Racial and Ethnic Disparities in Treatment of Critical Limb Ischemia: A National Perspective

Abstract

Background

Recent guidelines have emphasized the use of medical management, early diagnosis, and a multidisciplinary team to effectively treat patients with critical limb ischemia (CLI). Previous literature briefly highlighted the current racial disparities in its intervention. Herein, we analyze the trend over a 14‐year time period to investigate whether the disparities gap in CLI management is closing.

Methods and Results

The National Inpatient Sample was queried between 2005 and 2018 for hospitalizations involving CLI. Nontraumatic amputations and revascularization were identified. Utilization trends of these procedures were compared between races (White, Black, Hispanic, Asian and Pacific Islander, Native American, and Other). Multivariable regression assessed differences in race regarding procedure usage. There were 6 904 562 admissions involving CLI in the 14‐year study period. The rate of admissions in White patients who received any revascularization decreased by 0.23% (P<0.001) and decreased by 0.25% (P=0.025) for Asian and Pacific Islander patients. Among all patients, the annual rate of admission in White patients who received any amputation increased by 0.21% (P<0.001), increased by 0.19% (P=0.001) for Hispanic patients, and increased by 0.19% (P=0.012) for the Other race patients. Admissions involving Black, Hispanic, Asian and Pacific Islander, or Other race patients had higher odds of receiving any revascularization compared with White patients. All races had higher odds of receiving major amputation compared with White patients.

Conclusions

Our analysis highlights disparities in CLI treatment in our nationally representative sample. Non‐White patients are more likely to receive invasive treatments, including major amputations and revascularization for CLI, compared with White patients.

Nonstandard Abbreviations and Acronyms

CLI

critical limb ischemia

NIS

National Inpatient Sample

Clinical Perspective.

What Is New?

• In a national data set, disparities in critical limb ischemia treatment were identified. Although the general rates of revascularization are decreasing, non‐White patients with critical limb ischemia still receive more invasive therapy.

• Amputation rates are also higher among non‐White patients.

What Are the Clinical Implications?

• Our data highlight the importance of screening among patients with peripheral artery disease.

• Specialty vascular clinics and the emphasis on management of peripheral artery disease risk factors are some impactful methods of reducing gaps in quality of care.

• It begins with patient education and screening in the primary care setting and increasing referrals to vascular specialists to improve outcomes.

Peripheral artery disease (PAD) affects ≈230 million patients worldwide. ¹ Of these, roughly 11% present with critical limb ischemia (CLI), which has a poor prognosis. ¹ Patients with CLI have a mortality risk as high as 20% within 6 months of diagnosis, and 1 in 2 patients die within 5 years. ² Current guidelines emphasize the use of medical management, early diagnosis, and a multidisciplinary approach to effectively treat patients with peripheral vascular disease. ³ , ⁴ , ⁵ Over the years, treatment for this disease process has evolved, with new innovations enabling more endovascular and hybrid therapies. ⁶ Despite these advances, lower extremity amputations still occur, especially among patients with advanced disease. ⁶

Historically, Black patients were disproportionately affected by CLI and less likely to receive timely treatment. ⁷ , ⁸ As a result, they experience greater morbidity from higher amputation rates compared with White patients. ⁹ , ¹⁰ , ¹¹ , ¹² This stems in part from inherent social determinants of health, in which they do not receive adequate health care. ¹³ Previous studies have demonstrated that among Medicare beneficiaries, there was a higher incidence in endovascular intervention among Black patients compared with White patients and higher rates of adverse events attributable to higher burden of comorbidities. ¹⁴ With the evolution of new practice guidelines and the importance of racial disparities in treatment for CLI, it is imperative to investigate whether these disparities are seen in a broader population nationally. The purpose of this paper was to analyze the outcomes of CLI admissions over a 14‐year time period using the Nationwide Inpatient Sample (NIS) database to determine if the racial disparity gaps in treatment are closing.

Methods

All data used in this study can be purchased from the Healthcare Cost and Utilization Project and can be accessed at https://www.distributor.hcup‐us.ahrq.gov/. Analytical methods used in this study are all available within the article.

Data Source

The NIS database was queried from January 1, 2005, to December 31, 2018. This database is created by the Healthcare Cost and Utilization Project, which samples ≈7 million hospitalized patients per year representing 20% of all discharges annually. To improve national estimates, the sampling methods changed in 2012 to the current method. The Healthcare Cost and Utilization Project released the methodology to retroactively adjust national estimates for years before 2012. ¹⁵ This database is the largest public national all‐payer database, sponsored by the Agency for Healthcare Research and Quality. ¹⁵ Furthermore, the NIS contains weighted discharge information that allows investigators to extrapolate data to national estimates. Institutional review board approval was not required for this study; all included data were deidentified.

Cohort Selection

The International Classification of Diseases, Ninth and Tenth Revisions (ICD‐9 and ICD‐10), were used to identify hospitalizations involving PAD or CLI. Only primary and secondary diagnoses were considered. Hospitalizations including diagnosis codes for CLI only or PAD + CLI were then further identified from this cohort. Thus, admissions involving PAD only were omitted. The flowchart depicting the creation of the analytic cohort for this study is shown in Figure S1. The frequencies of admissions were stable between 2015 and 2016, giving confidence that the crosswalk from ICD‐9 and ICD‐10 was satisfactory. Procedures including amputations (minor and major) and revascularization (surgical and endovascular) were identified. Minor amputation included below‐ankle amputations, and major amputations included any lower extremity amputation proximal to the ankle. If an admission contained ICD codes for both minor and major amputation, this hospitalization was categorized as a major amputation. Additionally, admissions that contained both surgical and endovascular revascularization were categorized as hybrid revascularization. Smoking (nonsmoker, former smoker, current smoker) and dialysis status were also identified. Admissions involving patients under the age of 18 years, or admissions with missing data on race, were excluded. All included ICD‐9 and ICD‐10 codes are available in Table S1. Codes were derived from previous publications with careful selection from the authors. ¹ , ¹⁶

Outcomes and Variables of Interest

The following demographic variables were extracted: age, sex, race (White, Black, Hispanic, Asian and Pacific Islander, Native American, and Other), insurance type, and Elixhauser comorbidity indices. NIS classifies Hispanic as “race,” such that Hispanic ethnicity takes precedence over race when a patient is classified as Hispanic and a certain race. ¹⁵ This method was similar to other studies analyzing racial and ethnic disparities among different disease processes and their treatments. ¹⁷ , ¹⁸ , ¹⁹ , ²⁰ , ²¹ , ²²

Elixhauser comorbidity indices are based on 31 predefined comorbidities that utilize ICD‐9 and ICD‐10 codes to identify risk of poor outcomes. ²³ A summative score is created with weighting of each comorbidity ranging from −7 to +12. Lower numbers indicate a lower risk. The following hospital data were collated: bed size, location (rural/urban), teaching status, and region (Northeast, Midwest, South, and West). Discharge disposition was divided into routine (discharge to home or self‐care) and nonroutine discharge (transfer to short‐term hospital, transfer to skilled nursing facility or intermediate care facility, home health care).

Statistical Analysis

Continuous variables are reported as mean and SD) or median and interquartile range if not normally distributed. Categorical data are reported as frequencies and percentage. Chi‐squared tests were used to compare the proportions of each categorical variable between the 6 groups. ANOVA or Kruskal‐Wallis tests were used to compare the means of continuous variables between 6 groups if normally or non‐normally distributed data, respectively.

Cochran‐Armitage test was conducted to test for linear trend in proportions of utilization of types of revascularizations and amputations. The numerators were the number of interventions among each race, and the denominator was the total number of admissions involving each race. Trend lines were compared between the 4 groups using linear regression analysis, which produces a mean difference and 95% CI in trend compared with the reference group. ²⁴

Hierarchical multivariable logistic regression analysis, stratified by NIS‐defined strata and year, was conducted to assess patient profiles for any revascularization, major amputation, and nonroutine discharge. Four models were included: Model 1: Race alone (+ revascularization type+amputation type for nonroutine discharge); Model 2; Model 1+Elixhauser comorbidity indices score; Model 3: Model 2+age, sex, insurance status, household income quartile, smoking status and dialysis status; Model 4: Model 3+hospital characteristics including region, bed size, and teaching/location status. Additionally, a possible interaction between race and hospital region was assessed to interpret their relationship with major amputation using Wald test STATA command “testparm.” If the interaction was significant, the results for race were displayed for each region. Results were presented as odds ratios (ORs) and their respective 95% CIs. P values <0.05 were considered statistically significant. All estimates were nationalized using discharge weighting provided by the Healthcare Cost and Utilization Project. Statistical analysis was performed using STATA 17 (StataCorp 2021, Stata Statistical Software: Release 17, StataCorp LLC, College Station, TX).

Results

Patient Demographics

In total, there were 6 904 562 CLI admissions over the 14‐year period. Among these, 4 649 819 (67.3%) were White admissions, 1 249 636 (18.1%) were Black, 695 270 (10.1%) were Hispanic, 84 546 (1.2%) were Asian or Pacific Islander, 59 703 (0.86%) were Native American, and 165 588 (2.4%) were classified as Other race. The average age for White admissions was 67.5 (± 14) years, 61.8 (± 15) years for Black patients, 62.0 (± 15) years for Hispanic patients, 66.6 (± 15) for Asian or Pacific Islander patients, 59.4 (± 15) for Native American patients, and 64.5 (±15) years for Other race. Per race, women comprised 41% of White patients, 44% of Black patients, 37% of Hispanic patients, 40% of Asian or Pacific Islander patients, 43% of Native American pateints, and 39% of Other race. Additional characteristics are summarized in Table S2.

Trend Analysis—Revascularization

Among all admissions, the rate of admission in White patients who received any revascularization decreased by 0.23% per year (95% CI, −0.29 to −0.16; P<0.001), was not significantly different over time for admissions involving Black patients (Trend: 0.05% per year [95% CI, −0.06 to 0.15]; P=0.387), Hispanic patients (Trend: 0.003% per year [95% CI, −0.13 to 0.12]; P=0.958), Native American patients (Trend: −0.53% per year [95% CI, −1.10 to 0.04]; P=0.067), and those of Other race patients (Trend: −0.10% [95% CI, −0.35 to 0.16]; P=0.46) and decreased by 0.25% per year (95% CI, −0.46 to −0.03; P=0.025) for Asian or Pacific Islander patients.

Compared with admissions involving White patients, the rate of admissions involving Black patients who received any revascularization was higher by 0.27% per year (95% CI, 0.18−0.36; P<0.001). It was also higher for admissions involving Hispanic patients by 0.22% per year (95% CI, 0.10−0.34; P<0.001). Admissions involving Asian or Pacific Islander patients and Native American patients had a similar trend line compared with White patients (Asian: Trend: −0.02% [95% CI, −0.23 to 0.19], P=0.85; Native American: Trend: −0.31% [95% CI, −0.86 to 0.35]; P=0.28). Those of the Other races had a similar trend line compared with White patients (Trend: 0.13% [95% CI, −0.12 to 0.38]; P=0.31). These trends can be seen in Figure 1 and are displayed in Table S3.

Figure 1. Use of any revascularization for each race.

Among all admissions, the proportion of surgical and hybrid revascularization decreased by 0.22% per year (95% CI, −0.25 to −0.19; P<0.001) and 0.016% per year (95% CI, −0.02 to −0.01; P<0.001), respectively. Meanwhile, endovascular therapy increased by 0.10% per year (95% CI, 0.05−0.14; P<0.001). These trends are shown in Figure S2.

Among all admissions, the proportion of admissions following endovascular revascularization involving White patients was not significantly different over time (0.02% [95% CI, −0.03 to 0.07]; P=0.42), increased for Black patients by 0.21% per year (95% CI, 0.14−0.29; P<0.001), and increased for Hispanic patients by 0.23% per year (95% CI, 0.13−0.34; P<0.001). The proportion of endovascular interventions was not significantly different over time for Asian or Pacific Islander patients (Trend: 0.06% [95% CI, −0.13 to 0.24]; P=0.54) and for Native American patients (Trend: −0.28% [95% CI, −0.80 to 0.23]; P=0.28). As for admissions involving Other races, the proportion of endovascular interventions increased by 0.21% per year (95% CI, 0.01−0.41; P=0.039). These trends are shown in Figure S3.

Among all admissions, the rate of admission after surgical revascularization decreased for White patients by 0.22% per year (95% CI, −0.26 to −0.18; P<0.001), decreased for Black patients by 0.16% per year (95% CI, −0.20 to −0.11; P<0.001), decreased among Hispanic patients by 0.22% per year (95% CI, −0.27 to −0.17; P<0.001), decreased for Asian or Pacific Islander patients by 0.25% per year (95% CI, −0.34 to 0.16; P<0.001), decreased for Native American patients by 0.20% per year (95% CI, −0.32 to −0.08; P=0.001) and among Other races decreased by 0.27% per year (95% CI, −0.37 to −0.18; P<0.001). These trends are shown in Figure S4.

Among all admissions, the rate of admission in White patients who received hybrid revascularization decreased by 0.02% per year (95% CI, −0.03 to −0.01; P<0.001), decreased among Black patients by 0.01% per year (95% CI, −0.03 to −0.001; P=0.04), decreased among Hispanic patients by 0.01% per year (95% CI, −0.03 to −0.001; P=0.032), decreased among Asian or Pacific Islander patients by −0.05% per year (95% CI, −0.09 to −0.01; P=0.016), decreased among Native American patients by −0.05% per year (95% CI, −0.09 to −0.01; P=0.023), and decreased among Other races by 0.04% per year (95% CI, −0.06 to 0.005; P=0.021). These trends are shown in Table S3 and Figure S5.

Trend Analysis—Amputations

The minor amputation rate increased by 0.37% per year (95% CI, 0.34−0.39; P<0.001), while the major amputation rate decreased by 0.21% per year (95% CI, −0.23 to −0.18; P<0.001). This is shown in Figure S6.

The rate of any amputation in White admissions increased by 0.21% (95% CI, 0.17−0.25; P<0.001), was not significantly different over time for admissions in Black patients (Trend: −0.08% [95% CI, −0.15 to 0.002]; P=0.056), increased by 0.19% per year (95% CI, 0.08−0.30; P=0.001) for Hispanic patients, was not significantly different over time for admissions in Asian or Pacific Islander patients (Trend: −0.04% [95% CI, −0.23 to 0.16]; P=0.72), was not significantly different over time for admissions in Native American patients (Trend: 0.27% [95% CI, −0.04 to 0.58]; P=0.092), and increased by 0.19% (95% CI, 0.06−0.31; P=0.004) for the Other race patients.

Compared with admissions in White patients, the rate of admissions involving Black patients who received any amputation decreased by 0.29% per year (95% CI, −0.36 to −0.21; P<0.001) and decreased by 0.25% per year (95% CI, −0.44 to −0.05; P=0.014) for Asian or Pacific Islander patients. Admissions involving Hispanic patients (−0.02% [95% CI, −0.13 to 0.09; P=0.75), Native American patients (0.06% [95% CI, −0.26 to 0.37]; P=0.71), and those of the Other races (−0.02% [95% CI, −0.15 to 0.11]; P=0.71) were not significantly different over time compared with White patients. These trends can be seen in Figure 2 and are displayed in Table S3.

Figure 2. Use of any amputation for each race.

There was an increase in trends in proportion of minor amputation among White admissions by 0.36% per year (95% CI, 0.33−0.38; P<0.001), Black admissions by 0.30% per year (95% CI, 0.26−0.35; P<0.001), Hispanic admissions by 0.47% per year (95% CI, 0.40−0.54; P<0.001), Asian or Pacific Islander admissions by 0.31% per year (95% CI, 0.18−0.45; P<0.001), Native American admissions by 0.52% per year (95% CI, 0.28−0.77; P<0.001), and Other races admissions by 0.33% per year (95% CI, 0.23−0.44; P<0.001). This is shown in Figure S7.

There was a decrease in trends in proportion of major amputation among White admissions by 0.14% per year (95% CI, −0.17 to −0.12; P<0.001), Black admissions by 0.38% per year (95% CI, −0.44 to −0.32; P<0.001), Hispanic admissions by 0.28% per year (95% CI, −0.34 to −0.22; P<0.001), Asian or Pacific Islander admissions by 0.35% per year (95% CI, −0.48 to −0.22; P<0.001), Native American admissions by 0.25% per year (95% CI, −0.43 to −0.07; P=0.006), and Other races admissions by 0.15% per year (95% CI, −0.22 to −0.07; P<0.001). This is shown in Figure S8. A summary of these results can be seen in Table S4.

Multivariable Regression: Fully Adjusted Model

Admissions involving patients who identified as Black, Hispanic, Asian or Pacific Islander, or Other race had higher odds of receiving any revascularization compared with White patients (Black: OR, 1.04 [95% CI, 1.01–1.07]; P=0.005, Hispanic: OR, 1.17 [95% CI, 1.13–1.22]; P<0.001, Asian or Pacific Islander: OR, 1.29 [95% CI, 1.20–1.38]; P<0.001, and Other: OR, 1.25 [95% CI, 1.14–1.36]; P<0.001, respectively). Admissions involving Native American patients had similar odds of receiving any revascularization compared with White patients (OR, 1.19 [95% CI, 0.95–1.50]; P=0.14).

Minor and major amputation had higher odds of nonroutine discharge compared with no amputation (minor: OR, 1.66 [95% CI, 1.63–1.69]; P<0.001, major: OR, 6.21 [95% CI, 5.93–6.51]; P<0.001, respectively).

Those who identified as Black, Hispanic, Asian or Pacific Islander, Native American, or Other race had higher probability of receiving major amputation compared with those who identified as White (Black: OR, 1.63 [95% CI, 1.58–1.67]; P<0.001, Hispanic: OR, 1.29 [95% CI, 1.25–1.33]; P<0.001, Asian or Pacific Islander: OR, 1.30 [95% CI, 1.22–1.40]; P<0.001, Native American: OR, 1.36 [95% CI, 1.24–1.49]; P<0.001, and Other: OR, 1.11 [95% CI, 1.06–1.17]; P<0.001, respectively). Additional results can be seen in Table 1. The interaction between race and region was tested using the Wald test, which demonstrated that the interaction was statistically significant (P<0.001). Therefore, the results for race for each region were recorded. These additional results can be seen in Table S5.

Table 1.

Multivariable Regression Analyses for CLI Admissions

	Nonroutine discharge			Any revascularization			Major amputations
	Odds ratio	95% CI	P value	Odds ratio	95% CI	P value	Odds ratio	95% CI	P value
Race
White	1.00			1.00			1.00
Black	1.10	1.08–1.12	<0.001	1.04	1.01–1.07	0.005	1.63	1.58–1.67	<0.001
Hispanic	0.86	0.83–0.88	<0.001	1.17	1.13–1.22	<0.001	1.29	1.25–1.33	<0.001
Asian or Pacific Islander	0.80	0.75–0.85	<0.001	1.29	1.20–1.38	<0.001	1.30	1.22–1.40	<0.001
Native American	0.76	0.71–0.80	<0.001	1.19	0.95–1.50	0.135	1.36	1.24–1.49	<0.001
Other	0.89	0.86–0.93	<0.001	1.25	1.14–1.36	<0.001	1.11	1.06–1.17	<0.001
Revascularization type
No revascularization	1.00
Surgical revascularization	0.80	0.78–0.83	<0.001
Endovascular revascularization	0.51	0.50–0.53	<0.001
Hybrid revascularization	0.97	0.93–1.02	0.239
Amputation type
No amputation	1.00
Minor amputation	1.66	1.63–1.69	<0.001
Major amputation	6.21	5.93–6.51	<0.001
Elixhauser comorbidity score	1.15	1.15–1.16	<0.001	0.94	0.94–0.95	<0.001	1.07	1.06–1.07	<0.001
Age at admission (y)	1.03	1.03–1.03	<0.001	1.03	1.02–1.03	<0.001	1.01	1.01–1.01	<0.001
Women (vs men)	1.17	1.16–1.18	<0.001	0.98	0.97–0.99	0.004	0.75	0.74–0.76	<0.001
Primary expected payer
Medicare	1.00			1.00			1.00
Medicaid	0.76	0.75–0.78	<0.001	0.72	0.70–0.74	<0.001	0.95	0.93–0.98	<0.001
Private insurance	0.65	0.64–0.65	<0.001	1.12	1.10–1.15	<0.001	0.90	0.88–0.92	<0.001
Self‐pay	0.29	0.28–0.31	<0.001	0.63	0.60–0.67	<0.001	0.80	0.75–0.84	<0.001
No charge	0.32	0.27–0.36	<0.001	0.67	0.60–0.75	<0.001	0.68	0.58–0.80	<0.001
Other	0.56	0.53–0.59	<0.001	0.82	0.77–0.86	<0.001	0.89	0.84–0.95	0.001
Median household income national quartile for patient ZIP code
0–25 percentile	1.00			1.00			1.00
26–50 percentile	1.01	1.00–1.03	0.087	1.02	1.00–1.05	0.084	0.99	0.97–1.01	0.439
51–75 percentile	1.00	0.98–1.02	0.803	0.95	0.92–0.98	0.001	0.88	0.85–0.90	<0.001
>75 percentile	0.99	0.96–1.01	0.306	0.93	0.89–0.96	<0.001	0.79	0.77–0.82	<0.001
Smoking status
Never smoker	1.00			1.00			1.00
Former smoker	0.79	0.78–0.80	<0.001	1.98	1.94–2.03	<0.001	0.96	0.93–0.98	<0.001
Current smoker	0.78	0.77–0.79	<0.001	3.02	2.95–3.08	<0.001	1.11	1.09–1.14	<0.001
Dialysis	1.03	1.01–1.05	0.011	1.43	1.40–1.47	<0.001	1.86	1.82–1.91	<0.001
Region of hospital
Northeast	1.00			1.00			1.00
Midwest	0.67	0.65–0.70	<0.001	1.01	0.95–1.08	0.710	1.01	0.97–1.06	0.604
South	0.67	0.65–0.70	<0.001	1.20	1.14–1.27	<0.001	1.41	1.35–1.47	<0.001
West	0.61	0.59–0.64	<0.001	0.97	0.90–1.05	0.523	1.14	1.09–1.20	<0.001
Bed size of hospital
Small	1.00			1.00			1.00
Medium	1.03	0.99–1.07	0.097	1.25	1.14–1.38	<0.001	1.22	1.17–1.27	<0.001
Large	1.04	1.01–1.08	0.013	1.55	1.42–1.71	<0.001	1.43	1.38–1.49	<0.001
Location/teaching status of hospital
Rural	1.00			1.00			1.00
Urban nonteaching	1.13	1.10–1.17	<0.001	1.96	1.75–2.20	<0.001	1.12	1.05–1.20	0.001
Urban teaching	1.04	1.01–1.07	0.014	2.41	2.16–2.69	<0.001	1.31	1.22–1.40	<0.001

Only the final model is shown. Model 1: Race (+ revascularization type+amputation type for nonroutine discharge); Model 2; Model 1+ Elixhauser comorbidity indices score; Model 3: Model 1+ Model 2+demographic variables including age, sex, insurance status, household income quartile, smoking status, and dialysis status; Model 4: Model 3+hospital characteristics including region, bed size, and teaching/location status. CLI indicates critical limb ischemia.

Surgical and endovascular revascularization were associated with lower odds of nonroutine discharge compared with no revascularization (OR, 0.80 [95% CI, 0.78–0.83]; P<0.001, and OR, 0.51 [95% CI, 0.50–0.53]; P<0.001, respectively). In contrast to White patients, Black patients had higher odds of nonroutine discharge (OR, 1.10 [95% CI, 1.08–1.12]; P<0.001), while Hispanic, Asian or Pacific Islander, Native American, and Other race patients had lower odds of nonroutine discharge (Hispanic: OR, 0.86 [95% CI, 0.83–0.88]; P<0.001, Asian or Pacific Islander: OR, 0.80 [95% CI, 0.75–0.85]; P<0.001, Native American: OR, 0.76 [95% CI, 0.71–0.80]; P<0.001, and Other: OR, 0.89 [95% CI, 0.86–0.93]; P<0.001, respectively). Additional results can be seen in Table 1.

Models 1 to 3 for any revascularization, major amputations, and nonroutine discharge can be seen in Table S6 through S8, respectively.

Discussion

To our knowledge, this is the largest study investigating the role of race in the presentation and outcomes in patients presenting with CLI. We examined CLI admissions in the NIS database from 2005 to 2018 and analyzed gaps in treatment as well as trends in treatment utilization. Although revascularization rates among the entire cohort decreased over the time period, revascularization rates have increased among Black, Hispanic, and Native American patients while they have decreased among the White and Asian or Pacific Islander populations. Although the rate of major amputations has decreased, minorities in all racial and ethnic categories with CLI had higher major amputation rates compared with White patients. Lastly, Black patients had the highest odds of nonroutine discharge after treatment indicating greater protracted morbidity.

Studies have shown minority races are at higher risk for inadequate access to health care and particularly subspeciality care, which is often required for managing CLI. ¹³ , ²⁵ , ²⁶ The current analysis evaluated the rates of revascularization for CLI and found them to be increasing among Black patients. Furthermore, non‐White patients presented with more advanced disease as demonstrated by a higher proportion having CLI as well as more non‐White patients with CLI requiring intervention compared with Whites. The Asian multidisciplinary consensus statement provides valuable insights into the global prevalence of end‐stage renal disease and diabetes within the Asian population. These cardiometabolic conditions significantly contribute to the heightened incidence of CLI among this population, necessitating the implementation of comprehensive multidisciplinary care approaches. Notably, the consensus statement highlights the distinct susceptibility of Asians to nonatherosclerotic PAD associated with thrombophilia and vasculitides, indicating unique pathophysiologic mechanisms compared with the general population. ²⁷ Our data demonstrate that Asian or Pacific Islander patients had higher rates of renal failure among all race groups. Krawitz et al demonstrated that, in their Medicare fee‐for‐service database, Black patients underwent 928 endovascular interventions per 100 000 compared with 530 per 100 000 in White beneficiaries. Black patients also had worse comorbidities and more adverse outcomes, supporting our findings. ¹⁴ This finding mirrors the higher prevalence of CLI among non‐White patients. ²⁸

With respect to amputations, our study demonstrated that Blacks had the highest risk of amputation, followed by Native American, Asian or Pacific Islander, Hispanic, or Other race when compared with Whites. These findings are consistent with other studies. Soden et al observed similar results and found that Black patients were more likely to present with more severe symptoms and undergo major amputation. ²⁵ Using Vascular Quality Initiative data, Kalbaugh et al also showed that Black and Hispanic patients were more likely to receive amputations within 1 year of CLI diagnosis compared with White patients (5.8% and 5.6% higher, respectively), even when adjusting for disease stage and severity. ²⁹ Another study using the Veterans Affairs Corporate Data Warehouse similarly showed that the Black race was associated with a 37% higher amputation risk compared with White race. ³⁰

Black patients in this study were more likely to be discharged nonroutinely compared with White patients. Other studies have shown similar trends after aortic repair and cardiac intervention. ³¹ , ³² , ³³ Non‐White patients often present with more advanced disease before major vascular intervention, which may contribute to the higher rate of postoperative debility. ²⁵ However, comorbidities such as diabetes, as well as the number of comorbid diagnoses, have also been found to contribute to an increased risk for nonroutine discharge. ³⁴ , ³⁵ , ³⁶ Our data showed multiple comorbidities, including diabetes, end‐stage kidney disease, and hypertension, were less prevalent in the White cohort compared with Other races and ethnicities.

There was a difference in age and sex distribution for admissions in CLI in this study. Additionally, increase in income quartile was associated with similar odds of mortality and any revascularization. However, it was associated with lower odds of major amputation. Pabon et al emphasized the epidemiological differences among women versus men regarding PAD, with greater prevalence and lower frequency in evidence‐based therapies for women with PAD. ³⁷ Previous studies have also shown disparities on sex and income structure in outpatient care for PAD, which may contribute to the differences in undertreatment for CLI. ³⁸ , ³⁹

There is a growing body of evidence on the proper selection of patients for procedural intervention for CLI, because some intervention may negatively impact those with earlier stages of disease yet higher comorbidities. ⁴⁰ Therefore, patient selection should be studied further to overcome this clinical challenge. Our data highlighted an increase in revascularization from 2006 to 2009, which may be explained by the American Heart Association guidelines' statement on PAD that was released in 2005, advising thorough management of the disease process. ⁴¹ Our data demonstrated that non‐White patients with CLI were more likely to present with major risk factors; therefore, a more patient‐centered approach to management of this disease is warranted. The mechanisms responsible for this observation are mostly mediated by risk factors and social determinants of health. ¹³ Specialty vascular clinics and the emphasis on management of PAD risk factors are some impactful methods of reducing gaps in quality of care. It begins with patient education and screening in the primary care setting and increasing referrals to vascular specialists to improve outcomes. Our data on the increase in intervention rates in urban teaching hospitals highlights the importance of screening, especially among individuals in those locations. ⁴² Additionally, there is a paucity in literature about the disparities in CLI care among the Asian American and Native American populations. Presently, a dearth of scholarly literature exists on the inequities in CLI management within the Asian American and Native American communities. Recognizing this knowledge gap, the Society of Interventional Radiology has issued a consensus statement urging proactive measures, including the formulation of care guidelines and promoting research initiatives, aimed at addressing and alleviating disparities in health care access and outcomes for these specific populations. ⁴³

Limitations

Although this is a comprehensive study using a contemporary, nationally representative data set with thorough ICD code selection, it comes with limitations. Firstly, NIS does not capture follow‐up data, thus we were not able to analyze long‐term outcomes. Secondly, each observation does not represent a unique patient, but rather an admission. Therefore, some of these hospitalizations could have been for the same patient requiring repeat procedures and possibly more for Black patients compared with White patients, though this cannot be inferred from the database. Thirdly, we were not able to distinguish specific Rutherford classification in our regression model. Lastly, the nature of administrative databases is prone to misclassification of diagnosis and procedure codes. This study's method of selecting admissions was to capture all patients with CLI, but some admissions that involved patients with resolved disease may have been captured as well.

Conclusions

Our analysis highlighted major disparities in CLI treatment and outcomes for non‐White populations in this nationally representative database. Although the general rates of revascularization are decreasing, non‐White patients with CLI still receive more invasive therapy. Amputation rates are also higher among non‐White patients. However, Hispanic patients and those in the Other race category had lower odds of nonroutine discharge compared with White patients. The disparities gap is slowly closing for some, but much work is still necessary to ensure equitable care and better outcomes for patients with CLI.

Sources of Funding

None.

Disclosures

Dr Secemsky reports research grants from Beth Israel Deaconess Medical Center: National Institutes of Health/National Heart, Lung, and Blood Institute K23HL150290, Food & Drug Administration, BD, Boston Scientific, Cook, CSI, Laminate Medical, Medtronic and Philips, consulting/speaking for Abbott, Bayer, BD, Boston Scientific, Cook, CSI, Inari, Medtronic, Philips, Shockwave, and VentureMed. Dr Misra reports research grants National Institutes of Health/National Heart, Lung, and Blood Institute R01HL098967, Regenerative Medicine Minnesota, consulting for Medtronic, Founder Pavaj Vascular, Equity: Inova Vascular, DSMB: Humacyte, Penumbra. The remaining authors have no disclosures to report.

Supporting information

Tables S1–S8

Figures S1–S8