Table 1. Baseline characteristics of the 162 patients at risk of limb loss.
| Characteristic–No. (%) | Overall (n = 162) | Clinically Significant Disability (n = 119) | No Clinically Significant Disability (n = 43) | Absolute Standardized Differencea |
|---|---|---|---|---|
| Personal characteristics | ||||
| Age, years–median (IQR) | 70.0 (62.0–78.0) | 70.0 (60.0–77.0) | 71.0 (66.0–78.0) | 0.18 |
| Male gender | 96 (59.3) | 70 (58.8) | 26 (60.5) | 0.03 |
| Rural residence | 67 (41.4) | 44 (37.0) | 23 (53.5) | 0.34 |
| Long-term care facility resident | 5 (3.1) | 5 (4.2) | 0 (0) | 0.30 |
| Current smoker | 38 (23.4) | 30 (25.2) | 8 (18.6) | 0.16 |
| Past smoker | 62 (38.3) | 70.0 (60.0–77.0) | 71.0 (66.0–78.0) | 0.18 |
| Wound type (n = 139 with a documented etiology) | ||||
| Arterial | 52 (37.4) | 35/102 (34.3) | 17/37 (46.0) | 0.24 |
| Venous | 13 (9.4) | 7/102 (6.9) | 6/37 (16.2) | 0.30 |
| Diabetic | 10 (7.2) | 8/102 (7.8) | 2/37 (5.4) | 0.10 |
| Mixed | 15 (10.8) | 11/102 (10.8) | 4/37 (10.8) | 0.0009 |
| Postoperative | 36 (25.9) | 30/102 (29.4) | 6/37 (16.2) | 0.32 |
| Other | 13 (9.4) | 11/102 (10.8) | 2/37 (5.4) | 0.20 |
| Wound location (n = 139 with a documented location) | ||||
| Groin | 3 (2.2) | 2/102 (2.0) | 1/37 (2.7) | 0.05 |
| Thigh | 9 (6.5) | 6/102 (5.9) | 3/37 (8.1) | 0.09 |
| Leg | 39 (28.1) | 30/102 (29.4) | 9/37 (24.3) | 0.11 |
| Foot or ankle | 85 (61.2) | 62/102 (60.8) | 23 (62.2) | 0.03 |
| Other | 3 (2.2) | 2/102 (2.0) | 1 (2.7) | 0.05 |
| Wound size, cm–median (IQR) | ||||
| Width | 2.0 (1.0–4.0) | 1.8 (1.0–3.5) | 2.5 (1.2–5.0) | 0.38 |
| Length | 3.5 (1.7–6.0) | 3.2 (1.7–6.0) | 3.6 (1.9–7.5) | 0.24 |
| Depth | 0.40 (0.20–0.50) | 0.30 (0.20–0.50) | 0.40 (0.20–1.0) | 0.19 |
| Area | 7.5 (1.8–22.0) | 6.0 (2.0–18.0) | 8.6 (1.8–36.0) | 0.33 |
| Volume, cm3 | 2.5 (0.54–11.1) | 2.2 (0.50–9.0) | 3.8 (0.75–16.8) | 0.26 |
| Comorbidities recorded in the 3 years before clinic visit | ||||
| Acute coronary syndrome | 60 (37.0) | 46 (38.7) | 14 (32.6) | 0.13 |
| Cerebrovascular event (stroke or transient ischemic attack) | 22 (13.6) | 20 (16.8) | 2 (4.7) | 0.40 |
| Chronic kidney disease | 37 (22.8) | 27 (22.7) | 10 (23.3) | 0.01 |
| Chronic obstructive pulmonary disease | 21 (13.0) | 15 (12.6) | 6 (14.0) | 0.04 |
| Coronary artery disease | 69 (42.6) | 55 (46.2) | 14 (32.6) | 0.28 |
| Diabetes mellitus | 93 (57.4) | 74 (62.2) | 19 (44.2) | 0.37 |
| Dialysis | 14 (8.6) | 12 (10.1) | 2 (4.7) | 0.21 |
| Dyslipidemia | 99 (61.1) | 74 (62.2) | 25 (58.1) | 0.08 |
| Heart failure | 35 (21.6) | 30 (25.2) | 5 (11.6) | 0.36 |
| Hypertension | 126 (77.8) | 95 (79.8) | 31 (72.1) | 0.18 |
| Prior lower limb amputation | ||||
| Contralateral above- or below-knee amputation | 10 (6.2) | 9 (7.6) | 1 (2.3) | 0.24 |
| Ipsilateral toe or ray amputation | 42 (25.9) | 30 (25.2) | 12 (27.9) | 0.14 |
| Ipsilateral transmetatarsal amputation | 11 (6.8) | 9 (7.6) | 2 (4.7) | 0.12 |
| Ipsilateral lower limb revascularization procedures performed | ||||
| Iliac artery angioplasty and/or stenting | 23 (14.2) | 19 (16.0) | 4 (9.3) | 0.20 |
| Femoral and/or popliteal artery angioplasty and/or stenting | 52 (32.1) | 40 (33.6) | 12 (27.9) | 0.12 |
| Tibial and/or peroneal artery angioplasty | 50 (30.9) | 36 (30.3) | 14 (23.3) | 0.05 |
| Aortofemoral or aortobifemoral bypass | 1 (0.6) | 1 (0.8) | 0 (0) | 0.13 |
| Axillofemoral or axillobifemoral bypass | 10 (6.2) | 7 (5.9) | 3 (7.0) | 0.04 |
| Iliofemoral or femoral endarterectomy | 27 (16.7) | 22 (18.5) | 5 (11.6) | 0.19 |
| Femoral-popliteal bypass | 12 (7.4) | 11 (9.2) | 1 (2.3) | 0.30 |
| Femoral-tibial or -peroneal bypass | 10 (6.2) | 7 (5.9) | 3 (7.0) | 0.04 |
| Other revascularization procedure | 21 (13.0) | 13 (10.9) | 8 (18.6) | 0.22 |
Where IQR indicates interquartile range.
aThe absolute standardized difference allows comparison of the difference in prevalence of binary covariates, or the average of continuous covariates, between treatment groups without the influence of sample size. Values >0.1 indicate substantive differences [29].