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Australian Health Review Australian Health Review Society
Journal of the Australian Healthcare & Hospitals Association
RESEARCH ARTICLE

Prevalence and characteristics of potentially avoidable unplanned readmissions: a retrospective cohort study

Yogesh Sharma A B * , Arduino A. Mangoni B , Sudhir Rao https://orcid.org/0000-0003-2573-2577 A , Isuru Kariyawasam Batuwaththagamage A , Billingsley Kaambwa B , Richard Woodman B , Chris Horwood A and Campbell Thompson C
+ Author Affiliations
- Author Affiliations

A Department of Acute and General Medicine, Flinders Medical Centre, Adelaide, SA, Australia.

B College of Medicine & Public Health, Flinders University, Adelaide, SA, Australia.

C Discipline of Medicine, The University of Adelaide, Adelaide, SA, Australia.

* Correspondence to: Yogesh.Sharma@sa.gov.com

Australian Health Review 49, AH24261 https://doi.org/10.1071/AH24261
Submitted: 17 September 2024  Accepted: 9 June 2025  Published: 1 July 2025

© 2025 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of AHHA.

Abstract

Objective

Unplanned readmissions are key indicators of hospital care quality, yet research on potentially avoidable unplanned readmissions (PAURs) remains limited. This study aimed to assess the prevalence, causes, and predictors of PAURs in an Australian tertiary hospital.

Methods

This retrospective cohort study included all unplanned readmissions to a general medicine unit between 1 July and 30 September 2022, in South Australia. Patients aged ≥18 years readmitted within 30 days of discharge were included. A panel of senior clinicians assessed the preventability of each readmission using predefined criteria. Data on demographics, comorbidities, frailty, inflammatory markers, and discharge factors were collected. Predictors of PAURs were examined using multivariable logistic regression and LASSO (least absolute shrinkage and selection operator) regression for sensitivity analysis.

Results

Among 381 readmissions, 80 (21%) were classified as potentially avoidable. The mean age was 68.7 years (s.d. 18.2), and 58.3% were female. The most common cause of PAURs was relapse of the condition treated during the index admission (43%), followed by treatment-related complications (22.8%). Contributing factors included suboptimal care during the index admission (43.8%) and inadequate post-discharge follow-up (30%). Compared to non-avoidable readmissions, PAUR patients were older, more frequently readmitted within 7 days, and had higher rates of coronary artery disease and congestive heart failure (CHF). They also had higher neutrophil-to-lymphocyte ratios (NLR) on admission. Multivariable analysis identified CHF (aOR 2.46, 95% CI 1.28–4.71) and elevated NLR (aOR 1.05, 95% CI 1.02–1.08) as independent predictors.

Conclusions

Over one in five readmissions were potentially avoidable, and only a few patient characteristics can predict avoidable readmissions.

Keywords: congestive heart failure, discharge planning, discharge summary quality, health service quality, post-discharge follow-up, potentially avoidable readmissions, readmission predictors, unplanned hospital readmission.

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