Table 1

Baseline characteristics of patients starting hydroxychloroquine and other csDMARD* medications at time of start of drug for all starters and in the matched cohort

All startersMatched starters
Hydroxychloroquine(N=2270)Other csDMARD (N=4522)Hydroxy-chloroquine (N=1534)Other csDMARD (N=1534)
Mean (SD)Mean (SD)Std. Diff.†Mean (SD)Mean (SD)Std. Diff.
Age60.05 (13.99)60.38 (13.44)0.08460.11 (14.30)59.97 (13.69)0.010
Duration of RA‡5.66±8.005.45±8.360.0255.5±8.275.51±7.770.002
CDAI§12.7±10.8017.15±13.770.35913.38±11.2413.54±11.370.014
BMI29.53±6.9629.84±6.940.04529.54±6.9629.77±7.030.033
N(%)N(%)N(%)N(%)
Gender0.0770.012
 Men523 (23.2)1193 (26.5)368 (24)360 (23.5)
 Women1730 (76.8)3303 (73.5)1166 (76)1174 (76.5)
Hx of CVD311 (13.7)563 (12.5)0.037212 (13.8)216 (14.1)0.008
Hx of Diabetes228 (10)495 (10.9)0.029156 (10.2)162 (10.6)0.013
Smoking Status0.0040.011
 Never1146 (51.1)2256 (50.6)795 (52.2)783 (51.3)
 Previous723 (32.3)1478 (33.1)478 (31.4)491 (32.2)
 Current372 (16.6)728 (16.3)251 (16.5)251 (16.5)
Prednisone Dosage0.1840.013
 None1665 (74)3040 (68.4)1112 (72.5)1113 (72.6)
 <7.5 mg421 (18.7)780 (17.5)278 (18.1)289 (18.8)
 ≥7.5 mg165 (7.3)626 (14.1)144 (9.4)132 (8.6)
Number csDMARD0.8840.022
 One1083 (47.7)3878 (85.8)973 (63.4)989 (64.5)
 2+1187 (52.3)644 (14.2)561 (36.6)545 (35.5)
Hx of Serious Infection¶156 (6.9)254 (5.6)0.052105 (6.8)97 (6.3)0.021
  • *csDMARD medications refers to conventional disease-modifying antirheumatic drugs.

  • †Std. Diff. is the standardised difference between the two treatment groups.

  • ‡Duration of RA refers to duration of rheumatoid arthritis since initial diagnosis.

  • §CDAI refers to Clinical Disease Activity Index-a clinical measurement of RA disease severity.

  • ¶Hx of Serious Infection refers to history of serious upper respiratory infection, bronchitis or pneumonia prior to starting hydroxychloroquine or csDMARD medication.