Volume of Procedures Performed by Hospitals May Not Indicate Quality of Care, Studies Find
Hospitals that perform large numbers of certain procedures may not offer the best care, despite previous research demonstrating a link between procedure volume and mortality and complication rates, according to two studies in Wednesday's Journal of the American Medical Association, the Wall Street Journal reports. One study by Eric Peterson, an associate professor of medicine at Duke University, and colleagues analyzed outcomes for 267,089 coronary artery bypass graft procedures at 439 U.S. hospitals between 2000 and 2001. The researchers found that a hospital's volume of that procedure is only "modestly associated" with successful outcomes and "may not be an adequate quality indicator," according to the Journal (Rundle, Wall Street Journal, 1/14). For example, hospitals that performed more than 450 of the procedures annually had a mortality rate of 2.5%, compared with a 3.2% mortality rate at hospitals that performed fewer than 150 procedures per year (Kowalczyk, Boston Globe, 1/14). Researchers found that for patients younger than age 65, there was no link between volume and outcome. Peterson concluded that volume is a particularly "bad metric" for patients younger than age 65 and recommended that patients investigate a hospital's previous outcome history. He said, "[I]f you're a patient, you should be asking if the hospital tracks outcomes, or participates in a national program that allows it to compare its outcomes to those of its peers" (Wall Street Journal, 1/14). The second study by Jeannette Rogowski, a senior economist at RAND in Arlington, Va., and colleagues studied 94,110 infants with very low birth weights born at 332 Vermont Oxford Network hospitals between 1995 and 2000. They found that although babies in hospitals that treated 50 or fewer premature infants per year had higher mortality rates for such patients; overall, a hospital's past morality rate was a "far better predictor of patient outcomes," according to the Globe. The mortality rate for high-volume hospitals was 13%, compared with 15% for lower-volume hospitals. Rogowski said, "There was very little variation, so if insurers want to design a way to refer members to particular hospitals, volume is not a good way to do it. We need better quality measures and that's going to take more research" (Boston Globe, 1/14).
The studies "cast doubt" on previous research that has shown that hospitals that perform large numbers of a certain type of procedure are most likely to provide high-quality care for that procedure because they are well-equipped and have experienced staff, the Washington Post reports (Washington Post, 1/14). The Leapfrog Group, a coalition of large employers and insurance companies, has promoted volume as a standard for providers (Wall Street Journal, 1/14). On its Web site, the group publishes numbers of patients individual hospitals treat for six high-risk procedures, including coronary artery bypass surgery (Boston Globe, 1/14). R. Adams Dudley, a Leapfrog national advisory panel member and associate professor of medicine and health policy at the University of California-San Francisco, said he is not surprised by the latest studies' findings. "Volume is a weak indicator, but it's better than nothing. Until hospitals and surgeons are willing to give up the data that is needed to get risk-adjusted outcomes, you shouldn't be surprised if people use volume in the meantime" (Wall Street Journal, 1/14). An abstract of the Duke study is available online. An abstract of the RAND study is available online. PBS' "NewsHour with Jim Lehrer" Tuesday reported on the studies. The segment includes comments from Claire Turner, communications director for the Leapfrog Group, and Rogowski ("NewsHour with Jim Lehrer," PBS, 1/13). The complete transcript is available online.This is part of the California Healthline Daily Edition, a summary of health policy coverage from major news organizations. Sign up for an email subscription.