Performance of a point-of-care qualitative triple cardiac marker screen under controlled laboratory conditions and in an emergency department setting.
BACKGROUND
The performance of point-of-care testing under controlled laboratory conditions may vary from results obtained in actual patient care settings. User errors are a major cause of this discrepancy.


METHODS
We studied the clinical performance of the Cardiac STATus (Spectral USA, Frederick, MD), a qualitative triple cardiac marker point-of-care test, under controlled laboratory conditions and in actual practice in an emergency department (ED) satellite laboratory. First-draw samples obtained from patients presenting to the hospital emergency department with chest pain were used for the study. Tests were performed in the chemistry research laboratory by a company product specialist or in an emergency department satellite laboratory by hospital staff. Test results were analyzed by correlation to the clinical discharge diagnosis.


RESULTS
In the emergency department, for the test system as a whole (any one or more marker(s) positive versus all three markers negative), sensitivity was 63%, specificity was 81%, positive predictive value was 26%, and negative predictive value was 95%. A manufacturer-supplied product specialist in a laboratory setting achieved very similar sensitivity, specificity, and positive and negative predictive values.


CONCLUSIONS
The performance of this system under controlled laboratory conditions can be applied to estimate its performance at the point of care.
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002637:Chest Pain / Q000097:blood / Q000175:diagnosis*; D019411:Clinical Laboratory Techniques; D004636:Emergency Service, Hospital; D005260:Female; D006331:Heart Diseases / Q000097:blood / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019095:Point-of-Care Systems / Q000592:standards*; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity
D015415:Biomarkers