December 15, 1998
In the latest of a series of clinical outcomes studies at Johns Hopkins, researchers report that survival rates of colorectal cancer surgery patients increase with the experience of their surgeons. Patients also spend less time recuperating in the hospital after the surgery and have lower hospital charges.
In a related study, some of the same researchers found that compared to patients with traditional commercial insurance, Medicaid patients in Maryland undergo more operations, take longer to recuperate in the hospital, and had higher overall in-hospital mortality than do commercially insured patients.
For the cancer study, researchers examined data from 50 Maryland hospitals for the years 1992 through 1996. During the study period, 9,739 operations for colon and rectal cancer, performed by 812 surgeons, were grouped according to the surgeon's annual number of operations performed. Surgeons performing five or less surgeries per year were classified as low-volume, while high-volume surgeons performed more than 10 cases per year. Physicians doing between five and 10 operations per year were classified as medium-volume surgeons.
After adjusting for the differences in the severity of the patients' illnesses to ensure a more accurate comparison, the researchers found that patients operated on by high-volume surgeons had a 36 percent lower risk of death compared to patients operated on by low-volume surgeons. Patients treated by the medium-volume surgeons had a 20 percent lower risk of in-hospital death than the low-volume group.
Average hospital charges were significantly lower for both the high- ($11,642) and medium-volume ($11,735) groups compared to the low-volume ($13,025) group. In addition, patients undergoing surgery by the most experienced surgeons spent the fewest days in the hospital recuperating from their operations (9 days), compared to those treated by the least experienced surgeons (10.1 days). Patients operated on by the mid-volume surgeons spent an average of 9.5 days in the hospital following surgery.
"As with previous results in a study of pancreatic cancer surgery, this study provides further evidence that physician experience is strongly correlated to patient outcomes," says Toby Gordon, Sc.D., a co-author of the study. "The more often a surgeon performs a particular procedure, the better he or she becomes at doing that operation. This means better outcomes for the patient and less demands on increasingly limited health care resources."
In the second study, the Hopkins researchers examined data from 52 hospitals in Maryland for 403,821 inpatient surgery patients discharged during 1988 to 1994. Of these cases, 13.6 percent were Medicaid patients and 86.4 percent were commercially insured patients. While the number of total surgeries for the entire study population decreased 13.3 percent during the study period (61,542 in 1988 versus 53,364 in 1994), the number of surgeries for commercially insured patients decreased 15.7 percent, and the number for the Medicaid patients increased by 3.6 percent. Average length of hospital stay following surgery decreased more rapidly in the commercial insurance group than in the Medicaid group (17.2 percent versus 11 percent). While in-hospital surgical deaths rates declined 7 percent over the study period for commercial insurance patients, Medicaid patients experienced a 7 percent increase and had higher overall in-hospital mortality rates (2.05 percent versus 0.76 percent for commercially-insured patients in 1994.) Also, the Medicaid patients had a higher proportion of total inpatient operations performed at academic medical centers compared to commercially-insured patients (39.1 percent versus 11.5 percent in 1994).
The researchers suggest these differences most likely result from the generally sicker Medicaid population, a finding hospitals can use to help them plan around a national trend of shifting Medicaid patients into managed care, says Gordon. "We know that almost 38 percent of Medicaid patients having their operations at academic medical centers had twice the rate of high-risk surgeries compared to the patients under commercial insurance who received their care at the same centers," says Gordon.
"Although we don't know the reasons that Medicaid patients require more serious, high-risk surgeries, this knowledge helps us better understand the unique needs of Medicaid patients," Gordon notes. "Also, as we move increasingly toward a managed care structure for Medicaid that operates under a capitated, or flat rate, reimbursement system, hospitals need to take these facts into account for planning and budget purposes."
Both studies were presented at the 1998 meeting of the American College of Surgeons and published in a recent edition of the Surgical Forum of the American College of Surgeons.