TY - JOUR T1 - Characteristics of patients with mental illness and persistent high-cost status: a population-based analysis JF - Canadian Medical Association Journal JO - CMAJ SP - E1793 LP - E1801 DO - 10.1503/cmaj.200274 VL - 192 IS - 50 AU - Claire de Oliveira AU - Joyce Mason AU - Paul Kurdyak Y1 - 2020/12/14 UR - http://www.cmaj.ca/content/192/50/E1793.abstract N2 - BACKGROUND: Most of the literature on high-cost users of health care has evaluated this population as a whole, but few studies have focused on high-cost patients with mental illness and whether they persist in the high-cost state. We sought to analyze this patient population in depth and determine predictors of persistency in the high-cost state.METHODS: We used 8 years of longitudinal patient-level population data (2010–2017) from Ontario to follow high-cost patients (those in and above the 90th percentile of the cost distribution) with mental illness. We classified high-cost status, based on the proportion of the study period that patients spent in the high-cost state, as persistent (6–8 yr), sporadic (1–2 yr) or moderate (3–5 yr). We compared characteristics between groups and determined predictors of being a patient with mental illness and persistent high-cost status.RESULTS: Among 52 638 patients with mental illness and high-cost status, 18 149 (34.5%) were considered persistent high cost. These patients had higher mean annual costs of care ($44 714, 95% confidence interval [CI] $43 724–$45 703) than patients with sporadic ($23 205, 95% CI $22 741–$23 668) and moderate ($31 055, 95% CI $30 359–31 751) status, largely owing to psychiatric hospital admissions. Patients with mental illness and persistent high-cost status were more likely to be female, older, long-term residents of Ontario (information ascertained from the Immigrants, Refugees and Citizenship Canada Database), living in low-income or urban areas, or to have comorbidities. The strongest predictors of persistent (v. sporadic) high-cost status were HIV (relative risk ratio [RRR] 4.32, 95% CI 3.08–6.06), psychosis (RRR 3.41, 95% CI 3.25–3.58) and dementia (RRR 3.21, 95% CI 2.81–3.68).INTERPRETATION: Among patients with mental illness and high-cost status, persistence in the high-cost state was determined mainly by psychosis and other comorbidities. Quality-of-care interventions directed at managing psychosis and multimorbidity, as well as preventive interventions to target patients with mental illness before they enter the persistent high-cost state, are needed. ER -