Better Living Through Measurement
Each year, close to 3 million Traumatic Brain Injury (TBI)-related emergencies arrive at hospitals and ambulatory care centers across the country, according to the Centers for Disease Control. While many of those are relatively minor, stemming from a fall or a bump on the head, more serious cases can result in a disruption of normal brain function, bringing on an extended period of unconsciousness.
The more severe instances are categorized as Disorders of Consciousness, with symptoms ranging from a lack of concentration to chronic coma to brain death. Considering the number of people experiencing some type of serious brain injury annually, you might think there would be a wealth of clinical trials to address rehabilitation for these patients. Unfortunately, there aren’t.
“There really hasn’t been a successful clinical trial for severe TBI patients. They generally get stopped early, or they don’t appear to be effective,” explains Trudy Mallinson, PhD, OTR/L, FAOTA, FACRM, associate dean for research in health sciences and associate professor of clinical research and leadership and of health, human function, and rehabilitation sciences at the George Washington University School of Medicine and Health Sciences.
A key criticism of these trials, Mallinson explains, is there aren’t good assessment tools to measure recovery of consciousness.
To address that gap, Mallinson and Theresa Bender Pape, DrPH, clinical neuroscientist with the Edward Hines Jr. Veterans Administration (VA) Research and Development Service and a research associate professor at Northwestern University’s Feinberg School of Medicine, have collaborated on a series of studies, largely funded by the VA Health Services Research and Development Service and the Department of Defense, to establish and develop the Disorders of Consciousness Scale, or DOCS-25: a tool enabling clinical researchers to measure their work with severe TBI patients.
The tool uses a rating system consisting of 25 stimuli contained in four sensory domains to evaluate patients based on their responses. The four neurobehavioral domains assess specific capabilities: Auditory/Language, response to a voice or a command; Somatosensory, dealing with touch such as light touch or heavy pressure, hot or cold; Visual, a patient’s ability to focus on and track an object or face; and Gustation/Olfactory, relating to taste or smell, such as sweet or sour.
Responses are scored based on the patient’s best overall observable response to a sensory stimuli. Using a psychometric approach called Rasch analysis, these researchers have ordered the sensory items from low to high in terms of their relative difficulty to respond to.
“Our data show the items form a really nice hierarchy,” Mallinson says. “We are pretty convinced about the validity of DOCS-25. We know it’s reliable.”
The next big hurdle is establishing a minimally clinically important difference (MCID); basically finding out how much change in the measurement matters to patients, researchers, and clinicians. While developing DOCS-25, Mallinson and Pape realized none of the assessment tools, including DOCS, had a well-established MCID.
“If you have a 2-point change, does that matter?” asks Mallinson. “How much change is enough that researchers can say, ‘yes, that’s a real change?’ The reason that’s important is because that’s what you power clinical trials on. If you believe your clinical trial is going to produce a 6-point clinical change, plus or minus the standard deviation, that’s the information you use to power your clinical investigation.”
Mallinson says their focus now is on tying the kinds of meaningful change that clinicians and caregivers want to see to the recovery ruler. If they can do that, clinicians could then have the tools to show families and caregivers where things are in terms of recovery and help families and clinicians make better treatment decisions together.
“That’s really what drives us,” says Mallinson. “If we can measure things better, we can understand what we’re doing and how to treat patients better.”