Comparing Accredited and Nonaccredited Hospitals

In the past, evaluating the impact of hospital accreditation was challenging because there was no nationally standardized data. So the Joint Commission and the Centers for Medicare and Medicaid Services (CMS) compared hospitals it accredited with those it didn’t using other evidence-based measures of quality. Those included data that are mandatory to report publicly for common diseases such as heart failure and pneumonia.

From 2004 to 2008, according to a study in the Journal of Hospital Medicine, 8 in 10 accredited U.S. acute care and critical access hospitals outperformed nonaccredited hospitals by these measures.

The study concluded, “Hospitals accredited by The Joint Commission tended to have better baseline performance in 2004 than nonaccredited hospitals. Accredited hospitals had larger gains over time, and were significantly more likely to have high performance in 2008 on 13 out of 16 standardized clinical performance measures and all summary scores.”

The differences, the report says, became significantly more pronounced over five years of observation. But it also says that it’s unclear whether accreditation is solely responsible for improved performance or simply reflects general hospital characteristics associated with performance.

So the study’s authors note that nonaccredited hospitals shouldn’t necessarily be considered substandard because even hospitals lacking accreditation had a “reasonably strong” adherence to quality-of-care standards.

It’s a good idea, however, for hospital patients and prospective patients to find out if their treatment facility is accredited by the commission, simply because such status appears either to promote improved performance, or to indicate that a hospital’s standard procedures are associated with improved performance.

Other things to keep in mind about the Joint Commission’s accredited hospitals:

• They tend to be large, for-profit operations, located in urban areas.
• They are less likely to be government-owned, located in the Midwest or to be defined as critical access.
• The proportion considered high performers – 90% adherence to 13 of the 16 measures – was notably higher in accredited hospitals than those that were never accredited.