Reliability and validity of the Turkish version of the test of childhood stuttering (TOCS)

This study aimed to evaluate the reliability and validity of the Turkish version of the Test of Childhood Stuttering (TOCS).

The TOCS was translated into Turkish, then back into English by a linguist, and reviewed by an evaluation committee. The translated version was administered to 50 children who stutter (CWS) and 50 who do not (CWNS). After 7-10 days, 12 randomly selected children were re-evaluated. Reliability was assessed using Cronbach's alpha, test-retest methods, and inter-rater reliability. Content validity was confirmed through a pilot study and expert feedback. Construct validity was examined by analyzing test performance, comparing scores between CWS and CWNS, correlating modality test scores, and performing factor analysis. Criterion validity was assessed by correlating TOCS-TR scores with the Stuttering Severity Instrument-4 Turkish Version (SSI-4-TR).

Internal consistency was high, with Cronbach's alpha at .89. The test-retest correlation coefficient for Speech Fluency Measure subtest were .95, the Speech Fluency Rating Scale subtest was .91, and the Disfluency-Related Consequences Rating Scale Index was .91. Inter-rater reliability showed excellent agreement. Content validity was culturally appropriate. Construct validity indicated an 82% positive predictive value, 100% sensitivity, and 78% specificity for the Speech Fluency Rating Scale and Disfluency-Related Consequences Rating Scale. Criterion validity showed 80% agreement with SSI-4-TR.

The TOCS-TR demonstrated strong reliability and validity, making it a valuable tool for assessing stuttering severity in children and distinguishing between CWS and CWNS.