Critical Gaps in Addressing Comorbidities in Multiple Sclerosis Rehabilitation Intervention Trials

PURPOSE: To determine the extent to which investigators in multiple sclerosis (MS) rehabilitation intervention trials are addressing the comorbidities of their participants in scientific publications.

RATIONALE: There is growing interest in the provision of services to people with multiple and complex chronic conditions. In the field of MS care, this interest has manifested itself in a number of studies of the incidence, prevalence, and impact of comorbidities among people with this disease. Evidence is emerging that comorbidities are common and are associated with delays in MS diagnosis, faster progression of disability, reductions in quality of life, and changes in response to treatment.

To date, discussions of the impact of comorbidity on MS treatment has focused on use of medications. Given that rehabilitation services are a recognized component of comprehensive MS care, there is a need to understand the extent to which MS rehabilitation researchers are addressing comorbidities in the design, analysis, and reporting of their intervention trials.

DESIGN: Scoping review

PARTICIPANTS: Not applicable

METHOD: Searches of PubMed Central, Medline through OVID, EMBASE, CINAHL, and Web of Science were conducted to locate studies of rehabilitation interventions targeting people with MS.

MeSH, topic, and key word searches used the following terms: exercise, physical activity, motor activity, fitness, self-care, self-management, health promotion, health education, patient education, health behaviour, assistive technology, assistive device, self-help, behaviour modification, environment, home environment, and modification.

The full citations of identified studies were imported into EndNote and duplicates deleted. The remaining citations (N = 2,393) were screened for inclusion in the full-text review by two reviewers. Criteria for inclusion were randomized controlled trial of a rehabilitation intervention for humans with MS and written in English or French. Dissertations, conference abstracts, and trial protocols were excluded. After applying these criteria, 193 papers proceeded to full-text review.

ANALYSIS: The data extracted from the selected papers included aim/question, recruitment, intervention, primary outcome, sample size, age, percentage female, and level of disability. In addition, data were extracted on the comorbidities that led to exclusion from the trials, how comorbidity data were reported, and whether comorbidities were evaluated for potential moderating influence on trial outcomes. Data were collated and reported descriptively.

RESULTS: Across 193 studies of MS rehabilitation intervention trials, the most common comorbidities resulting in exclusion from participation were cardiovascular disease, cognitive impairment or dementia, “any condition that precludes safe exercise,” psychiatric illness (including depression), visual impairment, diabetes, orthopedic conditions, or “any other neurological condition.” Fewer than 10% of studies included information about the presence of comorbidities in the description of the study sample. Only 1 exploratory analysis evaluated the potential moderating influence of comorbid conditions on trial outcomes.

DISCUSSION: Despite the rhetoric about the need to provide evidence-based care to people with multiple and complex chronic conditions, this review indicates that MS rehabilitation researchers are not addressing the presence or impact of comorbid conditions on intervention outcomes.

IMPACT STATEMENT: To support the provision of evidence-based care to people with MS who also have other health conditions, MS rehabilitation researchers need to begin including, reporting, and evaluating comorbidity data in their trials.