Trends in unplanned readmissions over 15 years: a regional Australian perspective

Objective The aim of this study was to assess 15-year trends in unplanned readmissions in an Australian regional health service. Methods Drawing on data held in the Illawarra Health Information Platform (IHIP), this longitudinal retrospective study of adults admitted to hospital between 2001-02 and 2015-16 assessed rates of unplanned all-cause readmissions within 30 days ('early') and 1-6 months ('late') following discharge. Rates were compared over time and between patient groups. Results Age-adjusted early readmission rates declined over the 15 years by an average of 1.3% per annum, whereas late readmission rates increased by an average of 0.6% per annum. Together, there was an overall decline in readmission rates. The entire decline in early readmission rates and a reversal of the increasing trend in late readmission rates occurred since 2010-11. Similar trends occurred across age groups, but were most pronounced among those aged ≥75 years. Conclusions The decline in readmissions since 2010-11 suggests that the region has achieved improvements in discharge planning and in continuity between hospitals and community-based care. These improvements have occurred across broad patient groups. The longitudinal and linked data held in the IHIP provides a unique opportunity to examine patterns of service utilisation at a regional level. What is known about the topic? Published reports of longitudinal trends in readmissions are typically limited by short study periods and narrow criteria used to define study populations and readmissions. Australian longitudinal data suggest rates of early readmission have remained relatively unchanged in recent years, despite the focus on readmission rates as a metric to assess the quality and continuity of care. What does this paper add? This unique longitudinal study reports on long-term readmission trends over 15 years to hospitals within a single geographic area, with trends reported for both early (30-day) and late (1- to 6-month) readmissions by age group and major diagnostic categories. The findings reflect more complex patterns than are typically reported in cross-sectional and more limited longitudinal studies. What are the implications for practitioners? The results suggest improvements at a regional level that may be associated with care during the initial hospitalisation and discharge (reflected particularly in early readmissions) and in the community (reflected particularly in late readmissions). Future investigations will explore specific patient groups and the effects of specific initiatives, services and models of care to better predict those at risk of readmission and to inform translation locally and further afield. The relationship between readmissions and the use of ambulatory services (primary care, emergency department and out-patient) also warrants further investigation.