Validity and reliability of the duruoz hand index in patients with lateral epicondylitis

Objective and Aim: Standardized functional assessment scales should be used to objectively measure the effect on ADL's in chronic degenerative diseases such as lateral epicondylitis. The Duruoz Hand Index is one of the scales used in the literature for the functional evaluation of patients with lateral epicondylitis but; a study on the validity and reliability of the Duruoz Hand Index in patients with lateral epicondylitis has not been found. The aim of this study was to investigate the validity and reliability of Duruoz Hand Index in patients with lateral epicondylitis. Material and Method: Our study included 78 patients in the age range of 18-65 with lateral epicondylitis who had been admitted to the Ankara City Hospital Physical Medicine and Rehabilitation outpatient clinic for at least three weeks with pain in the forearm. Patients were evaluated by HAQ, PRTEEQ, DASH, Duruoz Hand Index scales at 0,1,4th weeks, measured grip strength by digital hydraulic hand dynamometer and they were questioned about the pain of rest, nights and activity by VAS. Duruoz Hand Index reliability (ICC, Cronbach's alfa), validity (face, content, criteria and construct) and factor analysis (exploratory and confirmatory) were performed with 70 and 49 patients who came to the control first and forth weeks. ES, SRM and MDC values were calculated. Results: Our study involved 78 patients with lateral epicondylitis with an mean age of 46,3±9,4 whom were 84.6% right-handed, 64,1% women. ICC coefficients were perfect with the test-retest method of the Duruoz hand index (ICC coefficients; total=0,943; kitchen=0,950; wear=0,888; clean=0,837; office=0,942; other=0,937). The internal consistency method with cronbach's Alpha coefficient was well-perfectly consistent (Cronbach's alfa; total=0,90; kitchen=0,94; wear= 0,75; clean= 0,70; office= 0,88; other= 0,85). Structure validity of Duruoz Hand Index; very strong with DASH (r=0,801; p<0,01), strong with the PRTEEQ and HAQ total score (r=0,793; p<0,01; r=0,744; p<0,01; r=0,784; p<0,01; r=0,785; p<0,01) and reasonably with the PRTEEQ pain score (r=0,570; p<0,01) were correlated. The Duruoz Hand Index was reasonably correlated with VAS rest pain, activity pain and night pain, and grip strength measured by the digital hydraulic hand dynamometer (r=0, 290; p<0,05; r=0, 473; p<0,01; r=0,374; p<0,01; r=0,224; p<0,05). Three main factors were obtained in our study and these factors ix were associated by us with strength-requiring activities of the hand and forearm, flexibility-grip strength of the hand, and fine skill-requiring activities of the hand. (KMO value= 0,880; Bartlett's test p<0,01). Our study found that the sensitivity of MDC and responsiveness was moderate (MDC=4,4; SEM= 1,61; ES=0,246 p<0,001; SRM=0,538 p<0,001). Conclusions: The Duruoz Hand Index is a reliable, valid and practical functional assessment scale in patients with lateral epicondylitis.