The association between diabetes mellitus control and advanced anti-rheumatic treatment, among rheumatoid arthritis patients: A nation-wide based, retrospective, cohort study.

INTRODUCTION

Diabetes Mellitus (DM) is a known risk factor for worse clinical outcomes among patient with Rheumatoid Arthritis (RA), yet the effect of glycemic control on RA treatment has not yet been investigated.

STUDY

OBJECTIVE

To examine the association between DM control and biologic or targeted synthetic Disease-Modifying Anti-Rheumatic Drug (b/tsDMARDs) use among RA patients.

METHODS

We conducted a retrospective population-based cohort study. RA patients were included if they had at least two recorded diagnoses of RA AND either one of the following: were Rheumatoid Factor (RF) or anti Cyclic Citrullinated Peptide (CCP) positive, OR purchased conventional synthetic DMARDs (csDMARDs) 1 year before 2nd documented diagnosis of RA. Patients were classified by median hemoglobin A1C% (HbA1c) during 12 months before the index date: managed DM (MDM) (HbA1c<8%) or unmanaged DM (UMDM) (HbA1c≥8%). The primary outcome was the proportion of patients prescribed a b/tsDMARDs within the first two years after the index date. Secondary outcomes included the number of b/tsDMARDs switches following the index date. Gradient Boosting Classifier was used for a comprehensive propensity score matching.

RESULTS

From a total of 3977 RA patients, 400 were selected for UMDM group and 800 for MDM group. In the UMDM group 12.25% of patients initiated b/tsDMARDs within two years from the index date, compared to 13.87% of MDM patients (OR 0.87, 95% CI 0.60-1.24, P=0.49). The mean number of b/tsDMARDs switches was not statistically significant between groups at 2 and 5 years.

CONCLUSION

RA patients with UMDM, as compared with MDM, do not have higher odds of being prescribed b/tsDMARDs within the first two years after RA diagnosis.