Effects of Age and Disease Duration on Excess Mortality in Patients With Multiple Sclerosis From a French Nationwide Cohort

The Canadian Collaborative Project on Genetic Susceptibility to Multiple Sclerosis cohort population structure and disease etiology

Background

Previous genetic and epidemiological studies have examined subpopulations from the Canadian Collaborative Project on Genetic Susceptibility to Multiple Sclerosis (CCPGSMS) patient cohort, but an encompassing analysis of the study population has not yet been carried out.

Objective

This study examines patterns of multiple sclerosis (MS) prevalence in 13,663 cohort members, including 4,821 patients with MS or suspected MS and 8,842 family members.

Methods

We grouped participants into epidemiologic subgroups based on age of MS onset, clinical stage at diagnosis, symptom type at disease onset, sex, proband status, disability as measured by the EDSS, and ancestry based on reported ethnicity.

Results

We observed a 2.7:1 MS prevalence ratio of women to men, though disease severity was greater for male patients. Variation in the age of disease onset between patients was only slightly associated with sex and strongly associated with disease type. Specific types of clinical symptoms at disease onset were associated with the prognosis. Regional residence did not correlate with disease onset, type, or severity.

Conclusion

Population trends, as presented here, are not explained by environmental factors alone, highlighting the need for a comprehensive genetic analysis to understand disease variance across families.

Impact of multiple sclerosis on employment and income: Insights from a random sample representative of private sector employees in France using longitudinal administrative data

In France, few data sources are available to estimate the impact of multiple sclerosis (MS) on job retention and its consequences on the level of resources, especially in large representative samples. The aim of the present study was to measure impact of MS on employment rates, wages and income (including unemployment benefit, sickness benefit and disability pension) by comparing work trajectories of people living with MS with those of a matched control group. We used the HYGIE database, which is the result of the linkage of two administrative databases in the private sector for a random sample of over 900,000 people. In order to identify the causal effect of MS on employment after 1 to 20 years, the difference-in-differences method with matching (age, sex, career and health history) was used, overall and in subgroups. The year of entry in long-term disease status for MS was used to approximate the onset of MS. Overall, 946 people with MS were included. Their situation was fairly favorable before MS (88.1% in employment, resources higher than the median for the general population), but MS had strong and continuous negative effects. Indeed, at 10 years, the employment rate fell by 28.6 percentage points (pp) and the disability pension allowance increased by 50.5 pp; the wage percentile fell by 19.2 pp and the replacement income accounted for a growing share of total income (+ 39.7 pp). Although administrative data had several strengths, clinical information on the severity of the disease or on its therapeutic management was not available. In conclusion, this study shows that the effects of MS on the employed population in the private sector occur early in the disease course and are cumulative, and that replacement income helps to reduce the loss of resources thanks to the French health and social system.

Risk of dementia in older veterans with multiple sclerosis

BACKGROUND

While it is widely accepted that multiple sclerosis (MS) often causes cognitive dysfunction, it is thought that these cognitive symptoms rarely progress to dementia. However, this has not been thoroughly investigated. The objectives of this cohort study are to determine whether people with MS have an increased risk of dementia compared to the general population and to identify factors, such as geographic latitude, which may modify this association.

METHODS

We studied data from a random sample of US veterans aged ≥ 55 years followed at Veterans Affairs Health Care Systems nationwide from 1999 to 2019. We identified all patients diagnosed with MS using ICD codes over a two-year baseline period. We then identified a comparison cohort of patients without MS matched 1:1 on sex, age, race, and first encounter date. We constructed Cox proportional hazards regression models to determine the association between MS and dementia while controlling for demographic factors and comorbidities, with additional models to examine subgroup effects. We used Fine-Gray subdistribution hazard models accounting for competing risk of death to evaluate the sensitivity of the findings.

RESULTS

The study included 4084 MS patients and a matched group of 4084 non-MS patients. Overall, patients had mean age 66, were 93.6% male, and 88.1% non-Hispanic White, with mean follow-up time 9.5 years (MS) and 10.8 years (non-MS). In unadjusted models, veterans with MS had greater risk of dementia compared to matched controls (cumulative incidence 16.7% vs 12.4%; Cox HR 1.58, 95% CI 1.41-1.78). The increased risk remained after adjustment for potential confounders (adjusted HR 1.56, 95% CI 1.39-1.76) and when considering death as a competing risk (Fine-Gray HR 1.36, 95% CI 1.21-1.53). The magnitude of the MS-dementia association increased with rising geographic latitude (North HR 1.86, 1.51-2.30; Central HR 1.61, 1.42-1.82; South HR 1.39, 1.18-1.64; interaction p = 0.04) and younger baseline age (interaction p<0.001).

CONCLUSIONS

Among older veterans with MS, risk of dementia diagnosis was higher compared to matched controls even after controlling for comorbidities. The risk difference was highest in northern regions and in younger patients. Clinicians caring for older MS patients should be aware of this risk and offer screening and treatment accordingly.

Comparison of 2 Methods for Estimating Multiple Sclerosis-Related Mortality

BACKGROUND AND OBJECTIVES

Determining whether multiple sclerosis (MS) causes death is challenging. Our objective was to contrast 2 frameworks to estimate probabilities of death attributed to MS (PMS) and other causes (Pother): the cause-specific framework (CSF), which requires the causes of death, and the excess mortality framework (EMF), which does not.

METHODS

We used data from the Observatoire Français de la Sclérose en Plaques (OFSEP, n = 37,524) and from a comparative subset where causes of death were available (4,004 women with relapsing-onset MS [R-MS]). In CSF, the probabilities were estimated using the Aalen-Johansen method. In EMF, they were estimated from the excess mortality hazard, which is the additional mortality among patients with MS as compared with the expected mortality in the matched general population. PMS values were estimated at 30 years of follow-up, (1) with both frameworks in the comparative subset, by age group at onset, and (2) with EMF only in the OFSEP population, by initial phenotype, sex, and age at onset.

RESULTS

In the comparative subset, the estimated 30-year PMS values were greater using EMF than CSF: 10.9% (95% CI 8.3-13.6) vs 8.7% (6.4-11.8) among the youngest and 20.4% (11.3-29.5) vs 16.2% (8.7-30.2) for the oldest groups, respectively. In the CSF, probabilities of death from unknown causes ranged from 1.5% (0.7-3.0) to 6.4% (2.5-16.4), and even after their reallocation, PMS values remained lower with CSF than with EMF. The estimated probabilities of being alive were close using the 2 frameworks, and the estimated POther (EMF vs CSF) was 2.6% (2.5-2.6) vs 2.1% (1.2-3.9) and 18.1% (16.9-19.3) vs 26.4% (16.5-42.2), respectively, for the youngest and oldest groups. In the OFSEP population, the estimated 30-year PMS values ranged from 7.5% (6.4-8.7) to 24.0% (19.1-28.9) in patients with R-MS and from 25.4% (21.1-29.7) to 36.8% (28.3-45.3) in primary progressive patients, depending on sex and age.

DISCUSSION

EMF has the great advantage of not requiring death certificates, their quality being less than optimal. Conceptually, it also seems more relevant because it avoids having to state, for each individual, whether death was directly or indirectly caused by MS or whether it would have occurred anyway, which is especially difficult in such chronic diseases.

Clinical trajectory of hypermobile Ehlers-Danlos syndrome/hypermobility spectrum disorders in older adults

BACKGROUND

Research on hypermobile Ehlers-Danlos syndrome and hypermobility spectrum disorder (hEDS/HSD) has described its natural history and clinical course in children, adolescents, and young to middle-aged adults. However, more research is needed on the clinical trajectory of hEDS/HSD into older age. Therefore, clinicians, including nurse practitioners, know little about identifying older adults with undiagnosed hEDS/HSD.

OBJECTIVE

This review sought to identify studies regarding aging in hEDS/HSD.

DATA SOURCES

This scoping review included PubMed, Cumulative Index to Nursing and Allied Health Literature, and Scopus and found 15 studies that mentioned age or aging on the symptoms and health-related quality of life.

CONCLUSIONS

No study had a stated aim regarding aging in hEDS/HSD, but all studies corroborated earlier natural history studies describing the age-related trajectory of manifestations in younger people. Studies found that symptom progression was heterogeneous, multisystemic, and unpredictable. Studies also noted prolonged diagnosis delays and long symptom duration, but the impact of these factors on outcomes was unclear. The high variability in patient outcomes precludes the prediction of outcomes based on the included studies. The clinical impact of aging on hEDS/HSD remains mostly speculative.

IMPLICATIONS FOR PRACTICE

Nurse practitioners, especially those in primary care, should consider that older adults presenting with multimorbidity may have undiagnosed hEDS/HSD. More research is needed to identify symptom patterns and clinical history that may suggest an underlying connective tissue disorder.

Effects of socioeconomic status on excess mortality in patients with multiple sclerosis in France: A retrospective observational cohort study

Background

The effects of socio-economic status on mortality in patients with multiple sclerosis is not well known. The objective was to examine mortality due to multiple sclerosis according to socio-economic status.

Methods

A retrospective observational cohort design was used with recruitment from 18 French multiple sclerosis expert centers participating in the Observatoire Français de la Sclérose en Plaques. All patients lived in metropolitan France and had a definite or probable diagnosis of multiple sclerosis according to either Poser or McDonald criteria with an onset of disease between 1960 and 2015. Initial phenotype was either relapsing-onset or primary progressive onset. Vital status was updated on January 1st 2016. Socio-economic status was measured by an ecological index, the European Deprivation Index and was attributed to each patient according to their home address. Excess death rates were studied according to socio-economic status using additive excess hazard models with multidimensional penalised splines. The initial hypothesis was a potential socio-economic gradient in excess mortality.

Findings

A total of 34,169 multiple sclerosis patients were included (88% relapsing onset (n = 30,083), 12% progressive onset (n = 4086)), female/male sex ratio 2.7 for relapsing-onset and 1.3 for progressive-onset). Mean age at disease onset was 31.6 (SD = 9.8) for relapsing-onset and 42.7 (SD = 10.8) for progressive-onset. At the end of follow-up, 1849 patients had died (4.4% for relapsing-onset (n = 1311) and 13.2% for progressive-onset (n = 538)). A socio-economic gradient was found for relapsing-onset patients; more deprived patients had a greater excess death rate. At thirty years of disease duration and a year of onset of symptoms of 1980, survival probability difference (or deprivation gap) between less deprived relapsing-onset patients (EDI = −6) and more deprived relapsing-onset patients (EDI = 12) was 16.6% (95% confidence interval (CI) [10.3%–22.9%]) for men and 12.3% (95%CI [7.6%–17.0%]) for women. No clear socio-economic mortality gradient was found in progressive-onset patients.

Interpretation

Socio-economic status was associated with mortality due to multiple sclerosis in relapsing-onset patients. Improvements in overall care of more socio-economically deprived patients with multiple sclerosis could help reduce these socio-economic inequalities in multiple sclerosis-related mortality.

Funding

This study was funded by the ARSEP foundation “Fondation pour l'aide à la recherche sur la Sclérose en Plaques” (Grant Reference Number 1122). Data collection has been supported by a grant provided by the French State and handled by the “Agence Nationale de la Recherche,” within the framework of the “Investments for the Future” programme, under the reference ANR-10-COHO-002, Observatoire Français de la Sclérose en Plaques (OFSEP).

Mortality and cause of death in multiple sclerosis in western Norway 1950-2021: a registry-based linkage study

BACKGROUND

Persons with multiple sclerosis (pwMS) have higher risk of mortality compared with the general population. Longitudinal studies are important for understanding the evolution of survival in pwMS.

OBJECTIVE

Examine changes in mortality among pwMS during the past seven decades.

METHODS

We followed pwMS from Hordaland and Møre and Romsdal in Western Norway, with disease onset from before 1950, identified from population-based epidemiological surveys and the Norwegian MS Registry and Biobank, until 1 January 2021. Data were linked to the Norwegian Cause of Death Registry to obtain underlying cause of death. We examined all-cause, and cause-specific mortality using standardised mortality ratios (SMR) and excess death rates (EDR). We calculated life expectancies and assessed survival stratified by sex, age and disease phenotype at onset. We compared hazard ratios (HRs) for mortality, in pwMS diagnosed before and after the era of disease-modifying treatment (DMT).

RESULTS

Of 3624 pwMS, 964 (55.5% women) had died, predominantly of multiple sclerosis (49.0%). Median life expectancy for pwMS was 74.3 years (95% CI 73.3 to 75.3), compared with 83.1 years for the general population (p<0.001). From disease onset, pwMS survived 14.6 years shorter than the general population (p<0.001). Overall, SMR was 2.3 (95% CI 2.13 to 2.42) and EDR was 6.8 (95% CI 6.42 to 7.09) for pwMS. Treatment-eligible pwMS diagnosed in the DMT era had the lowest risk of mortality, HR 0.49 (95% CI 0.34 to 0.70,p<0.001).

CONCLUSION

Excess mortality among pwMS declined during the past seven decades, possibly due to improved diagnostics, better symptomatic treatment and access to DMTs.

Hospitalization Risks for Neurological Disorders in Primary Sjögren's Syndrome Patients

Primary Sjögren’s syndrome (pSS) can be associated with neurological and cognitive involvement, negatively affecting patients’ quality of life. The aim of this study was to assess whether pSS patients are at higher risk of hospitalization for neurological diseases. Through a nationwide retrospective study using the French Health insurance database (based on International Classification for Disease codes, ICD-10), we selected patients hospitalized with new-onset pSS between 2011 and 2018. We compared the incidence of hospitalization for dementia, multiple sclerosis (MS), encephalitis, and peripheral neuropathy with an age- and sex-matched (1:10) hospitalized control group. Adjusted Hazard Ratios (aHR) considered confounding factors, particularly socio-economic status and cardiovascular diseases. We analyzed 25,661 patients hospitalized for pSS, compared with 252,543 matched patients. The incidence of hospitalization for dementia was significantly higher in pSS patients (aHR = 1.27 (1.04−1.55); p = 0.018), as well as the incidence of hospitalization for MS, encephalitis, and inflammatory polyneuropathies (aHR = 3.66 (2.35−5.68), p < 0.001; aHR = 2.66 (1.22−5.80), p = 0.014; and aHR = 23.2 (12.2−44.5), p < 0.001, respectively). According to ICD-10 codes, pSS patients exhibited a higher incidence of hospitalization for dementia, encephalitis, MS, and peripheral neuropathies than controls. Physicians must be aware of these neurological risks to choose the most appropriate diagnostic work-up.

The role of sex and pregnancy in multiple sclerosis: what do we know and what should we do?

INTRODUCTION

Multiple sclerosis (MS) is more prevalent in women than in men. The sex of the patient, and pregnancy, are reported to be associated with the clinical features of MS. The mechanism of this is unclear.

AREAS COVERED

This review summarizes data about sex differences in MS and the role of pregnancy. Possible mechanisms for the effects of sex and pregnancy are summarized, and practical suggestions for addressing these issues are provided.

EXPERT OPINION

There is considerable interdependence of the variables that are associated with MS. Men have a worse outcome of MS, and this could be due to the same factors that lead to greater incidence of neurodegenerative disease in men. The possible role of parity on the long-term outcome of MS is of interest. Future studies that look at the mechanisms of the effects of the sex of the patient on the outcome of MS are required. However, there are some actions that can be taken without further research. We can concentrate on public health measures that address the modifiable risk factors for MS and ensure that disease is controlled in women who intend to become pregnant and use appropriate disease modifying agents during pregnancy.

Comparative Effectiveness of Natalizumab Versus Anti-CD20 in Highly Active Relapsing-Remitting Multiple Sclerosis After Fingolimod Withdrawal

In France, two therapeutic strategies can be offered after fingolimod (FNG) withdrawal to highly active relapsing-remitting multiple sclerosis (RRMS) patients: natalizumab (NTZ) or anti-CD20. We compared the effectiveness of these two strategies as a switch for FNG within the OFSEP database. The primary endpoint was the time to first relapse. Other outcomes were the relapse rates over 3-month periods, time to worsening the EDSS score, proportion of patients with worsened 24-month MRI, time to treatment discontinuation, and incidence rates of serious adverse events. The dynamics of event rates over time were modeled using multidimensional penalized splines, allowing the possibility to model the effects of covariates in a flexible way, considering non-linearity and interactions. A total of 740 patients were included (337 under anti-CD20 and 403 under NTZ). There was no difference between the two treatments regarding the dynamic of the first occurrence of relapse, with a monthly probability of 5.0% at initiation and 1.0% after 6 months. The rate of EDSS worsening increased in both groups until 6 months and then decreased. No difference in the proportion of patients with new T2 lesions at 24 months was observed. After 18 months of follow-up, a greater risk of NTZ discontinuation was found compared to anti-CD20. This study showed no difference between NTZ and anti-CD20 after the FNG switch regarding the clinical and radiological activity. The effect of these treatments was optimal after 6 months and there was more frequent discontinuation of NTZ after 18 months, probably mainly related to JC virus seroconversions.