MADISON, N.J., April 3, 2013 /PRNewswire/ -- Despite increased public attention on the epidemic of prescription medication abuse, about three in five Americans tested misused their prescription drugs in 2012, virtually the same as in 2011, according to a national study issued today by Quest Diagnostics (NYSE: DGX), the world's leading provider of diagnostic information services. The new study, believed to be one of the largest to examine trends in the use of commonly abused drugs such as opioid pain killers based on objective laboratory data, suggests a substantial number of patients continue to use their prescribed medications in ways that put their health at risk. The report is now available at QuestDiagnostics.com/HealthTrends. "Despite public education and publicity surrounding the dangers of prescription drug abuse, our study shows that misuse rates continue to be alarmingly high for opioids and other powerful medications," said F. Leland McClure, Ph.D., director, pain management, mass spectrometry operations, Quest Diagnostics. "We are hopeful that recent efforts by policy makers and public and private health professionals will help to rein in the nation's prescription drug epidemic." The Quest Diagnostics Health Trends™ report, A Report on Marijuana and Prescription Drug Misuse in America, is based on an analysis of 227,402 de-identified urine lab-test results of patients, age 10 years and older, of both genders in 49 states and the District of Columbia performed by the company's clinical laboratories in 2011 and 2012. The testing was performed in connection with the company's prescription drug monitoring services. These services aid clinicians in monitoring patients for appropriate use of up to 26 commonly abused prescription medications, such as opioids and sedatives, and illicit drugs, such as marijuana and cocaine. Consistent results indicate that only the drug or drugs prescribed for the patient were detected. Inconsistent results suggest a patient has misused one or more drugs. Forms of misuse include combining a prescribed drug with other non-prescribed drugs, which can lead to dangerous drug combinations; not taking a prescribed drug, which contributes to healthcare waste and failed treatment; and using other drugs, which indicates illicit drug use without a clinician's oversight.