Table 2.
Univariate associations between mortality rates and reported mean or median population characteristics
| Trials reporting variable (% of n = 56) | Mean (SD) | Standardized regression coefficient β (R2) | P value | |
|---|---|---|---|---|
| Publication year | 65 (100) | 2013.3 (3.58) | − 0.19 (0.04) | 0.197 |
| Age, years | 64 (98) | 62.9 (3.80) | 0.18 (0.03) | 0.160 |
| Male patients % | 63 (97) | 60.5 (5.80) | 0.02 (0.00) | 0.927 |
| Comorbidity characteristics | ||||
| Charlson Comorbidity Index | 5 (8) | 1.90 (1.11) | 0.52 (0.27) | 0.183 |
| From long-term care facility % | 6 (9) | 5.8 (5.6) | 0.44 (0.20) | 0.312 |
| McCabe class I % | 6 (9) | 34.1 (15.2) | − 0.40 (0.16) | 0.374 |
| McCabe class II % | 6 (9) | 14.7 (12.9) | 0.02 (0.00) | 0.948 |
| McCabe class III % | 4 (6) | 16.2 (15.0) | 0.71 (0.50) | 0.120 |
| Diabetes mellitus % | 23 (36) | 24.4 (6.88) | 0.01 (0.00) | 0.856 |
| Heart failure or coronary disease % | 26 (40) | 20.7 (8.7) | 0.33 (0.11) | 0.133 |
| Chronic obstructive pulmonary disease % | 25 (39) | 15.1 (6.3) | 0.04 (0.00) | 0.911 |
| Chronic renal disease % | 21 (33) | 7.6 (5.0) | 0.06 (0.00) | 0.773 |
| Chronic liver disease % | 17 (26) | 5.5 (2.8) | 0.25 (0.06) | 0.320 |
| Cancer % | 20 (31) | 21.2 (8.1) | 0.19 (0.03) | 0.426 |
| Severity of illness scores | ||||
| APACHE II score | 33 (51) | 22.5 (3.65) | 0.21 (0.05) | 0.376 |
| APACHE III score | 1 (2) | – | – | – |
| APACHE IV score | 1 (2) | – | – | – |
| SAPS II score | 24 (37) | 55.7 (4.42) | 0.36 (0.13) | 0.079 |
| SAPS III score | 3 (4) | 77.6 (1.91) | 0.01 (0.00) | 0.644 |
| SOFA score | 37 (58) | 9.59 (2.47) | 0.57 (0.33) | 0.007** |
| Characteristics of acute illness | ||||
| Medical (non-surgical) % | 22 (34) | 69.7 (13.1) | 0.26 (0.07) | 0.314 |
| Time from diagnosis to randomization, hours | 13 (20) | 13.77 (8.84) | 0.47 (0.22) | 0.069 |
| Mechanical ventilation % | 33 (51) | 78.1 (28.3) | 0.61 (0.38) | 0.0005*** |
| Heart rate, 1/min | 39 (60) | 104 (8.8) | 0.13 (0.02) | 0.435 |
| Mean arterial pressure, mmHg | 43 (66) | 70.7 (6.65) | 0.06 (0.00) | 0.561 |
| Central venous pressure, mmHg | 22 (34) | 11.2 (2.21) | 0.17 (0.03) | 0.425 |
| Vasopressor support % | 38 (58) | 84.6 (30.0) | 0.57 (0.32) | 0.0019** |
| Serum lactate, mmol/l | 52 (80) | 4.00 (1.28) | − 0.13 (0.02) | 0.389 |
| Serum creatinine, µmol/l | 26 (40) | 168 (31.1) | 0.48 (0.23) | 0.007** |
| Fluids before randomization, ml | 19 (30) | 3209 (1637) | 0.31 (0.10) | 0.194 |
| Infection site characteristics | ||||
| Respiratory % | 53 (82) | 42.6 (13.7) | 0.27 (0.08) | 0.087 |
| Abdominal % | 51 (78) | 24.0 (15.0) | 0.06 (0.00) | 0.686 |
| Urogenital % | 41 (63) | 11.3 (5.7) | − 0.27 (0.07) | 0.094 |
| Central nervous system % | 19 (30) | 1.2 (1.6) | 0.03 (0.00) | 0.885 |
| Skin and soft tissue % | 28 (43) | 6.8 (3.6) | − 0.09 (0.01) | 0.803 |
| Bloodstream % | 32 (49) | 12.9 (8.2) | − 0.11 (0.01) | 0.487 |
| Pathogen characteristics | ||||
| Gram-negative % | 25 (39) | 32.0 (16.1) | 0.41 (0.17) | 0.0573 |
| Gram-positive % | 22 (34) | 24.6 (7.12) | − 0.41 (0.17) | 0.083 |
| Other pathogen % | 22 (34) | 44.0 (23.3) | − 0.13 (0.02) | 0.473 |
| Culture negative % | 18 (28) | 29.4 (8.3) | − 0.38 (0.14) | 0.085 |
Univariate associations between control group mortality rate and commonly reported mean baseline characteristics. Associations were estimated using a weighted random-effects model with mortality on the log-odds scale. Some baseline characteristics were reported by a minority of trials, which resulted in low power to detect a significant association. R2 can be interpreted as the proportion of heterogeneity that is explained by the population characteristic for the n trials that report that characteristic
APACHE Acute Physiology and Chronic Health Evaluation score, SAPS Simplified Acute Physiology score, SOFA Sequential Organ Failure Assessment score