title: Heavy users of emergency services: a population-based review.
authors.forename: H J
authors.initials: HJ
authors.lastname: Ovens
authors.forename: B T
authors.initials: BT
authors.lastname: Chan
mesh_terms: D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D009864:Ontario; D014600:Utilization Review / Q000379:methods