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Table 2 Primary and secondary outcomes according to foot ulceration status at follow-up

From: Risk factors for foot ulceration in adults with end-stage renal disease on dialysis: a prospective observational cohort study

 Total (N = 450)Foot ulceration
Yes (n = 81)No (n = 369)P-value*
Foot ulceration, n (%)a81 (18)81 (100)N/AN/A
Total number of new foot ulcersb211211  
 New, total no. (%)200 (95)200 (95)
 Reoccurring, total no. (%)11 (5)11 (5)
Time to onset of first foot ulcer, mean (SD), days164 (127)164 (127)
New lower extremity amputation, n (%)12 (3)12 (15)0 (0)
 Minor, n (%)12 (3)12 (15)0 (0)
 Major, n (%)2 (0.4)2 (3)0 (0)
Total number of amputationsb2020N/A
Minor, total no. (%)c18 (90)18 (90) 
Major, total no. (%)d2 (10)2 (10)
Reason for amputation  
 Infected foot ulcer, total no. (%)8 (40)8 (40)
 PAD/gangrene, total no. (%)9 (45)9 (45)
 Osteomyelitis, total no. (%)3 (15)3 (15)
Time to first amputation, mean (SD), days202 (104)202 (104)
Episodes of lower limb/foot infection, n (%)96 (21)53 (65)43 (12)< 0.001*
Total number of infectionsb18213052< 0.001*
Episodes of osteomyelitis, n (%)24 (5)23 (28)1 (0.3)< 0.001*
Foot-related hospitalizations, n (%)42 (9)35 (43)7 (2)< 0.001*
Total number of hospitalizationsb746680.08
Reason for hospital admission    
 Infected foot ulcer, n (%)17 (4)16 (20)1 (0.3)0.10
 Lower extremity amputation, n (%)5 (1)4 (5)1 (0.3)> 0.99
 Lower extremity revascularization procedure, n (%)8 (2)4 (5)4 (1)0.09
 PAD/gangrene, n (%)9 (2)8 (10)1 (0.3)0.69
 Cellulitis, n (%)7 (2)4 (5)3 (0.8)0.31
 Osteomyelitis, n (%)4 (0.9)4 (5)0 (0)0.65
 Other, n (%)10 (2)8 (10)2 (0.5)> 0.99
Length of stay, mean (SD), days25 (23)28 (23)10 (9)0.002*
Lower extremity revascularization procedure, n (%)24 (5)20 (25)4 (1)< 0.001*
Total number of lower extremity revascularization proceduresb423750.18
 Angioplasty, total no. (%)34 (81)30 (81)4 (80)Omitted
 Bypass, total no. (%)2 (5)2 (5)0 (0)Omitted
 Stent, total no. (%)6 (14)5 (14)1 (20)Omitted
New podiatry attendance, n (%)38 (8)13 (16)25 (7)< 0.001*
Kidney transplantation, n (%)30 (7)5 (6)25 (7)> 0.99
Time to transplant, mean (SD), days195 (115)191 (89)196 (121)0.91
All-cause mortality, n (%)52 (12)14 (17)38 (10)0.11
 Foot-related death, n (%)e6 (12)5 (36)1 (3)0.005*
  Sepsis due to infected foot ulcer, n (%)e5 (10)5 (36)0 (0)0.001*
  Complications of PAD, n (%)e1 (2)0 (0)1 (3)> 0.99
 Other causes of death, n (%)e46 (88)9 (64)37 (97)0.005*
  Myocardial infarction, n (%)e10 (19)3 (21)7 (18)> 0.99
  Withdrawal from dialysis, n (%)e8 (15)2 (14)6 (16)> 0.99
  Pneumonia, n (%)e8 (15)0 (0)8 (21)0.15
  Sepsis (not foot-related), n (%)e5 (10)0 (0)5 (13)0.37
  Intestinal necrosis, n (%)e3 (6)1 (7)2 (5)> 0.99
  ESRD, n (%)e3 (6)1 (7)2 (5)> 0.99
  Other, n (%)e9 (17)2 (14)7 (18)> 0.99
Time to death, mean (SD), days193 (115)192 (112)194 (118)0.96
  1. Data are n (%), unless otherwise specified. Percentages may not add up to 100%, as they are rounded to the nearest percent
  2. The complete dataset of primary and secondary outcomes can be found in Additional file 2
  3. SD Standard deviation, PAD Peripheral arterial disease, ESRD End-stage renal disease
  4. *Significant difference between ‘foot ulceration’ and ‘no foot ulceration’ groups, p < 0.05
  5. aIncludes new and reoccurring foot ulcers. Reoccurring ulcers were in 9 participants (2.0%)
  6. bTotal number
  7. cMinor amputations included: 10 single toe, 4 multiple toes, 1 partial toe, 1 single toe and metatarsal, and 2 transmetatarsal amputations
  8. dMajor amputations included: 2 below knee amputations
  9. ePercentage calculated from all-cause mortality data