Population-Based Analysis Finds Urban Residents Have Smaller Risk of Mortality from CLI

May 31, 2023—The Society for Cardiovascular Angiography & Interventions (SCAI) announced a new study using data from millions of patients hospitalized across the United States to determine whether population density and associated urban versus suburban versus rural environments predispose patients with peripheral vascular disease for critical limb ischemia (CLI).

The investigators queried deidentified patient data from the National Inpatient Sample (NIS) from 2001-2013. Of the > 100 million patients in the NIS, there were 1,907,089 patients identified with CLI.

Harsh Jain, DO, of Montefiore Health System, Albert Einstein College of Medicine, in New York, New York, was lead author of the study. The findings were presented at the SCAI 2023 Scientific Sessions held May 18-20 in Phoenix, Arizona.

As summarized in the SCAI press release, the study aimed to identify the role that sociodemographics, including population density in a patient’s hometown, affect outcomes including mortality from CLI.

Inclusion criteria included a diagnosis of CLI. Data were analyzed using SPSS software (IBM) in a binary logistic regression model, a P value < .001 was considered statistically significant, and samples were standardized for comparison using predicted probabilities.

The investigators found:

• Patients living in an urban setting with a population > 1 million people were at a statistically significant decreased risk of mortality from CLI (odds ratio [OR] = 0.647; P < .001).
• Females were at a statistically significant decreased risk of mortality (OR = 0.846; P < .001).
• There was no statistically significant increase in mortality among different age groups, races, insurance carriers, median household income, or elective admission status (P < .001).

“We now know that we need to ambulate our patients and encourage aggressive physical activity earlier and more frequently, especially for men,” commented Dr. Jain, in the SCAI press release. “This is a very low cost, low barrier to adoption that has significant ramifications including improved mortality for millions of people, decreased burden on healthcare resources, and millions of dollars in healthcare spending. Furthermore, men should be more vigilantly monitored when diagnosed with peripheral vascular disease, as they seem to fare worse regardless of where they are across the nation.”

The investigators suggest that, based on the findings, patients with CLI should be encouraged to maintain an active lifestyle and engage in vigorous exercise regimens earlier in their disease course to prevent progression and decrease their risk of mortality, noted SCAI.