Outcomes Assessment for Point-of-Care Testing

Department of Laboratory Medicine, Yale University School of Medicine, CB 506, Yale-New Haven Hospital, 20 York Street, New Haven, CT 06504, Fax 203-688-3725, E-mail petrie.rainey@yale.edu

"Outcomes Assessment" has become one of the enduring buzzwords of the decade. But it often seems to be like the weather: Everyone talks about it, but relatively few do anything about it. As clinical laboratory scientists, we have repeatedly challenged ourselves to demonstrate that laboratory results affect patient outcome. Yet very few well-done studies have been published. (How many times have you heard and read the results of those few studies by now?)

One difficulty is the universal use of laboratory testing. Would it be acceptable to deny laboratory testing to a control group? The field of point-of-care testing (POCT) offers a major opportunity, because there are many tests not yet in widespread use. This allows ethical comparisons to be designed. (Imagine presenting to the Human Investigation Committee a study of the benefit of digoxin monitoring using a control group in which no digoxin measurements were allowed. Would they approve it? Such a study was done when digoxin assays were just being introduced and convincingly demonstrated a 50% reduction in clinical digitalis toxicity in monitored patients (1).)

Another barrier is the tendency to focus on medical outcomes: decreased mortality or morbidity, shorter length of stay, decreased readmission rate, improved quality of life, etc. Medical interventions may directly alter medical outcomes, but laboratory tests do not. The effect of a test result is always filtered through the change in medical management it engenders. The ability to link the test result to the outcome requires a good correlation between the result and the therapeutic intervention. The size and duration of studies needed to establish the effectiveness of medical interventions are well known. How much larger and longer must a study be to average out the additional variation in the test itself and in the linkage between result and intervention? (Despite . . . [Full Text of this Article]

References

The following articles in journals at HighWire Press have cited this article:

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