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).