Table 1

Baseline characteristics among patients with RA at diagnosis and age-matched and sex-matched controls

RA (n=6591)No RA (n=6591)P value
Baseline characteristics
Age (years)58.67 (15.54)58.67 (15.54)NA
Male sex2142 (32.5)2142 (32.5)NA
Ethnicity*<0.001
 White4883 (91.6)4418 (94.6)
 Asian255 (4.8)147 (3.1)
 Black128 (2.4)69 (1.5)
 Mixed26 (0.5)18 (0.4)
 Other36 (0.7)18 (0.4)
Smoking status*<0.001
 Never smoked1853 (30.0)2247 (35.8)
 Active smoker1348 (21.9)1187 (18.9)
 Ex-smoker2968 (48.1)2838 (45.2)
Clinical measurements
BMI (kg/m2)*27.67 (5.97)27.23 (5.56)<0.001
Systolic BP, mm Hg*130.86 (16.19)131.10 (15.95)0.084
Diastolic BP, mm Hg*76.82 (9.68)77.31 (9.46)0.003
Total cholesterol (mmol/L)*5.07 (1.13)5.20 (1.12)<0.001
LDL cholesterol (mmol/L)*2.96 (1.00)3.05 (1.01)0.005
HDL cholesterol (mmol/L)*1.47 (0.45)1.50 (0.44)<0.001
Positive RF or anti-CCP antibodies*1885 (28.1)159 (2.4)<0.001
CRP (mg/L)*20.0 (32.7)7.4 (16.8)<0.001
Comorbidities
Chronic kidney disease (stage III–V)618 (9.4)614 (9.3)0.923
Diabetes (any)735 (11.2)635 (9.6)0.004
 Type 144 (0.7)26 (0.4)0.025
 Type 2691 (10.5)609 (9.2)<0.001
Atrial fibrillation237 (3.6)185 (2.8)0.009
Myocardial infarction202 (3.1)169 (2.6)0.079
Stroke254 (3.9)180 (2.7)<0.001
Heart failure108 (1.6)65 (1.0)0.001
Medication use†
ACE inhibitor1415 (21.5)1359 (20.6)0.203
Angiotensin receptor blocker536 (8.1)528 (8.0)0.816
Calcium channel blocker1297 (19.7)1184 (18.0)0.007
Beta-blocker1260 (19.1)1294 (19.6)0.452
Anti-platelet agents1374 (20.8)1371 (20.8)0.962
Lipid lowering medication1811 (27.5)1731 (26.3)0.078
NSAID1962 (29.8)430 (6.5)<0.001
Glucocorticoids2001 (30.4)899 (13.6)<0.001
Methotrexate992 (15.1)8 (0.1)<0.001
csDMARD1263 (19.2)90 (1.4)<0.001
bDMARD19 (0.3)0 (0.0)<0.001
  • Data are mean (SD) or n (%). P values from χ2 test or t-test are provided.

  • *The following variables had missing values (n): ethnicity in RA: n=1263; no RA: n=1921; smoking status in RA: n=422; no RA: n=319; BMI in RA: n=520; no RA: n=701; blood pressure in RA: n=191; no RA: n=221; cholesterol in RA: n=1678; no RA: n=2162; CRP in RA: n=2172; no RA: n=4499; one or more RA antibodies were measured in RA: n=3550, no RA: n=992.

  • †Any prescription on or within 3 months prior to the first diagnosis code in primary care.

  • anti-CCP, anti-cyclic citrullinated peptide ; bDMARD, biological disease-modifying anti-rheumatic drug; BMI, body mass index; BP, blood pressure; CRP, C reactive protein; csDMARD, conventional synthetic disease-modifying anti-rheumatic drug; HDL, high-density lipoprotein; LDL, low-density lipoprotein; NSAID, non-steroidal anti-inflammatory; RA, rheumatoid arthritis.