Therapy efficacy assessment in patients with rheumatoid arthritis by quality of life measures

Abstract

Objective. To determine minimal clinically significant changes of quality of life (QL) measures in pts with rheumatoid arthritis (RA) and to develop criteria for therapy efficacy assessment by QL measures. Material and methods. 258 pts with RA fulfilled ACR criteria and receiving standard antirheumatic therapy were assessed at baseline and after 6 months of follow up. The mean age was 51,4± 11,6 years, duration of the disease varied from 1 to 18 years (mean 9,0±8,7 years). 58,8% of pts had rheumatoid factor. 39,9% of pts had moderate and 54,3% - high activity of the disease according to DAS 28. 50,4% of pts had III or IV radiological stage, 42,7% of pts had III or IV functional class (FC). All pts filled validated HAQ, EQ-5D and SF-36 questionnaires. Therapy efficacy was assessed by ACR criteria. Minimal clinically significant changes (MCSC) were calculated according to effect value (EV). EV accordance to difference of QL measures before and after treatment was determined. Results. Minimal difference of values which was interpreted by pts as significant was 0,22 for HAQ, and 0,10 for EQ-5D. Therapy efficacy assessment can be done with following HAQ diapasons. Treatment is not effective if HAQ decrease is less than 0,22. Weak improvement corresponds to HAQ decrease from 0,22 to 0,36. 0,36<AHAQ<0,8 shows moderate improvement and AHAQ£0,8 can be interpreted as good effect. Therapy efficacy assessment with EQ-5D can be performed as follows. Therapy is not effective when AEQ- 5D<0,1. 0,1<AEQ-5D<0,24 corresponds to weak, 0,24<AEQ-5D<0,31 — to moderate and AEQ-5D>0,31 to good clinical response. Conclusion. General QL questionnaires EQ-5D and SF-36 are less sensitive than HAQ in assessment of therapy efficacy.