Table 3

Comparison of studies on disparities in PAD treatment and outcomes

Study	Population characteristics	Data source	Exposure with disparity assessed SES measure	SES measure	Pertinent findings
Current study	N=21 673 United States	VQI registry data and Medicare claims data	Medicare–Medicaid dual-eligible patients	Medicare–Medicaid dual-eligibility status	The delay in insurance for dual-eligible patients with PAD and subsequent delay in intervention cause worse postoperative outcomes when the patient presents with severe disease at the time of surgery.
O’Donnell et al26	N=90 418 USA and Canada	VQI registry data	Race	Insurance status (Medicaid or self-insured vs other)	Racial disparities in outcomes, regional variation in preoperative treatments but not postoperative
Arya et al13	N=155 647 USA	Veterans Affairs Corporate Data Warehouse	Race and SES	Median household income in residential zip code. Neighbourhood poverty level. Area Deprivation Index.	Low SES increases the risk of amputation. This finding suggests a role for early diagnosis and aggressive management of PAD in black patients.
Leifheit et al10	N=505 955	Medicare claims data	Medicare–Medicaid dual-eligible patients	Medicare–Medicaid dual-eligibility status	Dual-eligible patients had higher rates of hospitalisation and 1 year mortality than Medicare only patients with PAD.
McDermott et al27	N=1162 USA (Chicago only)	WALCS, WALCS II, WALCS III and Biomarker Risk Assessment in Vulnerable Outpatients Study	Race, SES and education level.	Education level. Median household income in residential zip code.	Black patients with PAD have higher rates of mobility loss and becoming unable to walk for 6 min continuously. These differences appear related to racial differences in SES.
Roumia et al28	N=1275 USA, Netherlands and Australia	Patient-Centred Outcomes Related to Treatment Practices in Peripheral Arterial Disease: Investigating Trajectories	Sex	Insurance status. Delayed care due to cost.	As compared with men, women more often lacked health insurance and avoided care due to cost. Women had poorer PAD-specific functioning as compared with men, impacting all major health status domains, independent of socioeconomic and clinical characteristics.
Vart et al25	N=12 517 USA (Midwest and Southeast)	Atherosclerosis Risk in Communities Study	SES, Area Deprivation Index (ADI)	Annual household income Educational attainment. Area Deprivation Index.	Incomes under $25K, education attainment less than high school and being in the highest quintile of the ADI are associated with higher rates of hospitalisation due to PAD.

ADI, Area Deprevation Index; PAD, peripheral artery disease; SES, socioeconomic status; VQI, Vascular Quality Initiative; WALCS, Walking and Leg Circulation Study.