In 2008, nearly one in five hospitalizations were diabetes-related, totaling more than 7.7 million stays and $83 billion in hospitalization costs--or 23 percent of total hospital costs in the U.S., according to a statistical brief released this month from the Agency for Healthcare Research and Quality's Healthcare Cost and Utilization Project (HCUP).

Taressa Fraze, PhD, research manager in the healthcare division of Thomson Reuters, and colleagues analyzed data from the HCUP 2008 Nationwide Inpatient Sample.

“There were over 540,000 hospital stays for patients with diabetes as a primary diagnosis,” the authors stated. “These counts may include hospitalizations by the same individuals, which is common among patients with diabetes. The mean cost of hospitalization for patients with diabetes was $10,937 in 2008 compared with $8,746 for patients without diabetes.”

The mean length of stay for patients with diabetes was 5.3 days, almost one day longer than for patients without diabetes (4.4 days), the authors found. Hospital stays for patients with diabetes were more likely to originate in the emergency department than stays for patients without diabetes, according to the statistical brief. “While patients with a principal diagnosis of diabetes accounted for only 1.4 percent of all hospital stays, almost 20 percent of all hospitalizations involved patients with diabetes,” the authors wrote. “This is significant because diabetes increases length of stay and therefore increases costs regardless of whether it is the primary reason for admission.”

Among hospitalized patients, the number of comorbidities was twice as high for patients with diabetes as for patients without diabetes (2.6 comorbid conditions for patients with diabetes vs. 1.3 for those without diabetes). “Hypertension was the most common comorbidity and was present in 69 percent of hospital stays for patients with diabetes [compared with 30 percent of stays for patients without diabetes],” Fraze and colleagues noted.

Diabetes was the most common principal diagnosis, or reason for hospital admission among patients with diabetes. Five of the top 10 principal diagnoses were circulatory disorders: congestive heart failure, coronary atherosclerosis, acute myocardial infarction, nonspecific chest pain and cardiac dysrhythmias.

The rates of hospital stays for patients with diabetes increased as the income level of the patient ZIP code decreased, the authors found. “[T]here were 3,232 diabetes-related stays out of every 100,000 persons from the lowest income quartile compared with 1,762 stays out of every 100,000 persons from the highest income quartile.”

The South had the highest rate of hospital stays for patients with diabetes (2,829 per 100,000 persons in the region), followed by the Midwest (2,742 hospitalizations per 100,000 persons) and the Northeast (2,565 hospitalizations per 100,000 persons). The West had the lowest rate (1,866 stays per 100,000 persons in the region), the authors noted.