Table 2

Multivariable Cox proportional hazards model for time to initiation of minocycline or doxycycline

Hazard ratio

95% confidence interval

Standard error

P value

Male sex

1.139

0.887, 1.464

0.146

0.308

Age

0.990

0.982, 0.998

0.004

0.021

Number of previous nonbiologic DMARDs

1.618

1.532, 1.710

0.045

< 0.001

Methotrexate use

0.728

0.596, 0.890

0.074

0.002

Leflunomide use

0.622

0.470, 0.822

0.089

0.001

Azathioprine use

0.378

0.186, 0.769

0.137

0.007

Patient Activity Score

1.049

1.000, 1.100

0.026

0.051

Comorbidity index

1.139

1.072, 1.210

0.035

< 0.001

Number of previous biologic DMARDs

0.779

0.676, 0.898

0.057

0.001

Calendar year

1.062

1.001, 1.127

0.032

0.046

n = 11,987. DMARD, disease-modifying anti-rheumatic drug.

Smith et al. Arthritis Research & Therapy 2011 13:R168   doi:10.1186/ar3491