Table 2.

Factors associated with time to biologic therapy initiation in patients with RA starting methotrexate, using multivariable Cox regression.

VariablesHR (95% CI), N = 17,514, 26,327 Person-yrs, Events = 3263p
Age, yrs
  < 50Reference
  50–650.74 (0.67–0.82)< 0.001
  65–800.42 (0.37–0.46)< 0.001
  ≥ 800.20 (0.16–0.26)< 0.001
Female0.99 (0.89–1.10)0.81
Race
  WhiteReference
  Nonwhite0.79 (0.72–0.87)< 0.001
  Unknown0.92 (0.81–1.04)0.19
Smoking1.09 (1.02–1.17)0.02
BMI, kg/m21.01 (1.00–1.02)0.003
Anti-CCP–positive1.16 (1.06–1.26)0.001
Congestive heart failure0.68 (0.54–0.84)0.001
Cancer0.78 (0.66–0.92)0.003
Myocardial infarction1.24 (0.97–1.60)0.09
Charlson score, per 1 point0.95 (0.92–0.98)0.002
Glucocorticoids1.49 (1.39–1.60)< 0.001
LEF1.48 (1.10–1.99)0.01
SSZ1.56 (1.36–1.79)< 0.001
Prior conventional DMARD0.82 (0.76–0.88)< 0.001
Years 2011–2014 vs 2005–20101.20 (1.11–1.29)< 0.001
  • Tested but excluded with p > 0.2: ln(CRP), depression, anxiety, PTSD, diabetes, chronic kidney disease, interstitial lung disease, asthma/COPD, concomitant hydroxychloroquine use. Ln(CRP): natural logarithm of C-reactive protein; PTSD: posttraumatic stress disorder; COPD: chronic obstructive pulmonary disease; BMI: body mass index; LEF: leflunomide; SSZ: sulfasalazine; RA: rheumatoid arthritis; CCP: cyclic citrullinated peptide; DMARD: disease-modifying antirheumatic drug.