Objectives To identify predictors of orthopaedic surgery and its impact on quality of life in a South-East Asian rheumatoid arthritis registry cohort.
Methods Data was collected from patients enrolled in the Tan Tock Seng Hospital Rheumatoid Arthritis Registry. All patients fulfilled the 1987 ACR criteria for RA. The clinical, extraarticular features (EAF), disease activity score (DAS 28), functional status (Health Assessment Questionnaire, HAQ) and health- related quality of life measures (SF-36) were prospectively collected since 2001. Comparison between those with and without orthopaedic surgical procedures (groups I and II respectively) at entry to the registry till 2013 or death was done. Risk factors for surgery at study entry were determined using logistic regression (STATA SE 10), adjusted for age and disease duration.
Results The study comprised of 1049 patients, predominately Chinese (77.9%); 190 patients (18.1%) had surgery (synovectomy 6.4%, arthroplasty 17.5%, arthodesis 1.1%). The mean age of groups I and II were similar (49.2 vs 48.2 years, p=0.35), mean duration from onset of RA to 1st joint surgery was 136.2 months. Group I had significantly longer symptoms before seeking rheumatologists (mean 63.5 vs 32.0 months, p<0.0001), duration from onset of RA to 1st disease modifying drug (74.2 vs 39.3 months, P<0.0001) and disease duration (243.1 vs 151.6 months, p<0.0001). Higher deformed joint count (mean 4.8 vs 1.7, OR 1.13, p<0.001), presence of radiographic erosions (70.4 vs 52.3%, OR 1.46, p<0.05), EAF (36.3 vs 24.1%, OR 1.67, p=0.004), HAQ score >1.5 (15.4 vs 7.5%, OR 3.08, p<0.001 and not DAS 28 or RF positivity were predictive of orthopaedic surgery. Lower scores were seen for the physical functioning domains of the SF36 in the group that had orthopaedic surgery, but there was no significant difference in the mental component between the two groups.
Conclusions Delayed diagnosis and delay in initiation of disease modifying therapy were positive predictors of orthopaedic surgery in our cohort of RA patients, independent of disease activity scores and rheumatoid factor positivity. RA patients in this cohort who required orthopaedic intervention report significantly poorer scores on physical quality of life measures.
Acknowledgements This study is supported by the Centre Grant, National Medical Research Council, Ministry of Health, Singapore. (CG12Aug17)
Disclosure of Interest None declared