Table 4.
Healing status by baseline factors, univariable and multivariable analysis for factors with a significant univariable association with the incidence of healing
| Baseline factora | Healed(%) | Not healed (%) | Reference levelb | Exploratory univariable analysis HR (95%CI) | Preliminary multivariable analysis HR (95%CI) | Final multivariable analysis HR (95%CI) |
|---|---|---|---|---|---|---|
| Ulcer type | ||||||
| Ischaemic or neuro‐ischaemic | 49 (34.5) | 93 (65.5) | Neuropathic | 0.5 (0.35 to 0.71)P<0.0001 | 1.09 (0.59 to 2.02)P=0.7837 | |
| Neuropathic only | 85 (54.8) | 70 (45.2) | ||||
| Wagner grade | ||||||
| Grade 1 | 56 (53.8) | 48 (46.2) | Grade 1 | |||
| Grade 2 | 41 (44.1) | 52 (55.9) | 0.65 (0.44 to 0.98)P=0.0397 | 0.56 (0.25 to 1.23)P=0.1477 | ||
| Grade 3, 4 or 5 | 39 (38.2) | 63 (61.8) | 0.55 (0.36 to 0.82)P=0.0038 | 0.59 (0.25 to 1.37)P=0.2159 | ||
| PEDIS: perfusion | ||||||
| Grade 1 | 85 (57.8) | 62 (42.2) | Grade 1 | 0.44 (0.31 to 0.62)P<0.0001 | 0.43 (0.22 to 0.83)P=0.0113 | 0.37 (0.25 to 0.55)P<0.0001 |
| Grade ≥2 | 51 (33.6) | 101 (66.4) | ||||
| PEDIS: depth | ||||||
| Grade 1 | 51 (53.1) | 45 (46.9) | Grade 1 | |||
| Grade 2 | 47 (47.0) | 53 (53.0) | 0.70 (0.47 to 1.05)P=0.0843 | 1.61 (0.74 to 3.49)P=0.2311 | ||
| Grade 3 | 38 (36.9) | 65 (63.1) | 0.54 (0.35 to 0.83)P=0.0046 | 1.16 (0.47 to 2.91)P=0.7451 | ||
| PEDIS: infectionc | ||||||
| Grade 2 | 55 (52.9) | 49 (47.1) | Grade 2 | 0.65 (0.46 to 0.91)P=0.0135 | 0.91 (0.59 to 1.41)P=0.6831 | |
| Grade 3 | 78 (42.2) | 107 (57.8) | ||||
| Grade 4 | 3 (30.0) | 7 (70.0) | ||||
| Wound duration | ||||||
| <56 days | 77 (53.8) | 66 (46.2) | <56 days | 0.54 (0.39 to 0.76)P=0.0004 | 0.46 (0.30 to 0.70)P=0.0003 | 0.55 (0.39 to 0.77)P=0.0005 |
| ≥56 days | 56 (36.8) | 96 (63.2) | ||||
| Prior antimicrobial dressing on ulcer | ||||||
| Yes | 69 (39.4) | 106 (60.6) | No | 0.65 (0.46 to 0.91)P=0.0123 | 0.77 (0.52 to 1.14)P=0.1934 | |
| No | 64 (53.8) | 55 (46.2) | ||||
| Only one (rather than≥2) ulcer on index foot | ||||||
| Yes | 113 (50.9) | 109 (49.1) | No | 1.96 (1.25 to 3.07)P=0.0034 | 1.91 (1.15 to 3.17)P=0.0122 | 1.90 (1.18 to 3.06)P=0.0081 |
| No | 23 (29.9) | 54 (70.1) | ||||
| Coagulase‐negative Staphylococcus reported | ||||||
| Yes | 24 (63.2) | 14 (36.8) | No | 1.69 (1.11 to 2.59)P=0.0147 | 1.98 (1.08 to 3.61)P=0.0270 | 1.53 (0.98 to 2.40)P=0.0603 |
| No | 112 (42.9) | 149 (57.1) | ||||
| Methicillin‐resistant S. aureus reported | ||||||
| Yes | 8 (29.6) | 19 (70.4) | No | 0.50 (0.26 to 0.97)P=0.0419 | 0.67 (0.28 to 1.63)P=0.3802 | |
| No | 128 (47.1) | 144 (52.9) | ||||
| Age (continuous ‐ per 5 year increase)d | 1.02 (0.95 to 1.09)P=0.5887 | 1.11 (1.02 to 1.22)P=0.0169 | 1.11 (1.03 to 1.19)P=0.0081 |
HR, hazard ratio. Bold numbers indicate the direction in which the event is more likely to occur (healing or not healing).
The following factors reported in Table 1 were also included in the exploratory univariable and preliminary multivariable analysis, however, no significant associations were detected at the 10% level: diabetes duration; diabetes type: type 2 vs type 1; insulin therapy; HbA1c; ulcer extent; PEDIS sensation grade; incident or recurrent ulcer; ulcer location; previous antibiotic therapy; any reported pathogens; overall anaerobes; Gram‐positive cocci; Gram‐negative bacilli; Enterobacteriaceae; Gram‐positive bacilli; MSSA; Streptococcus; Enterococcus excluding vancomycin resistant, Corynebacterium; Pseudomonas.
The reference level refers to the level of the factor used as the reference in the HRs, i.e. participants with ischaemic ulcers compared with the reference neuropathic ulcers have a lower rate of healing with a HR of 0.5 in univariable analysis.
PEDIS infection grades 3 and 4 were combined in the analysis.
The association with age was not supported when age was explored categorically at various ‘splits’ in the data.