Cholesterol Measurement: Variability in Methods and Test Results

GAO discussed how cholesterol is measured in different laboratory settings and whether cholesterol measurement techniques provide accurate results. GAO noted that: (1) individual cholesterol levels should be viewed in terms of ranges because instrument measurement errors and daily fluctuations in cholesterol levels make these levels difficult to measure; (2) over 160 different devices with different technologies and chemical formulations are available to perform cholesterol tests; (3) although research, clinical, and hospital laboratories tend to produce reasonably accurate cholesterol measurements, little is known about the accuracy of cholesterol measurements in other settings such as physicians' offices and public health screenings; (4) although cholesterol testing methods have improved in recent years, large variances exist in the accuracy and precision of tests performed across a broad range of devices and analytical settings; (5) it is impossible to determine whether the accuracy goals established for cholesterol measurement have been met, since there has been no overall evaluation of the different instruments and technologies laboratories use to conduct cholesterol tests; (6) biological and behavioral factors and the collecting and handling of blood specimens can cause individual cholesterol levels to vary; and (7) uncertain cholesterol measurements can affect individual diagnoses and treatment decisions.