Table 3.
Risk factors for treatment failure rifampin cohort (n = 407)
| Non-failures (n = 276) | Failures (n = 131) | P value | Adjusted OR (95% CI)a | P value | |
|---|---|---|---|---|---|
| Baseline characteristics | |||||
| Male sex | 40.2%(111/276) | 50.4% (66/131) | .05* | 2.07 (1.19 – 3.58) | .009 |
| Age >80 years | 21.1% (58/275) | 28.2% (37/131) | .11 | ||
| BMI >30 kg/m2 | 48.8% (122/250) | 46.6% (55/118) | .70 | ||
| Medical history | |||||
| Diabetes | 17.8% (49/276) | 26.7% (35/131) | .04* | 2.16 (1.12 – 4.15) | .022 |
| Renal failure | 6.2% (17.276) | 8.4% (11/131) | .41 | ||
| COPD | 17.8% (49/276) | 19.8% (26/131) | .61 | ||
| Liver cirrhosis | 3.6% (10/276) | 3.8% (5/131) | .92 | ||
| Malignancy | 13.8% (38/276) | 15.3% (20/131) | .67 | ||
| Rheumatoid arthritis | 6.9% (19/276) | 8.4% (11/131) | .59 | ||
| Characteristics implant | |||||
| Knee | 41.7% (115/276) | 35.1% (46/131) | .21 | ||
| Primary | 85.1% (235/276) | 78.6% (103/131) | .10 | ||
| Cemented | 75.4% (205/272) | 81.4% (105/129) | .18 | ||
| Fracture | 13.4% (37/276) | 19.8% (26/131) | .09* | 1.40 (0.68 – 2.91) | .36 |
| Clinical presentation | |||||
| CRP >115 mg/L | 23.3% (63/270) | 47.3% (61/129) | <.001* | 1.54 (0.85 – 2.79) | .16 |
| Leucocytes >12 cells/µL | 21.1% (57/270) | 44.4% (56/126) | <.001* | 2.79 (1.48 – 5.27) | .002 |
| Late acute PJI | 2.2% (6/276) | 5.4% (7/130) | .09 | ||
| Identified micro-organism | |||||
| Staphylococcus aureus | 57.2% (158/276) | 71.8% (94/131) | .01* | 1.63 (0.89– 2.97) | .11 |
| Polymicrobial | 37.3 (103/276) | 38.9% (51/131) | .75 | ||
| Surgical treatment | |||||
| Exchange modular components | 48.3% (131/271) | 39.8% (51/128) | .11 | ||
| Antibiotic treatment | |||||
| Co-antibiotic other than a fluoroquinolone or clindamycin | 30.4% (84/276) | 78.6% (103/131) | <.001* | 10.1 (5.65 – 18.2) | <.001 |
| Rifampin dose >600 mg/24h | 52.1% (139/267) | 72.6% (90/124) | <.001* | 1.23 (0.65 – 2.32) | .52 |
| BMI/mg rifampin ratio >30 | 87.6% (242/276) | 81.6% (107/131) | .12 | ||
| Start rifampin <5 days after surgical debridement | 44.1% (116/263) | 64.0% (80/125) | <.001* | 1.96 (1.08 – 3.56) | .03 |
* Variables with a P value <.1 were included in the multivariate binary logistic regression analysis.
Abbreviations: BMI, body mass index; COPD, chronic obstructive pulmonary disease; CRP, C-reactive protein; DAIR, debridement, antibiotics, and implant retention; PJI, periprosthetic joint infections. a For early acute (post-operative) PJI.