title: Assessing future need for acute care in adult asthmatics: the Profile of Asthma Risk Study: a prospective health maintenance organization-based study.
abstract: OBJECTIVE
  To develop simple clinical tools predictive of acute asthma care and to identify modifiable risk factors.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  A large health maintenance organization (430,000 members).
  
  
  METHODS
  Adult members (18 to 55 years old) with asthma.
  
  
  METHODS
  Data from a questionnaire, skin-prick testing for inhalant allergens, and spirometry were collected at the baseline visit. Acute care utilization data were obtained from administrative databases for a subsequent 30-month period.
  
  
  METHODS
  This two-phase study first identified and performed a split-sample validation on three clinical tools to determine their predictive ability by employing data from a questionnaire, questionnaire plus spirometry, and questionnaire plus spirometry and skin-prick testing. Second, it identified modifiable independent risk factors.
  
  
  RESULTS
  The 554 study participants generated 173 episodes of acute care over 1,258 person-years of follow-up (0.14 episodes per person per year). Of these, 101 participants had at least one episode, and one third of this group had two or more episodes. Clinical scoring into risk groups was done by reverse stepwise regression analyses. Using relative risks (RRs) as a guide, high-risk, moderate-risk, and low-risk groups were identified. The high-risk groups, 13 to 21% of the validation sample, had a 7- to 11-fold increased risk for hospital care compared to the low-risk groups. The moderate-risk groups, 46 to 50% of the validation sample, had a twofold- to fourfold-increased risk. FEV(1) was the most significant predictor (RR, 4.33). Of the four potentially modifiable risk factors identified, current cigarette smoke exposure (RR, 1.6) and ownership and skin-prick test positivity to cat or dog (RR, 1.5) were the most significant.
  
  
  CONCLUSIONS
  These models stratify asthma patients at risk for acute care. Patients with lower FEV(1) values are at significantly higher risk, underscoring the importance of spirometry in asthma care.
authors.affiliation: Mail code L102, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd, Portland, OR 97239, USA. osbornem@ohsu.edu
authors.forename: Molly L
authors.initials: ML
authors.lastname: Osborne
authors.forename: Kathryn L
authors.initials: KL
authors.lastname: Pedula
authors.forename: Mark
authors.initials: M
authors.lastname: O'Hollaren
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Ettinger
authors.forename: Thomas
authors.initials: T
authors.lastname: Stibolt
authors.forename: A Sonia
authors.initials: AS
authors.lastname: Buist
authors.forename: William M
authors.initials: WM
authors.lastname: Vollmer
mesh_terms: D000208:Acute Disease; D000328:Adult; D001249:Asthma / Q000453:epidemiology* / Q000503:physiopathology; D005260:Female; D005541:Forced Expiratory Volume; D006279:Health Maintenance Organizations; D006305:Health Status Indicators; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D018570:Risk Assessment; D013147:Spirometry; D011795:Surveys and Questionnaires