"The results are paradoxical since it is generally assumed that clinical experience enhances knowledge and skill and therefore leads to better patient care," says lead author Niteesh Choudhry, HMS instructor in medicine. Choudhry performed the research as a pharmaceutical policy research fellow at the Department of Ambulatory Care and Prevention, a unique research and teaching collaboration between Harvard Pilgrim Health Care and Harvard Medical School.
The study included a review of 59 previously published papers (comprising 62 individual studies) with a large sample size of doctors. These studies included measures of physician knowledge or quality of care and also included the time since the physician's medical school graduation or the physician's age. The researchers found that 73 percent of these studies (45 of 62) showed that a doctor's performance declines with time. More than half of these studies (32 of 62, or 52 percent) showed that performance declines for all of the outcomes measured, and 13 studies (21 percent) showed that some but not all aspects of a doctor's performance decline with time.
"The findings also reflect the substantial environmental changes that have occurred in medicine over the past several decades. Evidence-based medicine has been widely adopted and quality assurance techniques, such as disease management and performance evaluation, are frequently used. More experienced doctors may have less familiarity with these strategies and may be less accepting of them," says co-author Stephen Soumerai, HMS professor of ambulatory care and prevention.