Wellness screenings emerged as one of the signature benefits of the big federal health overhaul that Congress passed last year -- an effort to catch problems early, keep patients healthier and cut future Medicare costs. Some doctors, however, are having second thoughts. To get paid by Medicare, a physician and nurse must complete 15 steps during a 30- to 45-minute exam, including brief screenings for dementia and depression, an eye exam, a medical history and personalized health advice. They must also check weight, height and blood pressure -- the only time the patient must be touched. Although much touted in letters to the 46 million aged or disabled people on Medicare, the wellness visits haven't caught fire with patients either. Since Jan. 1, about 780,000 patients have received the new service, Medicare officials say.