Reliability of the Hand20 questionnaire: comparison with the 36-Item Short-Form Health Survey

Hand20 is an illustrated, self-administered questionnaire comprising 20 short and easy-to-understand questions to assess upper limb disorders. This study aimed to test the reliability, validity, and responsiveness of Hand20.

Eighty-five patients with three upper limb disorders (51 with trigger finger, 29 with ulnar impaction syndrome, and five with carpal tunnel syndrome) completed Hand20, the Japanese Society for Surgery of the Hand version of the Disabilities of the Arm, Shoulder, and Hand questionnaire (DASH-JSSH), and the 36-Item Short-Form Health Survey (SF-36). Reliability was assessed by internal consistency. To test the validity, a factor analysis of Hand20 was performed and the correlation coefficients between Hand20 and DASH-JSSH and those between Hand20 and SF-36 were calculated. Responsiveness was evaluated in 47 patients with trigger finger as the standardized response mean and effect size after treatment.

A Cronbach's α coefficient of 0.967 confirmed the unidimensionality of Hand20. The correlation coefficient between Hand20 and DASH-JSSH was 0.84. The correlations between Hand20 and the SF-36 subscales ranged from -0.236 to -0.596. Moderate correlations were observed for "Role-physical" (r = -0.596) and "Bodily pain" (r = -0.557). The correlation between the Hand20 and "Physical functioning" was weak (r = -0.313). The standardized response mean and effect size of Hand20 was 1.50 and 1.60, respectively.

The Hand20 has evaluation capacities equivalent to those of DASH-JSSH. There was a moderate correlation between Hand20 and SF-36.