More Medications, More Falls: A Prospective Cohort Study

Background: People with multiple sclerosis (MS) fall frequently and are often injured when they fall.  People with MS also take many medications.  In the elderly, the use of multiple medications, particularly medications affecting the nervous or cardiovascular system, is associated with increased fall risk. Relationships between medication use and fall risk in MS have not been evaluated.

Objectives: To assess relationships between medication use, falls and injurious falls in people with MS.

Methods: Subjects were 58 people with MS, aged 18-50 years, with Expanded Disability Status Scale scores ≤ 6.0.  Subjects documented all medications they were taking at baseline and completed fall calendars for the following 6 months. Medications were counted and classified into one of the 14 first level categories of the Anatomical Therapeutic Chemical system. The association between the number and categories of medications used and the odds of being a recurrent faller (≥ 2 falls) or having an injurious fall (≥1 injurious fall) were determined with logistic regression, adjusting for gender and disease duration.  Age, disease severity, use of a walk aide and comorbidities were excluded from the model due to small cell counts or lack of effect.

Results: 53 subjects completed the study and were included in the analysis. Twenty six were recurrent fallers and 24 sustained injurious falls. Subjects took 0 to 19 medications. Subjects taking no medications had a 27% odds of being a recurrent faller and an 11% odds of being an injurious faller. The adjusted relative odds for falls increased by 33%, for each additional medication taken (95% CI 5%-80%, p=0.04). The adjusted relative odds for injurious falls increased by 50% for each additional medication taken (95% CI 14% - 216%, p=0.01). Only nervous system, cardiac, and immunomodulating medication categories were used by enough subjects to be analyzed. Nervous system medications were associated with a significantly increased recurrent fall risk (OR 5.1, 95% CI 1.5-19.1, p= 0.01). There were trends to an increased recurrent fall risk with cardiac medications (OR 8.0, 95% CI 1.2-163, p= 0.07) and decreased recurrent fall risk with immunomodulating agents (OR 0.33, 95% CI 0.06-1.40, p= 0.15).

Conclusions: The use of more medications, particularly nervous system medications, is associated with an increased risk of recurrent falls and injurious falls in people with MS. Larger scale studies are needed to assess the relationships between other types of medications and fall risk in MS.