Abstract
Objectives: To investigate predictors of outcome and cost for patients treated by Mental Health Services in the south metropolitan area of Perth using logistic regression to control for potential confounding factors.
Method: Data were collected over a 3-month period on 2691 subjects (47% male, 53% female) as part of the Mental Health Classification and Services Cost Project.
Results: The average age of subjects was 44.3 years. Nearly 80% of care occurred in community settings and virtually all inpatient care was for acute emergencies. The most common diagnosis was schizophrenia (33%) followed by mood disorders (30%). Within the study period, 88% of patients had only one episode of care (n = 2361) and a further 8% two (n = 223). Patients with schizophrenia were one-third as likely to be discharged from care (95% Cl = 0.2–0.4) and 30% as likely to have longer episodes of care (95% Cl = 1.1–1.6). Patients with personality, substance or adjustment disorders spent less time in treatment, and those with personality or substance disorders were more likely to be discharged from psychiatric care. A past history of inpatient care was associated with a worse outcome in terms of length of care, or not being successfully discharged. Severity of illness as determined by involuntary treatment or elevated Health of the Nation Outcome Scales and Life Skills Profile (LSP) scores was associated with increased costs. Greater disability on the LSP was also associated with increased length of care. Sociodemographic factors were as least as important as diagnosis in predicting the cost and outcome of treatment.
Conclusions: Demographic factors may better predict increased health service use than diagnostic casemix. Since sociodemographic variables contribute as much to outcome as diagnosis, comparing results between units is likely to be misleading unless adjusted for these factors.