Small-scale geographical variation in multiple sclerosis: A case-control study using Danish register data 1971–2013

FutureMS cohort profile: a Scottish multicentre inception cohort study of relapsing-remitting multiple sclerosis

PURPOSE

Multiple sclerosis (MS) is an immune-mediated, neuroinflammatory disease of the central nervous system and in industrialised countries is the most common cause of progressive neurological disability in working age persons. While treatable, there is substantial interindividual heterogeneity in disease activity and response to treatment. Currently, the ability to predict at diagnosis who will have a benign, intermediate or aggressive disease course is very limited. There is, therefore, a need for integrated predictive tools to inform individualised treatment decision making.

PARTICIPANTS

Established with the aim of addressing this need for individualised predictive tools, FutureMS is a nationally representative, prospective observational cohort study of 440 adults with a new diagnosis of relapsing-remitting MS living in Scotland at the time of diagnosis between May 2016 and March 2019.

FINDINGS TO DATE

The study aims to explore the pathobiology and determinants of disease heterogeneity in MS and combines detailed clinical phenotyping with imaging, genetic and biomarker metrics of disease activity and progression. Recruitment, baseline assessment and follow-up at year 1 is complete. Here, we describe the cohort design and present a profile of the participants at baseline and 1 year of follow-up.

FUTURE PLANS

A third follow-up wave for the cohort has recently begun at 5 years after first visit and a further wave of follow-up is funded for year 10. Longer-term follow-up is anticipated thereafter.

Apparent changes in the epidemiology and severity of multiple sclerosis

Multiple sclerosis (MS) is an immunological disease that causes acute inflammatory lesions and chronic inflammation in the CNS, leading to tissue damage and disability. As awareness of MS has increased and options for therapy have come into use, a large amount of epidemiological data have been collected, enabling studies of changes in incidence and disease course over time. Overall, these data seem to indicate that the incidence of MS has increased, but the course of the disease has become milder, particularly in the 25 years since the first disease-modifying therapies (DMTs) became available. A clear understanding of these trends and the reasons for them is important for understanding the factors that influence the development and progression of MS, and for clinical management with respect to prevention and treatment decisions. In this Review, we consider the evidence for changes in the epidemiology of MS, focusing on trends in the incidence of the disease over time and trends in the disease severity. In addition, we discuss the factors influencing these trends, including refinement of diagnostic criteria and improvements in health-care systems that have increased diagnosis in people with mild disease, and the introduction and improvement of DMT.

Time trends of chronic immune diseases by year of birth in Danish registries

Chronic immune diseases are often reported to be on the rise and are speculated to share early life risk factors. Here, we investigated year of birth as a common denominator for time trends using the consistent data source of the Danish National Patient Registry with 35 years nationwide coverage. Observational nationwide birth cohort registry study, where persons born in Denmark since 1953 were investigated for chronic immune diseases per person years at risk. Outcomes were defined by inpatient hospitalizations in pre-chosen age bins by year of birth in 5 year bins. A population of 3.8 million persons born in Denmark since 1953 was investigated for a total sum of 68 million person years in the ages 5-34 years. We found increasing trends by year of birth for juvenile arthritis age 10-14, adult asthma age 20-24, inflammatory bowel diseases age 20-24, and multiple sclerosis age 25-29, whereas type 1 diabetes age 15-19 was declining until birth year mid 1980s followed by a subsequent increase. Childhood asthma age 5-9 inpatient hospitalizations were relatively stable over time. Nationwide introduction of measles, mumps, rubella vaccine in 1987 did not alter the trends. Hospitalization for the chronic immune diseases adult asthma, juvenile arthritis, inflammatory bowel diseases and multiple sclerosis showed a general increasing trend by birth year in recent 35 years while diabetes 1 and childhood asthma seemed stable in this period. These results were not affected by the introduction of vaccinations against the major childhood viral infections.

Use of geographical information systems in multiple sclerosis research: A systematic scoping review

INTRODUCTION

Geographical information system (GIS) and spatial analysis have an emerging role in the understanding and management of health-related outcomes. However, there is a knowledge gap about the extent to which GIS has supported multiple Sclerosis (MS) research. Therefore, this review aimed to explore the types of GIS applications and the complexity of their visualisation in MS research.

METHODS

A systematic scoping review was conducted based on York's five-stage framework. PubMed, Scopus and Web of Science were searched for relevant studies published between 2000 and 2020 using a comprehensive search strategy based on the main concepts related to GIS and MS. Grounded, inductive analysis was conducted to organize studies into meaningful application areas. Further, we developed a tool to assess the visualisation complexity of the selected papers.

RESULTS

Of 3,723 identified unique citations, 42 papers met our inclusion criteria for the final review. One or more of the following types of GIS applications were reported by these studies: (a) thematic mapping (37 papers); (b) spatial cluster detection (16 papers); (c) risk factors detection (16 papers); and (d) health access and planning (two papers). In the majority of studies (88%), the score of visualisation complexity was relatively low: three or less from the range of zero to six.

CONCLUSIONS

Although the number of studies using GIS techniques has dramatically increased in the last decade, the use of GIS in the areas of MS access and planning is still under-researched. Additionally, the capacity of GIS in visualising complex nature of MS care system is not yet fully investigated.

The Danish Multiple Sclerosis Registry

OBJECTIVES

The Danish Multiple Sclerosis Registry is the oldest operative and nationwide MS registry. We present The Danish Multiple Sclerosis Registry with its history, data collection, scientific contribution, and national and international research collaboration.

MATERIALS AND METHODS

Detailed description of data collection, completeness, quality optimizing procedures, funding, and legal, ethical and data protection issues are provided.

RESULTS

The total number of registered cases with clinical isolated syndrome and multiple sclerosis since 1956 was by start of May 2020 30,023 of whom 16,515 cases were alive and residing in Denmark, giving a prevalence rate of about 284 per 100,000 population. The mean annual number of new cases receiving an MS diagnosis was 649 per year in the period 2010 to 2019. In total, 7,945 patients (48.1%) are receiving disease modifying therapy at the start of May 2020.

CONCLUSIONS

Multiple Sclerosis registers are becoming increasingly important, not only for epidemiological research but also by quantifying the burden of the disease for the patients and society and helping health care providers and regulators in their decisions. The Danish Multiple Sclerosis Registry has served as data source for a number of scientific publications including epidemiological studies on changes in incidence and mortality, cohort studies investigating risk factors for developing MS, comorbidities and socioeconomic outcomes in the MS population, and observational studies on effectiveness of disease modifying treatments outside the narrow realms of randomized clinical trials.

Multiple sclerosis prevalence in 2000 and 2010 in Western Finland

OBJECTIVE

To study ten-year change in MS prevalence in the Province of Western Finland in Tampere University Hospital District located in 62.7°N, 23.7°E.

METHODS

Age-standardized prevalence/10⁵ by using direct standardization in European Standard Population (ESP2013) and crude prevalence/10⁵ with 95% confidence interval (95% CI) were assessed among resident MS cases fulfilling Poser criteria by sex and disease course in 31.12.2000 and 31.12.2010. MS-related disability and disease-modifying treatment (DMT) use were estimated in 31.12.2010.

RESULTS

Crude prevalence increased 49% from 129/10⁵ (95% CI 121-137) in 2000 (N 1080) to 196/10⁵ (187-203) in 2010 (N 1666). Age-standardized prevalence increased 45% from 133/10⁵ (127-140) to 192/10⁵ (184-200) and peaked in 40- to 49-year age-group. Age-standardized prevalence increased 58% among women from 176/10⁵ (171-176) to 277/10⁵ (270-284) and 31% among men from 91/10⁵ (87-95) to 119/10⁵ (115-124). Increase in RRMS was 61% from 111/10⁵ (105-117) to 179/10⁵ (171-186), and decrease in PPMS was 14% from 21/10⁵ (19-24) to 18/10⁵ (15-21).  In 2010 among the 52% RRMS cases on DMT, MS-related disability was mild in 50%. In total, cohort disability was mild in 46%, moderate to severe in 47%, and information was not available in 14%.

CONCLUSION

A significant increase in prevalence was observed in Western Finland. Increase was higher among women and in relapsing-remitting onset MS. Disability showed age- and disease course-specific variation.

The changing course of multiple sclerosis: rising incidence, change in geographic distribution, disease course, and prognosis

PURPOSE OF REVIEW

This review provides a brief update of new research findings on the changing epidemiology, disease course, and prognosis of multiple sclerosis (MS).

RECENT FINDINGS

Evidence not only continues to support the female predominance in incidence and prevalence of the disease but also supports an increase in incidence of MS in geographic areas that were previously considered to be low incidence for the disease.

SUMMARY

An increased interest in population-based registries and databases will provide more valid epidemiological measures and observational studies conducted in well-defined study populations. Such studies are crucial for an accurate description of both changing prognosis of MS and differential characteristics of the various MS phenotypes.