Skip to main content

Table 1 Demographic characteristics of 515 patients with rheumatoid arthritis and 769 population controls, Denmark 1998 to 2003

From: Environmental risk factors differ between rheumatoid arthritis with and without auto-antibodies against cyclic citrullinated peptides

  

Patients with rheumatoid arthritis

Population controls

Mean age at diagnosis, years (range) a

49 (18 to 65)

48 (16 to 68)

Gender

Women

366 (71.1%)

478 (62.2%)

 

Men

149 (28.9%)

291 (37.8%)

Birth year

Before 1940

71 (13.8%)

98 (12.7%)

 

1940 to 1949

171 (33.2%)

250 (32.5%)

 

1950 to 1959

145 (28.2%)

223 (29.0%)

 

1960 to 1969

77 (15.0%)

129 (16.8%)

 

1970 or after

51 (9.9%)

69 (9.0%)

Place of residence

Copenhagen

86 (16.7%)

102 (13.3%)

 

Suburbs of Copenhagen

90 (17.5%)

137 (17.8%)

 

Other towns with ≥100,000 inhabitants

78 (15.2%)

77 (10.0%)

 

Towns with 10,000 to 99,999 inhabitants

93 (18.1%)

197 (25.6%)

 

Rural areas/towns with <10,000 inhabitants

168 (32.6%)

256 (33.3%)

Education b

No post-school education

123 (23.9%)

120 (15.6%)

 

Semi-skilled worker, short education (<1 year) or apprentice

204 (39.6%)

293 (38.2%)

 

Short or middle length advanced studies (1 to 4 years)

156 (30.3%)

265 (34.5%)

 

Long advanced studies (>4 years)

32 (6.2%)

90 (11.7%)

  1. aAge in controls calculated as pseudo-year of diagnosis minus birth year. bOne control had missing information about education.