Case Volume-Outcomes Associations Among Patients With Severe Sepsis Who Underwent Interhospital Transfer*

Abstract

Objective Case volume-outcome associations bolster arguments to regionalize severe sepsis care, an approach that may necessitate inter-hospital patient transfers. Although transferred patients may most closely reflect care processes involved with regionalization, associations between sepsis case volume and outcomes among transferred patients are unclear. We investigated case volume-outcome associations among patients with severe sepsis transferred from another hospital. Design Serial cross-sectional study using the Nationwide Inpatient Sample Setting United States non-federal hospitals, years 2003 to 2011. Patients 141,707 patients (weighted national estimate of 717, 732) with severe sepsis transferred from another acute care hospital. Interventions None Measurements and Main Results We examined associations between quintiles of annual hospital severe sepsis case volume for the receiving hospital and in-hospital mortality among transferred patients with severe sepsis. Secondary outcomes included hospital length of stay (LOS) and total charges. Transferred patients accounted for 13.2% of hospitalized severe sepsis cases. In-hospital mortality was 33.2%, with median LOS 11 days (interquartile range 5 – 22), and median total charge $70,722 (interquartile range, $30,591–$159,013). Patients transferred to highest volume hospitals had higher predicted mortality risk, greater number of acutely dysfunctional organs and lower adjusted in-hospital mortality as compared to the lowest volume hospitals (OR 0.80; 95% CI, 0.67–0.90). In stratified analysis, (P<0.001 for interaction of case volume by organ failure) mortality benefit associated with case volume was limited to patients with single organ dysfunction (N = 48,607, 34.3% of transfers) (OR 0.66; 95% CI, 0.55–0.80). Treatment at highest volume hospitals was significantly associated with shorter adjusted LOS (incidence rate ratio 0.86; 95% CI 0.75–0.98), but not costs (% charge difference, 95% CI: (−)18.8, (−)37.9 – (+) 0.3). Conclusions Hospital mortality was lowest among patients with severe sepsis who were transferred to high volume hospitals, however case volume benefits for transferred patients may be limited to patients with lower illness severity.

Hospital Variation in Risk-Adjusted Pediatric Sepsis Mortality*

“…First, only 17% of Pennsylvania hospitals met our minimum volume threshold for inclusion in the study, reducing the number of hospitals that we were able to study. Although low case volumes themselves may be a marker of poor quality, the fact that no estimates could be made at 83% of Pennsylvania hospitals is concerning (31). Second, among those remaining, our hierarchical modeling approach, which is a standard approach to benchmarking (32), substantially shrunk the mortality rate toward the overall average.…”

Central Venous Access Capability and Critical Care Telemedicine Decreases Inter-Hospital Transfer Among Severe Sepsis Patients: A Mixed Methods Design

“…This fact is reinforced by observing that rural patients who bypass their local hospitals have 5.6% higher mortality than patients who were treated in rural hospitals, despite the fact that many were transferred. [7] In large-scale studies measuring the impact of hospital volume on survival, Ofoma et al showed that patients transferred to high-volume hospitals had better survival [12], but the impact of high-volume hospital care was not nearly as strong in transferred patients than in patients who presented to a high-volume hospital initially. [13] Interestingly, most of the benefit of being transferred to a higher volume hospital was observed in patients with the fewest organ failures [12], suggesting that a threshold may exist where even inter-hospital transfer cannot rescue patients from poor outcomes.…”

“…[7] In large-scale studies measuring the impact of hospital volume on survival, Ofoma et al showed that patients transferred to high-volume hospitals had better survival [12], but the impact of high-volume hospital care was not nearly as strong in transferred patients than in patients who presented to a high-volume hospital initially. [13] Interestingly, most of the benefit of being transferred to a higher volume hospital was observed in patients with the fewest organ failures [12], suggesting that a threshold may exist where even inter-hospital transfer cannot rescue patients from poor outcomes. We have previously observed that transferred patients have significantly lower adherence with Surviving Sepsis Campaign guidelines, suggesting that the timing of transfer and the care provided before transfer may be responsible for much of the outcome differences observed.…”

“…[7,11] Rural patients transferred to tertiary care hospitals continue to have worse outcomes than similar urban patients, possibly related to delayed and/or inappropriate early interventions. [6,12,13] This constellation of findings highlights the importance of improving early identification, appropriate intervention, and timely riskstratification for appropriate definitive care.…”

Regionalization of Emergency Care Conditions: Classifications, Comparisons, and Considerations

“…Timely care is associated with improved clinical outcome [56,130], and the conditions under which patients require sepsis care impair their ability to choose their setting for care (e.g., vulnerable population). Delays in sepsis recognition and transfer continue to put patients at risk [131]. While sepsis care does not require advanced technology, it does require staffing and procedural resources not available in all hospitals [132].…”