Medicare beneficiaries who underwent surgery at critical access hospitals had decreased risk-adjusted serious complication rates and lower adjusted expenditures compared with those treated at non-critical access hospitals, according to a cross-sectional retrospective review.

The groups had similar 30-day mortality rates, and patients at critical access hospitals were less medically complex.

Lead researcher Andrew M. Ibrahim, MD, of the University of Michigan in Ann Arbor, and colleagues published their results in JAMA on May 17.

The federal government created the critical access hospital designation in 1997 to increase reimbursements for hospitals that had fewer than 25 inpatient beds and were more than 35 miles from another hospital. The researchers said that critics cited the program’s $9 billion annual cost and the lack of evidence about outcomes and costs at critical access hospitals. However, advocates argued the hospitals served rural communities that have few other options for healthcare.

For this analysis, the researchers evaluated data from the MEDPAR (Medicare Provider Analysis and Review) file between 2009 and 2013. They included 1,631,904 Medicare beneficiary admissions to 828 critical access hospitals and 3,676 non-critical access hospitals for appendectomy, cholecystectomy, colectomy and hernia repair.

Patients who underwent surgeries at critical access hospitals had lower rates of heart failure (7.7 percent vs. 10.7 percent), diabetes (20.2 percent vs. 21.7 percent), obesity (6.5 percent vs. 10.6 percent) and multiple comorbidities (60.4 percent vs. 70.2 percent) compared with patients at non-critical access hospitals. They were also less likely to use skilled nursing care (21.7 percent vs. 37.9 percent) and were more likely to be transferred to another acute care hospital (4.7 percent vs. 0.8 percent).

The non-critical access hospitals had more operating rooms, more inpatient beds and a higher inpatient ratio, although both types of hospitals had a similar proportion of the operations examined. The annual median surgical volume was 1,624 at non-critical access hospitals and 140 at critical access hospitals.

After adjusting for patient factors, the 30-day mortality rates were 5.4 percent at critical access hospitals and 5.6 percent at non-critical access hospitals. The rates of serious complications were 6.4 percent and 13.9 percent, respectively, which was a significant difference.

Further, after adjusting for patient factors and procedure types, Medicare expenditures were significantly different: $14,450 at critical access hospitals and $15,845 at non-critical access hospitals.

The study had a few limitations, according to the researchers, including that it relied on administrative data that may not be reliable at assessing comorbid conditions and complication of care factors. They added that non-critical access hospitals may have documented more diagnoses codes because they have more resources and receive reimbursement based on disease severity.

Further, the study only evaluated Medicare beneficiaries, so the results may not be generalizable to younger patients.