California is the second state, after Pennsylvania, to include rates of 30-day readmission in its annual report on coronary artery bypass graft (CABG) surgery outcomes, which is posted Tuesday.
In addition to risk-adjusted rates of readmissions, the report also names the best and worst hospitals for CABG 30-day mortality, lists each hospital's rate of post-operative stroke—a consequence of heart surgery said to be preventable—and identifies five hospitals that have an undesirably low use of the internal mammary artery as the graft. Surgeons there instead use the less-preferred saphenous leg vein.
Adding information about readmission rates is an important measure hospitals should get used to. That's because the Centers for Medicare & Medicaid Services is considering adding readmissions for heart bypass surgery to the list of conditions for which hospitals with higher rates would suffer payment reductions in future years, along with congestive heart failure, pneumonia, and heart attack.
Readmissions for CABG was suggested for federal payment determination by a 2007 report from the Medicare Payment Advisory Commission.
CABG Mortality
Overall, the report shows that mortality rates within 30 days of the operation dropped from 2.8% in 1998-1999, to 2.24 in 2008 to 1.9% in 2009, when 13,260 isolated procedures were performed.
That's a significant decline from the 27,000 CABG procedures in 1998, the first year this state CABG report was published. CABG procedures are going down because of compelling research findings that in many cases, prescription drug management provides better long-term outcomes than major invasive surgery.
Because of the steady decline in CABG procedures in the last decade, those patients who do undergo the operation tend to have more co-morbidities, and so the mortality rate would be expected to hold steady or even increase. But the fact that it declined anyway indicates surgeons and hospital teams may be getting even better, Parker says.
"These patients (who undergo CABG surgery these days) are sicker," said Joe Parker, manager of the Healthcare Outcomes Center for OSHPD, the nation's largest state hospital database, which prepares an annual CABG report.
"While we have increasingly more morbidly ill CABG patients, the mortality rates continue to decline. And we attribute this to surgeons and hospitals and others focusing their efforts on quality and really achieving quite good outcomes."
The report lists 119 hospitals in the state where CABG surgery is performed, but for all four measures in this report, only five hospitals are named as "better" while only 12 are listed as "worse" than state average.
For example, for risk-adjusted 30-day mortality, only Scripps Memorial Hospital in La Jolla was listed as having a "better" performance rate, while Scripps Mercy Hospital in San Diego and West Hills Regional Medical Center of West Hills were listed as being "worse."
That doesn't give consumers or providers much quality information either for choosing care or for making improvements, acknowledges Parker, who said he would like to have at least five categories that can better discriminate and highlight the greater variation between the worst and best hospitals.
Unfortunately, he say, the report's Clinical Advisory Panel "felt this was the best way to present the data," and that this is the way they do it in other states. Parker says there are statistical challenges for spreading the data out in more categories. "I don't think folks across the country have come to a consensus on how you get to more categories."
Jan Emerson-Shea, spokeswoman for the California Hospital Association, was asked about the data's usefulness, given the fact that nearly all of the 119 hospitals were shown as not being statistically different. Previous reports showed hospital quality in charts with their place on a bar, showing whether and how far they were above or below state average.
"OSHPD consistently produces hospital quality reports that are thorough and reliable for consumers, based on a very strict use of a statistical model," she replied. "We support their efforts to continue to refine these reports to make them as useful as possible. What is important is that the data be scientifically valid and easy to understand for the public. The feedback that OSHPD has received over the years is that the bar graph has created confusion, so they have decided to modify the report accordingly."
CABG Readmissions
For the readmissions segment of the report, Parker explained, the committee included a readmission for anything that could be reasonably related to the regrafting procedure, including infections, bleeding, or a heart attack.
The report also said that of the 11,823 patients discharged after CABG surgery in 2009, 1,565 (13.2%) experienced a hospital readmission within 30 days. Rates of readmission also varied widely, from 0% to 29.77%.
Parker said that the report's findings in the category of 30-day readmissions "were relatively reassuring. There was fear that there might be some hospitals where patients were coming back with vey high rates, but we only found one that was statistically significantly high."
CABG Post-operative Stroke
California also is the only state in the nation to report on rates of post-operative stroke in CABG, a known rate of complication. And this report represents the third year of data in this category.
Of the 27,217 patients who underwent CABG surgery in 2008 and 2009 (for this category two years were combined), 1.41% experienced a post-operative stroke. There was wide variation among hospitals in this category as well, ranging from 0% to 8.87%.
In this category, Alta Bates Summit Medical Center in Oakland, St. Bernardine Medical Center in San Bernardino and St. Joseph's Medical Center of Stockton had better performance ratings. For Alta Bates, this is the third year it has performed statistically better than the state average.
But Bakersfield Memorial Hospital, Good Samaritan Hospital of San Jose, Providence Tarzana Medical Center, and Scripps Memorial Hospital in La Jolla had worse performance in stroke rates after heart bypass surgery.
CABG Use of Mammary Artery as Graft
California is the only state in the nation to report the use of the mammary artery instead of the leg vein in the re-grafting procedure. According to the report, " Evidence shows that the IMA, when grafted to a coronary artery, is less susceptible to obstruction over time and remains fully open longer than vein grafts."
The state found no hospitals used the IMA frequently enough to rate a higher performance rate. Five hospitals were listed has having low IMA usage rate.