Psychometric properties of the Persian version of the stuttering generalization self-measure tool in adults who stutter.

PURPOSE: Our study aimed to translate the Stuttering Generalization Self-Measure (SGSM) into Persian and investigate its validity, reliability, and internal responsiveness in the Iranian population.

METHOD: This study was conducted on 30 adults who stutter (AWS) and 30 adults who do not stutter (AWNS). The International Quality of Life Assessment protocol (IQOLA) was applied to translate SGSM into Persian. The face and content validity were determined. Also, the discriminant validity was evaluated by comparing the scores of two groups. In addition, the internal consistency test-retest, and inter-judge reliability were assessed with Cronbach's alpha and intra-class correlation coefficients (ICC). Moreover, the mean standardized response (MSR) and the standardized effect size were measured to determine the internal responsiveness using pre- and post-treatment data.

RESULTS: All the items were comprehensible and clear. The content validity ratio (CVR) and content validity index (CVI) for all nine questions were obtained higher than.62 and.9, respectively. The internal consistency value was high (Cronbach's alpha =.98). For the test-retest reliability, ICC values were excellent, ranging from.93 to.99. The discriminant validity results revealed a significant difference between AWS and AWNS (p < .001). Pre- and post-treatment results indicated high internal responsiveness to changes for percentage of syllable stuttered (SS%) (MSR = 1.09).

CONCLUSION: The Persian version of SGSM (P-SGSM) benefits from the high values for validity and reliability. Furthermore, it distinguishes the AWS and AWNS and reflects the treatment changes significantly.