Variation in seclusion rates across New Zealand's specialist mental health services: Are sociodemographic and clinical factors influencing this?

Rates of seclusion vary across New Zealand's publicly funded district health board (DHB) adult mental health inpatient services as indicated by national data. Anecdotally, this variation has been attributed to a range of factors directly relating to the people admitted to acute inpatient services. This study examined the extent to which variation in seclusion rates could be explained by the sociodemographic and clinical differences between populations admitted into adult mental health inpatient services. Retrospective data were obtained from the Programme for the Integration of Mental Health Data (PRIMHD). A logistic regression model was fitted to these data, with seclusion (yes/no) as the dependent variable and DHB groups as the independent variable. The DHBs were classified into four groups based on their seclusion rates. The model adjusted for ethnicity, age, number of bed nights, total Health of the Nation Outcome Scales (HoNOS) scores, and compulsory treatment status. Odds ratios remained virtually unchanged after adjustment for sociodemographic and clinical factors. People admitted to DHB Group 4 (highest secluding DHBs) were 11 times more likely to be secluded than people in Group 1 (lowest secluding DHBs), adjusted OR = 11.1, 95% CI [7.5,16.4], P < 0.001. Results indicate DHB variation in seclusion rates cannot be attributed to the sociodemographic and clinical factors of people admitted into DHB adult mental health inpatient services. Instead, this variation may be explained by differences in service delivery models and practice approaches. A model of system improvements aimed at reducing seclusion is discussed.