title: Incidence of Churg-Strauss syndrome in asthma drug users: a population-based perspective.
abstract: OBJECTIVE
  To estimate the incidence of Churg-Strauss syndrome (CSS) among a large population of asthma drug users.
  
  
  METHODS
  A retrospective study was conducted among patients who had been dispensed asthma drugs at 3 managed care organizations. Adults who received >or =3 dispensings of an asthma drug during any consecutive 12-month period between January 1, 1995 and June 30, 2000 were identified. Information on patient age, gender, enrollment status, asthma drugs dispensed, and inpatient and outpatient diagnoses and procedures was obtained from automated databases. Chart reviews were performed on persons identified by combinations of diagnostic and billing codes indicative of CSS. A rheumatologist reviewed abstracted information on all subjects; those who met >or =2 American College of Rheumatology criteria for CSS were reviewed by 2 clinical experts. Each clinical expert independently rated the cases; disagreements were resolved by consensus. Cases classified as having "probable/definite" CSS were included in these analyses. The incidence of CSS was estimated overall and according to patient gender, age, and calendar year.
  
  
  RESULTS
  From a population of 184,667 asthma drug users contributing 606,184 person-years of exposure, 21 incident cases of CSS were identified (overall incidence of 34.6 per million person-years; 95% confidence interval 21.4 to 53.0). Incidence rates did not differ by gender and age group. The incidence rates for 1995, 1996, 1997, 1998, 1999, and the first 6 months of 2000 were 0, 22, 52, 75, 14, and 14 per million person-years respectively.
  
  
  CONCLUSIONS
  Results from this population-based study suggest a somewhat lower incidence of CSS in asthma drug users than previously reported and provides important information as to the risk of developing CSS from a population-based perspective.
authors.affiliation: Meyers Primary Care Institute, University of Massachusetts Medical School and Fallon Foundation, Worcester, MA 01655, USA. HarroldL@ummhc.org
authors.forename: Leslie R
authors.initials: LR
authors.lastname: Harrold
authors.forename: Susan E
authors.initials: SE
authors.lastname: Andrade
authors.forename: Alan S
authors.initials: AS
authors.lastname: Go
authors.forename: A Sonia
authors.initials: AS
authors.lastname: Buist
authors.forename: Mark
authors.initials: M
authors.lastname: Eisner
authors.forename: William M
authors.initials: WM
authors.lastname: Vollmer
authors.forename: K Arnold
authors.initials: KA
authors.lastname: Chan
authors.forename: E Ann
authors.initials: EA
authors.lastname: Frazier
authors.forename: Peter F
authors.initials: PF
authors.lastname: Weller
authors.forename: Michael E
authors.initials: ME
authors.lastname: Wechsler
authors.forename: Robert A
authors.initials: RA
authors.lastname: Yood
authors.forename: Kourtney J
authors.initials: KJ
authors.lastname: Davis
authors.forename: Richard
authors.initials: R
authors.lastname: Platt
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018927:Anti-Asthmatic Agents / Q000009:adverse effects*; D001249:Asthma / Q000150:complications* / Q000188:drug therapy* / Q000453:epidemiology; D015267:Churg-Strauss Syndrome / Q000453:epidemiology / Q000209:etiology*; D019992:Databases as Topic; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D014481:United States / Q000453:epidemiology
chemical_list: D018927:Anti-Asthmatic Agents