Validity and Reliability of the Turkish Version of the Weiss Functional Impairment Rating Scale- Self Report Form (WFIRSS- TR)

The aim of this study was to demonstrate the validity and reliability of the WFIRS-S-TR, Turkish version of the Weiss Functional Impairment Rating Scale-Self Report form.

The study comprised two groups of participants of 15-18 years of age, one consisting of 35 children diagnosed with attention deficit and hyperativity disorder (ADHD) based on the DSM-IV criteria and the other, 510 healthy volunteers attending high school. Apart from the WFIRS-S-TR, the Health Questionnaire for Children and Adolescents (KIDSCREEN-10 Index) which is a general quality of life and functionality measurement instrument, was used to check the concurrent validity of the WFIRS-S-TR.

The Cronbach's alpha coefficient for the total scale was 0.939. The test-retest reliability assessed by repeated measurements two weeks apart gave a high correlation between the results (r=0.804, p<0.0001). Total mean score of the WFIRS-S-TR showed significant correlation with the KIDSCREEN-10 Index total mean score (r= -0.467, p<0.0001). Confirmatory factor analysis was carried out for the construct validity of the WFIRS-S-TR. The RMSEA and the CFI values were found to be 0.065 and 0.68, respectively.

The WFIRS-S-TR can be used as a valid and reliable tool both in clinical practice and for research purposes.