title: Frequent-user subgroups.
authors.forename: E S
authors.initials: ES
authors.lastname: Casper
authors.forename: J R
authors.initials: JR
authors.lastname: Regan
mesh_terms: D016000:Cluster Analysis; D003156:Community Mental Health Services / Q000706:statistics & numerical data*; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D001523:Mental Disorders / Q000453:epidemiology* / Q000628:therapy*