Table 1.
Baseline characteristics of the intention-to-treat population
| Characteristic | All | Enhanced therapy | Usual care | Missing values |
| Number of participants | 304 | 151 | 153 | |
| Age (years) | 64.6±10.5 | 65.0±10.6 | 64.2±10.5 | |
| Male sex | 220 (72.4%) | 109 (72.2%) | 111 (72.5%) | |
| Ethnic origin: Caucasian | 283 (93.1%) | 140 (92.7%) | 143 (93.5%) | |
| Type of diabetes | 4 (1.3%) | |||
| Type 1 | 66 (21.7%) | 30 (19.9%) | 36 (23.5%) | |
| Type 2 | 234 (77.0%) | 119 (79.9%) | 115 (75.3%) | |
| Years diagnosed with diabetes | 20±14 | 20±14 | 21±15 | 3 (1.0%) |
| HbA1c (mmol/mol) | 60.7±16.0 | 60.5±16.5 | 60.9±15.5 | 65 (21.4%) |
| Body mass index (kg/m2) | 29.8±5.3 | 29.6±5.4 | 30±5.3 | 1 (0.3%) |
| Retinopathy | 151 (49.7%) | 83 (55.0%) | 68 (44.4%) | 2 (0.7%) |
| Nephropathy | 60 (19.7%) | 31 (20.5%) | 29 (19.0%) | 1 (0.3%) |
| Dialysis | 4 (1.3%) | 0 (0.0%) | 4 (2.6%) | |
| Smoking or history of smoking | 169 (55.6%) | 88 (58.3%) | 81 (52.9%) | |
| ≥1 unit alcohol intake per week | 199 (65.5%) | 102 (67.5%) | 97 (63.4%) | |
| Living alone | 105 (34.5%) | 52 (34.4%) | 53 (34.6%) | |
| Using a walking aid | 89 (29.3%) | 49 (32.5%) | 40 (26.1%) | |
| Education | 2 (0.7%) | |||
| Low | 117 (38.5%) | 61 (40.4%) | 56 (36.6%) | |
| Medium | 96 (31.6%) | 45 (29.8%) | 51 (33.3%) | |
| High | 89 (29.3%) | 44 (29.1%) | 45 (29.4%) | |
| Employed | 75 (24.7%) | 38 (25.2%) | 37 (24.2%) | |
| Footwear | 2 (0.7%) | |||
| Conventional | 97 (31.9%) | 52 (34.4%) | 45 (29.4%) | |
| Semi custom-made | 37 (12.2%) | 19 (12.6%) | 19 (12.4%) | |
| Full custom-made | 168 (55.3%) | 80 (53.0%) | 89 (58.2%) | |
| Walking barefoot at home | 113 (37.2%) | 54 (35.8%) | 59 (38.6%) | |
| Participating center category | ||||
| University Medical Center | 88 (28.9%) | 42 (27.8%) | 46 (30.1%) | |
| Community hospital | 134 (44.1%) | 68 (45.0%) | 66 (43.1%) | |
| Podiatry practice | 82 (27.0%) | 41 (27.2%) | 41 (26.8%) | |
| Participating center | ||||
| Amsterdam UMC, location AMC | 95 (31.3%) | 47 (31.1%) | 48 (31.4%) | |
| Amsterdam UMC, location VUmc | 18 (5.9%) | 9 (6.0%) | 9 (5.9%) | |
| Maastricht UMC+ | 25 (8.2%) | 12 (7.9%) | 13 (8.5%) | |
| Ziekenhuisgroep Twente | 49 (16.1%) | 23 (15.2%) | 26 (17.0%) | |
| Reinier de Graaf Gasthuis | 41 (13.5%) | 21 (13.9%) | 20 (13.1%) | |
| Maxima Medisch Centrum | 64 (21.1%) | 32 (21.2%) | 32 (20.9%) | |
| Medisch Spectrum Twente | 12 (3.9%) | 7 (4.6%) | 5 (3.3%) | |
| Frequency of professional foot care, every: | ||||
| 1–4 weeks | 82 (27.0%) | 41 (27.2%) | 41 (26.8%) | |
| 5–8 weeks | 199 (65.5%) | 102 (67.5%) | 97 (63.4%) | |
| >8 weeks | 23 (7.6%) | 8 (5.3%) | 15 (9.8%) | |
| LOPS based on inability to sense | ||||
| 10 g monofilament | 276 (90.8%) | 138 (91.4%) | 138 (90.2%) | |
| 128 Hz tuning fork only | 28 (9.2%) | 13 (8.6%) | 15 (9.8%) | |
| Peripheral artery disease | ||||
| Grade 1 | 230 (75.7%) | 114 (75.5%) | 116 (75.8%) | |
| Grade 2 | 74 (24.3%) | 37 (24.5%) | 37 (24.2%) | |
| Foot deformity | ||||
| Absent | 17 (5.6%) | 10 (6.6%) | 7 (4.6%) | |
| Mild | 58 (19.1%) | 32 (21.2%) | 26 (17.0%) | |
| Moderate | 202 (66.4%) | 99 (65.6%) | 103 (67.3%) | |
| Severe | 27 (8.9%) | 10 (6.6%) | 17 (11.1%) | |
| Minor lesions at entry* | 121 (39.8%) | 54 (35.8%) | 67 (43.8%) | 31 (10.2%) |
| Amputation† | ||||
| No amputation | 223 (73.4%) | 110 (72.8%) | 113 (73.9%) | |
| Lesser toe(s) | 29 (9.5%) | 14 (9.3%) | 15 (9.8%) | |
| Hallux or ray | 39 (12.8%) | 19 (12.6%) | 20 (13.1%) | |
| Forefoot | 6 (2.0%) | 5 (3.3%) | 1 (0.7%) | |
| Major | 7 (2.3%) | 3 (2.0%) | 4 (2.6%) | |
| Previous ulcer site | 1 (0.3%) | |||
| Plantar forefoot | 95 (31.3%) | 50 (33.1%) | 45 (29.4%) | |
| Medial/lateral/interdigital/apex forefoot | 104 (34.2%) | 52 (34.4%) | 52 (34.0%) | |
| Plantar midfoot/hindfoot | 23 (7.6%) | 11 (7.3%) | 12 (7.8%) | |
| Dorsal side of the foot | 72 (23.7%) | 34 (22.5%) | 38 (24.8%) | |
| No previous ulcer (ie, Charcot foot)‡ | 9 (3.0%) | 4 (2.6%) | 5 (3.3%) | |
| Months between healing of most recent ulcer and study entry | 7 (2–14) | 8 (2–15) | 6 (2–12) | 10 (3.3%)‡ |
| Months duration of last two previous ulcers | 4 (2–9) | 4 (2–8) | 4 (2–9) | 1 (0.3%) |
Data are n (%), mean±SD, or median (IQR).
*Minor lesion defined as a hemorrhage, blister, abundant callus, or erythema, identified at entry and confirmed present from photographic assessment.
†In case of bilateral amputation, the highest level was chosen.
‡Including nine participants that were included based on having a history of Charcot neuro-osteoarthropathy and having no history of ulceration.
AMC, Academic Medical Center; LOPS, loss of protective sensation; UMC, University Medical Center; VUmc, Vrije Universiteit Medical Center.