Weekend hospital admissions are higher risk for acute kidney injury patients

Patients with acute kidney injury (AKI) who are admitted to the hospital on a weekend are more likely to die than those admitted on a weekday, according to a study appearing in an upcoming issue of the Journal of the American Society Nephrology (JASN). This disparity was most evident in smaller hospitals. The findings indicate that researchers should further investigate the availability and timing of care to patients hospitalised with AKI.

Studies have shown that for a variety of acute illnesses, patients admitted to the hospital on a weekend are more likely to die than those admitted on a weekday. To investigate whether this is true for patients with AKI, Matthew James, MD (University of Calgary, in Alberta, Canada), Glenn Chertow, MD (Stanford University School of Medicine), and colleagues examined information from the Nationwide Inpatient Sample, a large database of admissions to acute care, nonfederal hospitals in the United States.

They identified 963,730 admissions with a diagnosis of AKI between 2003 and 2006.  Of these, 214,962 admissions (22%) designated AKI as the primary reason for admission (45,203 on a weekend and 169,759 on a weekday).

The investigators found that during hospitalisation, 14,686 (6.8%) patients admitted with a primary diagnosis of AKI died. Patients admitted with a primary diagnosis of AKI on a weekend had a 22% increased risk of dying by day three of admission, and a 7% increase of dying during the duration of their hospital stay, compared with patients admitted on a weekday. In small hospitals, the risk was even greater. There, compared with patients admitted on a weekday, a patient’s risk of dying after admission on a weekend for AKI was 34% higher after day three of admission and 17% higher over the duration of their hospital stay.

The investigators also found an increased risk of death following a weekend admission among patients who were admitted for other conditions but later diagnosed with AKI during their hospital stay.

"There are many reasons why this research is important," said Chertow. "Optimising patient safety and nephrology resource utilisation are among the two most relevant," he noted.

While the underlying reasons for the observed increased deaths among AKI patients admitted on a weekend are unknown and require further investigation, other studies have described delays in assessment, diagnosis, and management of other acute medical conditions on weekends.

(Source: American Society Nephrology: Journal of the American Society Nephrology: April 2010)