title: Developing a risk stratification model for predicting future health care use in asthmatic children.
abstract: BACKGROUND
  Previous studies have stratified pediatric asthma patients for risk of future exacerbation and/or health care use, but most incorporate multiple clinical parameters.
  
  
  OBJECTIVE
  To determine whether historical acute care visits (ACVs) alone could predict risk of future health care use.
  
  
  METHODS
  Children seen for asthma in an outpatient visit during a 3-year period were identified. The number of ACVs in the 12 months before and after the outpatient visit was determined. Logistic regression models were used to determine the odds of a future ACV. Models were adjusted for age, sex, race, and insurance status.
  
  
  RESULTS
  Of 28,047 outpatient visits, 21,099 (75.2%) had no historical ACVs. The probability of a future ACV increased from 30% with one historical ACV to 87% with 5 or more historical ACVs. Outpatient visits with one historical ACV had significantly higher odds of a future ACV compared with those with no historical ACVs (adjusted odds ratio [OR], 3.60; 95% confidence interval [CI], 3.14-4.12; P < .001). The OR increased with each additional historical ACV to an adjusted OR of 58.71 (95% CI, 24.34-141.61; P < .001) with 5 or more historical ACVs. Outpatient visits with 5 or more historical ACVs represented only 1.1% of the study sample but accounted for a higher mean number of future ACVs.
  
  
  CONCLUSIONS
  The historical count of ACVs was predictive of future ACVs. A significant increase in the probability of future ACVs was observed with each additional historical visit, effectively stratifying risk by the historical visit count. Notably, a small group of patients accounted for a disproportionate number of future ACVs.
authors.affiliation: Department of Allergy, Asthma and Immunology, Children's Mercy Hospital, Kansas City, Missouri. Electronic address: jrhanson@cmh.edu.
authors.forename: Jill R
authors.initials: JR
authors.lastname: Hanson
authors.affiliation: Center for Clinical Effectiveness, Children's Mercy Hospital, Kansas City, Missouri.
authors.forename: Brian R
authors.initials: BR
authors.lastname: Lee
authors.affiliation: Department of Health Services and Outcomes Research, Children's Mercy Hospital, Kansas City, Missouri.
authors.forename: David D
authors.initials: DD
authors.lastname: Williams
authors.affiliation: Respiratory Care, Children's Mercy Hospital, Kansas City, Missouri.
authors.forename: Helen
authors.initials: H
authors.lastname: Murphy
authors.affiliation: Center for Environmental Health, Children's Mercy Hospital, Kansas City, Missouri.
authors.forename: Kevin
authors.initials: K
authors.lastname: Kennedy
authors.affiliation: Department of Health Services and Outcomes Research, Children's Mercy Hospital, Kansas City, Missouri.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: DeLurgio
authors.affiliation: Department of Allergy, Asthma and Immunology, Children's Mercy Hospital, Kansas City, Missouri.
authors.forename: Jay
authors.initials: J
authors.lastname: Portnoy
authors.affiliation: Department of Allergy, Asthma and Immunology, Children's Mercy Hospital, Kansas City, Missouri.
authors.forename: Mamta
authors.initials: M
authors.lastname: Reddy
mesh_terms: D000293:Adolescent; D000553:Ambulatory Care / Q000706:statistics & numerical data* / Q000639:trends; D001249:Asthma / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D008923:Missouri / Q000453:epidemiology; D008962:Models, Theoretical; D011320:Primary Health Care; D012044:Regression Analysis; D015203:Reproducibility of Results; D012306:Risk