Variability in Case-Mix Adjusted ln-Hospital Cardiac Arrest Rates

After adjustment for a hospital’s case-mix, the rates of in-hospital cardiac arrest (IHCA) vary considerably. Urban hospitals and those that treat more Blacks have higher rates, while larger hospitals have lower rates, raising troubling equity concerns about care quality.

Despite considerable focus on preventing in-hospital cardiac arrest, this study is the first national comparison of IHCA rates across hospitals. Researchers analyzed data related to 103,117 adult IHCA events that occurred from 2003-2007 at the 433 hospitals participating in the Get with the Guidelines Resuscitation national registry. Based on its mix of patients, each hospital was assigned an overall patient risk score to remove the distortion of treating patients more or less seriously ill.

Key Findings:

  • The rate of IHCAs was highly variable across hospitals. While the average was one incident per 1,000 bed-days, 8 percent, or 35 hospitals, had rates 50 percent below the median and 3 percent (13 hospitals) had rates more than double the median.
  • If a hospital was located in an urban area or treated more Black patients, it was more likely to have a higher IHCA rate.
  • If a hospital was larger, it was likely to have a lower IHCA rate.
  • Other factors, including nurse-to-bed ratio and patient age over 65 years, did not correlate to IHCA rates.

The authors hypothesize that larger hospitals may have more resources available to prevent IHCA, accounting for the lower rate in these institutions. But they find the higher rates among urban hospitals and those that treat a higher proportion of Black patients to be troubling and potentially reflective of other research that finds such hospitals provide lower quality inpatient care. The authors call for additional research into the mechanisms that lead to the notable variations in IHCA rates but believe this study begins to provide benchmarks for hospitals to compare themselves to peer institutions with regard to IHCA.