Emergency department presentation and readmission after index psychiatric admission: a data linkage study

OBJECTIVE: To use linked administrative datasets to assess factors associated with emergency department (ED) presentation and psychiatric readmission in three distinctive time intervals after the index psychiatric admission. DESIGN: A retrospective data-linkage study. SETTING: Cohort study using four linked government minimum datasets including acute hospital care from July 2005 to June 2012 in New South Wales, Australia. PARTICIPANTS: People who were alive and aged ≥18 years on 1 July 2005 and who had their index admission to a psychiatric ward from 1 July 2007 to 30 June 2010. OUTCOME MEASURES: ORs of factors associated with psychiatric admission and ED presentation were calculated for three intervals: 0–1 month, 2–5 months and 6–24 months after index separation. RESULTS: Index admission was identified in 35 056 individuals (51% -males) with a median age of 42 years. A total of 12 826 (37%) individuals had at least one ED presentation in the 24 months after index admission. Of those, 3608 (28%) presented within 0–1 month, 6350 (50%) within 2–5 months and 10 294 (80%) within 6–24 months after index admission. A total of 14 153 (40%) individuals had at least one psychiatric readmission in the first 24 months. Of those, 6808 (48%) were admitted within 0–1 month, 6433 (45%) within 2–5 months and 7649 (54%) within 6–24 months after index admission. Principal diagnoses and length of stay at index admission, sociodemographic factors, Charlson Comorbidity Index score, drug and alcohol comorbidity, intellectual disability and other inpatient service use were significantly associated with ED presentations and psychiatric readmissions, and these relationships varied somewhat over the intervals studied. CONCLUSION: Social determinants of service use, drug and alcohol intervention, addressing needs of individuals with intellectual disability and recovery-oriented whole-person approaches at index admission are key areas for investment to improve trajectories after index admission.