In the grand scheme of things, 12 percent of anything isn't much. It's a dime and some pennies out of a dollar, the merest sliver of a whole pie. But when 12 percent describes a group of people dying, the figure suddenly looms ugly and huge. That's the percentage of pneumonia patients at Norfolk, Va.-based HMO Sentara Health System who died in 1993 and 1994. Although lower than the national average of about 14 percent, the number still seemed too high to Sentara's doctors. What's more, a good many other pneumonia sufferers developed complications requiring expensive antibiotics and an average stay of two weeks, as opposed to the optimal three- to five-day stay of appropriately treated pneumonia patients without complications, says Robert D. Brickman, Sentara's medical director of clinical effectiveness.

The doctors at Sentara always knew something was wrong. When they ordered sputum cultures for pneumonia patients, they wouldn't hear back from the lab for several days—if at all. Without lab results, they could only guess what was wrong and how best to treat it; meanwhile, patients got sicker as they waited for results. Yet it wasn't until Sentara's quality improvement team began an exploratory mining foray into claims data in its Oracle-based data mart that the doctors' suspicions were confirmed. Besides uncovering the high pneumonia mortality and complication rates, the team noticed that doctors were ordering sputum cultures many times for the same patient; upon inspection, they learned that the doctors did so in hopes that at least one test would yield useful, timely information. The quality team quickly devised a new system of transferring the culture from the patient to the lab, and the lab results back to the doctor within two hours. Not only did the mortality rate for pneumonia patients fall to 9 percent, but their average stay dropped to one week and the cost of managing a single pneumonia case decreased by $2,000. "Attack the quality of health care, and amazingly the costs come down as well," says Bert Reese, Sentara's corporate director for information systems.

The process that led Sentara to improve the quality and efficiency of care for its pneumonia patients is known in the health-care industry as "outcomes measurement." A form of data mining—a means of searching for previously unknown, actionable information from large databases—outcomes measurement involves examining clinical encounter information, insurance claims and billing data to measure the results of past treatments and processes. By understanding what worked—or didn't—providers can identify areas for improvement or capitalize on successful methods.