Table 1.
Patient demographics and clinical characteristics at time of biologic initiation
| Biologic-naive patients (N = 3,923) | Initiated Bio MT (n = 750) | Initiated Bio CMB (n = 3,173) | P valuea | |
|---|---|---|---|---|
| Age, mean (SD), years | 57.33 (13.5) | 56.85 (14.7) | 57.45 (13.2) | 0.28 |
| Female, % | 75.86 | 74.42 | 76.19 | 0.32 |
| White, % | 81.55 | 83.56 | 81.08 | 0.13 |
| Duration of RA, mean (SD), years | 8.28 (9.3) | 8.47 (9.0) | 8.24 (9.3) | 0.54 |
| RF seropositivity, % | 75.43 | 75.43 | 75.43 | 1.00 |
| Disease activity, mean (SD) | ||||
| Tender joints, 28 count | 6.05 (6.8) | 5.98 (7.0) | 6.07 (6.8) | 0.75 |
| Swollen joints, 28 count | 6.15 (6.2) | 5.33 (6.0) | 6.34 (6.2) | <0.01 |
| Physician global assessment | 31.87 (22.1) | 31.02 (22.6) | 32.07 (22.0) | 0.24 |
| Patient global assessment | 38.63 (27.2) | 39.85 (29.1) | 38.35 (26.7) | 0.19 |
| Patient pain | 41.44 (29.1) | 43.22 (35.3) | 41.02 (27.5) | 0.07 |
| mHAQ score, mean (SD) | 0.47 (0.5) | 0.47 (0.5) | 0.47 (0.5) | 0.90 |
| CDAI score, mean (SD) | 19.27 (14.0) | 18.57 (14.3) | 19.43 (13.9) | 0.14 |
| Erosive disease, % | 46.63 | 41.93 | 47.73 | 0.02 |
| Current smoker, % | 19.69 | 20.50 | 19.50 | 0.57 |
| Comorbidities, % | ||||
| History of MI | 2.70 | 2.93 | 2.65 | 0.62 |
| History of stroke | 1.99 | 2.27 | 1.92 | 0.56 |
| History of CVD | 0.69 | 0.40 | 0.76 | 0.46 |
| History of cancer | 0.74 | 1.47 | 0.57 | 0.02 |
| History of serious infections | 1.02 | 1.52 | 0.89 | 0.27 |
| History of hepatic events | 0.99 | 2.67 | 0.60 | <0.01 |
| History of low platelet countsb | 0.46 | 0.92 | 0.37 | 0.13 |
| History of anemiac | 0.08 | 0.00 | 0.10 | 1.00 |
| History of lung diseased | 0.46 | 0.80 | 0.38 | 0.13 |
| History of low neutrophil countse | 1.77 | 4.05 | 1.29 | 0.03 |
| Prior DMARD use, % | 95.00 | 85.60 | 97.23 | <0.01 |
| Prior MTX use, % | 87.89 | 71.87 | 91.68 | <0.01 |
| Concurrent conventional DMARD use, % | ||||
| MTX only | – | – | 68.6 | – |
| >1 DMARD (including MTX) | – | – | 15.3 | – |
| Leflunomide | – | – | 6.5 | – |
| Hydroxychloroquine | – | – | 4.4 | – |
| >1 DMARD (excluding MTX) | – | – | 2.6 | – |
| Sulfasalazine | – | – | 1.5 | – |
| Other DMARDs | – | – | 1.2 | – |
| Prescription of biologic approved before 2006, %f | 65.10 | 64.00 | 65.36 | 0.50 |
| Initiation of biologic approved for monotherapy, % | 69.28 | 76.53 | 67.57 | <0.01 |
| Type of biologic initiated, % | ||||
| Anti-TNF | 90.95 | 88.93 | 91.43 | 0.03g |
| Non-anti-TNF | 9.05 | 11.07 | 8.57 | |
| Concurrent prednisone, % | 30.16 | 28.93 | 30.44 | 0.43 |
| Prednisone dose, mean (SD), mg/dayh | 6.4 (4.3) | 7.1 (4.9) | 6.3 (4.1) | <0.01 |
anti-TNF anti-tumor necrosis factor agent, Bio CMB biologic in combination with a conventional DMARD, Bio MT biologic monotherapy, CDAI clinical disease activity index, CVD cardiovascular disease, DMARD disease-modifying antirheumatic drug, mHAQ modified Health Assessment Questionnaire, MI myocardial infarction, MTX methotrexate, RA rheumatoid arthritis, RF rheumatoid factor
a P values are for comparisons between patients who initiated Bio MT vs Bio CMB
bLow platelets defined as platelets <100,000/mm3
cAnemia defined as hemoglobin <8 g/dL
dLung disease uses comorbidity indicators that varied across versions: lung disease, pulmonary fibrosis, or interstitial lung disease
eLow neutrophils defined as <1,000/mm3
fAfter 2006, more biologics became available
g P value assessed using Fisher’s exact test
hMean (SD) prednisone dose calculated only from patients receiving prednisone with dose reported (Bio MT, n = 205; Bio CMB, n = 912)