Shared decision making: the reliability of the OPTION scale in Italy.

Objective: To provide psychometric characteristics of the Italian language version of the OPTION scale and descriptive statistics on patients’involvement. The OPTION scale assesses the extent to which clinicians involve patients in therapeutic decisions. The English languageversion has a Cohen’s k score for individual items ranging from 0.45 to 0.98 and an intraclass correlation coefficient (ICC) for the total score of0.77.Methods: Six male GPs provided 235 audiotaped consultations with consecutive patients who had attended for a new illness episode over a 2-month period. Thirty interviews were rated by two raters to assess inter- and intra rater as well as test–retest reliability of the Italian languageversion of the OPTION scale. Based on the whole sample, Cronbach’s a and an exploratory factor analysis were performed to assess internalvalidity and to determine factor loadings.Results: Cohen’s k values were comprised between 0.29 and 0.73, the ICC at test and retest was 0.85 and 0.81 and Cronbach’s a 0.82. Theratings for each OPTION item showed a skewed distribution: the majority of scores (>70%) were between 0 (behaviour absent) and 2(minimum skill level).Conclusion: The reliability indices were satisfactory and similar to those reported for the original OPTION.Practice implications: OPTION can be used for both teaching purposes and research, as well as for future cross-national comparisons.