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Table 1 Participant characteristics – data are n (%), unless otherwise stated

From: Factors associated with foot ulceration and amputation in adults on dialysis: a cross-sectional observational study

  Current foot ulceration Lower extremity amputation
  Total
(N = 450)
Yes
(n = 45)
No
(n = 405)
P-value* Yes
(n = 46)
No
(n = 404)
P-value*
Mean age (SD), years 67.5 (13.2) 69.0 (10.3) 67.3 (13.5) 0.33 65.4 (11.2) 67.7 (13.4) 0.25
Male sex 291 (64.7) 36 (80.0) 255 (63.0) 0.035* 37 (80.4) 254 (62.9) 0.028*
Mean body mass index (SD), kg/m 2 28.2 (6.6) 29.1 (6.5) 28.1 (6.6) 0.30 30.4 (6.3) 27.9 (6.6) 0.014*
Current smoking 54 (12.0) 5 (11.1) 49 (12.1) 1.00 5 (10.9) 49 (12.1) 0.99
Living alone 75 (16.7) 6 (13.3) 69 (17.0) 0.67 10 (21.7) 65 (16.1) 0.44
Ethnicity
 Indigenous Australian 4 (0.9) 0 (0) 4 (1.0) 1.00 1 (2.2) 3 (0.7) 0.88
 English 85 (18.9) 9 (20) 76 (18.8) 1.00 12 (26.1) 73 (18.1) 0.94
 European 194 (43.1) 16 (35.6) 178 (44.0) 0.36 14 (30.4) 180 (44.6) 0.60
 American 4 (0.9) 0 (0) 4 (1.0) 1.00 0 (0) 4 (1.0) 1.00
 African 14 (3.1) 1 (2.2) 13 (3.2) 1.00 2 (4.3) 12 (3.0) 0.95
 Asian 67 (14.9) 5 (11.1) 62 (15.3) 0.60 1 (2.2) 66 (16.3) 0.88
 Pacific Islander 29 (6.4) 3 (6.7) 26 (6.4) 1.00 5 (10.9) 24 (5.9) 0.33
 Othera 53 (11.8) 11 (24.4) 42 (10.4) 0.011* 11 (23.9) 42 (10.4) 0.159
Cause of ESRD
 Diabetes mellitus 180 (40.0) 37 (82.2) 143 (35.3) <0.001* 42 (91.3) 138 (34.2) 0.98
 Hypertension 28 (6.2) 1 (2.2) 27 (6.7) 0.40 1 (2.2) 27 (6.7) 0.82
 Glomerulonephritis 97 (21.6) 2 (4.4) 95 (23.5) 0.006* 0 (0) 97 (24.0) 0.88
 Polycystic kidney disease 22 (4.9) 1 (2.2) 21 (5.2) 0.61 1 (2.2) 21 (5.2) 0.104
 Reflux 19 (4.2) 1 (2.2) 18 (4.4) 0.76 1 (2.2) 18 (4.5) 0.67
 Renovascular disease 10 (2.2) 0 (0) 10 (2.5) 0.59 1 (2.2) 9 (2.2) 0.58
 Vasculitis 9 (2.0) 0 (0) 9 (2.2) 0.65 0 (0) 9 (2.2) 0.64
 Unknown 15 (3.3) 1 (2.2) 14 (3.5) 1.00 0 (0) 15 (3.7) 0.37
 Other 70 (15.6) 2 (4.4) 68 (16.8) 0.05 0 (0) 70 (17.3) 0.88
Dialysis treatment
 Hemodialysis 423 (94.0) 42 (93.3) 381 (94.1) 1.00 43 (93.5) 380 (94.1) 0.41
Peritoneal dialysis
 CAPD 9 (2.0) 0 (0) 9 (2.2) 0.65 0 (0) 9 (2.2) 0.64
 APD 18 (4.0) 3 (6.7) 15 (3.7) 0.58 3 (6.5) 15 (3.7) 0.79
Median duration of dialysis (IQR), months 36.9 (16.6 to 70.1) 37.5 (20.0 to 64.1) 36.8 (16.5 to 71.8) 0.91 38.3 (17.7 to 72.6) 36.6 (16.6 to 69.5) 0.77
Diabetes mellitus 226 (50.2) 39 (86.7) 187 (46.2) <0.001* 43 (93.5) 183 (45.3) <0.001*
 Type 1 13 (5.8) 4 (10.3) 9 (4.8) 0.34 7 (15.2) 6 (1.5) 0.003*
 Type 2 213 (94.2) 35 (89.7) 178 (95.2) 0.34 36 (78.3) 177 (43.8) 0.003*
 Mean duration (SD), months 256.3 (152.6) 348.8 (167.6) 237.0 (142.3) <0.001* 301.8 (163.1) 245.6 (148.5) 0.043*
Retinopathy 132 (29.3) 28 (62.2) 104 (25.7) <0.001* 32 (69.6) 100 (24.8) <0.001*
Known peripheral neuropathyb 70 (15.6) 20 (44.4) 50 (12.3) <0.001* 26 (56.5) 44 (10.9) <0.001*
Known peripheral arterial diseaseb 79 (17.6) 27 (60.0) 52 (12.8) <0.001* 31 (67.4) 48 (11.9) <0.001*
Lower extremity revascularization procedure 35 (7.8) 22 (48.9) 13 (3.2) <0.001* 20 (43.5) 15 (3.7) <0.001*
Hypertension (requiring medication) 360 (80.0) 36 (80.0) 324 (80.0) 1.00 40 (87.0) 320 (79.2) 0.29
Dyslipidemia 301 (66.9) 38 (84.4) 263 (64.9) 0.013* 39 (84.8) 262 (64.9) 0.011*
Ischemic heart disease 263 (58.4) 36 (80.0) 227 (56.0) 0.003* 33 (71.7) 230 (56.9) 0.076
Congestive cardiac failure 122 (27.1) 18 (40.0) 104 (25.7) 0.061 15 (32.6) 107 (26.5) 0.48
Cerebrovascular disease 104 (23.1) 19 (42.2) 85 (21.0) 0.003* 15 (32.6) 89 (22.0) 0.153
Osteoarthritis 192 (42.7) 17 (37.8) 175 (43.2) 0.60 15 (32.6) 177 (43.8) 0.194
Inflammatory arthritis 183 (40.7) 14 (31.1) 169 (41.7) 0.22 13 (28.3) 170 (42.1) 0.099
Median C-reactive protein (SD), mg/L c,d 7.33 (2.83 to 19.67) 10.00 (4.82 to 43.83) 6.95 (2.67 to 18.08) 0.011* 10.89 (4.44 to 36.88) 6.90 (2.67 to 18.50) 0.026*
Mean serum albumin (SD), g/L c 33.73 (3.94) 31.12 (4.76) 34.01 (3.74) <0.001* 32.50 (4.32) 33.86 (3.88) 0.045
Mean total calcium (SD), mmol/L c 2.20 (0.14) 2.15 (0.13) 2.20 (0.14) 0.008* 2.21 (0.12) 2.20 (0.14) 0.69
Mean phosphate (SD), mmol/L c 1.55 (0.38) 1.64 (0.39) 1.54 (0.38) 0.135 1.59 (0.41) 1.55 (0.38) 0.53
Median parathyroid hormone (SD), pmol/L c 29.58 (18.04 to 45.84) 28.03 (20.70 to 43.02) 29.77 (17.38 to 46.25) 0.83 28.52 (21.56 to 50.24) 29.65 (17.38 to 45.43) 0.54
Mean glycated hemoglobin (SD), % c,d 6.14 (1.31) 6.89 (1.24) 6.05 (1.29) <0.001* 6.98 (1.36) 6.03 (1.27) <0.001*
Median hemoglobin (IQR), g/L c 111.33 (102.92 to 117.67) 108.00 (99.50 to 115.83) 111.67 (103.67 to 117.67) 0.060 108.50 (99.25 to 115.25) 111.67 (103.67 to 117.67) 0.080
Mean SF-36v2® PCS (SD) 38.14 (10.70) 33.08 (8.92) 38.71 (10.74) 0.001* 33.16 (9.93) 38.71 (10.65) 0.001*
Mean SF-36v2® MCS (SD) 48.55 (11.40) 47.08 (13.96) 48.71 (11.09) 0.45 47.11 (13.56) 48.71 (11.14) 0.44
Previous foot ulceration 97 (21.6) 32 (71.1) 65 (16.0) <0.001* 44 (95.7) 53 (13.1) <0.001*
Current foot ulceration 45 (10.0) 45 (100.0) N/A N/A 26 (56.5) 19 (4.7) <0.001*
Lower extremity amputation 46 (10.2) 26 (57.8) 20 (4.9) <0.001* 46 (100) N/A N/A
 Minor 39 (8.7) 22 (48.9) 17 (4.2) <0.001* 39 (84.8)   
 Major 12 (2.7) 8 (17.8) 4 (1.0) <0.001* 12 (26.1)   
 Combination 5 (1.1) 4 (8.9) 1 (0.2) <0.001* 5 (10.9)   
  1. *Significant difference between ‘foot ulceration/amputation’ and ‘no foot ulceration/amputation’ groups, p < 0.05. SD Standard deviation. a‘Ethnicity other’ were for participants that identified themselves as ‘Australian’ (excluding Indigenous Australians). ESRD End-stage renal disease. CAPD Continuous ambulatory peritoneal dialysis. APD Automated peritoneal dialysis. IQR Interquartile range. bKnown peripheral neuropathy/known peripheral arterial disease were defined as a history of peripheral neuropathy/peripheral arterial disease documented in the medical records. cAn average of the three latest laboratory test values was collected. dMaximum missing data were for glycated hemoglobin involving 39 participants overall (8.7%). Missing data were for glycated hemoglobin (n = 39) and C-reactive protein (n = 3). SF-36v2® = Short-Form-36 version 2.0. PCS Physical component score. MCS Mental component score. N/A Not applicable