title: Predictors of mental health-related acute service utilisation and treatment costs in the 12 months following an acute psychiatric admission.
abstract: OBJECTIVE
  A key step in informing mental health resource allocation is to identify the predictors of service utilisation and costs. This project aims to identify the predictors of mental health-related acute service utilisation and treatment costs in the year following an acute public psychiatric hospital admission.
  
  
  METHODS
  A dataset containing administrative and routinely measured outcome data for 1 year before and after an acute psychiatric admission for 1757 public mental health patients was analysed. Multivariate regression models were developed to identify patient- and treatment-related predictors of four measures of service utilisation or cost: (a) duration of index admission; and, in the year after discharge from the index admission (b) acute psychiatric inpatient bed-days; (c) emergency department (ED) presentations; and (d) total acute mental health service costs. Split-sample cross-validation was used.
  
  
  RESULTS
  A diagnosis of psychosis, problems with living conditions and prior acute psychiatric inpatient bed-days predicted a longer duration of index admission, while prior ED presentations and self-harm predicted a shorter duration. A greater number of acute psychiatric inpatient bed-days in the year post-discharge were predicted by psychosis diagnosis, problems with living conditions and prior acute psychiatric inpatient admissions. The number of future ED presentations was predicted by past ED presentations. For total acute care costs, diagnosis of psychosis was the strongest predictor. Illness acuity and prior acute psychiatric inpatient admission also predicted higher costs, while self-harm predicted lower costs.
  
  
  CONCLUSIONS
  The development of effective models for predicting acute mental health treatment costs using existing administrative data is an essential step towards a workable activity-based funding model for mental health. Future studies would benefit from the inclusion of a wider range of variables, including ethnicity, clinical complexity, cognition, mental health legal status, electroconvulsive therapy, problems with activities of daily living and community contacts.
authors.affiliation: Policy and Epidemiology Group, Queensland Centre for Mental Health Research, Queensland Health, Brisbane, Australia School of Population Health, The University of Queensland, Brisbane, Australia Diamantina Health Partners, Neuroscience, Recovery and Mental Health, Brisbane, Australia Metro South Addiction and Mental Health Service, Brisbane, Australia d.siskind@uq.edu.au.
authors.forename: Dan
authors.initials: D
authors.lastname: Siskind
authors.affiliation: Policy and Epidemiology Group, Queensland Centre for Mental Health Research, Queensland Health, Brisbane, Australia School of Population Health, The University of Queensland, Brisbane, Australia.
authors.forename: Meredith
authors.initials: M
authors.lastname: Harris
authors.affiliation: Policy and Epidemiology Group, Queensland Centre for Mental Health Research, Queensland Health, Brisbane, Australia School of Population Health, The University of Queensland, Brisbane, Australia.
authors.forename: Sandra
authors.initials: S
authors.lastname: Diminic
authors.affiliation: Policy and Epidemiology Group, Queensland Centre for Mental Health Research, Queensland Health, Brisbane, Australia School of Population Health, The University of Queensland, Brisbane, Australia.
authors.forename: Georgia
authors.initials: G
authors.lastname: Carstensen
authors.affiliation: Diamantina Health Partners, Neuroscience, Recovery and Mental Health, Brisbane, Australia Metro South Addiction and Mental Health Service, Brisbane, Australia Griffith Health Institute, Griffith University, Logan Academic Campus, Meadowbrook, Australia.
authors.forename: Gail
authors.initials: G
authors.lastname: Robinson
authors.affiliation: Policy and Epidemiology Group, Queensland Centre for Mental Health Research, Queensland Health, Brisbane, Australia School of Population Health, The University of Queensland, Brisbane, Australia.
authors.forename: Harvey
authors.initials: H
authors.lastname: Whiteford
mesh_terms: D000328:Adult; D001315:Australia / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D017048:Health Care Costs / Q000706:statistics & numerical data*; D006760:Hospitalization / Q000706:statistics & numerical data*; D006778:Hospitals, Psychiatric / Q000706:statistics & numerical data*; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D001523:Mental Disorders / Q000191:economics* / Q000453:epidemiology / Q000628:therapy*; D008605:Mental Health Services / Q000706:statistics & numerical data*
keywords: Health service costs; mental disorders; mental health services; service utilisation