TY - JOUR
T1 - Contemporary Improvements in Postoperative Mortality After Major Cancer Surgery are Associated with Weakening of the Volume-Outcome Association
AU - Wasif, Nabil
AU - Etzioni, David
AU - Habermann, Elizabeth B.
AU - Mathur, Amit
AU - Chang, Yu Hui
N1 - Funding Information:
This study was supported in part by the Mayo Clinic Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery.
Publisher Copyright:
© 2019, Society of Surgical Oncology.
PY - 2019/8/15
Y1 - 2019/8/15
N2 - Background: Regionalization of complex visceral surgery across the United States has followed identification of a volume-outcome association. However, improvements in postoperative mortality overall during the last decade may have weakened the strength of this association. Methods: The National Cancer Database was used to identify patients undergoing colon, esophageal, liver, and pancreatic surgery from 2003 to 2011. Hospitals were divided into low-volume (< 33rd %tile), medium-volume (34–66th %tile), and high-volume (> 67th %tile) groups. Annual cancer-specific adjusted observed versus expected (O/E) ratios for 30- and 90-day mortality for each volume strata were calculated and plotted over time. Results: In the year 2003, the O/E ratios decreased from low- to medium- to high-volume hospitals for all cancer surgeries for both 30- and 90-day mortality, indicating a strong volume-outcome relationship. For all volume strata, the O/E ratios trended downward from 2003 to 2011 for both 30- and 90-day mortality for all cancer surgeries. This trend was more pronounced for low- and medium-volume than for high-volume hospitals. Consequently, by 2011 the confidence intervals of the O/E ratios for the low-volume groups, and particularly for the medium-volume groups, overlapped those for the high-volume groups for most of the cancer surgeries studied. Conclusions: The volume-outcome association for major cancer surgery is dynamic and has attenuated over time primarily due to improvements in postoperative mortality at low- and medium-volume hospitals.
AB - Background: Regionalization of complex visceral surgery across the United States has followed identification of a volume-outcome association. However, improvements in postoperative mortality overall during the last decade may have weakened the strength of this association. Methods: The National Cancer Database was used to identify patients undergoing colon, esophageal, liver, and pancreatic surgery from 2003 to 2011. Hospitals were divided into low-volume (< 33rd %tile), medium-volume (34–66th %tile), and high-volume (> 67th %tile) groups. Annual cancer-specific adjusted observed versus expected (O/E) ratios for 30- and 90-day mortality for each volume strata were calculated and plotted over time. Results: In the year 2003, the O/E ratios decreased from low- to medium- to high-volume hospitals for all cancer surgeries for both 30- and 90-day mortality, indicating a strong volume-outcome relationship. For all volume strata, the O/E ratios trended downward from 2003 to 2011 for both 30- and 90-day mortality for all cancer surgeries. This trend was more pronounced for low- and medium-volume than for high-volume hospitals. Consequently, by 2011 the confidence intervals of the O/E ratios for the low-volume groups, and particularly for the medium-volume groups, overlapped those for the high-volume groups for most of the cancer surgeries studied. Conclusions: The volume-outcome association for major cancer surgery is dynamic and has attenuated over time primarily due to improvements in postoperative mortality at low- and medium-volume hospitals.
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U2 - 10.1245/s10434-019-07413-9
DO - 10.1245/s10434-019-07413-9
M3 - Article
C2 - 31065959
AN - SCOPUS:85065553746
SN - 1068-9265
VL - 26
SP - 2348
EP - 2356
JO - Annals of Surgical Oncology
JF - Annals of Surgical Oncology
IS - 8
ER -