The most compelling immediate advantage of electronic medical records is in their reduction of clerical errors. But once computers enter the picture, other benefits also become possible. Software can, for example, help doctors make better choices. So-called clinical decision-support programs can alert doctors to potentially dangerous problems with a drug or dosage, taking into account a patient’s weight, diagnosis, other medications, allergies, and factors, such as kidney function, that can affect drug metabolism. If the pneumonia patient already had been taking Lamictal to prevent seizures, the software might have flagged the prescription for Levaquin, which can exacerbate seizure disorders.Clinical decision support can improve patient care in other ways, too, by helping doctors hew to routine treatment guidelines. The software might, for example, suggest that patients who are older than 60 receive flu shots. Although this recommendation might seem obvious, it is easy for a busy doctor to forget. “Doctors are more likely to comply with prevention measures if they have decision support,” says David Bates, a Partners primary care physician who has studied the benefits of electronic medical records. Kaiser Permanente has been experimenting with electronic records since the early 1990s, and so it now has the country’s highest rates of mammography and Pap smear screening, according to Andy Wiesenthal, the lead physician on Kaiser’s national implementation team.