MS Speaks

Swedish investigators studied 16,915 MS patients diagnosed between 1980 and 2014 and noticed a dramatic decrease in the number diagnosed with PPMS, especially since the advent of the disease-modifying drugs. The abstract contains no mention of possible reasons for this decrease, but one has to wonder if the diagnosing doctors are reluctant to pin the PPMS label on a patient when the disease-modifying drugs are meant for those with relapsing MS?


From Multiple Sclerosis Journal, April 12, 2016:

A significant decrease in diagnosis of primary progressive multiple sclerosis: A cohort study

Helga Westerlind
Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden

Leszek Stawiarz
Department of Clinical Neuroscience (CNS), Karolinska Institutet, Stockholm, Sweden

Katharina Fink
Department of Clinical Neuroscience (CNS), Karolinska Institutet, Stockholm, Sweden/Department of Neurology, Karolinska University Hospital, Huddinge, Sweden

Jan Hillert
Department of Clinical Neuroscience (CNS), Karolinska Institutet, Stockholm, Sweden/Department of Neurology, Karolinska University Hospital, Huddinge, Sweden

Ali Manouchehrinia
Department of Clinical Neuroscience (CNS), Karolinska Institutet, Stockholm, Sweden

Department of Clinical Neuroscience (CNS), Karolinska Institutet, Tomtebodavägen 18a, Pl 5, 171 77 Stockholm, Sweden. Jan.Hillert@ki.se

Background:

Several reports indicate changes to prevalence, incidence, female-to-male ratio in multiple sclerosis. Diagnostic criteria, course definitions and clinical management of the disease have also undergone change during the recent decades.

Objective:

To investigate temporal trends in the diagnosis of primary progressive multiple sclerosis (PPMS) in Sweden.

Methods:

Through the Swedish MS registry we investigated the proportion of PPMS diagnosis in birth, diagnosis and age period cohorts using Poisson regression.

Results:

A total of 16,915 patients were categorised into six birth-cohorts from 1946 to 1975 and seven date-of-diagnosis-cohorts from 1980 to 2014. We observed a decrease in the uncorrected analysis of diagnosis of PPMS from 19.2% to 2.2% and an average decrease of 23% (p < 0.001) per 5-year birth-cohort in the adjusted analysis.

An average 21% (p < 0.001) decrease per diagnosis-cohort was seen. In the age-specific diagnosis period cohorts the same decreasing trend of PPMS diagnosis was observed in almost all groups.

Conclusion:

The diagnosis of PPMS has significantly decreased in Sweden specifically after introduction of disease-modifying treatments. Such decrease can have severe impacts on the future research on PPMS.

Our data also suggest that the current trend to emphasise presence or absence of inflammatory activity is already reflected in clinical practice.