Development of a Modified Hand Mobility in Scleroderma (HAMIS) Test and its Potential as an Outcome Measure in Systemic Sclerosis

Objective. To modify the hand mobility in scleroderma (HAMIS) test by reducing the number of items and amount of equipment needed, and to evaluate the construct validity of this modified HAMIS (mHAMIS). Methods. Our retrospective study is based on 266 patients previously examined using the original HAMIS test. Data were divided into 3 groups depending on disease duration after onset: (1) 0–3 years, (2) 3.1–5 years, and (3) 5.1–9 years. Disease variables included were skin involvement using the disease subset and the modified Rodnan skin score (mRSS), and digital lesions. Cronbach’s alpha coefficient was calculated separately for limited (lcSSc) and diffuse systemic sclerosis (dcSSc) for the right and left hand, and for the groups with different disease duration. The construct validity of the mHAMIS was assessed by searching for a correlation with hand skin score. Results. An mHAMIS test consisting of finger flexion, finger extension, finger abduction, and dorsal extension was developed. The internal consistency of this test was 0.78, 0.83, and 0.73 in the 3 groups with different disease duration. In the whole study group, mHAMIS showed a significant correlation with mRSS and hand skin score (rs = 0.39 and 0.43, respectively), and was able to discriminate between lcSSc and dcSSc (p = 0.001), and between patients with and without ulcers (p = 0.015). Conclusion. The mHAMIS involves 4 easily measurable items and has the potential to be a relevant clinical measure of outcome in the evaluation of fibrotic skin involvement in SSc.