Table 1

Patient characteristics, renal function and comorbidities at baseline

1362 ‘NSAID naive’2739 ‘NSAID users’
N, median*%, IQR**N or median% or IQRp Value
Female sex102275.2%206575.2%0.838
Age (years)5645–665546–640.069
RA duration (years)41–1041–110.109
DAS283.402.42–4.313.602.74–4.580.0001
BMI (kg/m2)24.221.5–27.424.621.9–27.80.020
eGFRCG
(mL/min)
*96.2**34.8*97.8**32.90.045
eGFRCKD
(mL/min/1.73 m2)
*85.3**20.4*85.5**20.00.96
eGFRMDRD
(mL/min/1.73 m2)
*86.1**25.2*86.7**40.40.56
CKD 1
eGFRCG ≥90 mL/min
N=69919%N=148818%0.53
CKD 2
eGFRCG 60–89 mL/min
N=50062%N=99364%0.146
CKD 3
eGFRCG 30–59 mL/min
N=15519%N=24918%0.371
CKD 4 or 5
eGFRCG <29 mL/min or dialysis
N=80.6%N=90.3%0.225
Hypertension31022.8%61422.4%0.777
Diabetes634.6%1304.7%0.858
Heart disease1027.6%1856.7%0.345
Renal disease272.0%491.8%0.669
MTX83160.9%175964.2%0.041
Sulfasalazine1077.8%2328.5%0.495
Other DMARDs18413.5%32711.9%0.155
TNF-antagonists1319.6%1354.9%<0.001
Glucocorticoids40629.8%88032.1%0.126
  • Comorbidities were registered at the discretion of the treating rheumatologist. Their treatment was not reported.

  • Normally distributed parameters are given in *mean±**SD.

  • BMI, body mass index; CKD, chronic kidney disease stages according to the National Kidney Foundation Kidney Disease Outcomes Quality Initiative (KDOQI)28; DAS28, disease activity score based on 28 joints evaluated for swelling and tenderness and erythrocyte sedimentation rate26; DMARD, disease-modifying antirheumatic drugs: listed are only substances or drug classes with at least 100 prescriptions; eGFRCG, estimated glomerular filtration rate according to the Cockroft–Gault formula22; eGFRMDRD, Modification of Diet in Renal Disease formula23; eGFRCKD , Chronic Kidney Disease Epidemiology Collaboration creatinine equation24; GI, gastrointestinal disease; NSAID, non-steroidal anti-inflammatory drug; RA, rheumatoid arthritis; TNF, tumour necrosis factor-α.