Table 1.
Bivariate comparisons between non-loading dose and loading dose patients
| Characteristic | No loading dose (n = 158) | Loading dose (n = 158) | P value |
|---|---|---|---|
| Demographics | |||
| Age, mean (SD) | 57.4 (15.3) | 56.8 (17.4) | 0.721 |
| Male | 74 (46.8) | 72 (45.6) | 0.821 |
| Health system | 1.000 | ||
| Detroit Medical Center | 118 (74.7) | 118 (74.7) | |
| Ascension St. John Hospital | 40 (25.3) | 40 (25.3) | |
| Clinical characteristics | |||
| Prior hospitalization (30 days) | 47 (29.7) | 49 (31.0) | 0.807 |
| Prior S. aureus infection (30 days) | 4 (2.5) | 6 (3.8) | 0.750 |
| Total body weight (kg) | 75 (64–90.8) | 70 (61–79.8) | 0.001 |
| Obesity (≥ 30 kg/m2) | 42 (26.6) | 20 (12.7) | 0.002 |
| Intravenous drug use | 40 (25.3) | 43 (27.2) | 0.701 |
| Diabetes | 50 (31.6) | 35 (22.2) | 0.057 |
| Cerebrovascular accident | 30 (19.0) | 17 (10.8) | 0.040 |
| Cirrhosis | 6 (3.8) | 1 (0.6) | 0.121 |
| Malignancy | 12 (7.6) | 16 (10.1) | 0.428 |
| HIV/AIDS | 6 (3.8) | 12 (7.6) | 0.145 |
| Creatinine clearance (mL/min) | 72.5 (52.7–102.5) | 75.9 (48.6–107.6) | 0.981 |
| Concomitant nephrotoxins | 118 (74.7) | 112 (70.9) | 0.448 |
| Number of concomitant nephrotoxins | 1 (0–2) | 1 (0–2) | 0.203 |
| LOS pre-bacteremia | 0 (0–1) | 0 (0–1) | 0.259 |
| Pitt bacteremia score | 1 (0–3) | 1 (0–2) | 0.166 |
| ICU at vancomycin initiation | 34 (21.5) | 54 (34.2) | 0.012 |
| Primary bacteremia source | 0.465 | ||
| Deep abscess | 5 (3.2) | 17 (10.8) | |
| Bone/joint | 20 (12.7) | 16 (10.1) | |
| Intravenous catheter | 15 (9.5) | 15 (9.5) | |
| Urinary | 3 (1.9) | 2 (1.3) | |
| Lower respiratory tract | 27 (17.1) | 24 (15.2) | |
| Skin/soft tissue | 46 (29.1) | 44 (27.8) | |
| Infective endocarditis | 16 (10.1) | 17 (10.8) | |
| Unknown | 22 (13.9) | 20 (12.7) | |
| Other | 4 (2.5) | 3 (1.9) | |
| Treatment information | |||
| Time to vancomycin (days) | 1 (0–1) | 0 (0–1) | 0.396 |
| First dose (mg) | 1000 (1000–1250) | 1500 (1500–2000) | < 0.001 |
| First dose (mg/kg) | 14.3 (12.2–17.1) | 23.0 (21.4–25.0) | < 0.001 |
| Initial maintenance dose (mg) | 1000 (1000–1250) | 1000 (1000–1250) | 0.470 |
| Initial maintenance dose (mg/kg) | 13.8 (11.7–16.6) | 15.7 (13.2–19.2) | < 0.001 |
| Initial trough concentration during first 72 h (mg/L) (n = 101 non-LD; 105 LD) | 12.8 (9.4–16.3) | 14.4 (10.6–17.9) | 0.081 |
| Initial trough concentration ≥ 15 mg/L (n = 101 non-LD; 105 LD) | 35 (34.7) | 48 (45.7) | 0.106 |
| Initial trough concentration ≥ 10 mg/L(n = 101 non-LD; 105 LD) | 72 (71.3) | 81 (77.1) | 0.336 |
| Inpatient duration of therapy (days) | 8 (5–12) | 8 (5–12) | 0.324 |
| Outcomes | |||
| Bacteremia duration (days) | 4 (2–6) | 3 (2–5) | 0.287 |
| ICU LOS | 6 (3–16) | 6 (2–10) | 0.181 |
| LOS post-bacteremia | 12 (8–18) | 10 (7–16) | 0.185 |
| Composite failure | 64 (40.5) | 58 (36.7) | 0.488 |
| 30-day mortality | 14 (8.9) | 18 (11.4) | 0.456 |
| Bacteremia duration ≥ 7 days | 21 (13.3) | 27 (17.1) | 0.347 |
| Persistent signs/symptoms ≥ 7 days | 30 (19.0) | 29 (18.4) | 0.885 |
| Switch to alternate agent due to treatment failure | 31 (19.6) | 23 (14.6) | 0.232 |
| Nephrotoxicity | 20 (12.7) | 26 (16.5) | 0.339 |
Data presented at n (%) or median (IQR) unless otherwise specified
HIV/AIDS human immunodeficiency virus/acquired immune deficiency syndrome, LOS length of stay, ICU intensive care unit, LD loading dose