Throughout the United States, reducing the rates of hospital readmissions has become a top priority, as evidenced by CMS planning to include surgical procedures in the expansion of the penalty program. “The hospital readmissions reduction program is predicated on the notion that decreasing the frequency with which patients return to hospitals can improve care and lower costs,” says Thomas C. Tsai, MD, MPH. “However, using medical readmission rates as a measure of hospital quality has been controversial.”

Hospitals vary substantially in their medical readmission rates, but these data generally do not correlate with the measures that are often used to identify high-quality hospitals, such as mortality. This raises the question of whether or not medical readmission rates
actually measure hospital quality or if they instead reflect other factors that are unrelated to hospital care.

The relationship between readmission rates and surgical care may be different than that of medical readmissions. Most patients undergo non-urgent major surgery when they’re clinically stable. As a result, surgical readmissions are more likely to result from complications of care received during index hospitalizations. “Clinicians have relatively little information on the types of hospitals that perform well or poorly with regard to surgical readmission rates,” says Dr. Tsai, “but we hypothesized that hospitals excelling in surgical care would generally have fewer readmissions.”

A Comprehensive Analysis

In a study published in the New England Journal of Medicine, Dr. Tsai and colleagues sought to determine the patterns of surgical readmissions among Medicare patients across a set of major procedures in a national sample of hospitals. The study team combined information from Medicare claims, the American Hospital Association annual survey, and quality measures from the Hospital Quality Alliance to look at six major surgical procedures: CABG, pulmonary lobectomy, endovascular repair of abdominal aortic aneurysms (AAAs), open repair of AAAs, colectomy, and hip replacement. They calculated composite readmission rates across all 3,004 hospitals that performed at least one of the six procedures analyzed in the study. They also calculated readmission rates for each procedure, adjusting for hospital characteristics and measures of surgical quality.

 “Incentives to reduce readmissions represent one of the few policy measures
that can decrease costs while improving quality.”

According to the findings, the median risk-adjusted composite 30-day readmission rate was 13.1%, or slightly less than one in seven patients. Patients who were readmitted were older than those who were not readmitted and had more coexisting conditions (Table 1). Rates ranged from 10.5% to 17.4% across the six procedures. Hospitals with readmission rates below the median were more likely than those with rates above the median to be non-profit, non-teaching, and located in the west. These hospitals also had a higher number of full-time nurses per 1,000 patient-days and a lower proportion of Medicaid patients than hospitals with readmission rates above the median (Table 2).



“Rates of 30-day readmission were better in hospitals with a high surgical volume or with lower surgical mortality rates,” adds Dr. Tsai. “On the other hand, good adherence to surgical process measures had only a small effect. These findings are different from previous studies that have analyzed patterns of readmission rates for medical care.”

Informative Data

Dr. Tsai says the findings of his study are informative in that they help delineate surgical readmission rates from those of medical services. “The data are becoming clearer that readmission rates are also high on the surgical services,” he says. “Our findings have important clinical and policy implications for health reform. Incentives to reduce readmissions represent one of the few policy measures that can decrease costs while improving quality.”

It is important to note that the study by Dr. Tsai and colleagues focused on Medicare patients, meaning the findings might not apply to younger patient groups. That said, the study captures the sickest and oldest patients. “This issue is of great importance to hospitals and clinicians caring for this patient population,” Dr. Tsai says. “With CMS planning to expand its readmissions penalty program to include surgical procedures, it’s critically important to collect and analyze data on readmission rates after major surgery. We also need to determine the relationship of readmissions to other markers of the quality of surgical care.”

Findings from the study offer evidence that surgical readmission rates are indeed associated with measures of surgical quality, according to Dr. Tsai. “The data support the notion that higher-volume and lower-mortality hospitals have lower readmission rates. The challenge that lies ahead is finding other factors that may be at play in order to appropriately measure surgical performance across U.S. hospitals.”