More people are canceling doctors' appointments, leaving prescriptions unfilled and skipping screenings such as Pap smears to save money, according to a national survey of family doctors. As a result, more patients are winding up with health problems that could have been prevented, the American Academy of Family Physicians said in its report. The academy e-mailed more than 8,000 doctors, asking questions about the effects of the recession, and 505 doctors completed the survey in March and April.