
POC vs Lab Hemoglobin
• Approach:
– Use DataDirect exclusively
– Find cases where there were more than one hemoglobin lab value within 10 minutes of each other.
– Sleuthing: Use ‘same minute’ data for other blood gas data points (pO2, etc) to determine which we POC
Hgb
– “As our lab system cannot easily differentiate point of care values from central lab values, those
hemoglobin values with an
– exact timestamp match to a blood gas measurement of arterial PaO2 were considered as point of
care values. Those hemoglobin values
– without an exact timestamp match were considered as central lab run values.
– Then, only matched samples within 10 minutes of each other where there was exactly one point of
care value and exactly one central lab value were used.”
Bland-Altman plot generated from this data