Background
Methods
Study population
Data collection
Study measures
Data analysis
Results
Baseline demographic characteristics
Overall | Diabetic foot infection | Surgical site infection | Deep soft tissue abscess | Cellulitis | |
---|---|---|---|---|---|
(N=1,033) | (N=278) | (N=330) | (N=147) | (N=278) | |
Age: mean (median, range) | 54.2 (54.0, 18–94) | 57.6 (57.0, 19–93) | 54.9 (55.5, 18–92) | 44.0 (43.0, 19–84) | 55.5 (53.0, 19–94) |
Female: N (%) | 474 (45.9) | 99 (35.6) | 189 (57.3) | 53 (36.1) | 133 (47.8) |
Ethnicity: N (%) | |||||
Hispanic/Latino | 80 (7.7) | 20 (7.2) | 19 (5.8) | 21 (14.3) | 20 (7.2) |
Not Hispanic/Latino | 952 (92.2) | 257 (92.4) | 311 (94.2) | 126 (85.7) | 258 (92.8) |
Missing | 1 (0.1) | 1 (0.4) | 0 (0.0) | 0 (0.0) | 0 (0.0) |
Race: N (%) | |||||
White | 790 (76.5) | 196 (70.5) | 270 (81.8) | 95 (64.6) | 229 (82.4) |
Black | 204 (19.7) | 64 (23.0) | 53 (16.1) | 42 (28.6) | 45 (16.2) |
Asian | 13 (1.3) | 7 (2.5) | 2 (0.6) | 3 (2.0) | 1 (0.4) |
American Indian or Alaska Native | 5 (0.5) | 0 (0.0) | 2 (0.6) | 3 (0.7) | 2 (0.7) |
Native Hawaiian or Pacific Islander | 20 (1.9) | 10 (3.6) | 3 (0.9) | 6 (4.1) | 1 (0.4) |
Missing | 1 (0.1) | 1 (0.4) | 0 (0.0) | 0 (0.0) | 0 (0.0) |
Admission source: N (%) | |||||
Nursing home | 4 (0.4) | 1 (0.4) | 3 (0.9) | 0 (0.0) | 0 (0.0) |
Emergency department | 767 (74.2) | 225 (80.9) | 211 (63.9) | 122 (83.0) | 209 (75.2) |
Physician’s office | 188 (18.2) | 37 (13.3) | 77 (23.3) | 20 (13.6) | 54 (19.4) |
Other | 74 (7.2) | 15 (5.4) | 39 (11.8) | 5 (3.4) | 15 (5.4) |
Clinical characteristics
Infection clinical presentation
Overall | Diabetic foot infection | Surgical site infection | Deep soft tissue abscess | Cellulitis | |
---|---|---|---|---|---|
(N=1,033) | (N=278) | (N=330) | (N=147) | (N=278) | |
Infection site (%) | |||||
Abdomen | 11.8 | 0.0 | 29.7 | 6.1 | 5.4 |
Upper leg | 6.8 | 0.0 | 12.1 | 9.5 | 5.8 |
Lower leg#
| 23.7 | 12.2 | 16.4 | 12.9 | 49.6 |
Foot | 28.5 | 87.1 | 6.4 | 1.4 | 10.4 |
Other* | 28.5 | 0.0 | 33.9 | 70.1 | 28.4 |
Missing | 0.8 | 0.7 | 1.5 | 0.0 | 0.4 |
Deepest involvement: N (%) | |||||
Epidermis/dermis | 274 (23.9) | 79 (28.4) | 55 (16.7) | 20 (13.6) | 120 (43.2) |
Subcutaneous tissue | 575 (55.7) | 153 (55.0) | 179 (54.2) | 101 (68.7) | 142 (51.1) |
Fascial plane | 115 (11.1) | 30 (10.8) | 56 (17.0) | 18 (12.2) | 11 (4.0) |
Muscle | 55 (5.3) | 12 (4.3) | 33 (10.0) | 8 (5.4) | 2 (0.7) |
Missing | 14 (13.6) | 4 (14.4) | 7 (2.1) | 0 (0.0) | 3 (1.1) |
Regional adenopathy: N (%) | |||||
Present | 114 (11.0) | 23 (8.3) | 20 (6.1) | 31 (21.1) | 40 (14.4) |
Absent | 901 (87.2) | 252 (90.6) | 299 (90.6) | 114 (77.6) | 236 (84.9) |
Missing | 18 (1.7) | 3 (0.1) | 11 (3.3) | 2 (1.4) | 2 (0.1) |
Erythema: N (%) | |||||
Absent | 73 (7.1) | 20 (7.2) | 38 (11.5) | 8 (5.4) | 7 (2.5) |
Mild | 218 (21.1) | 57 (20.5) | 102 (30.9) | 26 (17.7) | 33 (11.9) |
Moderate | 516 (50.0) | 154 (55.4) | 135 (40.9) | 76 (51.7) | 151 (54.3) |
Severe | 216 (20.9) | 44 (15.8) | 49 (14.8) | 37 (25.2) | 86 (30.9) |
Missing | 10 (1.0) | 3 (1.1) | 6 (1.8) | 0 (0.0) | 1 (0.4) |
Abscess: N (%) | |||||
Absent | 713 (69.0) | 214 (77.0) | 244 (73.9) | 15 (10.2)$
| 240 (86.3) |
Mild | 102 (9.9) | 30 (10.8) | 24 (7.3) | 35 (23.8) | 13 (4.7) |
Moderate | 160 (15.5) | 25 (9.0) | 43 (13.0) | 72 (49.0) | 20 (7.2) |
Severe | 46 (4.5) | 6 (2.2) | 11 (3.3) | 25 (17.0) | 4 (1.4) |
Missing | 12 (1.2) | 3 (1.1) | 8 (2.4) | 0 (0.0) | 1 (0.4) |
Induration: N (%) | |||||
Absent | 230 (22.3) | 72 (25.9) | 89 (27.0) | 20 (13.6) | 49 (17.6) |
Mild | 280 (27.1) | 75 (27.0) | 102 (30.9) | 24 (16.3) | 79 (28.4) |
Moderate | 390 (37.8) | 105 (37.8) | 99 (30.0) | 73 (49.7) | 113 (40.6) |
Severe | 120 (11.6) | 22 (7.9) | 33 (10.0) | 30 (20.4) | 35 (12.6) |
Missing | 13 (1.3) | 4 (1.4) | 7 (2.1) | 0 (0.0) | 2 (0.7) |
Tenderness: N (%) | |||||
Absent | 98 (9.5) | 55 (19.8) | 21 (6.4) | 6 (4.1) | 16 (5.8) |
Mild | 265 (25.7) | 85 (30.6) | 91 (27.6) | 21 (14.3) | 68 (24.5) |
Moderate | 445 (43.1) | 108 (38.8) | 147 (44.5) | 63 (24.5) | 127 (45.7) |
Severe | 213 (20.6) | 27 (9.7) | 64 (19.4) | 57 (38.8) | 65 (23.4) |
Missing | 12 (1.2) | 3 (1.1) | 7 (2.1) | 0 (0.0) | 2 (0.7) |
Pain: N (%) | |||||
Absent | 102 (9.9) | 56 (20.1) | 22 (6.7) | 5 (3.4) | 19 (6.8) |
Mild | 228 (22.1) | 81 (29.1) | 79 (23.9) | 14 (9.5) | 54 (19.4) |
Moderate | 425 (41.1) | 97 (34.9) | 142 (43.0) | 62 (42.2) | 124 (44.6) |
Severe | 268 (25.9) | 41 (14.7) | 82 (24.8) | 66 (44.9) | 79 (28.4) |
Missing | 10 (1.0) | 3 (1.1) | 5 (1.5) | 0 (0.0) | 2 (0.7) |
Local warmth: N (%) | |||||
Absent | 94 (9.1) | 22 (7.9) | 53 (16.1) | 9 (6.1) | 10 (3.6) |
Mild | 342 (33.1) | 105 (37.8) | 136 (41.2) | 31 (21.1) | 70 (25.2) |
Moderate | 478 (46.3) | 126 (45.3) | 109 (33.0) | 85 (57.8) | 158 (56.8) |
Severe | 105 (10.2) | 21 (7.6) | 24 (7.3) | 22 (15.0) | 38 (13.7) |
Missing | 14 (1.4) | 4 (1.4) | 8 (2.4) | 0 (0.0) | 2 (0.7) |
Open wound: N (%) | |||||
Yes | 682 (66.0) | 255 (91.7) | 249 (75.5) | 78 (53.1) | 100 (36.0) |
No | 343 (33.2) | 21 (7.6) | 76 (23.0) | 69 (46.9) | 177 (63.7) |
Missing | 8 (0.8) | 2 (0.7) | 5 (1.5) | 0 (0.0) | 1 (0.4) |
Wound score^: mean (median, range) | |||||
5-item | 8.4 (8.0, 0–15) | 7.5 (7.5, 0–15) | 7.8 (8.0, 0–15) | 10.0 (10.0, 0–15) | 9.3 (9.0, 2–15) |
8-item | 17.8 (17, 4–43) | 15.7 (15, 4–37) | 19.5 (18, 5–43) | 20.8 (20, 4–39) | 17.0 (16, 8–38) |
10-item | 20.2 (19, 5–46) | 17.8 (18, 5–41) | 22.5 (21, 8–46) | 23.5 (22.5, 7–43) | 18.6 (17, 8–41) |
Treatment patterns
Overall | Diabetic foot infection | Surgical site infection | Deep soft tissue abscess | Cellulitis | |
---|---|---|---|---|---|
(N=1,033) | (N=278) | (N=330) | (N=147) | (N=278) | |
Initial intravenous antibiotics: N (%) * | |||||
Glycopeptidesa
| 630 (61.0) | 167 (60.1) | 186 (56.4) | 109 (74.1) | 169 (60.4) |
Penicillinsb
| 386 (37.4) | 141 (50.7) | 101 (30.6) | 53 (36.1) | 91 (32.7) |
Beta-lactamase -inhibitorsc
| 380 (36.8) | 140 (50.4) | 98 (29.7) | 53 (36.1) | 89 (32.0) |
Beta-lactamase -resistantd
| 7 (0.7) | 1 (0.4) | 3 (0.9) | 0 (0.0) | 3 (1.1) |
Non-beta-lactamase inhibitorse
| 7 (0.7) | 2 (0.7) | 1 (0.3) | 0 (0.0) | 4 (1.4) |
Cephalosporinsf
| 188 (18.2) | 41 (14.8) | 64 (19.4) | 15 (10.2) | 68 (24.5) |
First-generation | 90 (8.7) | 13 (4.7) | 37 (11.2) | 3 (2.0) | 37 (13.3) |
Third-generation | 69 (6.7) | 18 (6.5) | 15 (4.5) | 11 (7.5) | 25 (9.0) |
Fourth-generation | 27 (2.6) | 9 (3.2) | 13 (3.9) | 0 (0.0) | 5 (1.8) |
Lincosamidesj
| 147 (14.2) | 31 (11.2) | 38 (11.5) | 25 (17.0) | 53 (19.1) |
Fluoroquinolonesk
| 90 (8.7) | 28 (10.1) | 35 (10.6) | 11 (7.5) | 16 (5.8) |
Daptomycin | 28 (2.7) | 5 (1.8) | 13 (3.9) | 4 (2.7) | 6 (2.2) |
Nitroimidazole derivativesm
| 27 (2.6) | 7 (2.5) | 14 (4.2) | 1 (0.7) | 5 (1.8) |
Other Antibiotics n
| 26 (2.5) | 8 (2.9) | 8 (2.4) | 4 (2.7) | 6 (2.2) |
Treatment duration of the most common initial intravenous antibiotics: mean (median, minimum-maximum) | |||||
First-generation cephalosporins | 2.5 (1.7, 0–27) | 1.5 (1.7, 0–3) | 3.2 (1.7, 0–27) | 1.6 (1.5, 0–3) | 2.2 (1.5, 0–12) |
Glycopeptides | 3.2 (2.6, 0–24) | 3.7 (2.7, 0–24) | 3.1 (2.6, 0–16) | 2.8 (2.6, 0–11) | 3.0 (2.7, 0–14) |
Lincosamides | 2.2 (1.6, 0–10) | 1.9 (1.2, 0–8) | 2.5 (1.5, 0–10) | 2.3 (2.3, 0–7) | 2.1 (1.7, 0–9) |
Penicillins (beta-lactamase-inhibitors) | 3.4 (2.6, 0–36) | 3.8 (2.8, 0–24) | 3.9 (2.9, 0–36) | 2.4 (2.1, 0–7) | 2.8 (2.4, 0–13) |
Reason for administration of initial intravenous antibiotics: N (%)* | |||||
Empiric treatment prior to culture test results | 917 (88.8) | 243 (87.4) | 292 (88.5) | 137 (93.2) | 245 (88.1) |
Not responding to previous antibiotic treatment | 42 (4.1) | 6 (2.2) | 13 (3.9) | 6 (4.1) | 17 (6.1) |
Other | 64 (6.2) | 13 (4.7) | 24 (7.3) | 6 (4.1) | 21 (7.6) |
Reason for discontinuation of initial antibiotics: N (%)* | 886 | 232 | 271 | 136 | 247 |
Switched to another route/formulation^ | 475 (53.6) | 108 (46.6) | 147 (54.2) | 82 (60.3) | 138 (55.9) |
Infection improved, resolved, or cured^ | 386 (43.6) | 105 (45.3) | 99 (36.5) | 62 (45.6) | 120 (48.6) |
Culture results indicate this antibiotic agent not needed | 155 (17.5) | 43 (18.5) | 56 (20.7) | 32 (23.5) | 24 (9.7) |
Pathogen not susceptible to this antibiotic agent^ | 36 (4.1) | 8 (3.4) | 19 (7.0) | 3 (2.2) | 6 (2.4) |
Procedures and outcomes
Overall | Diabetic foot infection | Surgical site infection | Deep soft tissue abscess | Cellulitis | |
---|---|---|---|---|---|
(N=1,033) | (N=278) | (N=330) | (N=147) | (N=278) | |
Surgical procedures related to study infection: N (%) | 426 (41.2) | 123 (44.2) | 148 (44.8) | 100 (68.0) | 55 (19.8) |
For source control: N (%) | 181 (17.5) | 56 (20.1) | 48 (14.5) | 56 (38.1) | 21 (7.6) |
Incision and drainage | 117 (11.3) | 25 (8.9) | 29 (8.8) | 47 (32.0) | 16 (5.8) |
Surgical debridement | 41 (3.9) | 11 (3.9) | 18 (5.5) | 8 (5.4) | 4 (1.4) |
Excision of wound | 5 (0.4) | 3 (1.1) | 0 (0.0) | 1 (0.7) | 1 (0.4) |
Amputation | 18 (1.7) | 17 (6.1) | 1 (0.3) | 0 (0.0) | 0 (0.0) |
Clinical assessment: N (%) | |||||
Resolved/cured | 82 (7.9) | 22 (7.9) | 15 (4.6) | 12 (8.2) | 33 (11.9) |
Improved | 836 (80.9) | 213 (76.6) | 274 (83.0) | 131 (89.1) | 218 (78.4) |
Unchanged | 32 (3.1) | 10 (3.6) | 13 (3.9) | 0 (0.0) | 9 (3.2) |
Worsened | 6 (0.6) | 3 (1.1) | 2 (0.6) | 0 (0.0) | 1 (0.4) |
Missing | 77 (7.5) | 30 (10.8) | 26 (7.9) | 4 (2.7) | 17 (6.1) |
Quality of life^ | |||||
Change in EQ-5D Index at discharge: mean (median, range) | 0.1 (0.1, -0.8-0.9) | 0.1 (0.1, -0.8-0.9) | 0.1 (0.1, -0.7-0.9) | 0.2 (0.2, -0.3-0.7) | 0.2 (0.1, -0.7-0.8) |
Change in EQ-VAS at discharge: mean (median, range) | 11.7 (10, -93-100) | 11.4 (10, -93-92) | 11.5 (10, -55-90) | 13.7 (10, -45-100) | 11.1 (10, -50-85) |
Length of stay: mean (median, range) | 7.1 (5, 1–55) | 7.6 (6, 1–26) | 8.1 (6, 1–55) | 5.8 (5, 2–31) | 6.0 (5, 1–35) |
Hospital mortality: N (%) | 4 (0.4) | 2 (0.7) | 2 (0.6) | 0 (0.0) | 0 (0.0) |
Discussion
Conclusions
Appendix
Appendix: clarification of DFI and SSI definitions*
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Have a history of diabetes mellitus
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Have an infection on or below the ankle
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Have a break (i.e., ulcer) in the epidermis where the infection started (“You must be able to answer “yes” to “open wound” on the Baseline Characteristics of Open Wound assessment)
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Have a purulent discharge or at least two of the following (on the Baseline Signs and Symptoms of Inflammation assessment):
-
○ Erythema
-
○ Pain
-
○ Tenderness
-
○ Local warmth
-
○ Induration
-
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Have an infection that occurred within 30 days after an operation
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Have an infection that involves only skin or subcutaneous tissue at the incision site
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Have at least one of the following:
-
Purulent drainage, with or without laboratory confirmation, from the surgical incision
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Organisms isolated from a culture of an aseptically obtained specimen of wound fluid or tissue from the surgical incision site
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At least two of the following signs or symptoms of infection: pain or tenderness, localized swelling, redness, or warmth
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Diagnosis of surgical incisional infection by the operating surgeon or attending physician
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An abscess or other evidence of infection involving the surgical site found on direct examination, during reoperation, or by histopathologic or imaging examination
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Stitch abscess (minimal inflammation and discharge confined to the points of suture penetration)
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Infection of an episiotomy or newborn circumcision site
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Infected burn wound or infected stab or traumatic wound