the instrument. Construct validity was assessed based on student's scores.

Inter-rater reliability for the instrument was 0.82 (intraclass correlation). Internal consistency for the full scale was 0.70 (KR20). Internal consistencies for the sub-scales were as follows: MI intervention component (KR20=.7); stage-appropriate MI-based intervention (KR20=.55); MI spirit (KR20=.5); appropriate assessment (KR20=.45) and appropriate assisting (KR20=.56).

The instrument demonstrated good inter-rater reliability and moderate overall internal consistency when used to assess performing brief behavioral change interventions by medical students.

This practical instrument can be used with minimal training and demonstrates promising psychometric properties when evaluated with medical students counseling standardized patients. Further testing is required to evaluate its usefulness in clinical settings.