title: Do specialized centers and specialists produce better outcomes for patients with chronic diseases than primary care generalists? A systematic review.
abstract: OBJECTIVE
  Although specialized centers are generally accepted for treatment of relatively uncommon diseases, such as cystic fibrosis, statements regarding the amount of expertise or minimum number of patients treated are increasingly included in guidelines for the treatment of other chronic diseases such as rheumatoid arthritis and diabetes mellitus.
  
  
  METHODS
  Medline and Embase from 1987 through March 2008 were searched.
  
  
  METHODS
  Studies reporting the effect of treatment in a specialized or high-volume center or by subspecialists on a clinically relevant outcome. Data extraction Two reviewers extracted the data independently and assessed the methodological quality.
  
  
  RESULTS
  We included 22 articles. Two randomized-controlled trials and a quasi-experimental study compared the effect of outpatient team care with traditional outpatient care for patients with rheumatoid arthritis. These studies showed no difference or were inconsistent. Studies on the outcomes of care for diabetic patients (5 prospective or historical cohort studies and 10 retrospective cohort studies) were generally of poor quality. Studies comparing the subspecialist care with the care provided by general internists or primary care providers produced inconsistent results. Similar inconsistency and poor quality were found for three observational studies on cystic fibrosis.
  
  
  CONCLUSIONS
  The available literature suggests that among patients with rheumatoid arthritis, diabetes mellitus or cystic fibrosis, outcomes are not superior in specialized centers or with subspecialists compared with other forms of chronic illness care.
authors.affiliation: Dutch Institute for Healthcare Improvement CBO, 3502 LB Utrecht, The Netherlands. p.post@cbo.nl
authors.forename: Piet N
authors.initials: PN
authors.lastname: Post
authors.forename: Jolanda
authors.initials: J
authors.lastname: Wittenberg
authors.forename: Jako S
authors.initials: JS
authors.lastname: Burgers
mesh_terms: D001172:Arthritis, Rheumatoid / Q000628:therapy; D002908:Chronic Disease / Q000628:therapy*; D003550:Cystic Fibrosis / Q000628:therapy; D003920:Diabetes Mellitus / Q000628:therapy; D006782:Hospitals, Special / Q000706:statistics & numerical data*; D006801:Humans; D010821:Physicians, Family / Q000706:statistics & numerical data*; D013038:Specialization; D016896:Treatment Outcome