WASHINGTON — Old checklist for doctors: order that test, write that prescription. New checklist for doctors: first ask yourself if the patient really needs it. Nine medical societies, including the American Society of Clinical Oncology and the American College of Cardiology, representing nearly 375,000 physicians are challenging the widely held perception that more health care is better, releasing lists Wednesday of tests and treatments their members should no longer automatically order. The 45 items listed include: * Don't repeat colonoscopies within 10 years of a first such test * Don't perform early imaging for most back pain * Don't do...