Cross-cultural adaptation, reliability, internal consistency and validation of the Hand Function Sort (HFS©) for French speaking patients with upper limb complaints.

INTRODUCTION: Functional evaluation of upper limb is not only based on clinical findings but requires self-administered questionnaires to address patients' perspective. The Hand Function Sort (HFS©) was only validated in English. The aim of this study was the French cross cultural adaptation and validation of the HFS© (HFS-F).
METHODS: 150 patients with various upper limbs impairments were recruited in a rehabilitation center. Translation and cross-cultural adaptation were made according to international guidelines. Construct validity was estimated through correlations with Disabilities Arm Shoulder and Hand (DASH) questionnaire, SF-36 mental component summary (MCS),SF-36 physical component summary (PCS) and pain intensity. Internal consistency was assessed by Cronbach's α and test-retest reliability by intraclass correlation.
RESULTS: Cronbach's α was 0.98, test-retest reliability was excellent at 0.921 (95 % CI 0.871-0.971) same as original HFS©. Correlations with DASH were-0.779 (95 % CI -0.847 to -0.685); with SF 36 PCS 0.452 (95 % CI 0.276-0.599); with pain -0.247 (95 % CI -0.429 to -0.041); with SF 36 MCS 0.242 (95 % CI 0.042-0.422). There were no floor or ceiling effects.
CONCLUSIONS: The HFS-F has the same good psychometric properties as the original HFS© (internal consistency, test retest reliability, convergent validity with DASH, divergent validity with SF-36 MCS, and no floor or ceiling effects). The convergent validity with SF-36 PCS was poor; we found no correlation with pain. The HFS-F could be used with confidence in a population of working patients. Other studies are necessary to study its psychometric properties in other populations.