Table 2

Comparison of pre-existing diseases before index date between patients with RA and non-RA controls

Pre-existing diseasesPatients with RA (n=13779)Non-RA patients (n=137790)p Value
Diabetes mellitus829 (6.0)9466 (6.9)<0.001
Sjögren's syndrome41 (0.3)25 (0.0)<0.001
Gingival and periodontal diseases* (ICD9-CM: 523.x)6179 (44.8)55784 (40.5)<0.001
Acute or chronic periodontitis* (ICD9-CM: 523.3–4)3185 (23.1)27866 (20.2)<0.001
Chronic periodontitis* (ICD9-CM: 523.4)1424 (10.3)12294 (8.9)<0.001
Periodontitis* (ICD9-CM: 523.3–5)5369 (39.0)48334 (35.1)<0.001
Time interval between the last periodontitis-related visit and the index date<0.001
 <3 Months492 (3.6)2971 (2.2)
 3–6 Months418 (3.0)3467 (2.5)
 6 Months–1 year695 (5.0)6325 (4.6)
 1–3 Years1857 (13.5)17674 (12.8)
 >3 Years1907 (13.8)17897 (13.0)
 Number of visits for periodontitis<0.001
 1–21936 (14.1)18190 (13.2)
 3–41196 (8.7)10730 (7.8)
 5–71007 (7.3)8933 (6.5)
 ≥81230 (8.9)10481 (7.6)
Cumulative cost of periodontitis-related visits (US$)<0.001
 0–481386 (10.1)12800 (9.3)
 49–981239 (9.0)11356 (8.2)
 99–2111331 (9.7)12086 (8.8)
 >2111413 (10.3)12012 (8.7)
History of periodontal surgery338 (2.5)2774 (2.0)
History of antibiotic treatment2463 (17.9)22254 (16.2)<0.001
Dental scaling ≤2 times a year with a coding of ICD9-CM: 523.3–53387 (24.6)35083 (25.5)<0.001
  • Results are shown as number (%).

  • *Patients received antibiotic treatment, or periodontal treatment other than dental scaling, or dental scaling more than twice a year.

  • ICD9-CM, International Classification of Diseases, 9th revision, clinical modification; RA, rheumatoid arthritis.