Introduction

Avoidable hospital readmissions, which affect 1 in 5 patients and account for $17.4 billion of the current $102.6 billion Medicare budget, are the focus of many quality-improvement initiatives.1 Trainees have been implicated in many cases of medical error2,3 and may also contribute to higher rates of readmission.

In training institutions medical care is rendered by a team of health care professionals, and each patient is cared for by several members of the team.4 Thus, quality of health care delivery is affected not only by individual performance, but also by a medical team's performance as a whole. Evidence suggests that team malfunction (ie, systemic failures) causes far more errors than the poor performance of individuals.5–7 This suggests that in addition to evaluating individual providers' quality performance, we should be evaluating the performance of care teams. In addition, determining the mechanism whereby busy teams have worse outcomes should be the object of future study. Evaluating medical teaching team performance outcomes separately from the care outcomes of individual providers may provide an interesting insight into interplay between the cumulative effect of individual workloads and the amount of oversight provided.

Although a substantial body of research has found an association between poor resident supervision and worse patient outcomes,8–10 less consistency was seen on the link between resident workload and outcomes.11–14 Even less is known about the association between the workload of a teaching team as a whole and patient outcomes. To determine whether the team's workload affects patient outcomes we examined the association between a total number of teaching team's monthly admissions, and 30-day readmission and 60-day mortality rates. We hypothesized that increased teaching team workload is associated with higher readmission rate.

Methods

Results

Of 12 119 admissions examined, 6398 (52.8%) were assigned to the less busy teams, and 5721 (47.2%) were assigned to the busy teams. Patients assigned to busy teams were older, more likely to be women, more likely to be non-Hispanic white, less likely to be black or Latino, more likely to have Medicare, less likely to have Medicaid, and had higher LAPS scores. Mean length of stay was not significantly different between the groups (5.2 vs 5.3 days; P  =  .08; Table 1).

TABLE 1 Characteristics of Patients in Study

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After adjustment for demographics (age, race, sex, ethnicity, insurance type) and clinical characteristics (LAPS and Charlson score), care by a busy team was associated with a greater 30-day readmission rate (odds ratio, 1.21; 95% confidence interval, 1.10–1.34). After adjustment for demographic and clinical characteristics, care on a busy team was not associated with increased risk of mortality (odds ratio, 1.05; 95% confidence interval, 0.88–1.27; Table 2).

TABLE 2 Primary Outcomes^a

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There was a significant linear association between the number of monthly admissions to teams and patients' readmission rate (Figure). As teams were placed into quintiles based on the number of monthly admissions, there was a roughly 4% increase in odds of readmission for patients admitted from one quintile to the next.

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Discussion

In this carefully controlled study we found that care by a busy teaching team is associated with increased risk of readmission. Further, we found a significant linear trend linking the number of admissions a team sees with incremental increases in risk for readmission. After adjustment, we found no association between number of admissions to a teaching team and 60-day mortality. Our data highlight the need to establish acceptable goals for teaching team workload to minimize unnecessary readmissions.

Patient safety outcome measures have traditionally focused on adverse event rates and mortality. Recently, as the length of stay in the hospitals shortened, the readmission rate became another indicator of adverse outcomes.18,19 The Patient Protection and Affordable Care Act will reduce Medicare payments to hospitals with excess hospital readmissions, so this potential loss of revenue might spur more hospitals to look harder at the factors influencing readmission rates.20 Although we have found an association between greater teaching team workload and increased readmissions, further research is needed to determine whether reducing team workload improves readmission rates.

We used a single simple measure of team workload, which was the total number of admissions seen by the team over the course of a month. Another commonly used measure of workload, the intern's daily census, may not accurately reflect the full amount of work an intern is doing. It has been suggested that as length of stay has shortened, number of admissions became more of a factor when defining medical team workload.21

Our study has several limitations. First, it is possible that patients admitted to busy teams were different from patients admitted to less busy teams in ways that we did not measure, confounding our analysis. We applied validated measures of comorbidity and severity of illness in risk-adjustment models in an attempt to minimize confounding. Second, it is possible that patients discharged from the busier teams had less consistent outpatient followup arranged upon discharge that had contributed to the increased readmission rate. In addition, our study is from a single institution and the results may not be generalizable to other teaching services.

Conclusions

In our study, admission to the busier team conferred a 21% increased odds of readmission to the hospital that could translate into billions of dollars of avoidable health care expenditures. Further research is needed to determine whether reducing a teaching team's monthly workload reduces readmissions.