title: Baseline comorbidity levels in biologic and standard DMARD treated patients with rheumatoid arthritis: results from a national patient register.
abstract: OBJECTIVE
  To describe the occurrence of baseline comorbidity in subjects with active rheumatoid arthritis starting treatment with biological agents. Such data are necessary to interpret the reported occurrence of adverse events following treatment.
  
  
  METHODS
  Baseline comorbidity was recorded in a large national cohort of patients with rheumatoid arthritis newly starting biological agents. The distribution of the number and types of comorbidities is presented.
  
  
  RESULTS
  In all, 7818 patients treated with biological agents (infliximab 3332, etanercept 3302, adalimumab 1059, anakinra 132) were included in the analysis. Comorbidity was common, with 58% of patients having at least one comorbid condition and 25% having more than one. The most frequent comorbid conditions were hypertension, depression, peptic ulcer disease, and respiratory disease.
  
  
  CONCLUSIONS
  In routine use, patients treated with biological agents have high levels of baseline comorbidity, which should influence the interpretation of reported adverse events.
authors.affiliation: ARC Unit, University of Manchester, Manchester, UK.
authors.forename: K
authors.initials: K
authors.lastname: Hyrich
authors.forename: D
authors.initials: D
authors.lastname: Symmons
authors.forename: K
authors.initials: K
authors.lastname: Watson
authors.forename: A
authors.initials: A
authors.lastname: Silman
mesh_terms: D000328:Adult; D000368:Aged; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000150:complications / Q000188:drug therapy*; D001249:Asthma / Q000150:complications; D015331:Cohort Studies; D016208:Databases, Factual; D003863:Depression / Q000150:complications; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications; D007155:Immunologic Factors / Q000627:therapeutic use*; D008171:Lung Diseases / Q000150:complications; D008232:Lymphoproliferative Disorders / Q000150:complications; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000150:complications; D009369:Neoplasms / Q000150:complications; D010437:Peptic Ulcer / Q000150:complications; D012955:Societies, Medical; D014376:Tuberculosis / Q000150:complications
chemical_list: D018501:Antirheumatic Agents; D007155:Immunologic Factors