# Comorbidities at MS Diagnosis and Their Association With Treatment Persistence: Real‐World Clinical Data

## TL;DR

This study found that about half of MS patients in Finland had comorbidities at diagnosis, and those with psychiatric conditions were less likely to stick with injectable treatments.

## Contribution

The study identifies a link between psychiatric comorbidities and reduced treatment persistence in MS patients using injectable disease-modifying therapies.

## Key findings

- Approximately 51.8% of RRMS patients had at least one comorbidity at diagnosis.
- Psychiatric comorbidities were associated with lower persistence in injectable DMTs and higher early discontinuation rates.
- Patients with psychiatric comorbidities had a higher annualized relapse rate at DMT initiation.

## Abstract

The objectives were to evaluate the prevalence of comorbidities at the time of multiple sclerosis (MS) diagnosis in a Finnish cross‐sectional cohort and to analyze whether comorbidities at diagnosis associate with clinical characteristics, treatment delays, initial disease‐modifying treatment (DMT) choice, DMT persistence, and disease activity.

Patients with relapsing‐remitting MS (RRMS) were recruited during their appointments at the neurology outpatient clinic of the Oulu University Hospital, Finland, between the years 2018 and 2022. The data was gathered from the hospital medical records.

The study cohort consisted of 421 Finnish RRMS patients, of whom 51.8% had at least one or more comorbidity at the time of MS diagnosis. Depression (16.2%) and migraine (11.6%) were the most common comorbidities. Medium‐efficacy injectable DMTs (interferon‐β and glatiramer acetate) were associated with lower treatment persistence in patients with any comorbidity or psychiatric comorbidity during the 4‐year follow‐up. Among patients with psychiatric comorbidity, the rate of DMT discontinuation was high shortly after the DMT initiation, and the annualized relapse rate at the start of the DMT was higher compared with those without psychiatric comorbidity (1.3 [SD 0.78] vs. 1.1 [SD 0.74], p = 0.026).

Comorbidities, especially psychiatric diseases, are associated with lower persistence on injectable DMTs. As comorbidities complicate the treatment of RRMS, it is crucial to identify their role from early on.

Comorbidity was present in approximately half of the patients with relapsing‐remitting multiple sclerosis in this Finnish cross‐sectional cohort. Comorbidities, especially psychiatric diseases, were associated with lower persistence on injectable disease‐modifying treatments.