Determinants of change in disease-modifying drugs in patients with multiple sclerosis: A registry-based study.

Multiple sclerosis (MS) is the most prevalent neuroinflammatory disorder significantly impacting patients' health outcomes and economic burden. The increasing incidence of MS in Tehran, Iran, underscores the urgent need for effective patient care and management. While disease-modifying drugs (DMDs) play a crucial role in enhancing patient quality of life and reducing disease progression, they also contribute substantially to healthcare expenditures. Understanding the factors influencing changes in DMDs is essential for optimizing treatment strategies and managing costs effectively. This study aims to elucidate the underlying reasons for DMD changes among patients with MS (PwMS) in Tehran, Iran and to identify associated demographic and clinical factors. A registry-based cross-sectional study was conducted involving 2,771 PwMS who altered their DMD regimen within five years prior to October 15, 2023. Data were sourced from the National Multiple Sclerosis Registry of Iran (NMSRI) and analyzed using descriptive and inferential statistics with a significance level set at P < 0.05. The primary outcome focused on the reasons for DMT changes, while secondary outcomes included disease severity metrics, initial symptoms, and treatment history. Among the participants, 70.3% reported a change in their DMD regimen. The primary reasons for these alterations included inadequate disease control or relapse (62.3%), adverse drug reactions (30.7%), and non-adherence (11.3%). Notably, demographic factors such as gender and age did not significantly correlate with changes in DMDs. Patients with progressive forms of MS exhibited a higher frequency of DMT modifications compared to those with non-progressive forms. Additionally, initial symptoms such as motor dysfunction significantly influenced the likelihood of changing therapies. The findings underscore that inadequate disease control and adverse drug reactions are significant determinants driving DMT modifications among MS patients in Tehran. The higher rates of changes observed in patients with progressive forms of MS reflect the need for more effective treatment strategies tailored to individual clinical presentations. Overall, this study highlights the importance of personalized care approaches that consider disease severity and symptomatology to optimize therapeutic outcomes for patients with MS.