Researchers reviewing a decade of studies from the New England Journal of Medicine have found what many have suspected for years: Unnecessary testing is rampant, and many procedures just don't work. In the analysis, researchers examined 363 articles that tested current medical practices and found that more than 40 percent of the common procedures were ineffective. Among them is the now widely suspect PSA screening test for prostate cancer, which can reveal false positives and lead to unnecessary biopsies and surgery, especially for men under the age of 55 without family history. Arthroscopic knee surgery for men with osteoarthritis was also on the list, where removing debris was found in two papers to be "no better than a sham procedure," says lead researcher Dr. Vinay Prasad, of the National Institutes of Health. Other procedures include surgery for ACL tears, where rehabbing turned out to be just as effective, and the growing use of stress tests prior to surgery to determine cardiovascular health, which can lead surgeons to recommend unnecessarily stenting arteries to increase blood flow. "When someone recommends a test or procedure, you have to think through the ifs, " says Prasad. "What would you do if it's positive, and what would you do if it's negative? If it's going to be the same thing no matter the result, then it's probably unnecessary."