We identified 2958 patients with community treatment orders from November 1997 to December 2008, and 2958 controls matched by age, sex and psychiatric diagnosis. The number of patients with community treatment orders per year varied between 221 and 324, equating to about 12 per 100 000 population. Of the patients with community treatment orders we identified, 2398 (81.1%) were given the orders on discharge from hospital, whereas 560 were issued orders in the community. The mean age of patients with community treatment orders was 36.7 (standard deviation [SD] 13.6) years, and 1885 (63.7%) of them were men. The most common diagnoses among participants were schizophrenia and other nonaffective psychoses (73.4%), followed by affective disorders (14.4%).
Matching of cases and controls was successful, in that there were no significant differences in age, sex or diagnosis (). Patients in the case group were more likely than controls to have always been single or born outside of Australia; they were less likely to be engaged in work, study or home duties, or to have been admitted to hospital for nonpsychiatric reasons (a measure of physical comorbidity). In addition, patients with community treatment orders had greater overall use of health services, both during the year before their order was issued and before community treatment orders were implemented in 1997 (). There were no other differences between the two groups, including length of psychiatric history before being given a community treatment order.
Characteristics of patients with (case group) or without (control group) community treatment orders
During the 11 years of follow-up, 492 participants (cases and controls combined, 8.3%) died. Only 6.5% of patients with community treatment orders died during this period (206/2958), compared with 9.6% of controls (286/2958) (OR 0.70, 95% confidence interval [CI] 0.58–0.84).
Mortality at 2-years’ follow-up
A total of 163 patients died within 2 years of their index date. The causes of death included deliberate self-harm (n = 39), accidental injury (n = 35) and physical illness (n = 67). Of the deaths resulting from physical illness, 38 were due to cancer, cardiovascular disease or diseases of the central nervous system. The cause of death was unknown for 22 patients. Compared with controls, patients with community treatment orders were less likely to die in the 2 years after their index date (Kaplan–Meier survival analysis, log-rank χ2 5.14, p = 0.02).
Compared with controls, patients with community treatment orders had nearly one-half of the all-cause risk of death (Wald 8.27, p = 0.004) ( and ). Older patients had higher all-cause mortality. A greater number of psychiatric outpatient contacts and nonpsychiatric admissions were associated with increased risk of death, whereas rural residence was associated with reduced risk (). We found similar results with stepwise regression, when we restricted the models to involuntary treatment before receiving a community treatment order while keeping all other variables, and when we used log-transformed data for all of the continuous variables. In addition, we found similar results using propensity score analysis (adjusted hazard ratio [HR] 0.63, 95% CI 0.44–0.90; Wald 6.55, p = 0.01).
Predictors of death within 2 years of receiving a community treatment order or discharge from hospital for patients without a community treatment order
Mortality curves for patients with community treatment orders (cases) and their matched controls at 2-years’ follow-up. HR = hazard ratio.
Compared with patients in the control group, patients with community treatment orders had a significantly higher number of psychiatric admissions (0.31 [SD 4.40] v. 0.22 [SD 3.97]; t test 8.55), bed-days (0.90 [SD 16.98] v. 0.41 [SD 10.71]; t test 11.71) and psychiatric outpatient contacts (10.23 [SD 8.79] v. 2.81 [SD 14.41]; t test 20.23) (5914 degrees of freedom, all p < 0.001). Including psychiatric admissions or bed-days in the Cox regression had no effect on our results, but including psychiatric outpatient contacts did — the greater the number of outpatient contacts, the lower the subsequent all-cause mortality (adjusted HR 0.61, 95% CI 0.50–0.75; Wald 27.94, p < 0.001). When we adjusted for psychiatric outpatient contacts, community treatment orders no longer showed an association with all-cause mortality (adjusted HR 0.79, 95% CI 0.55–1.13; Wald 1.66, p = 0.19).
In terms of subgroup analysis, removing deaths by suicide made no difference to our results (adjusted HR 0.55, 95% CI 0.38–0.81; Wald 9.48, p = 0.002). By cause of death, the strongest effect was seen in deaths from cancer, cardiovascular disease or diseases of the central nervous system (adjusted HR0.28, 95% CI 0.13–0.61; Wald 9.21, p = 0.001).
In terms of sensitivity analyses, replacing use of health services during the year before the community treatment order was issued with use of health services before community treatment orders were implemented in 1997 had no effect on the association between community treatment orders and reduced all-cause mortality (adjusted HR 0.67, 95% CI 0.50–0.95; Wald 5.49, p = 0.02). Restricting admissions during the year before the community treatment order was issued to only those that were involuntary also showed no effect on this association (adjusted HR 0.61, 95% CI 0.43–0.87; Wald 7.39, p = 0.01). We found similar results when we restricted our sample to patients who were given community treatment orders on discharge from hospital (n = 2398). In this population of patients and matched controls, there were 154 deaths (58 patients with community treatment orders, 96 controls; adjusted HR 0.65, 95% CI 0.46–0.92; Wald 5.81, p = 0.01).
We calculated the NNT to avoid a single death over a 2-year follow-up to be 102.
Mortality at 1 and 3 years’ follow-up
A total of 91 patients died during the year after they received their community treatment order (35 patients with community treatment orders, 56 controls). Patients with a community treatment order had a significant reduction in all-cause mortality (adjusted HR 0.58, 95% CI 0.37–0.90; Wald 5.80, p = 0.003). The same was true for the 234 patients who died before the 3-year follow-up (103 patients with community treatment orders, 131 controls; adjusted HR 0.72, 95% CI 0.55–0.95; Wald 5.50, p = 0.02).