Author Of 1 Presentation
PS05.04 - Ongoing disease modifying treatment associated with mis-classification of secondary progressive as relapsing-remitting multiple sclerosis
Until recently, disease modifying treatment options for MS patients with a secondary progressive course (SPMS) were limited, leading to the common practice of off-label treatment with drugs approved for relapsing-remitting MS. We previously showed that applying objective algorithms tend to increase the proportion of SPMS in MS registries, suggesting that SPMS is under-diagnosed in clinical practice, possibly related to available treatment options.
To compare characteristics of patients clinically assigned an RRMS course that are re-classified when an algorithm-based SPMS assignment method is applied.
Data from MS registries in the Czech Republic (11,336 patients), Denmark (10,255 patients), Germany (23,185 patients), Sweden (11,247 patients) and the United Kingdom (5,086 patients) were used. Inclusion criteria were patients with relapsing remitting (RR)MS or SPMS with age ≥ 18 years at the beginning of the study period (1 January 2017 – 31 December 2019). In addition to clinically assigned SPMS a data-driven assignment method was applied in the form of a decision tree classifier based on age and last EDSS (Ramanujam, R. et al., 2020. medRxiv, 2020.07.09.20149674).
Across the five registries 8,372 RRMS patients were re-assigned as SPMS (Denmark: n=1,566, Czech Republic: n=1,958, Germany: n=2,906, Sweden: n=648, United Kingdom: n=1,294) increasing the overall SPMS proportion from 17% to 31%. Re-assigned patients tended be younger, were older at onset and had experienced a quicker progression to SPMS. The overall proportion of clinically assigned SPMS patients on disease modifying treatments (DMTs) was 36% but varied greatly between registries (Czech Republic: 18%, Denmark: 35%, Germany: 50%, Sweden: 40%, and the United Kingdom: 12%) whereas a higher proportion of 69% (OR=4.0, P<0.00004) were on DMTs among RRMS patients re-assigned as SPMS (Czech Republic: 71%, Denmark: 68%, Germany: 78%, Sweden: 80%, and the United Kingdom 40%).
SPMS patients on DMTs may be clinically mis-classified as RRMS, most likely by not being re-assigned to SPMS after conversion has occurred. This challenges the use of time to SPMS conversion as an outcome in comparative effectiveness studies using real world evidence data and argues for the use of objective classification tools in the analysis of MS patient populations.
Author Of 1 Presentation
P0482 - Objective classification methods result in an increased proportion of secondary progressive multiple sclerosis in five patient registries (ID 1120)
Secondary progressive MS (SPMS) is a research area that is attracting more attention as better treatment options are still needed for this patient group. The assignment of SPMS by clinicians can differ between countries and may be influenced by drug prescription guidelines, reimbursement issues and other societal limitations.
To compare the clinically assigned SPMS proportion to three objective SPMS classification methods in five MS registries.
Data from MS registries in the Czech Republic (CR) (11,336 patients), Denmark (10,255 patients), Germany (23,185 patients), Sweden (11,247 patients) and the United Kingdom (UK) (5,086 patients) were used. Inclusion criteria were patients with relapsing remitting (RR)MS or SPMS with age ≥ 18 years at the beginning of the index period (1 January 2017 – 31 December 2019). In addition to clinically assigned SPMS three different classification methods were applied; method 1: modified real world EXPAND criteria (Kappos et al, Lancet 2018:391; 1263-1273), method 2: the data-derived definition from Melbourne University without the pyramidal Functional Systems Score (Lorscheider et al, Brain 2016:139; 2395-2405) and method 3: the decision tree classifier from Karolinska Institutet (Ramanujam, R. et al., 2020. medRxiv, 2020.07.09.20149674).
The SPMS proportions per registry, when comparing the clinically assigned SPMS with the results of the three classification methods, were CR: 8.8%, 21.3%, 22.1%, 25.0%; Denmark: 15.5%, 27.5%, 25.4%, 28.0%; Germany: 15.6%, 15.4%, 16.7%, 25.4%; Sweden: 23.7%, 20.8%, 23.2%, 24.6% and UK: 34.3%, 21.7%, 38.4%, 58.3% for clinical SPMS and methods 1, 2 and 3, respectively.
The proportion of clinically assigned SPMS patients varies between MS registries. When applying other classification methods, the SPMS proportion generally increases but remains variable between registries. As some of the classification methods have extensive requirements regarding data density, the number of unclassifiable samples created are considerable for some of the registries, which will influence the results. Providing a classification method that depends on objective information could prove useful when attempting to estimate the proportion of SPMS patients in MS populations but the choice of method may depend on the data characteristics of the individual MS registry.