The Short Form Score for the Assessment and Quantification of Chronic Rheumatic Affections of the Hands in Daily Clinical Routines—Its Sensitivity to Change and Preliminary Patient Relevant Variation Values: A Pilot Study

OBJECTIVE The SF-SACRAH was developed to assess the involvement of the hand in rheumatoid arthritis (RA) and hand osteoarthritis (HOA) patients in daily clinical routines. In this pilot study, its sensitivity to change will be assessed longitudinally, and preliminary thresholds for patient relevant changes are derived. METHODS Ninety-nine outpatients suffering from HOA (n = 55) or RA (n = 44) completed the SF-SACRAH once initially. After approximately 3 months, patients repeated the SF-SACRAH. At both visits, patients rated their satisfaction (PATSAT) with the state of their disease (1 = very good to 5 = unsatisfactory). For assessing its sensitivity to change, SF-SACRAH changes in patients with stable, improving, or worsening conditions according to PATSAT were calculated in HOA and RA patients. The respective medians and highest values were used to estimate patient relevant variation values. SF-SACRAH changes and positive or negative PATSAT changes in HOA as well as RA patients were analyzed by applying the Kruskal-Wallis test. In RA patients, the DAS28 was also calculated. Spearman's rho was calculated to correlate SF-SACRAH changes with the EULAR response criteria. RESULTS In HOA and RA patients, a statistically high correlation between PATSAT changes and SF-SACRAH values was revealed (p < 0.0001 in HOA and p < 0.01 in RA patients, respectively). The median changes in SF-SACRAH in patients with improving, stable, or worsening conditions according to PATSAT were HOA patients: PATSAT improving: ΔSF-SACRAH -1.6, PATSAT stable: ΔSF-SACRAH +0.8, PATSAT worsening: ΔSF-SACRAH +1.0; RA patients: PATSAT improving: ΔSF-SACRAH -0.9, PATSAT stable: ΔSF-SACRAH +0.2, PATSAT worsening: ΔSF-SACRAH +0.8. In RA patients, there is a moderate, but significant, correlation between DAS28 EULAR response criteria and SF-SACRAH changes (ΔDAS28 improving >0.6: ΔSF-SACRAH -0.4, ΔDAS28 <0.6: ΔSF-SACRAH +0.0, ΔDAS28 worsening >0.6: ΔSF-SACRAH +0.5; r = 0.433, p < 0.01). CONCLUSION The SF-SACRAH constitutes a reliable tool for the assessment of hand impairment in patients with chronic rheumatic diseases. It proved to be sensitive to change in this short-term evaluation in both HOA and RA patients. Additionally, preliminary patient variation values for improvement (-1.60) and deterioration (+1.0) could be derived.