Appropriate duty hour reform must consider the interests of all stakeholders involved. In a review of the frameworks used to conceptualize this discussion, Schwartz et al. point out that it is imperative to work from models that take into account the trade-offs associated with public policy issues such as this one.84
A recent review by Jamal and colleagues focused on the effects of duty hour limits on surgeons85
, and a second review by Reed et al. examined evidence specifically pertaining to shift length and night float86
. Our review differs from and expands upon these prior reviews by providing a comprehensive synthesis of the impact of the 2003 duty hour policy reforms on the most important stakeholder groups: patients and residents of all specialties.
Our major findings were in the areas of patient safety, resident education, and resident well-being. With respect to patient safety, our meta-analysis suggested an improvement in mortality between the pre- and post-2003 time periods. Medical and surgical complications were more variable, with some improving and others worsening. Resident burnout was improved.
The finding that mortality has improved over time must be considered with several important caveats. First, we used unadjusted odds ratios to conduct our analyses. Therefore, we cannot account for differences in patient characteristics between the two time periods. Of particular importance is the fact that we could not take advantage of the adjustments made in the subset of studies that used non-teaching hospitals as controls to account for temporal trends.17,18,27,28
It is important to note that after adjustment those studies largely found no change in mortality between pre- and post-2003. Therefore, our meta-analysis results could easily reflect improvements in quality of care that occurred over the time period studied rather than a direct result of the duty hour rules.
Complications were more nuanced, with some improving and some worsening in the post-2003 time period. One possible explanation for these variable results is that strategies for complying with duty hour reform may lead to improvements in certain types of complications, and a worsening in others. Another possible explanation is that certain complications are more sensitive to fatigue, and these improved post-reform, whereas outcomes more sensitive to discontinuity of care worsened. For example, in one surgical study, bile duct injuries decreased in the post-2003 time period, but conversion from laparoscopic to open cholecystectomy was significantly more common in the post-2003 time.20
Improved manual dexterity from being better rested could account for the former finding, consistent with prior simulation studies.87–89
The latter finding of more conversions to open procedures could reflect the impact of less resident experience with laparoscopy in the post-2003 time period. Less continuity of care may also contribute to certain complications. For example, if doctors are less familiar with patients, this could lead to delayed decisions and therapeutic interventions. This phenomenon could partially explain the increase in the number of cardiac surgery patients that remained on ventilators for >48 h in one of our studies.90
A third possibility is that these inconsistencies simply represent variation due to local factors or chance. For example, the complication of postoperative pneumonia was increased in one study67
and lessened in another.52
We are unable to explain the specific patterns found in these studies by any one of these explanations alone, so other factors are likely involved as well. Regardless, many complications appear to be worsening in the post-reform period, and this deserves further study as additional changes to duty hour rules are made.
The impact of duty hour reform on resident experience is also important. Today’s residents will become tomorrow’s independent doctors, and we must be confident that they are ready for practice.91,92
Most studies in our review did not demonstrate significant differences in overall resident operative experience between the pre-2003 and post-2003 time periods. However, the role of residents in surgeries may be evolving to one in which they have less responsibility. In addition, none of the studies assessed residents who had trained entirely after the 2003 reform compared with those who trained before the reform. Moving forward into an era of further restrictions, it will be essential to study not only the number
of surgeries performed, but also the specific
surgeries performed and the residents’ roles in those surgeries. This will allow us to better understand the full effect of reform on residents’ operative experience. There remains a paucity of data on patient care experience in the non-operative specialties. The non-surgical specialties could easily track the admitting diagnoses of all patients their interns see or the non-operative procedures that they perform. It is important to determine whether other specialties are struggling to maintain training experiences.
Another interesting finding from this review was the improvement in resident well-being following the 2003 duty hour reforms, which has been noted in prior work.9
We focused on burnout in this review, but other studies have corroborated the improvement in well-being by documenting more residents having babies in the post-2003 time period,93
greater ability to attend family events,38
and less perceived stress.94
However, other aspects of well-being such as rates of depression do not seem to have changed between the pre-2003 period and the post-2003 period.21,22,36,95
Prior research has demonstrated links between resident well-being and quality of patient care,96,97
making preservation of resident well-being extremely important. This improvement in well-being may be one explanation for why some patient care parameters are improving in the post-2003 time period.
Our study has limitations. Perhaps the greatest limitation of this review is that our conclusions rest upon studies demonstrating association, not causality. It is likely that other contextual changes unrelated to duty hour rules contribute to the observed effects. These confounders may explain much of the heterogeneity that we observe. However, decisions must frequently be made in the context of incomplete evidence. While a causal relationship between the duty hour rules and outcomes cannot be determined with certainty from the studies cited, we have diligently identified and synthesized the best available evidence. The possibility of publication bias is also a limitation. We reviewed abstracts from recent meetings in order to capture studies that have not yet made it to publication and also asked an expert to review our bibliography for omissions. Other limitations include the wide range of quality of the included studies. To account for this variability, we used the MERSQI to rate and compare study quality objectively. However, since the MERSQI is designed to measure quality across the full range of quantitative study designs, the instrument incorporates only broad aspects of methodological quality and thus does not account for finer methodological differences within study types. The decision about whether to include a study was made by a single reviewer, although we erred on the side of inclusion and discussed studies about which we were unsure. Additionally, most data from each study were abstracted by a single reviewer and could have been inaccurate. Finally, the reviewers were not blinded to the study authors or journals, which could result in bias as well. Despite these limitations, this review was comprehensive, including over 60 studies. This allows conclusions to be drawn that were not possible when the last comprehensive reviews on this subject were published.8,9
Limitations notwithstanding, this review provides a comprehensive synthesis of the evidence base for the 2003 duty hour reforms in the US. The balance of evidence suggests that burnout among residents has decreased. Given the unacceptably high prevalence of burnout among trainees,96
the reduction in burnout represents an important success of the 2003 reforms. In contrast, data on residents’ educational outcomes, such as test scores and clinical experience, with the 2003 reforms are more mixed, preventing the formulation of any firm conclusions. Moreover, while our review included several studies that examined surgical residents’ operative experience before and after duty hour reform, we were unable to identify any study assessing the impact of the 2003 duty hour rules on the clinical experience of non-surgical residents (e.g., the number of patients seen with specific diagnoses or the number of bedside procedures done). As the new 2011 duty hour rules are implemented, it will be important to quantify any changes in the breadth of clinical exposure for all residents. While this review suggests a modest decrease in mortality following the 2003 duty hour limits, we are unable to exclude the possibility of secular trends playing a role. Nevertheless, because several studies reported increased rates of certain complications, special attention should be paid to monitoring these complications during future reforms. Future efforts to evaluate the impact of the 2011 duty hour limits should build upon this evidence base by using rigorous methods to examine the most important outcomes related to patient care and residents’ education.