Table 3. Odds ratio ranges for estimates of key risk factors for all SSIs, stratified by unadjusted and adjusted methods.
| n regression models reported | Range of estimates |
n (%) models with statistically significant estimates
1
|
|||||
|---|---|---|---|---|---|---|---|
| Risk factor |
Risk factors
|
Protective effect
|
|||||
| Unadjusted results | |||||||
| Female gender | 31 | 0.4 - 3.5 | 5 | (16.1) | 4 | (12.9) | |
| Increasing age | 21 | 0.6 - 8.5 | 9 | (42.9) | 1 | (4.8) | |
| Increasing BMI | 23 | 0.4 - 9.8 | 12 | (52.2) | 0 | (0.0) | |
| More severe ASA score | 19 | 0.5 - 44.8 | 12 | (63.2) | 0 | (0.0) | |
| More severe NNIS score | 5 | 0.7 - 4.3 | 4 | (80.0) | 0 | (0.0) | |
| Diabetes | 24 | 0.7 - 29.6 | 10 | (41.7) | 0 | (0.0) | |
| Smoking status | 11 | 0.3 - 27.0 | 2 | (18.2) | 2 | (18.2) | |
| Increased patient dependence | 5 | 0.4 - 6.3 | 4 | (80.0) | 1 | (20.0) | |
| S. aureus colonization | 7 | 0.0 - 15.5 | 5 | (71.4) | 1 | (14.3) | |
| Increased length of hospital stay | 10 | 1.0 - 12.9 | 7 | (70.0) | 0 | (0.0) | |
| Use of medical device3 | 4 | 0.3 - 5.6 | 1 | (25.0) | 1 | (25.0) | |
| More severe wound class | 14 | 1.0 - 17.4 | 9 | (64.3) | 0 | (0.0) | |
| Increased surgery duration | 19 | 0.7 - 9.0 | 12 | (63.2) | 0 | (0.0) | |
| Prophylaxis | 16 | 0.6 - 18.1 | 5 | (31.3) | 0 | (0.0) | |
| Adjusted results | |||||||
| Female gender | 14 | 0.4 - 3.3 | 5 | (35.7) | 2 | (14.3) | |
| Increasing age | 15 | 1.0 - 14.0 | 10 | (66.7) | 0 | (0.0) | |
| Increasing BMI | 20 | 1.0 - 7.1 | 17 | (85.0) | 0 | (0.0) | |
| More severe ASA score | 7 | 0.7 - 4.2 | 3 | (42.9) | 0 | (0.0) | |
| More severe NNIS score | 5 | 1.4 - 4.7 | 3 | (60.0) | 0 | (0.0) | |
| Diabetes | 12 | 1.5 - 24.3 | 11 | (91.7) | 0 | (0.0) | |
| Smoking status | 3 | 1.2 - 16.8 | 2 | (66.7) | 0 | (0.0) | |
| Increased patient dependence | 4 | 0.0 - 4.4 | 3 | (75.0) | 0 | (0.0) | |
| S. aureus colonization | 7 | 0.7 - 12.5 | 5 | (71.4) | 0 | (0.0) | |
| Increased length of hospital stay | 5 | 0.8 - 10.7 | 5 | (100.0) | 1 | (20.0) | |
| Use of medical device2 | 2 | 4.0 - 670.4 | 2 | (100.0) | 0 | (0.0) | |
| More severe wound class | 10 | 1.7 - 10.7 | 8 | (80.0) | 0 | (0.0) | |
| Increased surgery duration | 12 | 0.1 - 3.2 | 8 | (66.7) | 0 | (0.0) | |
| Prophylaxis | 7 | 0.4 - 20.5 | 6 | (85.7) | 0 | (0.0) | |
Abbreviations: ASA = American Society of Anesthesiologists; BMI = body mass index; ICU = intensive care unit; NNIS = National Nosocomial Infections Surveillance; n = number; OR = odds ratio; S. aureus = Staphylococcus aureus.
1 Statistical significance defined as p ≤0.05
2 Restricted to studies reporting foreign body medical devices that are permanently implanted during surgery