title: Space and time clustering of adolescents' emergency department use and post-visit physician care for mood disorders in Alberta, Canada: A population-based 9-year retrospective study.
abstract: OBJECTIVE
  We used a statistical cluster detection technique to identify geographic areas with higher numbers of adolescents who 1) presented to an emergency department (ED) for a mood disorder, and 2) were without a physician follow-up visit for mental health within 30 days of an ED visit.
  
  
  METHODS
  We conducted a population-based analysis of ED visits (n = 6,829) made by adolescents aged 10-17 years (n = 5,877) using administrative databases from Alberta, Canada (2002-2011). Statistical analyses included summaries, directly standardized rates (DSRs per 100,000), and the spatial scan cluster test.
  
  
  RESULTS
  Sex- and age-adjusted DSRs increased by 21.8% from 2002 to 2011 (160.2/100,000 to 195.1/100,000). Northern Alberta had consistently higher DSRs than other areas of the province and areas in the north, southwest and central parts were identified as geographical and temporal clusters with relative risks of 1.67, 2.78 and 1.42 respectively. Many of these areas also had higher relative risks for adolescents who did not have a mental health-related visit with a physician within 30 days of the ED visit. About 32% (n = 1,870) did not have a post-ED physician visit.
  
  
  CONCLUSIONS
  The potential clusters identified may represent geographic areas with higher disease severity or more acute care sought because of less availability of other services. The clusters are not all likely to have occurred by chance and further investigations and discussions with local health care policy makers about reducing the number of ED visits for mood disorders and increasing physician follow-up after the ED visit is an important next step.
authors.affiliation: University of Alberta. rhonda.rosychuk@ualberta.ca.
authors.forename: Rhonda J
authors.initials: RJ
authors.lastname: Rosychuk
authors.forename: Amanda S
authors.initials: AS
authors.lastname: Newton
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Niu
authors.forename: Liana
authors.initials: L
authors.lastname: Urichuk
mesh_terms: D000293:Adolescent; D000416:Alberta; D002648:Child; D003266:Continuity of Patient Care / Q000706:statistics & numerical data*; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D019964:Mood Disorders / Q000628:therapy*; D010820:Physicians / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D013029:Space-Time Clustering
keywords: Adolescence; cluster analysis; disease clustering; emergency services; mood disorders; space-time clustering