Public Reporting of PCI Mortality May Have Unintended Consequences

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Public identification of hospitals as negative ‘outliers’ with regard to expected mortality after percutaneous coronary intervention (PCI) appears to lead to more cautious patient selection, according to a study published in the June 2013 issue of JACC: Cardiovascular Interventions. The authors suggest that this measure, intended to help patients find the best treatment, may have the unintended consequence of depriving the sickest patients of appropriate intervention. 

Investigators led by James M. McCabe, MD, of Brigham and Women’s Hospital (Boston, MA), analyzed the impact of public reporting on 24 nonfederal PCI-capable hospitals in Massachusetts which performed the procedure on 116,227 patients between 2003 and 2010.

Drawing on patient-specific data collected from each hospital, the Massachusetts Data Analysis Center (Mass-DAC) used risk prediction models to calculate expected mortality rates for all PCI patients based on clinical characteristics and presenting conditions. Separate models, updated yearly, were used for patients with shock or STEMI (SOS) and those without such presentations (non-SOS).

Mortality Rates Respond to ‘Negative Outlier’ Label

During this period, Mass-DAC identified 4 hospitals as negative outliers”—1 in 2005, 2 in 2007, and 1 in 2009.

The prevalence-weighted mean expected mortality rate for all PCI cases during the study period was 1.38 ± 0.36% (5.3 ± 1.96% for SOS patients and 0.58 ± 0.19% for non-SOS patients).

On average, after hospitals were labeled negative outliers, their expected post-PCI mortality rate was lower than at nonoutlier institutions (1.08 ± 0.23% vs. 1.58 ± 0.29%; P < 0.01), suggesting that the average PCI patient at outlier hospitals had fewer cormorbidities. More specifically, expected mortality of non-SOS patients at outlier institutions was lower than at nonoutlier institutions (0.47 ± 0.18% vs. 0.60 ± 0.18%; P < 0.01), while expected mortality of SOS patients remained similar between outlier and nonoutlier institutions (P = 0.87), suggesting no change in illness severity.

When the performance of outlier hospitals after public labeling was compared to their performance before labeling, the former showed substantial improvement in expected mortality rates for both non-SOS (0. 47 ± 0.18% vs. 0.71 ± 18%; P < 0.01) and SOS (5.22 ± 1.78% vs. 7.49 ± 3.47%; P = 0.03) patients.

Overall Decline in Mortality

Interestingly, in the years since the inception of public reporting of PCI outcomes, the average expected 30-day mortality rates for CABG at the 4 PCI outlier hospitals decreased (from 2.50 ± 0.39% to 1.23 ± 0.03%; P for trend = 0.01), suggesting that the decline in average illness severity of the PCI population at those institutions after public labeling was probably not due to steering the most severely ill patients toward surgical revascularization.

The authors say they “suspect that the mechanism for the decreased average illness severity among PCI case mix at outlier hospitals is [avoidance of] PCI altogether in the most severely ill SOS patients.” They add that although they did not observe a difference in the expected risk of SOS patients who underwent PCI after the hospital was labeled an outlier, “our analysis cannot account for patients who might qualify for PCI but were no longer offered this therapy.” The net effect, they explain, would be to “decrease that institution’s aggregate expected mortality rate by relatively increasing the proportion of lower risk, nonshock, non-STEMI patients among the total PCI population.”

An important study limitation, Dr. McCabe and colleagues say, is that it could not account for differences in how hospitals documented patient risk factors. So-called up-coding to higher risk status may have been common, they note, and carries the potential to falsely inflate predicted mortality rates, thereby diluting evidence of operators’ risk aversion after outlier status identification.

Adapting to the ‘New Era of Transparency’

“The challenges ahead are how best to develop public reporting for a good purpose and yet avoid unintended consequences such as . . . risk-averse behavior,” observes Gregory J. Dehmer, MD, of Texas A&M University Health Science Center College of Medicine (Temple, TX), in an accompanying editorial.

He points to the pitfalls of using statistical models to label a hospital an outlier, especially if it performs relatively few PCIs annually. For example, at a volume of 200 procedures per year, it would take almost 4 years of data to be certain that a 1% excess in mortality compared with the statewide average was significant rather than a simple variation.

To adapt to the “new era of transparency,” Dr. Dehmer recommends that interventionalists follow clinical guidelines and know where they stand on key metrics with regard to national benchmarks. “Know your data and be proactive in efforts to improve,” he urges.

The Role of Physician Mistrust

In a similar vein, Mauro Moscucci, MD, of the University of Miami Miller School of Medicine (Miami, FL), agreed that public reporting is here to stay. And on the plus side, the practice carries the potential to increase accountability and promote better care, he told TCTMD in a telephone interview.

The catch is that many physicians do not trust the reporting process, he observed, citing a survey of New York State interventional cardiologists (Narins CR, et al. Arch Intern Med. 2005;165:83-87). About 80% said that statistical models of risk cannot adequately adjust for all confounders, and that public reporting of mortality would influence their decisions about whether or not to perform PCI in certain high-risk patients.

Dr. Moscucci said the current study is the latest of several provocative papers that have raised concerns about the unintended consequences of public reporting, including reluctance to revascularize patients who might benefit the most, up-coding, and the flight of high-risk patients from states with public reporting to states without such reporting in the (probably mistaken) belief that the latter offer better treatment.

As for the overall trend toward lower PCI mortality, Dr. Moscucci said public reporting may have contributed to some degree, but there are 2 other possible explanations. One is that there has been a reduction in the population’s overall cardiovascular risk. The other is that patients with acute MI and shock are now less likely to undergo catheterization.

“The problem [in interpreting the trend] is that we have the number of patients who underwent PCI, but we don’t have the denominator of all patients that came in with shock and may or may not have gone on to PCI,” he said.

It is crucial to understand the net consequences of public reporting, Dr. Moscucci asserted, and that will require linking acute outcome databases to overall, long-term outcome databases.

Study Details 

On average, outlier hospitals were larger than nonoutlier centers (P = 0.03) and performed more PCIs annually (192 ± 80 vs. 112 ± 76 SOS cases and 1,163 ± 200 vs. 780 ± 408 non-SOS cases; both P < 0.01). 

 


Sources:
1. McCabe JM, Joynt KE, Welt FGP, et al. Impact of public reporting and outlier status identification on percutaneous coronary intervention case selection in Massachusetts. J Am Coll Cardiol Intv. 2013;6:625-630.

2. Dehmer GJ. Public reporting in interventional cardiology: The challenges ahead [editorial]. J Am Coll Cardiol Intv. 2013;6:631-633.

 

 

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Public Reporting of PCI Mortality May Have Unintended Consequences

Public identification of hospitals as negative ‘outliers’ with regard to expected mortality after percutaneous coronary intervention (PCI) appears to lead to more cautious patient selection, according to a study published in the June 2013 issue of JACC Cardiovascular Interventions. The authors
Disclosures
  • Drs. McCabe, Dehmer, and Moscucci report no relevant conflicts of interest.

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