High nationwide incidence of multiple sclerosis in Sweden

Incidence rate and prevalence of pediatric-onset multiple sclerosis in Sweden: A population-based register study

BACKGROUND AND PURPOSE

Pediatric-onset multiple sclerosis (PoMS) is associated with high health care use. To plan resource allocation for this patient group, knowledge of the incidence rate and prevalence is important. However, such studies are scarce, few are population-based, and the methodology varies widely. We aimed to address this knowledge gap by performing a nationwide study of the incidence rate and prevalence of PoMS in Sweden, an area of high multiple sclerosis (MS) incidence and prevalence.

METHODS

MS cases were identified by linking two nationwide registers, the National Patient Register and the Swedish MS Registry. MS cases having their first central nervous system demyelinating event or MS clinical onset before age 18 years were classified as pediatric onset. Incidence rate and prevalence were estimated annually over the study period (2006-2016) for the total population and stratified by sex and age group (<12, 12-15, and 16-17 years). Temporal trends and ratios between sexes and age groups were estimated.

RESULTS

We identified 238 incident cases from 2006 to 2016, corresponding to an overall crude incidence rate of 1.12 per 100,000 person-years and an overall crude prevalence of 2.82 per 100,000 population. There was a higher incidence rate among females and the highest age category. The overall incidence rate and prevalence estimates remained stable during the study period.

CONCLUSIONS

Sweden exhibits a consistently high incidence rate and prevalence of PoMS that has remained stable over time. This knowledge serves as a tool to aid in planning resource allocation and health services for this patient population.

Risk of Multiple Sclerosis in People Living with HIV: An International Cohort Study

OBJECTIVE

There has been interest in a possible negative association between HIV and multiple sclerosis (MS). We aimed to compare the risk of MS in a cohort of individuals living with HIV to that in the general population.

METHODS

Population-based health data were accessed for 2 cohorts of HIV-positive persons from Sweden and British Columbia, Canada. Incident MS was identified using MS registries or a validated algorithm applied to administrative data. Individuals with HIV were followed from 1 year after the first clinical evidence of HIV or the first date of complete administrative health data (Canada = April 1, 1992 and Sweden = January 1, 2001) until the earliest of incident MS, emigration, death, or study end (Canada = March 31, 2020 and Sweden = December 31, 2018). The observed MS incidence rate in the HIV-positive cohort was compared to the expected age-, sex-, calendar year-, income-specific, and region of birth-specific rates in a randomly selected sample of >20% of each general population. The standardized incidence ratio (SIR) for MS following the first antiretroviral therapy exposure ("ART-exposed") was also calculated.

RESULTS

The combined Sweden-Canada cohort included 29,163 (75% men) HIV-positive persons. During 242,248 person-years of follow-up, 14 incident MS cases were observed in the HIV-positive cohort, whereas 26.19 cases were expected. The SIR for MS in the HIV-positive population was 0.53 (95% confidence interval [CI] = 0.32-0.90). The SIR for MS following the first ART exposure was 0.55 (95% CI = 0.31-0.96).

INTERPRETATION

This international population-based study demonstrated a lower risk of MS among HIV-positive individuals, and HIV-positive ART-exposed individuals. These findings provide support for further exploration into the relationship among HIV, ART, and MS. ANN NEUROL 2024;95:487-494.

Disclosing or concealing multiple sclerosis in the workplace: two sides of the same coin-insights from a Swedish population-based survey

Background

People with multiple sclerosis (PwMS) face health and social challenges of living with a chronic and potentially disabling condition. To disclose or conceal MS at work may critically affect individuals' work situation, career opportunities, and health. PwMS may experience a dilemma when assessing if the possible benefits of disclosing the diagnosis outweigh the possible risks. However, concealing in the long-term may have health implications and prevent opportunities for support and work adjustments. Few studies have examined what drives PwMS to disclose or conceal MS at work and the consequences of these ways of managing MS.

Objectives

To explore the reasons PwMS report for disclosing and/or concealing their MS diagnosis in the workplace, as well as the consequences they have experienced.

Methods

A web-based survey of PwMS was conducted in 2021. All individuals aged 20-50 listed in the Swedish MS registry were invited to participate. The response rate was 52% and among these participants, 3,810 (86%) completed questions regarding workplace disclosure and/or concealment of MS. Free-text responses on these topics were analyzed using inductive content analysis.

Results

It was common to disclose MS in the workplace (85%). Identified drivers for disclosure and concealment related to four categories: Work-related, Social, Personal and Circumstantial. Work-related drivers focused on employment or protecting one's career, and changing one's work situation versus maintaining it. Social drivers included the need for support, addressing or preventing stigma, and being considerate of others. Personal drivers were linked to moral values/personal beliefs and processing of the diagnosis. Circumstantial drivers related to involuntary or unforeseen events, timing factors, one's medical condition and external opinion/advice. Identified consequences for disclosure and concealment related to three categories: Work-life, Social, and Personal. Work-life consequences included work arrangements, and career opportunities. Social consequences were linked to MS awareness, stigma, interactions and social support, as well as dynamics of work relationships. Personal consequences involved levels of disease acceptance, and attitudes toward managing MS.

Conclusion

PwMS often described the question of disclosure as challenging and navigated it with caution, as both disclosure and concealment can yield favorable and unfavorable outcomes.

Experiences of being treated with autologous haematopoietic stem cell transplantation for aggressive multiple sclerosis: A qualitative interview study

BACKGROUND

Autologous haematopoietic stem cell transplantation (AHSCT) is increasingly used as a treatment for aggressive multiple sclerosis (MS) and has the potential to induce long-term remission and resolution of disease activity. Despite the extensive research on treatment outcome after AHSCT, the experience of living with MS after AHSCT has not been previously described in the scientific literature. The aim of this study was to explore long-term lived experience of people with MS treated with AHSCT.

METHODS AND FINDINGS

To exclude selection bias, all persons treated with AHSCT for MS at Uppsala University Hospital, Sweden, between 2004 and 2007 (n = 10), were asked to participate in the study, and all accepted. Open-ended interviews were conducted, digitally recorded, transcribed verbatim, and then subjected to qualitative content analysis with an inductive approach. Five main themes emerged from the interviews: (I) being diagnosed with MS-an unpredictable existence; (II) a new treatment-a possibility for a new life; (III) AHSCT-a transition; (IV) reclaiming life; and (V) a bright future accompanied by insecurity. AHSCT was described by the participants in terms of a second chance and an opportunity for a new life. The treatment became a transition from a state of illness to a state of health, enabling a previous profound uncertainty to wane and normality to be restored. Although participants of different age and sex were included, the main limitation of this study is the relatively small number of participants. Also, the inclusion of persons from one centre alone could restrict transferability of the results.

CONCLUSIONS

The results give a first insight into lived experience following a highly effective induction treatment for MS, and the experience of not having MS anymore. Underpinned by previously described outcome following AHSCT, the results of this study challenge the current view on MS as a chronic disease with no possible cure.

Disease-modifying therapies and cost-of-illness progression among people newly diagnosed with multiple sclerosis: a national register-based cohort study covering treatment initiation with interferons, glatiramer acetate or natalizumab

OBJECTIVES

Disease-modifying therapies (DMTs) can slow disease progression in multiple sclerosis (MS). The objective of this study was to explore the cost-of-illness (COI) progression among newly diagnosed people with MS in relation to the first DMT received.

DESIGN AND SETTING

A cohort study using data from nationwide registers in Sweden.

PARTICIPANTS

People with MS (PwMS) in Sweden first diagnosed in 2006-2015, when aged 20-55, receiving first-line therapy with interferons (IFN), glatiramer acetate (GA) or natalizumab (NAT). They were followed up through 2016.

OUTCOME MEASURES

Outcomes (in Euros, €) were: (1) secondary healthcare costs: specialised outpatient and inpatient care including out-of-pocket expenditure, DMTs including hospital-administered MS therapies, and prescribed drugs, and (2) productivity losses: sickness absence and disability pension. Descriptive statistics and Poisson regression were computed, adjusting for disability progression using the Expanded Disability Status Scale.

RESULTS

3673 newly diagnosed PwMS who were treated with IFN (N=2696), GA (N=441) or NAT (N=536) were identified. Healthcare costs were similar for the INF and GA groups, while the NAT group had higher costs (p value<0.05), owing to DMT and outpatient costs. IFN had lower productivity losses than NAT and GA (p value>0.05), driven by fewer sickness absence days. NAT had a trend towards lower disability pension costs compared with GA (p value>0.05).

CONCLUSIONS

Similar trends over time for healthcare costs and productivity losses were identified across the DMT subgroups. PwMS on NAT maintained their work capacity for a longer time compared with those on GA, potentially leading to lower disability pension costs over time. COI serves as an objective measure to explore the importance of DMTs in maintaining low levels of progression of MS over time.

Epidemiology of multiple sclerosis in the Campania Region (Italy): Derivation and validation of an algorithm to calculate the 2015-2020 incidence

OBJECTIVE

We aim to validate an algorithm based on routinely-collected healthcare data to detect incidence of multiple sclerosis (MS) in the Campania Region (South Italy) and to explore its spatial and temporal variations.

METHODS

We included individuals resident in the Campania Region who had at least one MS record in administrative datasets (drug prescriptions, hospital discharge, outpatients), from 2015 to 2020. We merged administrative to the clinical datasets to ascertain the actual date of diagnosis, and validated the minimum interval from our study baseline (Jan 1, 2015) to first MS records in administrative datasets to detect incident cases. We used Bayesian approach to explore geographical distribution, also including deprivation index as a covariate in the estimation model. We used the capture-recapture method to estimate the proportion of undetected cases.

RESULTS

The best performance was achieved by the 12-month interval algorithm, detecting 2,150 incident MS cases, with 74.4% sensitivity (95%CI = 64.1%, 85.9%) and 95.3% specificity (95%CI = 90.7%, 99.8%). The cumulative incidence was 36.68 (95%CI = 35.15, 38.26) per 100,000 from 2016 to 2020. The mean annual incidence was 7.34 (95%CI = 7.03, 7.65) per 100,000 people-year. The geographical distribution of MS relative risk shows a decreasing east-west incidence gradient. The number of expected MS cases was 11% higher than the detected cases.

CONCLUSIONS

We validated a case-finding algorithm based on administrative data to estimate MS incidence, and its spatial/temporal variations. This algorithm provides up-to-date estimates of MS incidence, and will be used in future studies to evaluate changes in MS incidence in relation to different risk factors.

Exposure to specific tumour necrosis factor inhibitors and risk of demyelinating and inflammatory neuropathy in cohorts of patients with inflammatory arthritis: a collaborative observational study across five Nordic rheumatology registers

OBJECTIVE

To compare incidences of neuroinflammatory events, including demyelinating disease (DML), inflammatory polyneuropathies (IPN) and multiple sclerosis (MS), in patients with rheumatoid arthritis (RA) or spondyloarthritis (SpA; including psoriatic arthritis) starting a tumour necrosis factor inhibitor (TNFi), investigating whether monoclonal TNFi antibodies (other TNFis (oTNFis)) confer higher risk than etanercept.

METHODS

This is an observational cohort study including patients from the five Nordic countries starting a TNFi in 2001-2020. Time to first neuroinflammatory event was identified through register linkages. We calculated crude incidence rates (cIR) per 1000 person-years and used multivariable-adjusted Cox regression to compare incidences of neuroinflammatory events overall and for DML, IPN and MS with oTNFi versus etanercept. We further examined individual TNFis and indications.

RESULTS

33 883 patients with RA and 28 772 patients with SpA were included, initiating 52 704 and 46 572 treatment courses, respectively. In RA, we observed 135 neuroinflammatory events (65% DML) with cIR of 0.38 with oTNFi and 0.34 with etanercept. The HR of oTNFi versus etanercept was 1.07 (95% CI 0.74 to 1.54) for any neuroinflammatory event, 0.79 (95% CI 0.51 to 1.22) for DML, 2.20 (95% CI 1.05 to 4.63) for IPN and 0.73 (95% CI 0.34 to 1.56) for MS. In SpA, we observed 179 events (78% DML) with cIR of 0.68 with oTNFi and 0.65 with etanercept. The HR for any neuroinflammatory event, DML, IPN and MS was 1.06 (95% CI 0.75 to 1.50), 1.01 (95% CI 0.68 to 1.50), 1.28 (95% CI 0.61 to 2.69) and 0.94 (95% CI0.53 to 1.69), respectively.

CONCLUSION

The cIRs of neuroinflammatory events are higher in SpA than in RA, but the choice of specific TNFi does not seem to play an important role in the risk of neuroinflammatory events.

High-resolution HLA class II sequencing of Swedish multiple sclerosis patients

Multiple sclerosis (MS) is a chronic neurological disease believed to be caused by autoimmune pathogenesis. The aetiology is likely explained by a complex interplay between inherited and environmental factors. Genetic investigations into MS have been conducted for over 50 years, yielding >100 associations to date. Globally, the strongest linkage is with the human leukocyte antigen (HLA) HLA-DRB5*01:01:01-DRB1*15:01:01-DQA1*01:02:01-DQB1*06:02:01 haplotype. Here, high-resolution sequencing of HLA was used to determine the alleles of DRB3, DRB4, DRB5, DRB1, DQA1, DQB1, DPA1 and DPB1 as well as their extended haplotypes and genotypes in 100 Swedish MS patients. Results were compared to 636 population controls. The heterogeneity in HLA associations with MS was demonstrated; among 100 patients, 69 extended HLA-DR-DQ genotypes were found. Three extended HLA-DR-DQ genotypes were found to be correlated to MS; HLA-DRB5*01:01:01-DRB1*15:01:01-DQA1*01:02:01-DQB1*06:02:01 haplotype together with (A) HLA-DRB4*01:01:01//DRB4*01:01:01:01-DRB1*07:01:01-DQA1*02:01//02:01:01-DQB1*02:02:01, (B) HLA-DRBX*null-DRB1*08:01:01-DQA1*04:01:01-DQB1*04:02:01, and (C) HLA-DRB3*01:01:02-DRB1*03:01:01-DQA1*05:01:01-DQB1*02:01:01. At the allelic level, HLA-DRB3*01:01:02 was considered protective against MS. However, when combined with HLA-DRB3*01:01:02-DRB1*03:01:01-DQA1*05:01:01-DQB1*02:01:01, this extended haplotype was considered a predisposing risk factor. This highlights the limitations as included with investigations of single alleles relative to those of extended haplotypes/genotypes. In conclusion, with 69 genotypes presented among 100 patients, high-resolution sequencing was conducted to underscore the wide polymorphisms present among MS patients. Additional studies in larger cohorts will be of importance to define MS among the patient group not associated with HLA-DRB5*01:01:01-DRB1*15:01:01-DQA1*01:02:01-DQB1*06:02:01.

Burden of illness the first year after diagnosed bladder dysfunction among people with spinal cord injury or multiple sclerosis - a Danish register study

BACKGROUND

People with spinal cord injury (SCI) or multiple sclerosis (MS) are often living with some degree of bladder and/or bowel dysfunction due to acquired neurogenic damage. The objective was to estimate the burden of illness of SCI and MS the first year after diagnosed bladder dysfunction.

METHODS

Data were extracted from registers covering all Danish citizens. People with SCI or MS were indexed at diagnosis of bladder dysfunction. Inclusion period was 2002-2015 and cases and matched controls were followed for one year.

RESULTS

A total of 2,132 subjects with SCI and 1,887 subjects with MS were identified. Healthcare utilization and societal costs per patient-year were significantly higher for cases compared to controls driven primarily by inpatient care. Cases with urinary tract infection had significantly higher inpatient costs per patient-year compared to controls (SCI: 544 EUR vs 23, p < 0.05; MS: 497 EUR vs 6, p< 0.05) and medication for constipation was significantly more costly per patient-year (SCI: 178 EUR vs 3, p < 0.05; MS: 78 vs 1, p < 0.05).

CONCLUSIONS

The study demonstrates heavy societal and personal costs in the first year after bladder dysfunction in people with SCI or MS. This emphasizes the need for medical and social interventions to reduce the burden of illness.

Incidence and Prevalence of Multiple Sclerosis in Malmö, Southern Sweden

Objectives

To estimate the incidence and prevalence of multiple sclerosis (MS) in Malmö municipality in southwestern Sweden.

Materials and Methods

Multiple sources were used in the case identification process. Case ascertainment was assessed by medical chart review including examinations such as magnetic resonance imaging, cerebrospinal fluid analyses, and relevant laboratory tests. Cases were classified according to the 2010 McDonald's diagnostic criteria. Onset-adjusted prevalence and a definition of onset symptoms were applied.

Results

The crude incidence of MS in 2001-2010 in Malmö municipality was 5.3/100,000 (95% confidence interval (CI): 4.5 to 6.2). There was a relapsing onset in 90.5% of cases. The female to male ratio was 1.8. The onset-adjusted prevalence for Dec 2010 was 133/100,000 (95% CI, 120 to 146) with a female to male ratio of 2.1.

Conclusions

This is the first population-based epidemiological study in Skåne, the most southwestern part of Sweden showing a high incidence and prevalence. We found a lower incidence than expected according to previous nationwide figures, probably due to methodological differences between the studies. Our findings support the presence of a north-south gradient of MS prevalence in Sweden.

Validating the diagnosis of multiple sclerosis using Swedish administrative data in Värmland County

OBJECTIVES

Multiple sclerosis (MS) is a chronic neurodegenerative disease of the central nervous system. Identifying MS at the population level is important for disease surveillance and allocation of resources. The Swedish National Patient Registry (NPR) has been used to study the epidemiology of MS, but the accuracy of this resource is not known. We aimed to validate a definition of MS using the Swedish NPR in Värmland County using a longitudinal cohort design.

MATERIALS AND METHODS

Data were extracted from the NPR, the Total Population Register, the Swedish MS Register, and medical records for the years 2001-2013. Fifteen algorithms of hospitalizations and clinic visits for MS were developed and compared with findings in medical records, which acted as the "gold standard" definition. Sensitivity, specificity, and positive and negative predictive values (PPV, NPV) were estimated.

RESULTS

Of 805 eligible persons identified in the NPR, 763 had MS (94.8%) according to medical records. Of these, 544 (71.3%) were also registered in the SMSreg. The case definition that had a well-balanced sensitivity and specificity required three or more clinic or hospital visits for MS (sensitivity of 85.3% (95% CI: 82.6-87.8) and specificity of 81.0% (95%CI: 65.9-91.4).

CONCLUSIONS

Multiple case definitions with high sensitivity and moderate specificity were found, suggesting that the NPR can be used to accurately identify persons with MS.

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.

Cost-of-Illness Progression Before and After Diagnosis of Multiple Sclerosis: A Nationwide Register-Based Cohort Study in Sweden of People Newly Diagnosed with Multiple Sclerosis and a Population-Based Matched Reference Group

BACKGROUND

Multiple sclerosis (MS) is a chronic disease associated with increased healthcare utilisation and productivity losses.

OBJECTIVE

The objective of this study was to explore the progression of healthcare costs and productivity losses before and after diagnosis of MS in comparison to that of a population-based matched reference group.

METHODS

We conducted a nationwide, Swedish register-based cohort study of working-aged people with MS diagnosed in 2010-12 (n = 1988) and population-based matched references without MS (n = 7981). Nine years of observation spanned from 4 years prior (Y_-4) to 4 years (Y₊₄) after the year of diagnosis (Y₀). Differences in annual all-cause healthcare costs (inpatient and specialised outpatient healthcare as well as pharmacy-dispensed prescribed drugs) and costs of productivity loss (days with sickness absence and disability pension) were estimated between the people with MS and references using t tests with 95% confidence intervals. The average excess costs of MS were estimated using generalised estimating equation models.

RESULTS

People with multiple sclerosis had higher costs before the diagnosis of MS and also thereafter. The mean differences in healthcare costs and productivity losses between the people with MS and matched references in Y_-4 were 216 EUR (95% confidence interval 58-374) and 1540 EUR (95% confidence interval 848-2233), with larger cost excesses observed in later study years. Summarising the 9 study years, people with MS had fivefold higher excess healthcare costs than references, and more than twice as high productivity losses.

CONCLUSIONS

Excess healthcare costs and productivity losses occur already before the diagnosis of MS and increase with time. The excess costs findings before diagnosis could suggest that an earlier diagnosis might lead to reduced excess costs of MS over time.

Temporal trends in the incidence and prevalence of Multiple Sclerosis in the Northwest of Spain

BACKGROUND

During the last decades, the frequency of multiple sclerosis (MS) is increasing worldwide. Nevertheless, the higher sensibility of the new diagnostic criteria obscures the comparison between studies performed in different decades.

METHODS

The evolution of the frequency of MS in Santiago de Compostela (North-West of Spain) between 2003 and 2015 was analyzed using Poisson regression. The diagnosis was confirmed according to Poser criteria. Several sources were consulted for case ascertainment: databases from the MS Unit, the Infusion Center, and the Departments of Neurology, Pharmacy, Pediatric Neurology and Codification of the public Hospital of Santiago, private hospitals, neurologists with private activity, general practitioners, and associations of patients.

RESULTS

In 12 years, the prevalence increased from 68 to 143 cases/100,000 inhabitants, from 83 to 176 in females; and from 49 to 106 in males (p <0.0001, 0.0001, and 0.0002 respectively). The incidence rise was not significant (from 5 to 8 cases/ 100,000 inhabitants/ year (p=0.4243). The mean age of the population growth 5.7 years (p=0.008). The changes in female: male ratio (12.9%), in the age at the first symptom (2.2 years), and the diagnosis delay (0.12 years) did not achieve significance (p=0.7750, 0.1606, 0.8581).

CONCLUSION

The prevalence of MS doubled in 12 years whilst the difference in incidence was lower and not significant. The disproportion in the growth of both parameters, as well as the higher mean age in the last study, suggest a longer survival of patients with MS.

The "Managing Fatigue" programme - experiences shared by MS participants

BACKGROUND

The "Managing Fatigue" (MF) programme can help people living with Multiple sclerosis (MS) manage fatigue in their everyday lives. The programme has been proven feasible with Swedish occupational therapists, but there is a lack of knowledge of how MS participants experience the programme, and what they learned from participating in the programme.

AIM

To describe how Swedish MS participants experience the content and structure of the Swedish MF programme, as well as what they learned from participating in the programme.

MATERIAL AND METHODS

Qualitative interviews were performed with nine MS participants, and data were analysed according to direct content analysis.

RESULTS

Participants experienced programme material was relevant, and they valued the structured sessions that utilised different teaching forms. Participants described the group format and the experienced course leader nurtured their learning process. They learned occupational skills to save energy, to re-value daily occupations, and initiated a process of change, but individual support is needed after programme completion.

CONCLUSION AND SIGNIFICANCE

Findings support programme feasibility among MS participants, and show the importance of being able to practice skills to handle fatigue in everyday life. Future studies should consider adding outcome measures focussing on engagement in occupations when evaluating programme effectiveness.

Reduction of the risk of PML in natalizumab treated MS patients in Sweden: An effect of improved PML risk surveillance

BACKGROUND

Natalizumab (NTZ) treatment of multiple sclerosis (MS) has been associated with increased risk of progressive multifocal leukoencephalopathy (PML). The aim of the present study was to evaluate the impact of PML risk assessment on PML incidence in NTZ treated MS patients.

METHODS

By using information from the population-based Swedish MS registry a retrospective cohort was established of patients treated with NTZ between 2006-2018. The effect on PML incidence before and after utilizing a risk management plan, including JC virus (JCV) serology, was analyzed.

RESULTS

In December 2018, 804 PML cases associated with NTZ therapy of MS had been reported globally, including 9 cases from Sweden. The estimated PML incidence 2018 in Sweden and globally was 0.7 (0.3-1.4) and 4.15 (3.9-4.4) per 1,000 person years, respectively. In Sweden, JCV serology was introduced 2012 for PML risk assessment and the cumulative risk of PML was significantly lower 2012-2018 compared to the period 2006-2011 (p=0.042). The mean NTZ exposure time was 60.1 months (SD 37.2) in the first period (2006-2011) and 32.6 months (SD 22.0) in the second period (2012-2018). The number of patients treated with NTZ decreased, and the number of patients at increased risk of PML was 1.9 % at the end of the study period.

CONCLUSION

Since 2006 the incidence of PML associated with NTZ treatment of MS has decreased in Sweden. Our findings suggest that this reduction is due to an effective adoptation and adherence to the established risk management plan that implies switching patients at increased PML risk from NTZ to other highly efficacious therapies. A less pronounced decline in PML incidence has recently been observed in France, but not globally.

Stressful life events are associated with the risk of multiple sclerosis

BACKGROUND AND PURPOSE

Unexpected stressful life events may alter immune function and affect susceptibility to autoimmune diseases including multiple sclerosis (MS). Current results from epidemiological investigations examining the role of stress in MS remain inconsistent. The aim was to conduct the hitherto largest population-based case-control study on this topic.

METHODS

Extensive questionnaire information collected on lifestyle environmental factors available for 2930 incident MS cases and 6170 controls were used to assess the association of 10 major life events that had occurred before disease onset with the risk of MS by unconditional logistic regressions, adjusting for potential confounders. Stratified analyses were also performed by sex and time.

RESULTS

Compelling evidence was found for a link between major life events and risk of MS - most events significantly increased disease risk by 17%-30%. It was further observed that women were affected to a greater extent than men under certain stressful scenarios, and that most events that happened recently (≤5 years prior to MS onset) had significant effects on MS, indicating a critical window in disease development.

CONCLUSION

Stressful life events may have an adverse effect on the risk of MS. Research into the mechanisms of this observation may give important clues to triggering pathogenetic events in MS.

Joinpoint Regression Analysis of Trends in Multiple Sclerosis Incidence in Kuwait: 1980-2019

BACKGROUND

Multiple sclerosis (MS) is a chronic inflammatory demyelinating and neurodegenerative disease of the central nervous system with unknown precise etiology. Temporally, a tendency for increasing MS incidence has been recorded worldwide. This cross-sectional cohort study sought to quantify trends in the age-standardized incidence rates (ASIRs) (per million person-years) of MS in Kuwait from 1980 to 2019, overall and by subcohorts defined by age at MS onset, sex, and nationality.

METHODS

MS incidence data from 1980 to 2019 were obtained from the Kuwait National MS Registry (KNMSR). Using midyear relevant Kuwait population as denominator and the World Standard Population as a reference, MS ASIRs overall and by subcohorts defined by age at onset (0-19, 20-39, and 40+ years), sex (male and female), and nationality (Kuwaiti and non-Kuwaiti) were computed. Joinpoint regression analysis was conducted to estimate average annual percent change (AAPC) and its 95% confidence interval (CI) overall and by subcohorts.

RESULTS

During 1980-2019, a total of 1,764 MS incident cases of 95.6 million person-years at-risk were diagnosed and registered in KNMSR. The overall MS ASIR (per million person-years) during the study period was 34.1 (95% CI: 16.1, 52.1). Between 1980 and 2010, in the total cohort, ASIRs of MS significantly increased by 13% (AAPC = 13.0; 95% CI: 10.8, 15.3; p < 0.001), followed by statistically nonsignificant declining trend during the ensuing period (AAPC = -3.8; 95% CI: -14.8, 8.8; p = 0.522). Joinpoint regression analysis revealed that 2 subcohorts of Kuwaiti females each with one joinpoint had significant increasing trends in MS ASIRs (0- to 19-year-old Kuwaiti females, AAPC: 1980-2009, 81.0; 95% CI: 58.2, 107.0; p = 0.001; 20- to 39-year-old Kuwaiti females, AAPC: 1980-1999, 131.7; 95% CI: 26.9, 322.8; p = 0.021). Additionally, of remaining 10, 6 subcohorts had significantly (p < 0.05) increasing trends in MS ASIRs from 1980 to 2019.

CONCLUSIONS

From 1980 to 2010, Kuwait has an overall significantly increasing trend in MS ASIRs followed by a nonsignificant declining drift in the ensuing period. The increasing trend in MS risk appeared to be driven by increased risk among Kuwaiti females younger than 40 years. The underlying factors modulating MS risk in Kuwait need further studies.

Changes in multiple sclerosis epidemiology in Finland over five decades

Finland is a high-risk region for multiple sclerosis (MS) with several epidemiological studies on the subject published since 1964, but these have not been comprehensively scrutinized. The objective of this study was to review previous studies of Finnish MS epidemiology, introduce new data on MS prevalence in western parts of Finland and do further analyses on data from previous studies. We performed a systematic search on articles regarding MS epidemiology in Finland in PubMed database, and all relevant articles were included in this review. MS prevalences in the western hospital districts of Vaasa, South Ostrobothnia and Pirkanmaa were calculated in 1980-2007 by using previously unpublished data obtained from a retrospective search from hospital administrative registries. To enhance comparability of the epidemiological figures, we calculated age-standardized prevalence of MS from the new data from western hospital districts and previous data from North Ostrobothnia, Southwest Finland and North Karelia. Marked regional differences in MS epidemiology were confirmed with concentration of the disease in the western and south-western parts of the country. The highest regional age-standardized MS prevalence of 288/100 000 was reported in South Ostrobothnia in 2007. A clear and stable increase in MS prevalence was observed through the decades, but the only marked increase in incidence happened in 1990s. Methodological differences hampered direct comparisons of different studies, highlighting the importance of common principles of reporting and standardizing the epidemiological figures. More comprehensive studies on MS epidemiology are still warranted to yield important information concerning the aetiology of the disease.

Non-infectious comorbidity in patients with multiple sclerosis: A national cohort study in Sweden

Background

Comorbidity is of significant concern in multiple sclerosis (MS). Few population-based studies have reported conditions occurring in MS after diagnosis, especially in contemporary cohorts.

Objective

To explore incident comorbidity, mortality and hospitalizations in MS, stratified by age and sex.

Methods

In a Swedish population-based cohort study 6602 incident MS patients (aged ≥18 years) and 61,828 matched MS-free individuals were identified between 1 January 2008 and 31 December 2016, using national registers. Incidence rates (IRs) and incidence rate ratios (IRRs) with 95% CI were calculated for each outcome.

Results

IRs of cardiovascular disease (CVD) were higher among MS patients than MS-free individuals, (major adverse CVD: IRR 1.42; 95% CI 1.12–1.82; hemorrhagic/ischemic stroke: 1.46; 1.05–2.02; transient ischemic attack: 1.65; 1.09–2.50; heart failure: 1.55; 1.15–2.10); venous thromboembolism: 1.42; 1.14–1.77). MS patients also had higher risks of several non-CVDs such as autoimmune conditions (IRR 3.83; 3.01–4.87), bowel dysfunction (2.16; 1.86–2.50), depression (2.38; 2.11–2.68), and fractures (1.32; 1.19–1.47), as well as being hospitalized and to suffer from CVD-related deaths ((1.91; 1.00–3.65), particularly in females (3.57; 1.58–8.06)).

Conclusion

MS-patients experience a notable comorbidity burden which emphasizes the need for integrated disease management in order to improve patient care and long-term outcomes of MS.

Impact of variable look-back periods on the incidence rates of chronic diseases using real world data

PURPOSE

Estimating disease incidence based on secondary data requires a look-back period to exclude patients with pre-existing disease from the incidence risk set. However, the optimal length of the look-back period and its impact on incidence rates are often unknown. We studied the impact of the length of the look-back period on incidence rates of 24 different chronic diseases.

METHODS

Everyone residing in Sweden between January 1, 2005 and December 31, 2013 were identified from national registries and followed up to 2 years (through December 31, 2015). Outcome events were identified from inpatient and outpatient hospital contacts and incidence rates were calculated per 100 000 person-years. The length of the look-back period was varied with 6-month increments, starting at 6 months. The maximum look-back period of 9 years was used as reference period.

RESULTS

There were 7 943 807 individuals with a look-back period of at least 9 years (mean age 46.5 years) and a mean follow-up time of 1.97 years. Incidence rates were higher across all diseases when restricting the look-back to 1 year compared to 9 years, with a magnitude of overestimation of the incidence rates between 13% (temporal arteritis) and 174% (type 1 diabetes). However, for most diseases the effect of extending the look-back period beyond 3-5 years appeared comparably small.

CONCLUSIONS

This study illustrates how short look-back periods cause overestimation of the incidence rates of chronic diseases, suggesting that sensitivity analyses with respect to look-back period are considered, particularly using data sources with limited information on past medical history.

Age and sex-adjusted incidence and yearly prevalence of multiple sclerosis (MS) in Mazandaran province, Iran: An 11-years study

INTRODUCTION

The incidence rate of MS is a valuable indicator of the recent changes in the risk of this disease, and it is widely implicated for health planning purposes.

OBJECTIVES

This study aims to determine the MS incidence over the past eleven years in Mazandaran province and to compare it with the other parts of Iran and the world.

MATERIALS AND METHODS

This retrospective study is conducted in Mazandaran province by using registered data in the files of the patients with their consent. The yearly crude incidence rates, age, and sex-specific incidence rates and directly standardized incidence rates of this population are calculated, and the temporal changes in the incidence rates are analyzed.

RESULTS

662 (26%) male patients with the mean (SD) age of 32.6 (9.48) and 1884 (74%) female patients with the mean (SD) age of 31.9 (9.15) are studied. The direct standardized incidence rate of MS was 3.28 in 100.000 in 2008 and reached 4.17 in 100.000 in 2018, and this increase was significant (p<0.05). Also, the yearly prevalence of MS increased from 24.4 to 72.5 in this period.

CONCLUSIONS

The MS incidence has increased in Mazandaran. The potential role of some genetic or environmental factors needs further investigation.

Healthcare, Sickness Absence, and Disability Pension Cost Trajectories in the First 5 Years After Diagnosis with Multiple Sclerosis: A Prospective Register-Based Cohort Study in Sweden

OBJECTIVES

The aim was to longitudinally explore the healthcare, sickness absence (SA), and disability pension (DP) cost trajectories among newly diagnosed people with multiple sclerosis (MS), and investigate whether trajectories differ by year of MS diagnosis, sociodemographics, and multi-morbidity.

METHODS

People with MS in Sweden, aged 25-60 years and with a new MS diagnosis in the years 2006, 2007, 2008, or 2009 (four different cohorts) were identified in nationwide registers and followed prospectively for 5 years, determining the annual, per patient, direct (inpatient and specialised outpatient healthcare, co-payments, and dispensed drugs) and indirect (SA and DP) costs. Descriptive statistics and group-based trajectories were computed.

RESULTS

In total, 3272 people with new MS were identified. In all cohorts, direct costs increased the year after diagnosis and thereafter declined (e.g. from €8261 to €9128, and to €7953, 5 years after diagnosis, for the 2006 cohort). SA costs continuously decreased over 5 years, while DP costs increased (e.g. from €9795 to €2778 vs. from €7277 to €15,989, respectively, for the 2006 cohort). When pooling all cohorts, four trajectories of direct and indirect costs were identified. A total of 32.1% of people with MS had high direct and indirect costs, which first increased and then decreased; the contrary was seen for trajectories with low direct and indirect costs.

CONCLUSIONS

There is heterogeneity in the development of MS costs over time after diagnosis; decreasing cost trajectories could be associated with the use of innovative MS therapies, slowing disease progression over time.

Changes in the Risk of Reaching Multiple Sclerosis Disability Milestones In Recent Decades: A Nationwide Population-Based Cohort Study in Sweden

Importance

Clinicians' experience and findings from recent natural history studies suggest that multiple sclerosis (MS) may now be running a more slowly progressing course than before.

Objective

To investigate whether the risk of reaching MS disability milestones has changed over the last decade in Sweden.

Design, Setting, and Participants

A nationwide population-based retrospective cohort study. By April 2017, 12 512 patients with available information on demographics, MS phenotype, and date of MS onset and diagnosis were registered in the Swedish MS Registry of which 7331 patients with at least 2 recorded Expanded Disability Status Scale scores (EDSS) and diagnosed between January 1995 and December 2010 were included. No further exclusion criteria were applied. Patients were followed up until December 2016 with a median duration follow-up of 8.5 (interquartile range, 4.7-13.8) years. Statistical analysis began in April 2017.

Main Outcomes and Measures

Patients were followed up from MS onset date to the date of sustained EDSS 3.0, 4.0, and 6.0. To handle interval-censored observations, a Weibull model was fit, and the change in the risk of EDSS 3.0, 4.0, and 6.0 over calendar years was estimated and hazard ratios (HRs) with corresponding CIs were calculated.

Results

Of 7331 patients, 5196 (70.9%) were women, and the mean (SD) age at diagnosis was 38.3 (11.7) years. Adjusting for sex, number of clinic visits, diagnostic delay, and onset age, a 3% decrease per calendar year of diagnosis for the risk of sustained EDSS 3.0 (HR, 0.97; 95% CI, 0.96-0.97), a 6% decrease for the risk of EDSS 4.0 (HR, 0.94; 95% CI, 0.93-0.95), and a 7% decrease for the risk of EDSS 6.0 (HR, 0.93; 95% CI, 0.91-0.94) among patients with relapsing-onset MS was found. The trends were not significant for patients with progressive-onset MS (EDSS 3.0: HR, 1.01; 95% CI, 0.98-1.03; EDSS 4.0: HR, 1.00; 95% CI, 0.98-1.02; EDSS 6.0: HR, 1.00; 95% CI, 0.98-1.02).

Conclusions and Relevance

Risk of reaching major disability milestones has significantly decreased over the last decade in patients with relapsing-onset MS in Sweden. Several factors could potentially be responsible for this observation. However, given that no change was seen in disability accrual of patients with progressive-onset MS and the absence of efficacious treatment option in this group, increased use of more efficacious disease-modifying treatments could be a possible driver of this change.

Cerebrospinal Fluid Analysis in Multiple Sclerosis Diagnosis: An Update

Multiple sclerosis (MS) is an immune-mediated demyelinating disease of the central nervous system (CNS) with brain neurodegeneration. MS patients present heterogeneous clinical manifestations in which both genetic and environmental factors are involved. The diagnosis is very complex due to the high heterogeneity of the pathophysiology of the disease. The diagnostic criteria have been modified several times over the years. Basically, they include clinical symptoms, presence of typical lesions detected by magnetic resonance imaging (MRI), and laboratory findings. The analysis of cerebrospinal fluid (CSF) allows an evaluation of inflammatory processes circumscribed to the CNS and reflects changes in the immunological pattern due to the progression of the pathology, being fundamental in the diagnosis and monitoring of MS. The detection of the oligoclonal bands (OCBs) in both CSF and serum is recognized as the “gold standard” for laboratory diagnosis of MS, though presents analytical limitations. Indeed, current protocols for OCBs assay are time-consuming and require an operator-dependent interpretation. In recent years, the quantification of free light chain (FLC) in CSF has emerged to assist clinicians in the diagnosis of MS. This article reviews the current knowledge on CSF biomarkers used in the diagnosis of MS, in particular on the validated assays and on the alternative biomarkers of intrathecal synthesis.

Lower risk of multiple sclerosis in patients with chronic hepatitis C: a nationwide population-based registry study

Background

Multiple sclerosis (MS) is an immune-mediated neurological disease that causes demyelination. The etiology is unknown, but patients with a previous viral infection, such as Epstein–Barr virus, have been shown to be at a higher risk of developing MS. In contrast, people living with HIV have a lower risk of developing MS. Hepatitis C virus (HCV) mainly infects the liver, but patients with HCV can experience several extrahepatic manifestations and studies have shown an association with several autoimmune conditions such as neuropathy and myelitis. The present study aimed to investigate the risk of MS in patients with chronic HCV infection compared with matched comparators.

Methods

Patients were identified using the nationwide Swedish inpatient (2001–2013) and outpatient care registers (2001–2013) for HCV (B18.2) and MS (G35) according to the International Classification of Diseases-10. Up to five comparators (matched on age/sex/place of residency) were drawn from the general population for each HCV patient. Follow-up started at the first HCV visit from 2001 and the patients’ accrued person-time until death, emigration or 31 December 2013. Risk of MS diagnosis was calculated as standardized incidence ratio (SIR) with 95% confidence intervals (CIs).

Results

HCV patients were at lower risk of MS diagnosis (SIR 0.37; 95% CI 0.26–0.50). The incidence of MS during the study in the HCV cohort was 0.087% compared with 0.27% in the matched comparator cohort.

Conclusion

Surprisingly, these data suggest HCV patients to have a lower risk of MS diagnosis.

Electronic supplementary material

The online version of this article (10.1007/s00415-019-09397-8) contains supplementary material, which is available to authorized users.

Mitochondrial Dysfunction and Multiple Sclerosis

In recent years, several studies have examined the potential associations between mitochondrial dysfunction and neurodegenerative diseases such as multiple sclerosis (MS), Parkinson’s disease and Alzheimer’s disease. In MS, neurological disability results from inflammation, demyelination, and ultimately, axonal damage within the central nervous system. The sustained inflammatory phase of the disease leads to ion channel changes and chronic oxidative stress. Several independent investigations have demonstrated mitochondrial respiratory chain deficiency in MS, as well as abnormalities in mitochondrial transport. These processes create an energy imbalance and contribute to a parallel process of progressive neurodegeneration and irreversible disability. The potential roles of mitochondria in neurodegeneration are reviewed. An overview of mitochondrial diseases that may overlap with MS are also discussed, as well as possible therapeutic targets for the treatment of MS and other neurodegenerative conditions.

Multiple sclerosis epidemiology in Finland: Regional differences and high incidence

OBJECTIVES

Studies on the east-west gradient of multiple sclerosis (MS) are scarce. In Finland, epidemiological differences have been only partially elucidated, but the MS risk is high, and it has been claimed that the occurrence follows a longitudinal gradient. In this register-based study, we updated the MS epidemiology in southwest Finland (SwF) and compared it to the easternmost hospital district, North Karelia (NK), for which no previous data exist.

MATERIALS AND METHODS

Patients with ICD-10 code G35 were identified from hospital district administrative data. Patient records were reviewed to include only cases with a definitive diagnosis. Incidence period covered 5 years (2012-2016), and the prevalence date was December 31, 2016. Results were standardized using the direct method.

RESULTS

A total of 1184 persons had MS in SwF and 253 persons in NK at the end of 2016. The prevalence was 280/100 000 (95% CI 264-296) in SwF and 168/100 000 (95% CI 148-190) in NK (age-standardized for the European standard population 2013). During the incidence period, 211 new MS diagnoses were made in SwF and 49 in NK. The annual age-standardized (ESP 2013) incidence was 12.1/100 000 person-years (95% CI 10.5-13.8) in SwF and 8.6/100 000 person-years (95% CI 6.4-11.2) in NK in the age-group 10-69 years.

CONCLUSIONS

There are regional differences in MS epidemiology in Finland, possibly related to demographic, social, and genetic circumstances, but the retrospective nature and limited sample size of this study might introduce some uncertainty to the calculations. SwF is a region with a globally very high risk for MS.

Neurotoxic effects of mercury exposure in dental personnel

Numerous studies have reported neurobehavioural effects in dental personnel occupationally exposed to chronic low levels of mercury (Hg). Hg exposure from dental work may also induce various chronic conditions such as elevation of amyloid protein expression, deterioration of microtubules and increase or inhibition of transmitter release at motor nerve terminal endings. Therefore, clinical studies of Hg toxicity in dentistry may provide new knowledge about disturbed metal homeostasis in neurodegenerative diseases such as Alzheimer's disease, multiple sclerosis and mood disorders. The purpose of this MiniReview is to evaluate the evidence of possible relevance between Hg exposure in dentistry and idiopathic disturbances in motor functions, cognitive skills and affective reactions, as well as dose-response relationships.

Age at Menarche and Risk of Multiple Sclerosis: Current Progress From Epidemiological Investigations

Multiple sclerosis (MS) is a chronic autoimmune inflammatory disorder of the brain and spinal cord in which focal lymphocytic infiltration leads to the damage of myelin and axons. As a multi-factorial complex trait, both genetic background and environmental factors are involved in MS etiology. The disease is more prevalent among women, and an overall female-to-male sex ratio of around 3 is usually reported. The fact that the female preponderance is only apparent among patients with disease onset after age 12 points toward a role of puberty in MS. A key marker of female pubertal development is menarche, however, evidence from previous epidemiological investigations has been sparse and conflicting: although some studies have linked earlier age at menarche (AAM) to an increased risk of MS, others have found no association or an inverse association. Understanding the effect of AAM in MS could increase our knowledge to the disease etiology, as well as deliver meaningful implication to patients' care by aiding clinical diagnosis. Therefore, we reviewed all the currently available epidemiological studies conducted for AAM and risk of MS in adult human populations. We found evidence supporting a possible favorable role of late AAM on MS risk, but this should be further confirmed by well-designed large-scale epidemiological studies and meta-analysis. Future work may be focused on Mendelian randomization analysis incorporating genetic markers to provide additional evidence of a putative causal relationship between AAM and MS. More work should be conducted for non-European populations to increase generalizability, and among the males to complementary with results from females. Future work may also be conducted focusing on hormonal reproductive factors other than menarche, and their effects in MS prognosis, severity, and drug response.

Making it work: experience of living with a person who falls due to multiple sclerosis

Purpose: The purpose of this study was to describe how everyday life is experienced by next of kin sharing residence with a person who falls due to multiple sclerosis (MS).Methods: Twenty face-to-face interviews were analysed using a qualitative content analysis.Results: The overall theme "Making it work" represents the next of kin's struggle to make life work. It comprises three themes: "Taking responsibility", "Making adjustments", and "Standing aside for someone else". The two first themes reflect what relatives do to make the situation work, and the last theme represents what they give up.Conclusion: Next of kin who share residence and everyday life with a person with MS are affected by that person's occasional falls. They often take on the responsibility of preventing such falls and adapt their lives practically and emotionally. However, adaptation is neither always enough or always possible. In these cases, relatives often deprioritize their own needs and free time to make everyday life in the home work.Implications for rehabilitationBy highlighting that next of kin also are affected by the falls of their cohabiting person with multiple sclerosis enhances the importance of fall prevention activities that should include the next of kin.Next of kin to people who occasionally fall due to multiple sclerosis can be in need of both practical and emotional support from the health care system.Enhanced information from the health care system can empower and help them to take care of themselves while managing to live with, care for, and protect the person with multiple sclerosis from falls.

Hypothesis: Multiple sclerosis is caused by three-hits, strictly in order, in genetically susceptible persons

Multiple Sclerosis is a chronic, progressive and debilitating neurological disease which, despite extensive study for over 100 years, remains of enigmatic aetiology. Drawn from the epidemiological evidence, there exists a consensus that there are environmental (possibly infectious) factors that contribute to disease pathogenesis that have not yet been fully elucidated. Here we propose a three-tiered hypothesis: 1) a clinic-epidemiological model of multiple sclerosis as a rare late complication of two sequential infections (with the temporal sequence of infections being important); 2) a proposal that the first event is helminthic infection with Enterobius Vermicularis, and the second is Epstein Barr Virus infection; and 3) a proposal for a testable biological mechanism, involving T-Cell exhaustion for Epstein-Barr Virus protein LMP2A. We believe that this model satisfies some of the as-yet unexplained features of multiple sclerosis epidemiology, is consistent with the clinical and neuropathological features of the disease and is potentially testable by experiment. This model may be generalizable to other autoimmune diseases.

Trajectories of disposable income among people of working ages diagnosed with multiple sclerosis: a nationwide register-based cohort study in Sweden 7 years before to 4 years after diagnosis with a population-based reference group

OBJECTIVES

To describe how disposable income (DI) and three main components changed, and analyse whether DI development differed from working-aged people with multiple sclerosis (MS) to a reference group from 7 years before to 4 years after diagnosis in Sweden.

DESIGN

Population-based cohort study, 12-year follow-up (7 years before to 4 years after diagnosis).

SETTING

Swedish working-age population with microdata linked from two nationwide registers.

PARTICIPANTS

Residents diagnosed with MS in 2009 aged 25-59 years (n=785), and references without MS (n=7847) randomly selected with stratified matching (sex, age, education and country of birth).

PRIMARY AND SECONDARY OUTCOME MEASURES

DI was defined as the annual after tax sum of incomes (earnings and benefits) to measure individual economic welfare. Three main components of DI were analysed as annual sums: earnings, sickness absence benefits and disability pension benefits.

RESULTS

We found no differences in mean annual DI between people with and without MS by independent t-tests (p values between 0.15 and 0.96). Differences were found for all studied components of DI from diagnosis year by independent t-tests, for example, in the final study year (2013): earnings (-64 867 Swedish Krona (SEK); 95% CI-79 203 to -50 528); sickness absence benefits (13 330 SEK; 95% CI 10 042 to 16 500); and disability pension benefits (21 360 SEK; 95% CI 17 380 to 25 350). A generalised estimating equation evaluated DI trajectory development between people with and without MS to find both trajectories developed in parallel, both before (-4039 SEK; 95% CI -10 536 to 2458) and after (-781 SEK; 95% CI -6988 to 5360) diagnosis.

CONCLUSIONS

The key finding of parallel DI trajectory development between working-aged MS and references suggests minimal economic impact within the first 4 years of diagnosis. The Swedish welfare system was responsive to the observed reductions in earnings around MS diagnosis through balancing DI with morbidity-related benefits. Future decreases in economic welfare may be experienced as the disease progresses, although thorough investigation with future studies of modern cohorts are required.

New insights into the burden and costs of multiple sclerosis in Europe: Results for Denmark

Background:

To estimate the value of treatments in multiple sclerosis (MS) – where lifetime costs and outcomes cannot be observed – outcome data have to be combined with cost data. This, in turn, requires that cost data be regularly updated.

Objectives and Methods:

This study is part of a cross-sectional retrospective study in 16 countries collecting current data on resource consumption, work capacity, health-related quality of life (HRQoL) and prevalent symptoms for patients with MS. Descriptive analyses are presented by level of severity, from the societal perspective, in 2015 Danish Kronor (DKK).

Results:

A total of 830 patients (mean age of 54 years) participated; 78% were below retirement age and of these, 43% were employed. Employment was related to disease severity, and MS was felt to affect productivity at work by 73% of patients, most often through fatigue. Overall, 95% and 65% of patients felt that fatigue and cognition, respectively, were a problem. Mean utility and costs were 0.770 and 196,900DKK at Expanded Disability Status Scale (EDSS) 0–3, 0.619 and 287,300DKK at EDSS 4–6.5, and 0.302 and 533,250DKK at EDSS 7–9. The average cost of a relapse was estimated at 19,000DKK.

Conclusion:

This study illustrates the burden of MS on Danish patients and provides current data that are important for the development of health policies.

New insights into the burden and costs of multiple sclerosis in Europe: Results for Sweden

Background:

To assess the value of management strategies in multiple sclerosis (MS), outcome data have to be combined with cost data. This requires that cost data be regularly updated.

Objective and methods:

This study is part of a cross-sectional retrospective study in 16 countries collecting current data on resource consumption, work capacity and health-related quality of life (HRQoL). Descriptive analyses are presented by level of severity; costs are estimated in the societal perspective, in 2015 SEK.

Results:

A total of 1864 patients (mean age 56 years) participated in Sweden; 74% were below retirement age, and of these, 55% were employed. MS was reported to affect productivity at work in 78% of patients. Overall, 94% and 72% of patients felt that fatigue and cognition were a problem, respectively. The mean utility and costs were 0.757 and 244,000SEK at Expanded Disability Status Scale (EDSS) 0–3, 0.563 and 384,000SEK at EDSS 4–6.5 and 0.202 and 888,000SEK at EDSS 7–9, respectively. The average cost of a relapse was 36,900SEK.

Conclusion:

This study illustrates the burden of MS on Swedish patients and provides current data that are important for the development of health policies.

Guidelines for the use of magnetic resonance imaging in diagnosing and monitoring the treatment of multiple sclerosis: recommendations of the Swedish Multiple Sclerosis Association and the Swedish Neuroradiological Society

Multiple sclerosis (MS) is associated with inflammatory lesions in the brain and spinal cord. The detection of such inflammatory lesions using magnetic resonance imaging (MRI) is important in the consideration of the diagnosis and differential diagnoses of MS, as well as in the monitoring of disease activity and predicting treatment efficacy. Although there is strong evidence supporting the use of MRI for both the diagnosis and monitoring of disease activity, there is a lack of evidence regarding which MRI protocols to use, the frequency of examinations, and in what clinical situations to consider MRI examination. A national workshop to discuss these issues was held in Stockholm, Sweden, in August 2015, which resulted in a Swedish consensus statement regarding the use of MRI in the care of individuals with MS. The aim of this consensus statement is to provide practical advice for the use of MRI in this setting. The recommendations are based on a review of relevant literature and the clinical experience of workshop attendees. It is our hope that these recommendations will benefit individuals with MS and guide healthcare professionals responsible for their care.

Multiple Sclerosis Epidemiology in Europe

Multiple sclerosis is characterized by a non-homogeneous distribution around the world. Some authors in past described a latitude gradient, with increasing risk from the equator to North and South Poles, but this theory is still controversial. Regarding Europe, there are many articles in the literature concerning the epidemiology of this disease but, unfortunately, they are not always comparable due to different methodologies, they do not cover all countries in the continent, and most of them reported data of small areas and rarely at a national level. In 2012 there were 20 national registries that could help to describe the epidemiology of the disease and, in addition, there is an European Register for Multiple Sclerosis that collect data from already existing national or regional MS registries and databases. Another valid alternative to obtain epidemiological data, also at national level, in a routinely and cost-saving way is through administrative data that are of increasing interest in the last years.

Clinical course of multiple sclerosis: A nationwide cohort study

Background:

The course of multiple sclerosis (MS) has been studied in several cohorts; however, results have varied significantly.

Objective:

To describe the clinical course of MS in a nationwide cohort of patients.

Method:

Data from the Swedish MS register (SMSreg) were used to estimate the median time to the sustained Expanded Disability Status Scale (EDSS) scores 3.0, 4.0 and 6.0, onset of secondary progressive multiple sclerosis (SPMS) and death using Kaplan–Meier method. A possible effect of first-line treatments on age at EDSS 6.0 and SPMS was estimated.

Results:

In all, 12,703 patients were included. Median ages at EDSS scores 3.0, 4.0 and 6.0 were 55.4 (95% confidence interval (CI): 54.8−55.8), 60.7 (95% CI: 60.1−61.2) and 64.3 (95% CI: 63.6−64.7), respectively. Median age at SPMS was 57.4 (95% CI: 56.9−57.9). The median age at the time of death was 80.5 (95% CI: 79.9−81.1). Males and progressive-onset patients showed higher risks of disability worsening. On average, treated patients gained 1.6 years (95% CI: 0.2−3) to EDSS 6.0 as a result of treatment.

Conclusion:

Ages at disability milestones in this population-based cohort were higher than previously described in clinic- and regional-based samples. Nevertheless, MS patients die at younger age and live at an average almost 20 years with moderate and 30 years with severe disability.

Identification of a gene expression signature in peripheral blood of multiple sclerosis patients treated with disease-modifying therapies

Multiple Sclerosis (MS) is an inflammatory disease with neurodegenerative alterations, ultimately progressing to neurological handicap. Therapies are effective in counteracting inflammation but not neurodegeneration. Biomarkers predicting disease course or treatment response are lacking. We investigated whether altered gene and protein expression profiles were detectable in the peripheral blood of 78 relapsing remitting MS (RR-MS) patients treated by disease-modifying therapies. A discovery/validation study on RR-MS responsive to glatiramer acetate identified 8 differentially expressed genes: ITGA2B, ITGB3, CD177, IGJ, IL5RA, MMP8, P2RY12, and S100β. A longitudinal study on glatiramer acetate, Interferon-β, or Fingolimod treated RR-MS patients confirmed that 7 out of 8 genes were downregulated with reference to the different therapies, whereas S100β was always upregulated. Thus, we identified a peripheral gene signature associated with positive response in RR-MS which may also explain drug immunomodulatory effects. The usefulness of this signature as a biomarker needs confirmation on larger series of patients.

Incidence of Radiologically Isolated Syndrome: A Population-Based Study

BACKGROUND AND PURPOSE

Incidental MR imaging findings resembling MS in asymptomatic individuals, fulfilling the Okuda criteria, are termed "radiologically isolated syndrome." Those with radiologically isolated syndrome are at high risk of their condition converting to MS. The epidemiology of radiologically isolated syndrome remains largely unknown, and there are no population-based studies, to our knowledge. Our aim was to study the population-based incidence of radiologically isolated syndrome in a high-incidence region for MS and to evaluate the effect on radiologically isolated syndrome incidence when revising the original radiologically isolated syndrome criteria by using the latest radiologic classification for dissemination in space.

MATERIALS AND METHODS

All 2272 brain MR imaging scans in 1907 persons obtained during 2013 in the Swedish county of Västmanland, with a population of 259,000 inhabitants, were blindly evaluated by a senior radiologist and a senior neuroradiologist. The Okuda criteria for radiologically isolated syndrome were applied by using both the Barkhof and Swanton classifications for dissemination in space. Assessments of clinical data were performed by a radiology resident and a senior neurologist.

RESULTS

The cumulative incidence of radiologically isolated syndrome was 2 patients (0.1%), equaling an incidence rate of 0.8 cases per 100,000 person-years, in a region with an incidence rate of MS of 10.2 cases per 100,000 person-years. There was no difference in the radiologically isolated syndrome incidence rate when applying a modified version of the Okuda criteria by using the newer Swanton classification for dissemination in space.

CONCLUSIONS

Radiologically isolated syndrome is uncommon in a high-incidence region for MS. Adapting the Okuda criteria to use the dissemination in space-Swanton classification may be feasible. Future studies on radiologically isolated syndrome may benefit from a collaborative approach to ensure adequate numbers of participants.

Increasing prevalence of multiple sclerosis in Västerbotten County of Sweden

OBJECTIVES

To update the incidence and prevalence of multiple sclerosis (MS) in Västerbotten County, Sweden, and to compare this to previous investigations in the same area.

BACKGROUND

Northern Sweden is a high-risk area for developing MS. Västerbotten County has previously been surveyed in detail regarding the occurrence of MS. In several countries, increases in MS prevalence and incidence as well as a change in the sex ratio have been reported.

MATERIALS AND METHODS

Multiple sources were used to identify MS cases in Västerbotten that either had their onset of the disease from 1998 to 2010 and/or lived in Västerbotten, the two dates chosen for prevalence calculation: the 31st of December 2005 and 2010.

RESULTS

The mean yearly incidence of MS in Västerbotten during the entire period 1998-2010 was 6.0/100,000. The female to male ratio was 2.1. The prevalence of MS in Västerbotten was 188/100,000 on 31st of December 2005 and 215/100,000 on 31st of December 2010. The MS prevalence increased over time from 1990 to 2010.

CONCLUSIONS

The prevalence of MS in Västerbotten County has increased between 1990 and 2010, while no statistically significant increase in incidence was seen.

Conclusion: National incidence and risk factor assessments may become a basis for the evaluation of prevention trials – prospects from the Third Nordic MS Symposium

This symposium started with an overview of recent incidence and prevalence data from the Scandinavian national registers and continued with a critical analysis of several alleged risk factors for MS. These risk factors are constantly changing and therefore might explain current incidence changes. In addition, they may be the subject of preventive measures.