title: Previous history of tuberculosis is associated with rheumatoid arthritis.
abstract: BACKGROUND
  Previous studies have suggested that mycobacterial infections could trigger autoimmune diseases, including rheumatoid arthritis (RA).
  
  
  OBJECTIVE
  To explore the association between previous tuberculosis (TB) and RA.
  
  
  METHODS
  We conducted a case-control study using data obtained from the National Health Insurance (NHI) system of Taiwan. We identified 26 535 adults with RA from 2002 to 2011, with the date of diagnosis as the index date. This number was randomly selected and frequency-matched four times by age, sex and the year of index date from among non-RA individuals. Odds ratios (ORs) of RA were calculated for associations with TB.
  
  
  RESULTS
  Compared with controls, RA patients had a crude OR of 1.77 for TB (95%CI 1.61-1.94). The strength of the association between RA and TB remained at the same level after controlling for other potential risk factors (adjusted OR 1.73, 95%CI 1.57-1.90), although RA patients tended to have a higher prevalence of hypertension, coronary artery disease and kidney disease.
  
  
  CONCLUSIONS
  TB was much more prevalent in RA patients than in control subjects. Prospective cohort studies are required to establish a causal relationship between previous TB and RA.
authors.affiliation: Graduate Institute of Clinical Medicine Science, College of Medicine, China Medical University Hospital, Taichung, Taiwan; Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan; Intensive Care Unit, Chu Shang Show Chwan Hospital, Nantou, Taiwan.
authors.forename: T-C
authors.initials: TC
authors.lastname: Shen
authors.affiliation: Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan.
authors.forename: C-L
authors.initials: CL
authors.lastname: Lin
authors.affiliation: Division of Nephrology, Department of Paediatrics, China Medical University Hospital, Taichung, Taiwan.
authors.forename: C-C
authors.initials: CC
authors.lastname: Wei
authors.affiliation: Graduate Institute of Clinical Medicine Science, College of Medicine, College of Medicine, China Medical University Hospital, Taichung, Taiwan; Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan.
authors.forename: C-H
authors.initials: CH
authors.lastname: Chen
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan.
authors.forename: C-Y
authors.initials: CY
authors.lastname: Tu
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan.
authors.forename: T-C
authors.initials: TC
authors.lastname: Hsia
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan.
authors.forename: C-M
authors.initials: CM
authors.lastname: Shih
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan.
authors.forename: W-H
authors.initials: WH
authors.lastname: Hsu
authors.affiliation: Department of Health Risk Management, College of Public Health, China Medical University, Taichung, Taiwan.
authors.forename: C-J
authors.initials: CJ
authors.lastname: Chung
authors.affiliation: Graduate Institute of Clinical Medicine Science, College of Medicine, China Medical University Hospital, Taichung, Taiwan; Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan.
authors.forename: F-C
authors.initials: FC
authors.lastname: Sung
authors.affiliation: Graduate Institute of Clinical Medicine Science, College of Medicine, China Medical University Hospital, Taichung, Taiwan; Department of Nuclear Medicine and PET Center, China Medical University Hospital, Taichung, Taiwan.
authors.forename: C-H
authors.initials: CH
authors.lastname: Kao
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000150:complications*; D016022:Case-Control Studies; D016208:Databases, Factual; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology; D014376:Tuberculosis / Q000453:epidemiology*; D055815:Young Adult