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Table 2 Baseline demographics, disease characteristics, tumor necrosis factor inhibitor line of therapy, and concomitant medications, before and after propensity score matching

From: One-year risk of serious infection in patients treated with certolizumab pegol as compared with other TNF inhibitors in a real-world setting: data from a national U.S. rheumatoid arthritis registry

 

Before PS matching

After PS matching

CZP (n = 975)

Other TNFi (n = 5240)

Nominal p value

CZP (n = 952)

Other TNFi (n = 952)

Nominal p value

Demographics

 Age, years, median (IQR)

58 (18.0)

56 (16.5)

< 0.001

58 (17.0)

58 (16.0)

0.48

 Female sex, n (%)

769 (78.9)

4107 (78.4)

0.74

751 (78.9)

750 (78.8)

0.96

 Race, white, n (%)

840 (86.2)

4310 (82.3)

< 0.001

820 (86.1)

786 (82.6)

0.03a

 BMI, kg/m2, mean (SD)

30.0 (7.3)

30.1 (7.3)

0.49

30.0 (7.3)

30.1 (7.5)

0.68

Insuranceb

 Medicare, n (%)

321 (32.9)

1363 (26.0)

< 0.001

315 (33.1)

293 (30.8)

0.28

 Medicaid, n (%)

48 (4.9)

327 (6.2)

0.12

48 (5.0)

59 (6.2)

0.32

 Private, n (%)

712 (73.0)

4034 (77.0)

0.01

700 (73.5)

719 (75.5)

0.32

 None, n (%)

23 (2.4)

136 (2.6)

0.74

22 (2.3)

14 (1.5)

0.24

Clinical characteristics

 Age at RA onset, years, mean (SD)

46.9 (14.4)

47.4 (13.5)

0.35

47.0 (14.4)

46.7 (13.8)

0.73

 Disease duration, years, median (IQR)

9 (12.0)

5 (10.0)

< 0.001

9 (12.0)

8 (12.5)

0.26

 CDAI, median (IQR)

19.0 (20.2)

17.0 (19.0)

0.01

19.0 (20.2)

18.5 (20.0)

> 0.99

 mHAQ, median (IQR)

0.5 (0.8)

0.4 (0.8)

< 0.001

0.5 (0.8)

0.5 (0.8)

0.89

History of comorbidities

 Diabetes, n (%)

75 (7.7)

467 (8.9)

0.22

75 (7.9)

96 (10.1)

0.09

 Pulmonary disease,c n (%)

58 (5.9)

347 (6.6)

0.43

58 (6.1)

64 (6.7)

0.57

 Cardiovascular disease,d n (%)

57 (5.8)

283 (5.4)

0.57

54 (5.7)

57 (6.0)

0.77

 Malignancy,e n (%)

48 (4.9)

225 (4.3)

0.38

46 (4.8)

45 (4.7)

0.91

 Serious infection,f n (%)

64 (6.6)

348 (6.6)

0.93

63 (6.6)

80 (8.4)

0.14

Comorbidity indexg

 Median score (IQR)

1 (0)

1 (0)

0.60

1 (0)

1 (0)

0.12

 Score ≥ 2, n (%)

197 (21.1)

1029 (20.3)

0.60

191 (20.9)

216 (23.7)

0.16

Line of TNFi therapy

  

< 0.001h

  

0.69h

 First, n (%)

253 (25.9)

2594 (49.5)

 

250 (26.3)

236 (24.8)

 

 Second, n (%)

285 (29.2)

1593 (30.4)

 

276 (29.0)

290 (30.5)

 Third or later, n (%)

437 (44.8)

1053 (20.1)

 

426 (44.7)

426 (44.7)

Concomitant DMARD use

 Nonbiologic DMARDs (excluding MTX), n (%)

146 (15.0)

819 (15.6)

0.60

143 (15.0)

166 (17.4)

0.15

 MTX and other nonbiologic DMARDs, n (%)

85 (8.7)

661 (12.6)

< 0.001

84 (8.8)

105 (11.0)

0.11

 MTX (excluding other nonbiologic DMARDs), n (%)

469 (48.0)

2597 (49.6)

0.40

456 (47.9)

450 (47.3)

0.78

Concomitant prednisone use

  

0.45h

  

0.26h

 None, n (%)

679 (70.1)

3695 (70.9)

 

661 (69.9)

658 (69.3)

 

  < 10 mg/day, n (%)

197 (20.4)

982 (18.8)

 

193 (20.4)

179 (18.9)

  ≥ 10 mg/day, n (%)

92 (9.5)

538 (10.3)

 

91 (9.6)

112 (11.8)

  1. Abbreviations: CZP Certolizumab pegol, TNFi Tumor necrosis factor inhibitor, PS Propensity score, BMI Body mass index, RA Rheumatoid arthritis, CDAI Clinical Disease Activity Index, mHAQ, Modified Health Assessment Questionnaire (disability index), COPD Chronic obstructive pulmonary disease, NMSC Nonmelanoma skin cancer, DMARD Disease-modifying antirheumatic drug, MTX Methotrexate
  2. aRace was statistically different between the PS-matched groups (p = 0.03), but this was not thought to be clinically significant
  3. bInsurance categories were not mutually exclusive; therefore, patients could be captured in more than one category
  4. cPulmonary disease included asthma, COPD, and interstitial lung disease/pulmonary fibrosis
  5. dCardiovascular disease included coronary artery disease, myocardial infarction, coronary heart failure requiring hospitalization, acute coronary syndrome, unstable angina, cardiac revascularization procedure, cardiac arrest, ventricular arrhythmia, and other cardiovascular diseases
  6. eMalignancy included lung cancer, breast cancer, melanoma skin cancer, and other cancers
  7. fSerious infection was defined as any infection for which the patient was hospitalized and/or received intravenous antibiotics
  8. gComorbidity index was a modified version of the Charlson comorbidity index and corresponded to the sum of scores for current and physician-reported prior comorbid conditions, namely myocardial infarction, congestive heart failure, peripheral vascular disease, cerebrovascular disease (captured as stroke or transient ischemic attack), COPD, history of bleeding and/or peptic ulcer, diabetes mellitus, leukemia, lymphoma, solid tumor cancer (excluding nonmelanoma skin cancer [NMSC]), liver disease, and connective tissue disease (including RA, so all patients had a comorbidity index ≥ 1)
  9. h p Values were based on chi-square tests to ascertain if the overall distribution differed significantly between the CZP and other TNFi groups
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Arthritis Research & Therapy

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