title: Distinctive trajectory groups of mental health functioning among assertive community treatment clients: an application of growth mixture modelling analysis.
abstract: OBJECTIVE
  Assertive community treatment (ACT) studies that have used conventional, statistical growth modelling methods have not examined different trajectories of outcomes or covariates that could influence different trajectories, even though heterogeneity in outcomes has been established in other research on severe mental illness. The purpose of our study was to examine the general trend in mental health functioning of ACT clients over a 2-year follow-up time period, to discover groups of ACT clients with distinctive longitudinal trajectories of mental health functioning, and to examine if some of the key sociodemographic and illness-related factors influence group membership.
  
  
  METHODS
  A 2-year, prospective, within-subjects study of 216 ACT clients within southern Ontario, collected functional outcome data at baseline and 12 and 24 months using the Colorado Client Assessment Record. Baseline covariates included sex, primary diagnosis, number of comorbidities, hospitalization history, and duration of illness. Growth mixture modelling (GMM) was used to examine trajectories.
  
  
  RESULTS
  Clinical staff assessments of ACT clients showed a statistically significant improvement in functioning and 84% achieved successful community tenure. GMM analysis identified 2 classes of ACT clients: class 1 (79.63% of clients) experienced lower and stable overall functioning, and class 2 (20.37%) showed a better baseline functioning score and improvement in the overall functioning over time. Class membership was predicted by the number of comorbidities and diagnosis.
  
  
  CONCLUSIONS
  Our study suggests general stability in overall functioning for the sampled ACT clients over 2 years, but significant heterogeneity in trajectories of functioning.
authors: Assistant Professor, Departments of Epidemiology and Biostatistics, The University of Western Ontario, London, Ontario; Scientist, Children's Health Research Institute, London, Ontario.
authors: Piotr
authors: P
authors: Wilk
authors: Professor, Departments of Family Medicine and Epidemiology and Biostatistics, The University of Western Ontario, London, Ontario; Director, Population and Community Health Unit, Department of Family Medicine, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario.
authors: Evelyn
authors: E
authors: Vingilis
authors: Psychiatrist, Psychosocial Rehabilitation Program, Waypoint Centre for Mental Health Care, Penetanguishene, Ontario; Professor Emeritus, Department of Psychiatry, The University of Western Ontario, London, Ontario.
authors: Joan E H
authors: JE
authors: Bishop
authors: Associate Professor, Statistical and Actuarial Sciences, The University of Western Ontario, London, Ontario.
authors: Wenqing
authors: W
authors: He
authors: Professor, Statistical and Actuarial Sciences, The University of Western Ontario, London, Ontario.
authors: John
authors: J
authors: Braun
authors: Associate Director Nursing Research, Arthur Labatt Family School of Nursing, The University of Western Ontario, London, Ontario; Assistant Director, Lawson Health Research Institute, London, Ontario.
authors: Cheryl
authors: C
authors: Forchuk
authors: Project Coordinator, Department of Family Medicine, The University of Western Ontario, London, Ontario.
authors: Jane
authors: J
authors: Seeley
authors: Director, Mental Health Care Program, London Health Sciences Centre, London, Ontario.
authors: Beth
authors: B
authors: Mitchell
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000628:therapy*; D003156:Community Mental Health Services / Q000379:methods*; D018450:Disease Progression; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009864:Ontario; D011446:Prospective Studies; D011618:Psychotic Disorders / Q000628:therapy*; D012559:Schizophrenia / Q000628:therapy*; D016896:Treatment Outcome
keywords: Colorado Client Assessment Record; Ontario; assertive community treatment; growth mixture modelling; mental health functioning; serious mental illness