THU0133 DIAGNOSES AND COMORBIDITIES IN PRE-RHEUMATOID ARTHRITIS: COMPARISON BETWEEN SEROPOSITIVE AND SERONEGATIVE PATIENTS AND MATCHED NON-RA SUBJECTS
Authors: J. M. Davis III, E. Myasoedova, T. Gunderson, C. S. Crowson
Journal: Annals of the Rheumatic Diseases (2020)

Background: Previous studies have suggested that comorbidities accumulate before the clinical diagnosis of RA, i.e., ‘pre-RA’ (1). Understanding patterns of diagnoses and comorbidities during the pre-RA period may provide new insights into pathogenesis. Objectives: To elucidate diagnoses and comorbidities before the onset of clinically apparent RA compared to non-RA subjects, and for seropositive (RF and/or CCP positive) compared to seronegative (RF and CCP negative) patients with RA. Methods: Adult residents of Olmsted County, Minnesota, with incident RA in 1999-2013 fulfilling the 1987 ACR classification criteria were identified by medical record review. Patients were age- and sex-matched 1:1 to non-RA controls from the same underlying population. The index date for each control corresponded to the incidence date of the matched RA patient. ICD9/10 diagnosis codes (≥2 codes ≥30 days apart prior to index date) were categorized using 161 chronic conditions identified by Clinical Classification Software. Logistic regression models adjusted for age and sex were used to estimate odds ratios (OR) and 95% confidence intervals (CI). Results: The study included 597 RA patients (388 seropositive, 209 seronegative) and 594 controls. The median (range) age was 55 (19-91) years and 70% were female. The median (IQR) of total comorbidities at index was higher among RA patients at 3 (1-6) than controls at 2 (1-5) (p&lt;.001). The median (IQR) of total comorbidities at index was higher in seronegative RA at 4 (2-7) compared to seropositive RA at 3 (1-5) (p=.001); the proportion with six or more was 37% vs. 24% respectively (p&lt;.001). The Table shows the ORs (95% CI) for comorbidities with statistically significant associations with RA overall. The magnitude of the association between total comorbidities and RA peaked at 5+ comorbidities (OR 1.84; 95% CI 1.4-2.43). Spondylosis, intervertebral disc disorders, and back problems (OR 2.38; 95% CI 1.31-4.34); polymyalgia (OR 3.84; 95% CI 1.71-9.16); and systemic lupus erythematosus or other connective tissue disorders (OR 5.3; 95% CI 1.78-19.4) were more prevalent than among seronegative than seropositive patients. Table. Statistically significant associations between comorbidity categories and RA, adjusting for age and sex. Comorbidity Category Description Non-RA N (%) RA N (%) Odds Ratio (95% CI) Polymyalgia 1 (0.2%) 30 (5%) 35.8 (7.51-643) Systemic lupus erythematosus and connective tissue disorders 0 (0%) 15 (2.5%) 31.7 (4.25-4051) Other respiratory disease 1 (0.2%) 6 (1.0%) 6.17 (1.03-118) Hypertension with complications and secondary hypertension 2 (0.3%) 9 (1.5%) 4.57 (1.16-30.2) Anemia (including pregnancy) 3 (0.5%) 11 (1.8%) 3.7 (1.15-16.4) Other circulatory disease 4 (0.7%) 12 (2.0%) 3.03 (1.05-10.9) Osteoarthritis 67 (11.3%) 138 (23.1%) 2.6 (1.87-3.67) Other connective tissue disease 17 (2.9%) 35 (5.9%) 2.19 (1.21-4.12) Fibromyalgia 16 (2.7%) 34 (5.7%) 2.19 (1.21-4.11) Other nervous system disorders 43 (7.2%) 82 (13.7%) 2.04 (1.39-3.04) Other upper respiratory disease 23 (3.9%) 41 (6.9%) 1.83 (1.09-3.14) Asthma 37 (6.2%) 63 (10.6%) 1.78 (1.17-2.74) Coronary atherosclerosis and other heart disease 44 (7.4%) 63 (10.6%) 1.56 (1.01-2.43) Thyroid disorders 78 (13.1%) 107 (17.9%) 1.46 (1.06-2.02) Conclusion: The findings provide new insights about diagnoses and comorbidities preceding clinically apparent RA. Future studies of retrospective medical records for patients with particular comorbidities may provide new insights into the pathogenesis and clinical features of the transition from pre-RA to clinically overt RA, especially for seronegative disease. References: [1]Kronzer VL, Crowson CS, Sparks JA, Myasoedova E, Davis JM, 3rd. Comorbidities As Risk Factors for Rheumatoid Arthritis and Their Accrual After Diagnosis. Mayo Clin Proc. 2019;94(12):2488-98. Disclosure of Interests: John M Davis III Grant/research support from: Research grants from Pfizer, Consultant of: Served on advisory boards for Abbvie and Sanofi-Genzyme, Elena Myasoedova: None declared, Tina Gunderson: None declared, Cynthia S. Crowson Grant/research support from: Pfizer research grant