ABSTRACT
BACKGROUND: There has been growing interest in the performance of diagnostic testing in physician office laboratories (POLs). Since the measurement of cholesterol is a well-defined and standardized laboratory test, it was selected to assess factors related to test accuracy in POLs. METHODS: One hundred thirty-one family practice offices were eligible to participate in the survey. Each was mailed a cholesterol specimen with a standardized value in October 1988. The laboratory characteristics of those POLs with results that were within 10% of the true specimen value were compared with those with results that were greater than 10% in error. RESULTS: Of the 131 POLs, 122 returned an answer for the unknown specimen. Ninety-eight (80%) were within 10% of the true value, and 114 (93%) were within 15%. Factors that were related to lower error rates (more likely to be within 10% total error) were whether the laboratory performed more than 25 laboratory tests per day, participated in a proficiency testing program, and ran daily quality controls, as well as the type of instrument the laboratory used. CONCLUSIONS: Overall performance of the POLs compared favorably with reference laboratories; however, running controls and participating in a proficiency testing program may further improve POL test accuracy.
