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.