HETEROGENEITY Study. Are multiple sclerosis (MS) phenotypes influenced by the type of referral MS center?

---

Introduction and aims
Multiple sclerosis (MS) is characterized by phenotypical heterogeneity that may result from the different contributions of demographic and environmental risk factors, and from overall disease severity. However, socio-economic factors and the characteristics of the local MS facilities can also influence the clinical features of patients seen in MS Centers.
This retrospective study included patients with a confirmed diagnosis of MS enrolled in the Italian MS and Related Disorders Register in 2000-2021. Patients were classified according to the following phenotypes at first visit: clinically isolated syndrome (CIS), relapsing-remitting (RR), primary progressive (PP), progressive-relapsing (PR), and secondary progressive (SP) MS. Patients’ demographic and clinical characteristics were analyzed, along with Centers’ structures, capabilities, patient loads, geographic macro-areas, and deprivation index. We computed the odds ratios (OR) for CIS, PP/PR, and SP phenotypes, compared to the RR phenotype, according to selected patients’ and Centers’ characteristics, using multivariate, multinomial, mixed-effects logistic regression models, adjusted for age, sex, and interval between disease onset and first visit.

Results
The study included 35,243 eligible patients from 106 MS Centers. The OR of presenting more advanced MS phenotypes at first visit, compared to the RR phenotype, significantly diminished in relation to calendar period (OR=0.74 of PP/PR for 2010-2014 period and 2015-2021 vs 2000-2009 periods, and OR=0.50 of SP for 2015-2021 vs 2000-2009 periods). Females had a significantly lower risk than males of PP/PR or SP phenotype. Older age at first visit was associated with CIS (OR=1.37 for ≥ 35 vs <35 years), PP/PR (OR=9.21), and SP (OR=4.53). The risk of longer interval between disease onset and first visit was lower for the CIS phenotype (OR=0.11 for ≥13 vs <13 months), but higher for PP/PR (OR=1.49) and SP phenotypes (OR=10.19). The probability of having SP at first visit was greater in the South (OR=1.86 vs North-West), and the probability of having CIS was higher in the North-East (OR=1.64).

Conclusion
Differences in the phenotype of MS patients can be only partly explained by differences in the centers’ structures, capabilities, and patient loads. The demographic and socio-economic characteristics of MS patients seem to be the main determinants of the phenotypes at first referral.


Pubblicazioni e Comunicazioni a Congressi/ Publications and Congress Presentations
Bergamaschi R, Beghi E, Bosetti, Ponzio M, Santucci C, Lepore V, Mosconi P on behalf of the Italian Multiple Sclerosis and Related Disorders Register Centers Group, and the Scientific Committee of Italian SM and Related Disorders Register. Do patients’ and referral centers’ characteristics influence multiple sclerosis phenotypes? Results from the Italian Multiple Sclerosis and Related Disorders Register. Submitted to Neurological Sciences, under revision

Bergamaschi R, Beghi E, Bosetti C, Ponzio M, Santucci C, Lepore V, Mosconi P, on behalf of the Italian Multiple Sclerosis and Related Disorders Register Centers Group and the Scientific Committee of Italian SM and Related Disorders Register.
Do patients' and referral centers' characteristics influence multiple sclerosis phenotypes? Results from the Italian multiple sclerosis and related disorders register.
Neurological Sciences

https://doi.org/10.1007/s10072-022-06169-7