CALCA and infection: Initial PCT levels (days 1 and 2 after trauma) were significantly higher in patients who subsequently developed infections: 2.69 ng/ml versus 0.54 ng/ml (median, P < 0.001) for suspected infection versus no suspected infection, and 3.01 ng/ml versus 0.57 ng/ml for proven infection versus no proven infection (P < 0.001).