According to the U.S. National Institutes of Health’s 20-year study of medical malpractice case outcomes, winning a suit largely depends on the strength of the evidence. Patients won just 10% to 20% of jury trial cases with weak evidence, compared to 30% of lawsuits with midrange evidence. Patients succeeded in 50% of cases with strong evidence. In addition to evidence, factors such as an attorney’s familiarity with the practice of medicine, and the attorney’s specialized background in medical malpractice law, may contribute to the success of the lawsuit.