Incidence and causes of early unplanned readmission after hospitalisation with peripheral arterial disease in Australia and New Zealand

Objective: To evaluate the characteristics and predictors of unplanned readmission within 30 days of hospitalisation for the treatment of peripheral arterial disease (PAD) in Australia and New Zealand. Design: Analysis of hospitalisations data in the Admitted Patient Collection for each Australian state and territory and the New Zealand National Minimum Dataset (Hospital Events). Setting: All public and 80% of private hospitals in Australia and New Zealand. Participants: Adults (18 years or older) hospitalised with a primary or conditional secondary diagnosis of PAD during 1 January 2010 ‒ 31 December 2015. Main outcome measure: Rate of unplanned readmission (any cause) within 30 days of hospitalisation with PAD. Results: Of 104 979 admissions included in our analysis (mean patient age, 73.7 years; SD, 12.4 years), 9765 were followed by at least one unplanned readmission within 30 days of discharge (9.3%): 3395 within one week (34.8%) and 7828 within three weeks (80.2%). The most frequent readmission primary diagnoses were atherosclerosis (1477, 15.3%), type 2 diabetes (1057, 10.8%), and “complications of procedures not elsewhere classified” (963, 9.9%). Readmission was more frequent after acute (4830 of 26 304, 18.4%) than elective PAD hospitalisations (4935 of 78 675, 6.3%), but the readmission characteristics were similar. Factors associated with greater likelihood of readmission included acute PAD hospitalisations (odds ratio [OR], 2.04; 95% CI, 1.96‒2.17), surgical intervention during the PAD hospitalisation (OR, 1.74; 95% CI, 1.64–1.84), and chronic limb-threatening ischaemia (OR, 1.55; 95% CI, 1.47–1.63). Conclusion: Unplanned readmissions within 30 days of hospitalisation for PAD are often for potentially preventable reasons. Their number should be reduced to improve clinical outcomes for people with PAD.