 This is true both for individuals and the system itself since patients with complications due to DDI will likely re-enter the system at a costlier level.
<clarity>  This is true both for individuals and the system itself since patients with complications due to DDI will likely re-enter the system at a costlier level.
 This is true both for individuals and health-care systems, since patients with complications due to DDI will likely re-enter the system at a costlier level.