DENVER—A weak correlation was found between physical and patient-reported outcome measures among patients with multiple sclerosis (MS), according to results of a study presented at the 22nd Annual Meeting of the Consortium of Multiple Sclerosis Centers. Stephen Kirzinger, MD, and colleagues suggested that the true disease impact might be underrepresented, as clinical trials and office evaluations tend to focus on physical measures. Dr. Kirzinger is an Assistant Professor of Neurology and Director of the Multiple Sclerosis Program at the University of Louisville.
Clinical trials involving patients with MS generally focus on the severity and frequency of relapses, as well as on use of MRI to measure disease activity. However, evaluating clinical outcomes by assessing lesions is challenging, as the effects can vary and be unpredictable. Physical assessments, such as the Expanded Disability Status Scale (EDSS), are also commonly used in clinical practice.
Patient-reported outcomes are increasingly being incorporated into clinical trials. They can provide valuable insights by revealing patient perception of disease progression, treatment, and quality of life, noted Dr. Kirzinger. However, he pointed out that relationships between disease progression, physical outcomes, and patient-reported outcomes have been unclear.
Physical Versus Patient-Reported Outcomes
Dr. Kirzinger and colleagues conducted a retrospective chart review of 151 randomly selected patients who were observed for the past decade at the Multiple Sclerosis Center of Baptist Hospital East in Louisville. The investigators sought to determine if correlations existed between patient-reported outcomes of fatigue, depression, and sleepiness with objective measures of fine and gross motor control.
A majority of patients were female (75%), with a median age of 38.8 at diagnosis. Nine percent did not have a disease type noted; 72% had relapsing-remitting MS, 13% had secondary progressive MS, and 5% had primary progressive MS. The most commonly reported symptoms at baseline were fatigue (78%), numbness and tingling (71%), balance problems (70%), weakness (70%), and bladder problems (60%).
Baseline and follow-up data were obtained for five physical disability measures and three patient-reported outcomes. Fine motor control was evaluated with use of the Box and Block Test and the Nine-Hole Peg Test of arm and hand function. Gross motor control was assessed with the 25-ft timed walk; the Tinetti test of gait and balance; and the EDSS, for ambulation ability and disease severity. Patient-reported outcomes were determined with use of the Modified Fatigue Impact Scale (MFIS), Beck Depression Inventory, and Epworth Sleepiness Scale.
The Spearman’s rank correlation test was used to determine the rank coefficient (r) between the physical measures and the patient-reported outcome tests during the patients’ most recent visit, with an r of 1 being a perfect positive correlation and -1 representing a perfect negative correlation. Moderate to strong positive correlations were found among the physical measures, with the strongest correlations occurring between the Box and Block and Nine-Hole Peg tests (r, 0.86). Moderate to strong positive correlations were also observed among the patient-reported outcomes. However, physical and patient-reported outcome measures only weakly correlated with each other, and the only statistically significant r correlations were seen with the MFIS, in comparison with the 25-ft timed walk and the EDSS.
An algorithm was used to determine whether any demographic, disease, or physical factors could be identified as predictors of fatigue. The physical outcome that was most predictive of fatigue was EDSS score, with scores of 1.5 or lower associated with lesser degrees of fatigue and scores of 1.5 or above associated with greater degrees of fatigue.
True Impact of MS Underestimated
The researchers theorized that aspects of MS measured by patient-reported outcomes and physical assessments may develop independently of one another. Also, it is likely that clinicians do not fully understand the true impact of MS on patients. They recommended that future studies expand on relationships between patient-reported outcomes, physical measures, and other aspects, such as cognition, to develop more comprehensive and accurate insights into disease activity and treatment strategies.
—Beth Tansey Peller