ST. LOUIS — St. Louis-based SSM Health laid off 350 employees, or about 1 percent of its 35,000-person workforce, last week, according to the St. Louis Post-Dispatch.

In addition to the layoffs, an undisclosed number of positions will be lost to attrition.

In a statement to the St. Louis Post-Dispatch, SSM Health said the cuts will help ensure “long-term sustainability” for the system. SSM did not disclose what positions would be eliminated.

SSM Health has operations in Illinois, Missouri, Oklahoma and Wisconsin.

The system includes 20 hospitals, 63 outpatient care sites, two nursing homes and home care and hospice services.

SSM also has a pharmacy benefit company, an insurance company and two ACOs