# Table 2 Independent risk factors for prolonged intensive care unit stay

Co-efficient SE Adjusted OR (95% CI) P Value
Renal dysfunction 1.6066 0.2162 4.99 (3.3 – 7.6) <0.001
Angina class IV 0.4950 0.1048 1.64 (1.3 – 2.0) <0.001
Ejection fraction <30% 0.7771 0.1397 2.17 (1.6 – 2.9) <0.001
Peripheral vascular disease 0.4809 0.1288 1.62 (1.2 – 2.1) <0.001
BMI ≥ 30 and <35 kg/m2 0.3338 0.1194 1.39 (1.1 – 1.8) 0.005
BMI ≥ 35 kg/m2 0.7436 0.1935 2.1 (1.4 – 3.1) <0.001
Age ≥ 70 and <75 years 0.5313 0.1283 1.7 (1.3 – 2.2) <0.001
Age ≥ 75 years 0.7972 0.1640 2.22 (1.6 – 3.1) <0.001
Current smoker 0.5238 0.1291 1.69 (1.3 – 2.2) <.0001
Diabetes 0.4381 0.1207 1.55 (1.2 – 2.0) <0.001
Emergent procedure 0.7124 0.2510 2.04 (1.2 – 3.3) 0.004
Hypercholesterolaemia 0.3507 0.1282 1.42 (1.1 – 1.8) 0.006
Hypertension 0.2577 0.1039 1.29 (1.1 – 1.6) 0.013
Use of CPB 0.8904 0.1734 2.44 (1.7 – 3.4) <0.001
Intercept -4.4390
1. Calculation of predicted risk using patient data and logistic regression co-efficients:
2. Calculate the odds of prolonged intensive care unit stay = exp (-4.4390 + [1.6066 × renal dysfunction] + [0.4950 × angina class IV] + [0.7771 × ejection fraction <30%] + [0.4809 × peripheral vascular disease] + [0.3338 × BMI ≥ 30 and <35 kg/m2] + [0.7436 × BMI ≥ 35 kg/m2] + [0.5313 × age ≥ 70 and < 75 years] + [0.7972 × age ≥ 75 years] + [0.5238 × current smoker] + [0.4381 × diabetes] + [0.7124 × emergent procedure] + [0.3507 × hypercholesterolaemia] + [0.2577 × hypertension] + [0.8904 × use of CPB]).
3. Predicted risk of prolonged intensive care unit stay as a percentage = [odds/(1 + odds)] × 100.
4. SE, Standard Error; OR, Odds Ratio; CI, Confidence Intervals; BMI, Body Mass Index; CPB, Cardiopulmonary Bypass.