Test- retest reliability was studied in 47 subjects during the time interval of 3 weeks
The Kappa forfrequency scoring ranged from 0.95 to 1.0
while Kappa for severity scores ranged from 0.57 to 1.0.
Reliability coefficient of item scores ranged from 0.91 to 1.0.
The Cronbach alpha of the scale (internal consistency among items of questions) was 0.65.
The standard item alpha, in which all items variances were standardized, was 0.67.