Why carry out this study?
| |
Peripheral artery disease (PAD) is a common condition with significant racial variation in the rate of diagnosis, treatment, and outcomes. | |
To build upon the existing literature, we conducted a comprehensive, retrospective study evaluating trends in diagnostic testing, treatment patterns, and patient health outcomes after diagnosis of PAD between commercially insured Black and White patients in the United States. | |
What was learned from the study?
| |
Compared to White patients, Black patients were observed to have higher disease severity leading up to the PAD diagnosis and increased risk of long-term cardiovascular and limb complications, despite increased diagnostic testing and medication use following PAD diagnosis. | |
The findings suggest that Black patients with PAD experience substantial disease burden under the current standard of care. Future interventions should be tailored to facilitate earlier diagnosis of PAD and to improve the standard of care for Black patients with PAD, which, in turn, could reduce disparate adverse outcomes following diagnosis. |
Introduction
Methods
Data Source
Study Design and Population
Study Outcomes
Statistical Analysis
Results
Study Population
Baseline Patient Characteristics
Characteristics | White patients [A] | Black patients [B] | Std. diff.a,b (%) |
---|---|---|---|
(n = 454,382) | (n = 96,162) | [A] vs. [B] | |
Observation periodc, days, mean ± SD [median] | 581 ± 414 [500] | 588 ± 419 [508] | 1.6 |
Demographicsd | |||
Age, years, mean ± SD [median] | 74.2 ± 10.7 [75] | 71.8 ± 10.9 [72] | 22.2 |
Female, n (%) | 243,271 (53.5) | 58,959 (61.3) | 15.7 |
Geographic region, n (%) | |||
South Atlantic | 109,332 (24.1) | 45,565 (47.4) | 48.7 |
West South Central | 58,660 (12.9) | 15,866 (16.5) | 10.1 |
East North Central | 65,465 (14.4) | 8966 (9.3) | 15.7 |
Pacific | 50,403 (11.1) | 2525 (2.6) | 33.5 |
Middle Atlantic | 47,902 (10.5) | 9191 (9.6) | 3.3 |
Mountain | 44,093 (9.7) | 1753 (1.8) | 33.8 |
West North Central | 38,385 (8.4) | 3599 (3.7) | 19.7 |
East South Central | 20,220 (4.5) | 7525 (7.8) | 14.1 |
New England | 19,922 (4.4) | 1172 (1.2) | 19.2 |
Insurance plan type, n (%) | |||
Medicare advantage | 400,882 (88.2) | 86,782 (90.2) | 6.5 |
Commercial insurance | 53,500 (11.8) | 9380 (9.8) | 6.5 |
HMO | 6180 (1.4) | 1456 (1.5) | 1.3 |
POS | 37,329 (8.2) | 6203 (6.5) | 6.8 |
PPO | 685 (0.2) | 88 (0.1) | 1.7 |
EPO | 5968 (1.3) | 1411 (1.5) | 1.3 |
IND | 3022 (0.7) | 228 (0.2) | 6.4 |
Other | 473 (0.1) | 22 (0.0) | 3.2 |
Education level, n (%) | |||
Less than 12th grade | 937 (0.2) | 299 (0.3) | 2.1 |
High school diploma | 119,083 (26.2) | 52,052 (54.1) | 57.0 |
Less than bachelor’s degree | 264,512 (58.2) | 39,727 (41.3) | 33.8 |
Bachelor’s degree or higher | 69,245 (15.2) | 3975 (4.1) | 37.5 |
Unknown | 605 (0.1) | 109 (0.1) | 0.6 |
Household income, n (%) | |||
< $40K | 143,824 (31.7) | 52,529 (54.6) | 46.4 |
$40K–$49K | 41,041 (9.0) | 10,521 (10.9) | 6.4 |
$50K–$59K | 43,000 (9.5) | 8872 (9.2) | 0.8 |
$60K–$74K | 52,763 (11.6) | 7366 (7.7) | 13.4 |
$75K–$99K | 67,341 (14.8) | 6147 (6.4) | 27.4 |
≥ $100K | 82,842 (18.2) | 4210 (4.4) | 43.8 |
Unknown | 23,571 (5.2) | 6517 (6.8) | 6.7 |
Year of index dated, n (%) | |||
2016 | 72,134 (15.9) | 14,971 (15.6) | 0.8 |
2017 | 120,798 (26.6) | 25,588 (26.6) | 0.1 |
2018 | 112,054 (24.7) | 23,308 (24.2) | 1.0 |
2019 | 97,089 (21.4) | 20,619 (21.4) | 0.2 |
2020 | 49,504 (10.9) | 10,925 (11.4) | 1.5 |
2021 | 2803 (0.6) | 751 (0.8) | 2.0 |
Total healthcare costse,f, US$ 2021, mean ± SD [median] | $17,578 ± 40,980 | $19,425 ± 47,531 | 4.2 |
Quan-CCIe,g, mean ± SD [median] | 1.5 ± 1.8 [1] | 1.7 ± 1.9 [1] | 10.1 |
PAD diagnosis typed, n (%) | |||
ALI only | 9510 (2.1) | 3082 (3.2) | 6.9 |
CLI only | 4440 (1.0) | 1045 (1.1) | 1.1 |
ALI and CLI | 247 (0.1) | 81 (0.1) | 1.1 |
No ALI or CLI | 440,185 (96.9) | 91,954 (95.6) | 6.6 |
Selected comorbidities and risk factors for PADc,g, n (%) | |||
Hypertension | 311,622 (68.6) | 76,928 (80.0) | 26.1 |
Diabetes | 145,969 (32.1) | 45,574 (47.4) | 31.2 |
Coronary artery disease (polyvascular diseases) | 108,874 (24.0) | 20,704 (21.5) | 5.8 |
Current or prior tobacco | 100,014 (22.0) | 21,353 (22.2) | 0.5 |
Renal failure or end stage renal disease (eGFR < 60 ml/min) | 82,507 (18.2) | 22,302 (23.2) | 12.4 |
Obesity | 54,612 (12.0) | 15,387 (16.0) | 11.5 |
Cerebrovascular disease | 58,055 (12.8) | 11,931 (12.4) | 1.1 |
Heart failure | 53,282 (11.7) | 13,557 (14.1) | 7.1 |
Atrial fibrillation | 43,611 (9.6) | 5576 (5.8) | 14.3 |
Venous thromboembolism | 23,213 (5.1) | 5167 (5.4) | 1.2 |
Transient ischemic attack | 7471 (1.6) | 1466 (1.5) | 1.0 |
Intracranial hemorrhage | 442 (0.1) | 83 (0.1) | 0.4 |
Concomitant comorbidities and risk factors | |||
0 | 83,652 (18.4) | 11,122 (11.6) | 19.2 |
1 | 97,297 (21.4) | 17,472 (18.2) | 8.1 |
2 | 103,931 (22.9) | 24,693 (25.7) | 6.5 |
≥ 3 | 169,502 (37.3) | 42,875 (44.6) | 14.8 |
CV-related medication usee, n (%) | |||
Antihypertensives | 231,119 (50.9) | 61,881 (64.4) | 27.3 |
Antihyperlipidemic agents | 207,965 (45.8) | 49,890 (51.9) | 12.2 |
Antihyperglycemic agents | 72,046 (15.9) | 22,709 (23.6) | 19.5 |
Antiplatelet agents | 44,862 (9.9) | 11,015 (11.5) | 5.1 |
Other CV agents | 116,302 (25.6) | 38,478 (40.0) | 30.7 |
CV procedurese, n (%) | |||
Cardiography procedures | 169,433 (37.3) | 37,900 (39.4) | 4.4 |
Echocardiography procedures | 68,670 (15.1) | 15,499 (16.1) | 2.8 |
CV monitoring devices, services, and evaluations | 27,899 (6.1) | 4952 (5.1) | 4.3 |
Cardiac catheterization procedures | 10,544 (2.3) | 2048 (2.1) | 1.3 |
Percutaneous coronary intervention | 4162 (0.9) | 731 (0.8) | 1.7 |
Coronary bypass graft | 906 (0.2) | 171 (0.2) | 0.5 |
Non-invasive physiologic studies and procedures | 372 (0.1) | 58 (0.1) | 0.8 |
Home and outpatient INR monitoring services | 347 (0.1) | 20 (0.0) | 2.5 |
Therapeutic CV services and procedures (excluding PCI) | 1799 (0.4) | 326 (0.3) | 0.9 |
Other CV procedures | 1563 (0.3) | 216 (0.2) | 2.2 |
Other selected procedurese, n (%) | |||
Dialysis | 4035 (0.9) | 2477 (2.6) | 12.9 |
Non-traumatic lower limb
amputation | 890 (0.2) | 202 (0.2) | 0.3 |
Foot and ankle (minor) | 775 (0.2) | 165 (0.2) | 0.0 |
At and below knee (major) | 101 (0.0) | 29 (0.0) | 0.5 |
Above knee (major) | 43 (0.0) | 14 (0.0) | 0.5 |
Knee replacement | 1754 (0.4) | 300 (0.3) | 1.3 |
Hip replacement | 1493 (0.3) | 210 (0.2) | 2.1 |
Kidney transplant | 485 (0.1) | 184 (0.2) | 2.2 |
Diagnostic testinge, n (%) | |||
ABI | 11,808 (2.6) | 3353 (3.5) | 5.2 |
Vascular ultrasound | 11,876 (2.6) | 2890 (3.0) | 2.4 |
Angiography | 3168 (0.7) | 789 (0.8) | 1.4 |
Aortography | 147 (0.0) | 34 (0.0) | 0.2 |
Medical Management
Treatments | From 0 to 3 months | From 3 to 6 months | From 6 to 9 months | From 9 to 12 months | ||||
---|---|---|---|---|---|---|---|---|
White patients | Black patients | White patients | Black patients | White patients | Black patients | White patients | Black patients | |
(n = 454,382) | (n = 96,162) | (n = 414,085) | (n = 87,650) | (n = 361,709) | (n = 76,520) | (n = 322,029) | (n = 68,214) | |
Revascularization procedures, n (%) | 12,610 (2.8) | 3262 (3.4)* | 3864 (0.9) | 1043 (1.2)* | 2242 (0.6) | 601 (0.8)* | 1808 (0.6) | 522 (0.8)* |
Diagnostic testing, n (%) | ||||||||
Vascular ultrasound | 71,117 (15.7) | 18,200 (18.9)* | 9287 (2.2) | 2387 (2.7)* | 7934 (2.2) | 2072 (2.7)* | 7261 (2.3) | 1918 (2.8)* |
ABI | 70,695 (15.6) | 18,856 (19.6)* | 7297 (1.8) | 2340 (2.7)* | 6336 (1.8) | 1975 (2.6)* | 6012 (1.9) | 1779 (2.6)* |
Angiography | 22,729 (5.0) | 5419 (5.6)* | 4951 (1.2) | 1351 (1.5)* | 3231 (0.9) | 854 (1.1)* | 2704 (0.8) | 775 (1.1)* |
Aortography | 2838 (0.6) | 738 (0.8)* | 598 (0.1) | 169 (0.2)* | 344 (0.1) | 95 (0.1)* | 244 (0.1) | 71 (0.1)* |
Medication use, n (%) | ||||||||
Antihypertensives | 217,166 (47.8) | 57,228 (59.5)* | 188,512 (45.5) | 49,659 (56.7)* | 166,077 (45.9) | 43,784 (57.2)* | 149,684 (46.5) | 39,375 (57.7)* |
Antihyperlipidemic agents | 195,181 (43.0) | 45,756 (47.6)* | 168,891 (40.8) | 39,196 (44.7)* | 148,866 (41.2) | 34,818 (45.5)* | 135,355 (42.0) | 31,787 (46.6)* |
Antihyperglycemic
agents | 63,410 (14.0) | 19,456 (20.2)* | 55,211 (13.3) | 16,956 (19.3)* | 48,600 (13.4) | 14,840 (19.4)* | 44,089 (13.7) | 13,406 (19.7)* |
Antiplatelet agents | 53,375 (11.7) | 13,103 (13.6)* | 44,957 (10.9) | 11,037 (12.6)* | 38,874 (10.7) | 9578 (12.5)* | 35,047 (10.9) | 8665 (12.7)* |
Anticoagulant agents | 11,335 (2.5) | 2090 (2.2)* | 11,136 (2.7) | 2107 (2.4)* | 10,857 (3.0) | 2100 (2.7)* | 10,966 (3.4) | 2093 (3.1)* |
Other cardiovascular agents | 108,337 (23.8) | 35,045 (36.4)* | 92,537 (22.3) | 30,149 (34.4)* | 81,577 (22.6) | 26,794 (35.0)* | 74,586 (23.2) | 24,300 (35.6)* |
Treatmentsa | Raceb | PAD patients | Adjusted ORc (95% CI) |
---|---|---|---|
(n = 550,544) | |||
Medication use onlyd, n (%) | White patients | 313,664 (57.0) | – |
Black patients | 75,649 (13.7) | 1.47 (1.44–1.49)* | |
Both revascularization procedures and medication used, n (%) | White patients | 18,200 (3.3) | – |
Black patients | 5231 (1.0) | 1.26 (1.22–1.31)* | |
Revascularization procedures only, n (%) | White patients | 3284 (0.6) | – |
Black patients | 408 (0.1) | 0.67 (0.60–0.74)* | |
No revascularization or medicationd, n (%) | White patients | 119,234 (21.7) | – |
Black patients | 14,874 (2.7) | 0.60 (0.59–0.61)* | |
Lower-limb amputatione, n (%) | White patients | 7518 (1.4) | – |
Black patients | 2449 (0.4) | 1.36 (1.30–1.43)* | |
High amputation, n (%) | White patients | 3620 (48.2) | – |
Black patients | 1525 (62.3) | 1.74 (1.64–1.86)* | |
Low amputation, n (%) | White patients | 5726 (76.2) | – |
Black patients | 1630 (66.6) | 1.18 (1.11–1.25)* | |
High-to-low amputation ratio | White patients | 0.63 | – |
Black patients | 0.94 | – |
Incidence of MALE and CV Events
Outcomesa | Event | Adjusted hazard ratiob,c (95% CI) | P value | |
---|---|---|---|---|
Frequency | Rate (per 100 person-years) | |||
MALE | ||||
Acute limb ischemia | ||||
White patients | 5431 | 0.75 | Reference | |
Black patients | 2019 | 1.30 | 1.56 (1.48–1.64) | < 0.001 |
Chronic limb ischemia | ||||
White patients | 3923 | 0.50 | Reference | |
Black patients | 1208 | 0.80 | 1.33 (1.24–1.42) | < 0.001 |
Lower-limb amputation | ||||
White patients | 7518 | 1.00 | Reference | |
Black patients | 2449 | 1.60 | 1.32 (1.26–1.39) | < 0.001 |
High amputation | ||||
White patients | 3620 | 0.50 | Reference | |
Black patients | 1525 | 1.00 | 1.68 (1.58–1.79) | < 0.001 |
Low amputation | ||||
White patients | 5726 | 0.80 | Reference | |
Black patients | 1630 | 1.10 | 1.15 (1.09–1.22) | < 0.001 |
CV outcomes | ||||
Myocardial infarction | ||||
White patients | 19,342 | 2.70 | Reference | |
Black patients | 4150 | 2.70 | 1.00 (0.97–1.04) | 0.840 |
All-cause stroke | ||||
White patients | 26,106 | 3.60 | Reference | |
Black patients | 6439 | 4.20 | 1.19 (1.16–1.23) | < 0.001 |
Composite (MALE or CV) | ||||
White patients | 52,627 | 7.30 | Reference | |
Black patients | 12,727 | 8.20 | 1.13 (1.11–1.15) | < 0.001 |
Revascularization procedures | ||||
White patients | 21,484 | 3.00 | Reference | |
Black patients | 5639 | 3.60 | 1.16 (1.13–1.20) | < 0.001 |