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Table 6 Logistic regression model for renal replacement therapy in critically ill H1N1 patients

From: Acute kidney injury among critically ill patients with pandemic H1N1 influenza A in Canada: cohort study

Variable RRT No RRT Crude OR P value Adjusted OR P value
n = 85 n = 476 (95% CI) (95% CI)
Demographics and comorbidities
Age (yr) 46.2 (13.1) 48.4 (15.3) 0.99 (0.98-1.01) 0.21 0.98 (0.96-1.00) 0.07
Female sex 43 (50.6) 256 (53.8) 0.88 (0.55-1.40) 0.59 1.81 (0.91-3.58) 0.09
Ethnicity (n = 554, 85, 469)
 White/Caucasian (reference) 56 (65.9) 271 (57.8) 1.00   1.00  
 Unknown/Other 19 (22.4) 97 (20.7) 0.95 (0.54-1.68) 0.85 0.53 (0.22-1.28) 0.16
 Aboriginal 6 (7.1) 68 (14.5) 0.43 (0.18-1.03) 0.06 0.40 (0.13-1.20) 0.10
 Asian 4 (4.7) 33 (7.0) 0.59 (0.20-1.7) 0.33 1.11 (0.31-3.95) 0.88
Obesity 33 (38.8) 117 (24.6) 1.95 (1.20-3.16) 0.007 2.25 (1.14-4.44) 0.02
Diabetes mellitus 23 (27.1) 123 (25.8) 1.06 (0.63-1.79) 0.81   
Chronic obstructive pulmonary disease 5 (5.9) 93 (19.5) 0.26 (0.10-0.65) 0.004 0.26 (0.06-1.20) 0.08
Alcohol abuse 10 (11.8) 64 (13.5) 0.86 (0.42-1.75) 0.67   
Chronic kidney disease 15 (17.7) 33 (6.9) 2.88 (1.49-5.57) 0.002 0.85 (0.28-2.57) 0.78
Day 1 support, physiology, and laboratory values
APACHE II score (n = 507, 80, 427) 27.6 (9.2) 19.8 (8.6) 1.10 (1.07-1.13) <0.0001 1.07 (1.03-1.12) 0.0009
Invasive mechanical ventilation (n = 552, 85, 467) 72 (84.7) 311 (66.6) 2.78 (1.49-5.17) 0.001 4.09 (1.21-13.84) 0.02
Inotrope or vasopressor 44 (51.8) 206 (43.3) 1.41 (0.89-2.23) 0.15 0.78 (0.37-1.61) 0.50
Mean arterial pressure (mmHg) (n = 521, 79, 442) 70.4 (16.9) 75.2 (19.2) 0.87 (0.76-0.995) 0.04 0.97 (0.81–1.16) 0.75
PaO2/FiO2 (n = 495, 76, 419) 132 (95) 156 (96) 0.97 (0.94-1.00) 0.046 0.97 (0.93-1.01) 0.16
Platelets (109/L) (n = 519, 76, 443) 164 (84) 192 (96) 0.97 (0.94-0.995) 0.02 0.99 (0.95-1.03) 0.64
Creatinine (μmol/L) (n = 536, 79, 457) 233 (185) 105 (93) 1.07 (1.05-1.09) <0.0001 1.06 (1.03-1.10) <0.0001
  1. Categorical data are presented as n (%) and continuous data as mean (SD). Heart rate, temperature, creatine kinase, WBC, albumin, urea, and urine output were excluded due to a high proportion of missing data. SOFA score was excluded because it was highly collinear with APACHE II (Pearson r = 0.6). For each variable, we specify n when it differs from the totals in the first row. The final model included 411 patients and did not have evidence of lack of goodness of fit (p = 0.17). ORs for continuous variables refer to an increment of 1 unit (age, APACHE II), 10 units (mean arterial pressure, PaO2/FiO2, platelets, creatinine), or 100 units (urine output).