Table 4.

Multivariable analyses.

VariableAdjusted* HR (95% CI)
OntarioQuebec
Time-dependent variables
  Main exposures, cumulative use in the first yr, mos**
    Methotrexate0.97 (0.96–0.98)0.96 (0.94–0.98)
    Other DMARD0.98 (0.97–1.00)0.99 (0.97–1.00)
  Other exposures, cumulative use over followup, yrs***
    Glucocorticosteroids1.02 (0.99–1.06)0.97 (0.89–1.05)
    NSAID1.20 (1.16–1.24)1.33 (1.18–1.49)
    COXIB1.11 (1.06–1.16)1.22 (1.10–1.35)
    Anti-TNF2.50 (0.72–8.65)1.13 (0.91–1.39)
    Other biologics1.01 (0.95–1.07)0.17 (0.00–36.07)
  Extraarticular RA0.93 (0.85–1.02)1.14 (0.93–1.39)
  Rheumatology visits over followup††1.10 (1.05–1.16)1.22 (1.07–1.39)
Time-independent baseline variables
  Age1.36 (1.14–1.63)2.02 (1.26–3.25)
  Sex, reference: male0.81 (0.73–0.89)0.76 (0.61–0.94)
  Rheumatology visits in 1 yr prior††0.97 (0.90–1.06)1.22 (1.07–1.39)
  High healthcare use at baseline, reference: low1.14 (1.02–1.27)0.96 (0.76–1.21)
  Prior joint replacement1.87 (1.67–2.10)2.48 (1.83–3.35)
  Baseline comorbidities
    Acute myocardial infarction1.17 (0.90–1.53)0.79 (0.40–1.55)
    Diabetes0.86 (0.76–0.96)0.91 (0.67–1.23)
    Osteoporosis0.92 (0.79–1.07)0.79 (0.61–1.02)
    Cerebrovascular disease1.06 (0.69–1.64)1.38 (0.43–4.41)
    Acute renal failure0.96 (0.65–1.42)0.86 (0.45–1.63)
    Chronic renal failure0.92 (0.65–1.29)2.11 (1.13–3.95)
    Coronary artery disease0.89 (0.79–1.02)1.14 (0.89–1.46)
    COPD/asthma0.96 (0.87–1.06)0.91 (0.71–1.16)
    Cancer1.12 (1.00–1.26)1.07 (0.74–1.54)
    Osteoarthritis1.49 (1.36–1.64)1.97 (1.61–2.41)
  Drug use 1 yr prior to cohort entry‡‡, reference: non-use
    Methotrexate1.17 (0.99–1.39)1.18 (0.82–1.71)
    Other DMARD0.97 (0.84–1.13)0.99 (0.73–1.34)
    Glucocorticosteroids1.12 (1.01–1.23)1.18 (0.95–1.45)
    Anti-TNF0.49 (0.13–1.90)1.20 (0.32–4.49)
    NSAID1.03 (0.95–1.13)0.78 (0.63–0.96)
    COXIB1.08 (0.98–1.19)0.87 (0.71–1.07)
  • * Adjusted for all covariates including socioeconomic status (defined by census data), age (squared), patient residence, and Charlson index.

  • ** HR expressed as per month of additional use.

  • *** HR expressed as per year of additional use.

  • Extraarticular RA manifestations.

  • †† Log-transformed.

  • Binary indicator reflecting at least 20 outpatient physician visits in at least 1 year of the 3 years before baseline.

  • ‡‡ Binary indicator reflecting use during the 1-year prior to cohort entry. DMARD: disease-modifying antirheumatic drug; NSAID: nonsteroidal anti-inflammatory drug; COXIB: cyclooxygenase-2 inhibitor; anti-TNF: anti-tumor necrosis factor; RA: rheumatoid arthritis; COPD: chronic obstructive pulmonary disease.