Reducing the number of unplanned returns to hospital after treatment for peripheral artery disease

Improved, integrated care for older patients with complex medical needs could avert some modifiable causes of readmission

The incidence of peripheral artery disease (PAD) is rising around the world as populations age and the prevalence of diabetes, obesity, and cardiovascular disease increase.1 The clinical manifestations of lower limb PAD range from asymptomatic atherosclerosis and exertional pain caused by intermittent claudication, to chronic limb‐threatening ischaemia with rest pain, ulceration, and necrosis. Long term survival is poorer for patients with PAD than for people with many common cancers,1 and quality of life and patient‐reported outcomes are impaired.2 A recently published analysis of Global Burden of Disease Study data found that lower limb amputation rates were higher in Australia than in eighteen other high income countries, highlighting the need to improve outcomes for people with PAD.3

In this issue of the MJA, Woelk and colleagues report their analysis of routinely collected population health data to evaluate 30‐day unplanned readmissions of people admitted with PAD to public and most private hospitals in Australia and New Zealand (Aotearoa).4 More than one‐fifth of PAD‐related hospitalisations were followed by at least one planned or unplanned readmission within 30 days of discharge; just under one‐half of the readmissions were unplanned. A recent meta‐analysis of fourteen publications similarly found that readmission rates after PAD surgery ranged between 11% and 30%.5 The mean age of people who had unplanned readmissions was slightly higher than of those who did not, the clinical severity of their PAD was greater, and they more frequently had comorbid conditions.4 While disease progression was the major reason for unplanned readmissions, a substantial proportion were attributable to potentially modifiable causes, including peri‐operative complications, pneumonia, cellulitis, and sepsis.

A number of promising interventions aim to reduce the number of unplanned readmissions and to improve quality of care for people with PAD. Multidisciplinary models of care, such as collaborative care involving geriatricians or comprehensive geriatric assessment, can reduce hospital‐acquired complication rates, especially for the older patients with multiple clinical conditions who are readmitted more frequently than younger patients.6,7 Peri‐operative interventions, such as prehabilitation or allied health support, may also avert complications and reduce hospital length of stay, but less is known about how they influence readmission rates.7

Woelk and colleagues4 and investigators in other countries5,8 have reported that PAD severity and operative interventions are major predictors of unplanned readmission. PAD progression can be slowed by aggressive primary and secondary preventive care, and modifying secondary risk factors can reduce the risk of major adverse cardiac and limb events, including further interventions and amputation.9 Nevertheless, several studies have found considerable scope for improving cardiovascular risk prevention and medical therapy for people with PAD.5,9 Models for slowing disease progression using integrated care may avoid unplanned readmissions, but the influence of secondary risk prevention on acute unplanned readmission rates is unclear.4,5,7

In Australia and New Zealand, government‐supported data linkage services facilitate the analysis of routinely collected health data, and the value and limitations of these rich sources of information on population health outcomes are increasingly recognised.10 Such research provides unique opportunities for assessing outcomes for people with PAD at the national level and to identify factors which indicate that the intensity of hospital‐based treatment should be increased. However, routinely collected health data typically lack detailed anatomic and surgical descriptors, particularly for endovascular therapy. While Woelk and her co‐authors4 found that unplanned readmissions were more frequent after elective hospitalisations in which people with PAD underwent surgical or endovascular interventions, their analysis of the influence of revascularisation on readmission rates was limited.4 Planned Medicare Benefit Schedule reforms, including revision of the descriptors for endovascular procedure codes,11 will benefit future analyses of routinely collected health data.

Woelk and colleagues4 did not define “unplanned admissions”. Study endpoints for such analyses should be clearly defined outcome measures linked to standardised hospital performance metrics, such as mortality or readmission rates.10 If readmission rates are to be used as quality indicators, it is important that “unplanned readmission” be defined precisely, as coding of admission acuity varies between hospitals and confounding factors may obscure differences in quality of care.

Investigating the reasons for the high unplanned readmission rates for people with PAD is essential to providing quality patient‐centred care and improving long term outcomes. The study by Woelk and colleagues4 provides an important baseline for assessing PAD outcomes in Australia and New Zealand, and will assist clinicians and health care services design more nuanced and targeted models of care with the aim of reducing readmission rates.