Exposing physicians to reduced residency work hours did not adversely affect patient outcomes after residency

Abstract

In 2003, work hours for physicians-in-training (residents) were capped by regulation at eighty hours per week, leading to the hotly debated but unexplored issue of whether physicians today are less well trained as a result of these work-hour reforms. Using a unique database of nearly all hospitalizations in Florida during 2000-09 that were linked to detailed information on the medical training history of the physician of record for each hospitalization, we studied whether hospital mortality and patients' length-of-stay varied according to the number of years a physician was exposed to the 2003 duty-hour regulations during his or her residency. We examined this database of practicing Florida physicians, using a difference-in-differences analysis that compared trends in outcomes of junior physicians (those with one-year post-residency experience) pre- and post-2003 to a control group of senior physicians (those with ten or more years of post-residency experience) who were not exposed to these reforms during their residency. We found that the duty-hour reforms did not adversely affect hospital mortality and length-of-stay of patients cared for by new attending physicians who were partly or fully exposed to reduced duty hours during their own residency. However, assessment of the impact of the duty-hour reforms on other clinical outcomes is needed.

Keywords: Health Professions Education; Hospitals; Workforce Issues.

EXHIBIT 1 (figure)

Difference-in-difference approach to estimating the effect of duty hour reforms on outcomes of physicians after completion of residency Notes: The effect of physician exposure to duty hour reforms on subsequent clinical outcomes after completion of residency was identified by comparison of three groups: physicians with zero years of exposure to duty hour reforms (those completing residency before 2003), partial exposure (i.e, 1 or 2 years), and 3 full years of exposure. Exposure to duty hour reforms was confounded with the year in which a physician began practice (i.e., a comparison of outcomes of physicians with 3 versus zero years of exposure to duty hour reforms would be confounded by any secular time trends in patient outcomes). Therefore, outcomes were compared in post-residency years by using a difference-in-difference analysis. The difference-in-difference model compared outcomes of fully and partially exposed residency cohorts to similarly experienced cohorts in earlier years, and compared this difference to the trend in outcomes between 2000 and 2009 among physicians with zero exposure to duty hour reforms (control group). For example, the effect of full exposure to duty hour reforms was identified by (1) first comparing hospitalization outcomes in 2006–2009 of physicians who began residency after 2003 to similarly experienced cohorts in earlier years and (2) comparing this difference to the difference in outcomes before and after duty hour reforms among physicians with zero years of exposure to duty hour reforms during their own residency (control group). Trends in this control group of ‘senior physicians’ captured changes in hospital care that affected outcomes of all physicians, irrespective of the physician’s exposure to duty hour reforms during their own residency.

EXHIBIT 3 (figure)

Trends in hospital mortality of Florida inpatients whose physician of record was in their first year after residency completion Source: Authors’ analysis of Florida hospital and physician license data. Notes: Figure plots unadjusted hospital mortality in each year for two groups of inpatients: those whose physician of record was an internist who completed residency 1 year prior to the hospitalization year (newly independent internist) versus 10 or more years prior (senior internist).