The main driver of cardiovascular disease risk is atherogenic low density lipoprotein (LDL) particles in addition to other risk factors. Patients with elevated risk are prescribed lipid modifying drugs like statins and fibrates for preventing potential atherosclerotic plaque accumulation. In conjunction with a CDC study investigating association between atherosclerosis risk and lipoprotein levels, a liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed and optimized to screen for the presence or absence of statins or fibrates in the plasma samples collected from study participants. The comprehensive panel of statins, fibrates, and their metabolites were identified with a high sensitivity, 4-minute-long method, using a low plasma volume of 10 µL. The presence and identification of the medications were compared to medical records. The comparison revealed many discrepancies that had significant impact on scientific conclusions concerning correlations between LDL levels and coronary artery disease (CAD) risk score determined by cardiac catheterization.