Results

Demography data of study subjects

The ICD-9 coding of 714.0 found 49,690 RA patients among the NHI system data source. We excluded patients with missing data (n=20), under the age of 16 years old (n=1118) and dated before 2002 (n=22,318). We also excluded patients who had a concomitant diagnosis of ulcerative colitis, Crohn’s disease, psoriasis, or psoriatic arthritis (n=90). After that, we picked up patients who had been prescribed biologics three times within six months with continuous treatment in outpatient clinics (n=4813). Among these patients, we further excluded one patient who used biologics prior to RA coding, 13 patients who used biologics only during hospitalization, and 125 patients who had expired during the follow-up period. Finally, we excluded those patients prescribed biologics after November 30, 2012 or before January 01, 1998. Overall, we included 821 RA patients in this study.
Among the 821 patients, 410 patients (50%) were classified in the Early group, and the other 411 patients (50%) were classified in the Late group (Table 1). Male RA patients had a higher ratio of receiving early treatment with biologics than female patients (Table 1, p = 0.0379). On the average, RA patients used biological agents for 2.89± 2.13 years. The age, income, living area (city or country), types of biologics, hepatitis B or C virus carrier, with or without chronic kidney disease, and heart failure diseases did not influence the timing of prescribing biologics for RA patients (Table 1, all p>0.05).

Comparison of prescribed days in one year before and after the biologics treatment.

The use of any of these three types of medication, including steroids, DMARDs, and NSAID was changed significantly after biologics treatment. Comparing 12 months before biologics, i.e., traditional treatment, and after the use of biological agents, oral medication significantly tapered after biologics compared to before biologics (Table 2, all p <0.0001), and the significance persisted even after study subjects were divided into early and late treatment (p<0.0001) (Table 2).
Duration of biologics treatment more than three-fourths of their length of traditional treatment reduces the prescribed days of steroid.
For patients who use biologics treatment more than three-fourths of their length of traditional treatment, we observed a decreasing trend of combinations of traditional treatments, DMARDs, NSAIDs, or steroids. The use of steroids, in particular, reached statistical significance (Table 3, p<0.05).

Biologics treatment contributes greatly to the reduced days of steroids and NSAID treatment.

Afterwards, we determined the odds ratio of each factor. The results show that men are 1.81 times more likely than women to taper oral glucocorticoids and NSAIDs. Younger age (<45) patients are 1.91 times more likely to taper steroids and NSAIDs than those aged over 65 years old. We found that RA patients receiving etanercept were 2.92 times more likely to taper oral medication, and those receiving adalimumab tend to have a 2.88-fold greater tendency to taper oral medication than other biologics (all demonstrated in Table 4).