A separate analysis of just the 2010-2012 data evaluated outcomes by surgeons’ operation volume.
In the first epoch, in-hospital mortality was about 12%. In the second, it fell to 8%, and by the third, to 4%. Patients whose surgeons performed one to nine procedures (up to three per year) were hospitalized an average of about 14 days. Those whose surgeons performed 19 to 36 procedures (up to 12 per year) stayed an average of 8 days – a significant difference.
Mortality followed the same pattern. About 9% of patients whose surgeons performed one to three procedures per year died after surgery, compared with 2% of those whose doctors performed 12 procedures per year.
These more experienced surgeons also discharged more patients to home rather than nursing facilities (88% vs. 82%, a significant difference).
Both hospital and surgeon volume also affected costs. Overall, hospital costs increased significantly, even after adjustment for inflation, jumping from $93,000 to $133,000. But surgeons who performed at least 12 Whipples per year did so at a half the cost of those who performed 1-3 per year ($100,000 vs. $200,000).
"Suffice it to say, the busiest surgeons got the best results," Dr. Wood said.
Dr. Jeffrey Sutton
Despite advances in centralizing this kind of specialized care, though, many low-volume centers are still performing the operations, said Dr. Jeffrey Sutton of the University of Cincinnati. "Research continues to show that high-volume centers have better outcomes," he said. "And yet a significant number of cases are still being done at hospitals that do less than one per year."
If research data aren’t enough to persuade hospitals to send patients to regional centers, Dr. Sutton wondered, could money be a motivating factor? He examined the records of almost 10,000 Whipple operations performed at 419 centers that are part of the University Health Systems Consortium clinical database. Of these, 120 were academic centers and 299 were affiliated hospitals. The procedures were performed from 2009 to 2011. Clinical outcomes included length of stay, mortality, and readmissions. He also assessed the cost of both the index admission and readmissions.
Hospitals were divided into volume quintiles of lowest, low, middle, high, and highest. The lowest-volume centers performed up to 21 cases/year in 2009 to up to 23 in 2011. The highest-volume centers performed up to 180 cases/year in 2009 and up to 216 in 2011.
Intraoperative mortality hovered around 2% at the middle-, high-, and highest-volume centers. At the low-volume centers, it reached 2.5% – not significantly different. But at the lowest-volume centers, 30-day mortality was significantly higher – nearly 4%.
Length of stay was similarly associated with volume. In low-, middle-, and high-volume centers, it was about 9 days. But in the lowest-volume centers, the average length of stay was 11 days – significantly longer than any of the others.
Readmission rates over the first postoperative month were also lowest in the highest-volume centers (16.5%). In the low-volume centers, 30-day readmission was just under 19%. But in the middle-, low-, and lowest-volume centers, it was significantly greater, hovering at nearly 20%.
"It’s not only that lower-volume centers are holding on to patients longer, they also are readmitting those same patients significantly more often," Dr. Sutton noted.
The cost analysis looked at Medicare charge data. "When both index and readmission costs were considered, the median per-patient cost at the lowest-volume centers was $23,005 – 11% more than at the highest-volume center."
But there was no significant difference in the cost of readmissions. "That means that the difference of about $2,263 extra per case was based solely on the index admission," Dr. Sutton said. "Essentially what we saw was that the more cases that are performed, the cheaper each individual case becomes."
"To put it bluntly, some low-volume centers are currently reimbursed higher sums of money for delivering suboptimal care to patients," Dr. Sutton said in an interview. In our current health care climate, which emphasizes improved outcomes at lower costs, this is a travesty. As health service researchers, it is our obligation to our patients to analyze and disseminate these data in an effort to urge policymakers to limit the financial reimbursements for poorer-performing providers."
None of the researchers quoted in this article reported any financial disclosures.