title: Alcoholism treatment episodes validly defined using mental health care utilization records.
abstract: OBJECTIVE
  We propose a method for defining and empirically validating episodes of alcoholism treatment from health care utilization records.
  
  
  METHODS
  The study includes utilization records from 86,207 patients enrolled in a large managed behavioral care company who had at least one alcoholism encounter between 1991 and 1998. Treatment episodes are defined as a minimum number of alcoholism treatment encounters with the behavioral care company prior to a "clear zone" of no encounters. Statistical procedures to select a subset of episode definitions from a number of candidate definitions and methods for assessing the convergent and criterion validity of the definitions are presented.
  
  
  RESULTS
  The percentage of patients having at least one episode of alcoholism treatment varies from 43% to 77%, with the results being more sensitive to the minimum number of encounters required than the length of the clear zone. Criterion validity does not reveal any clear "winning" definitions; positive predictive ability increases most rapidly when going from 2 to 3 encounters required.
  
  
  CONCLUSIONS
  The most robust definitions of an alcoholism treatment episode entail 3 to 4 encounters with a clear zone of 3 to 4 months.
authors.affiliation: Division of Biostatistics, University of Minnesota School of Public Health, Mail Code 303, 420 Delaware Street SE, Minneapolis, MN 55455, USA. melanie@biostat.umn.edu
authors.forename: Melanie M
authors.initials: MM
authors.lastname: Wall
authors.forename: Kurt D
authors.initials: KD
authors.lastname: Stromberg
authors.forename: Sandra
authors.initials: S
authors.lastname: Pothoff
authors.forename: Robert L
authors.initials: RL
authors.lastname: Kane
mesh_terms: D000437:Alcoholism / Q000628:therapy*; D017050:Episode of Care; D006801:Humans; D008499:Medical Records / Q000706:statistics & numerical data; D008605:Mental Health Services / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D013223:Statistics as Topic; D013997:Time Factors; D014481:United States