Psychometric properties of the Calgary Cambridge guides to assess communication skills of undergraduate medical students

OBJECTIVES: The aim of this study was to analyse the psychometric properties of the short version of the Calgary Cambridge Guides and to decide whether it can be recommended for use in the assessment of communications skills in young undergraduate medical students. METHODS: Using a translated version of the Guide, 30 members from the Department of General Practice rated 5 videotaped encounters between students and simulated patients twice. Item analysis should detect possible floor and/or ceiling effects. The construct validity was investigated using exploratory factor analysis. Intra-rater reliability was measured in an interval of 3 months, inter-rater reliability was assessed by the intraclass correlation coefficient. RESULTS: The score distribution of the items showed no ceiling or floor effects. Four of the five factors extracted from the factor analysis represented important constructs of doctor-patient communication The ratings for the first and second round of assessing the videos correlated at 0.75 (p < 0.0001). Intraclass correlation coefficients for each item ranged were moderate and ranged from 0.05 to 0.57. CONCLUSIONS: Reasonable score distributions of most items without ceiling or floor effects as well as a good test-retest reliability and construct validity recommend the C-CG as an instrument for assessing communication skills in undergraduate medical students. Some deficiencies in inter-rater reliability are a clear indication that raters need a thorough instruction before using the C-CG.