Study: Higher hospital volumes lead to safer surgeries
Researchers have found an inverse relationship between hospital volume and inhospital adverse events, according to a study published Aug. 30 in Health Services Research.
Tina Hernandez-Boussard, PhD, of the department of surgery at Stanford University School of Medicine in Palo Alto, Calif., and colleagues found that high hospital volume was associated with significantly lowered risk-adjusted patient safety indicator (PSI) rates, as compared with mid-volume and lower-volume hospitals.
“Our analysis of hospital volume confirms previous findings and provides further evidence that high-volume hospitals have superior risk-adjusted inpatient mortality rates and less resource utilization on the basis of length of stay and total charges,” wrote Hernandez-Boussard et al.
The researchers analyzed data collected from the Nationwide Inpatient Sample discharge database from 2005 through 2008 that included abdominal aortic aneurysm (AAA), coronary artery bypass graft (CABG) and Rouxen-Y gastric bypass procedures (RNYGB).
Each cohort was divided into three groups: high-volume, mid-volume and low-volume hospitals, based on the total number of each type of procedure performed at a given hospital. Patient safety indicator software was used to identify preventable adverse events from 2005 to 2008, using statistical analysis systems.
Over the study period, researchers found final weighted cohorts consisted of 182,843 AAA, 1,093,825 CABD, and 354,478 RNYGB discharges. High-volume hospitals performed 26 percent of AAA procedures, 16 percent of CABG procedures and 22 percent of RNYGB procedures.
“In all procedures, high-volume hospitals had lower risk-adjusted inpatient mortality rates, followed by mid-volume hospitals with low-volume hospitals having the highest risk-adjusted inpatient mortality rates,” the authors wrote.
“The importance of hospital volume on absolute differences of having any adverse event, as detected by the PSI software, varied according to type of procedures. In RNYGB patients, low-volume hospitals had four times more patients with an adverse event compared to high-volume hospitals,” wrote Hernandez-Boussard et al. “Relatively large differences in the number of patients with adverse events by hospital volume also existed for AAA patients. Although present, this difference was less pronounced for CABG patients.”
The researchers described their findings as an “inverse relationship” between hospital volume and patient safety events. Higher volume resulted in lower adverse events in the three procedures studied.
“Further examination of structural and process differences between outcomes and hospital volume will help identify means of closing the quality gap,” the researchers concluded. “Research in this area will elucidate specific areas for improvement in low-volume hospitals with the ultimate goal of improving mortality, morbidity, and overall healthcare quality associated with high-risk surgical procedures.”
Tina Hernandez-Boussard, PhD, of the department of surgery at Stanford University School of Medicine in Palo Alto, Calif., and colleagues found that high hospital volume was associated with significantly lowered risk-adjusted patient safety indicator (PSI) rates, as compared with mid-volume and lower-volume hospitals.
“Our analysis of hospital volume confirms previous findings and provides further evidence that high-volume hospitals have superior risk-adjusted inpatient mortality rates and less resource utilization on the basis of length of stay and total charges,” wrote Hernandez-Boussard et al.
The researchers analyzed data collected from the Nationwide Inpatient Sample discharge database from 2005 through 2008 that included abdominal aortic aneurysm (AAA), coronary artery bypass graft (CABG) and Rouxen-Y gastric bypass procedures (RNYGB).
Each cohort was divided into three groups: high-volume, mid-volume and low-volume hospitals, based on the total number of each type of procedure performed at a given hospital. Patient safety indicator software was used to identify preventable adverse events from 2005 to 2008, using statistical analysis systems.
Over the study period, researchers found final weighted cohorts consisted of 182,843 AAA, 1,093,825 CABD, and 354,478 RNYGB discharges. High-volume hospitals performed 26 percent of AAA procedures, 16 percent of CABG procedures and 22 percent of RNYGB procedures.
“In all procedures, high-volume hospitals had lower risk-adjusted inpatient mortality rates, followed by mid-volume hospitals with low-volume hospitals having the highest risk-adjusted inpatient mortality rates,” the authors wrote.
“The importance of hospital volume on absolute differences of having any adverse event, as detected by the PSI software, varied according to type of procedures. In RNYGB patients, low-volume hospitals had four times more patients with an adverse event compared to high-volume hospitals,” wrote Hernandez-Boussard et al. “Relatively large differences in the number of patients with adverse events by hospital volume also existed for AAA patients. Although present, this difference was less pronounced for CABG patients.”
The researchers described their findings as an “inverse relationship” between hospital volume and patient safety events. Higher volume resulted in lower adverse events in the three procedures studied.
“Further examination of structural and process differences between outcomes and hospital volume will help identify means of closing the quality gap,” the researchers concluded. “Research in this area will elucidate specific areas for improvement in low-volume hospitals with the ultimate goal of improving mortality, morbidity, and overall healthcare quality associated with high-risk surgical procedures.”