Inside the Index: TIRR Memorial Hermann’s Case Mix Index Highlights Its Unique Patient Care Capabilities

TIRR Memorial Hermann cares for patients with some of the most complex disorders in physical and rehabilitation medicine.

This comprehensive capability is reflected in our case mix index (CMI), a measure that assesses the severity and complexity of patients treated in a health care facility.

“Our case mix index is in keeping with what TIRR Memorial Hermann is known to do—provide rehabilitation medicine services to the most catastrophically injured patients or those with the most complex neurological diagnoses,” says TIRR Memorial Hermann Chief Medical Officer Gerard E. Francisco, MD.

For the Fiscal Year 2025 (June 2024 – July 2025), TIRR Memorial Hermann has an overall CMI of 1.9, the highest among all designated national innovation centers. In our brain injury and stroke programs, our CMI is 1.86, compared to the national average of 1.77. And in our Spinal Cord Injury (SCI) program, our CMI is 2.13 — among the highest of any rehabilitation hospital in the country.

These numbers tell a powerful story: Patients facing limited options for high-quality care can find innovative and patient-centered treatment at TIRR Memorial Hermann. Our mission is to redefine what’s possible in rehabilitation and provide hope to those who need our care.

TIRR Memorial Hermann’s CMI reflects the complexity of its patient population. For example, the TIRR Memorial Hermann SCI program treats patients who have suffered traumatic spinal injuries, have been diagnosed with a spinal cord disease that causes paralysis or with neuromuscular diseases (i.e., amyotrophic lateral sclerosis) and those with cancers that have metastasized to the spinal cord. However, it is one of the few spinal cord injury programs in the United States that accepts patients requiring ventilators, a population that includes nearly 90% of all cervical SCI patients and 40% of those with complete cervical lesions.

“Being intubated increases the complexity of the patient’s condition, which drives the CMI to be higher,” Dr. Francisco explains.

“Our clinicians are truly leading the field in managing complex patients with SCI, not only in terms of clinical outcomes but also in addressing nonmedical drivers of their health,” adds TIRR Memorial Hermann CEO Rhonda Abbott. “We offer the supportive services they and their families need in order to be able to successfully discharge home and back into their communities.”

In addition, TIRR Memorial Hermann is among a handful of hospitals across the country that manage patients with neurobehavioral disorders as a result of brain injury. Our approach to this population is unique: Care teams strive to minimize the use of sedative medication to allow for optimal cognitive function levels to be achieved earlier in patient recovery.

The hospital’s Neurobehavioral Program includes a full staff of rehabilitation medicine specialists, psychologists and neuropsychologists, speech language pathologists, care team coordinators, physical and occupational therapists, nurses, nurse aides and technicians, all of whom are experienced and specially trained in caring for patients with these complex disorders.

In another example of patient complexity, TIRR Memorial Hermann’s Disorders of Consciousness (DoC) Program provides state-of-the-art care for patients in an unresponsive wakefulness or minimally conscious state. Disorders in consciousness can arise from a variety of types of brain injuries, including traumatic brain injuries and injuries due to hypoxia, stroke or aneurysm rupture.

The DoC program admits and treats patients regardless of the etiology of their injury and is the only such program in the country that admits consciousness-challenged patients who require ventilators, thanks to a respiratory therapy team that is available 24/7.

“TIRR Memorial Hermann’s mission is to provide hope to patients who have been turned away by other institutions because they don’t have the same expertise and/or resources we have here,” Dr. Francisco says. “Our commitment is to care for the sickest of the sick, and our case mix index reflects that.”