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.

Association of multiple-sclerosis-related mortality with COVID-19 and other common infections: a multiple causes of death analysis.

BACKGROUND AND PURPOSE: People with multiple sclerosis (MS) suffer from higher infection-related mortality compared to the general population; however, sparse data are available on the increased risk of death associated with coronavirus disease 2019 (COVID-19) and other common types of infections. METHODS: All mortality records and multiple-cause-of-death data in 2010-2021 of residents in the Veneto region (northeastern Italy) were extracted. Mention of specific infections was compared between death certificates reporting MS or not. Odds ratios (OR) with 95% confidence intervals (95% CI) were estimated by conditional logistic regression matching by age, sex and calendar year. The bimonthly averages of MS-related deaths in 2010-2019 were compared with those registered during the pandemic (2020-2021). RESULTS: Of 580,015 deaths through 2010-2021, MS was mentioned in 850 cases (0.15%), 59.3% women. Influenza and pneumonia were reported in 18.4% of MS-related compared to 11.0% non-MS-related deaths (OR 2.72, 95% CI 2.28-3.25). The odds of mention of urinary tract infections was significantly greater in MS-related deaths of men (OR 8.16, 95% CI 5.23-12.7) than women (OR 3.03, 95% CI 1.82-5.02). Aspiration pneumonia, pressure ulcers/skin infections and sepsis were also significantly associated with MS-related deaths. Reporting of COVID-19 as a cause of death did not significantly differ between deaths with and without mention of MS (approximately 11% of both). However, compared to 2010-2019, peaks in MS-related deaths were observed during the pandemic waves. CONCLUSIONS: Infections continue to play a significant role in MS-related deaths, underlying the need to improve prevention and management strategies.

Sex and age differences in the Multiple Sclerosis prodrome.

Background and objectives: Little is known of the potential sex and age differences in the MS prodrome. We investigated sex and age differences in healthcare utilization during the MS prodrome. Methods: This was a population-based matched cohort study linking administrative and clinical data from British Columbia, Canada (population = 5 million). MS cases in the 5 years preceding a first demyelinating event ("administrative cohort;" n = 6,863) or MS symptom onset ("clinical cohort;" n = 966) were compared to age-, sex- and geographically-matched controls (n = 31,865/4,534). Negative binomial and modified Poisson models were used to compare the rates of physician visits and hospitalizations per international classification of diseases chapter, and prescriptions filled per drug class, between MS cases and controls across sex and age-groups (< 30, 30-49, ≥50 years). Results: In the administrative cohort, males with MS had a higher relative rate for genitourinary-related visits (males: adjusted Rate Ratio (aRR) = 1.65, females: aRR = 1.19, likelihood ratio test P = 0.02) and antivertigo prescriptions (males: aRR = 4.72, females: aRR = 3.01 P < 0.01). Injury and infection-related hospitalizations were relatively more frequent for ≥50-year-olds (injuries < 30/30-49/≥50: aRR = 1.16/1.39/2.12, P < 0.01; infections 30-49/≥50: aRR = 1.43/2.72, P = 0.03), while sensory-related visits and cardiovascular prescriptions were relatively more common in younger persons (sensory 30-49/≥50: aRR = 1.67/1.45, P = 0.03; cardiovascular < 30/30-49/≥50: aRR = 1.56/1.39/1.18, P < 0.01). General practitioner visits were relatively more frequent in males (males: aRR = 1.63, females: aRR = 1.40, P < 0.01) and ≥50-year-olds (< 30/≥50: aRR = 1.32/1.55, P = 0.02), while differences in ophthalmologist visits were disproportionally larger among younger persons, < 50-years-old (< 30/30-49/≥50: aRR = 2.25/2.20/1.55, P < 0.01). None of the sex and age-related differences in the smaller clinical cohort reached significance (P ≥ 0.05). Discussion: Sex and age-specific differences in healthcare use were observed in the 5 years before MS onset. Findings demonstrate fundamental heterogeneity in the MS prodromal presentation.

Disease-Modifying Drugs for Multiple Sclerosis and Association With Survival.

BACKGROUND AND OBJECTIVES: We examined the association between the disease-modifying drugs (DMDs) for multiple sclerosis (MS) and survival in a multiregion population-based study. METHODS: We accessed multiple administrative health databases from 4 Canadian provinces. Persons with MS were identified and followed from the most recent of the first MS or demyelinating event or January 1, 1996 (index date), until death, emigration, or December 31, 2017. Association between the first-generation and second-generation DMDs and all-cause mortality was examined using stratified Cox proportional hazard models, reported as adjusted hazard ratios (aHRs). Timing of DMD initiation was explored, with findings reported at 2, 5, or 10 years postindex date, representing very early, early, or late initiation. RESULTS: We identified 35,894 persons with MS; 72% were female. The mean age at index date was 44.5 years (SD = 13.6). The total person-years of follow-up while DMD-exposed was 89,180, and total person-years while unexposed was 342,217. Compared with no exposure, exposure to any DMD or to any first-generation DMD was associated with a 26% lower hazard of mortality (both aHRs 0.74; 95% CI 0.56-0.98), while any second-generation DMD exposure was associated with a 33% lower hazard (aHR 0.67; 95% CI 0.46-0.98). Earlier DMD initiation (beta-interferon or glatiramer acetate vs no exposure) was associated with a significant mortality effect (p < 0.05), while later initiation was not (95% CIs included 1). However, the survival advantage with earlier initiation diminished over time, no longer reaching statistical significance at 15 years postindex date. DISCUSSION: Our study demonstrates an association between the DMDs for MS and improved survival in the real-world setting.

Care consumption of people with multiple sclerosis: A multichannel sequence analysis in a population-based setting in British Columbia, Canada.

BACKGROUND: Persons with multiple sclerosis (PwMS) typically require complex multidisciplinary care, which is rarely formally assessed. OBJECTIVES: We applied multichannel sequence analysis (MCSA) to identify care consumption patterns by PwMS in British Columbia, Canada. METHODS: We created two cohorts, comprising incident and prevalent MS cases, using linked clinical and administrative data. We applied MCSA to quantify and compare the care pathways of PwMS, based on all-cause hospitalizations and physician visits (divided into five specialities). Care consumption clusters were characterized using demographic and clinical features. RESULTS: From 1048 incident and 3180 prevalent PwMS, the MCSA identified 12 and 6 distinct care consumption clusters over a median follow-up of 9.6 and 13.0 years, respectively. Large disparities between clusters were observed; the median number of annual consultations ranged from 5.6 to 21.3 for general practitioners, 1.2 to 4.6 for neurologists and 0 to 5.3 for psychiatrists in the incident cohort. Characteristics at MS symptom onset associated with the highest care consumption included high comorbidity burden and older age. There were similar disparities and associations for prevalent PwMS. CONCLUSION: The distinct patterns of care consumption, which were reminiscent of the heterogeneity of MS itself, may facilitate health service planning and evaluation, and provide a novel outcome measure in health research.

Disease-modifying drugs for multiple sclerosis and subsequent health service use.

OBJECTIVE: We assessed the relationship between the multiple sclerosis (MS) disease-modifying drugs (DMDs) and healthcare use. METHODS: Persons with MS (aged ⩾18 years) were identified using linked population-based health administrative data in four Canadian provinces and were followed from the most recent of their first MS/demyelinating event or 1 January 1996 until the earliest of death, emigration, or study end (31 December 2017 or 31 March 2018). Prescription records captured DMD exposure, examined as any DMD, then by generation (first-generation (the injectables) or second-generation (orals/infusions)) and individual DMD. The associations with subsequent all-cause hospitalizations and physician visits were examined using proportional means model and negative binomial regression. RESULTS: Of 35,894 MS cases (72% female), mean follow-up was 12.0 years, with person-years of DMD exposure for any, or any first- or second-generation DMD being 63,290, 54,605 and 8685, respectively. Any DMD or any first-generation DMD exposure (versus non-exposure) was associated with a 24% lower hazard of hospitalization (adjusted hazard ratio, aHR: 0.76; 95% confidence intervals (CIs): 0.71-0.82), rising to 29% for the second-generation DMDs (aHR: 0.71; 95% CI: 0.58-0.88). This ranged from 18% for teriflunomide (aHR: 0.82; 95% CI: 0.67-1.00) to 44% for fingolimod (aHR: 0.56; 95% CI: 0.36-0.87). In contrast, DMD exposure was generally not associated with substantial differences in physician visits. CONCLUSION: Findings provide real-world evidence of a beneficial relationship between DMD exposure and hospitalizations.

Medication adherence in multiple sclerosis as a potential model for other chronic diseases: a population-based cohort study.

OBJECTIVE: To determine whether better medication adherence in multiple sclerosis (MS) might be due to specialised disease-modifying drug (DMD) support programmes by: (1) establishing higher adherence in MS than in other chronic diseases and (2) determining if higher adherence is associated with patient-specific or treatment-specific factors. DESIGN: Retrospective cohort study with data from 1 January 1996 to 31 December 2015. SETTING: Population-based health administrative data from three Canadian provinces. PARTICIPANTS: Individual cohorts were created using validated case definitions for MS, epilepsy, Parkinson's disease (PD) and rheumatoid arthritis (RA). Subjects were included if they received ≥1 dispensation for a disease-related drug between 1 January 1997 and 31 December 2014. MAIN OUTCOME MEASURES: Proportion of subjects with optimal adherence (≥80%) measured by the medication possession ratio 1 year after the index date (first dispensation of disease-related drug). RESULTS: 126 478 subjects were included in the primary analysis (MS, n=6271; epilepsy, n=55 739; PD, n=21 304; RA, n=43 164). Subjects with epilepsy (adjusted OR, aOR 0.29; 95% CI 0.19 to 0.45), PD (aOR 0.42; 95% CI 0.29 to 0.63) or RA (aOR 0.26; 95% CI 0.19 to 0.35) were less likely to have optimal 1-year adherence compared with subjects with MS. Within the MS cohort, adherence was higher for DMD than for chronic-use non-MS medications, and no consistent patient-related predictors of adherence were observed across all four non-MS medication classes, including having optimal adherence to DMD. CONCLUSIONS: Subjects with MS were significantly more likely to have optimal 1-year adherence than subjects with epilepsy, RA and PD, and optimal adherence appears related to treatment-specific factors rather than patient-related factors. This supports the hypothesis that higher adherence to the MS DMDs could be due to the specialised support programmes; these programmes may serve as a model for use in other chronic conditions.

A multiple sclerosis disease progression measure based on cumulative disability.

BACKGROUND: Existing severity measurements in multiple sclerosis (MS) are often cross-sectional, making longitudinal comparisons of disease course between individuals difficult. OBJECTIVE: The objective of this study is to create a severity metric that can reliably summarize a patient's disease course. METHODS: We developed the nARMSS - normalized ARMSS (age-related MS severity score) over follow-up, using the deviation of individual ARMSS scores from the expected value and integrated over the corresponding time period. The nARMSS scales from -5 to +5; a positive value indicates a more severe disease course for a patient when compared to other patients with similar disease timings. RESULTS: Using Swedish MS registry data, the nARMSS was tested using data at 2 and 4 years of follow-up to predict the most severe quartile during the subsequent period up to 10 years total follow-up. The metric used was area under the curve of the receiver operating characteristic (AUC-ROC). This resulted in measurements of 0.929 and 0.941. In an external Canadian validation cohort, the equivalent AUC-ROCs were 0.901 and 0.908. CONCLUSION: The nARMSS provides a reliable, generalizable and easily measurable metric which makes longitudinal comparison of disease course between individuals feasible.

Disease-Modifying Drug Uptake and Health Service Use in the Ageing MS Population.

Background: Evidence regarding the efficacy or effectiveness of the disease-modifying drugs (DMDs) in the older multiple sclerosis (MS) population is scarce. This has contributed to a lack of evidence-based treatment recommendations for the ageing MS population in practice guidelines. We examined the relationship between age (<55 and ≥55 years), DMD exposure and health service use in the MS population. Methods: We conducted a population-based observational study using linked administrative health data from British Columbia, Canada. We selected all persons with MS and followed from the most recent of their first MS or demyelinating event, 18th birthday or 01-January-1996 (index date) until the earliest of emigration, death or 31-December-2017 (study end). We assessed DMD exposure status over time, initially as any versus no DMD, then by generation (first or second) and finally by each individual DMD. Age-specific analyses were conducted with all-cause hospitalizations and number of physician visits assessed using proportional means model and negative binomial regression with generalized estimating equations. Results: We included 19,360 persons with MS (72% were women); 10,741/19,360 (56%) had ever reached their 55th birthday. Person-years of follow-up whilst aged <55 was 132,283, and 93,594 whilst aged ≥55. Any DMD, versus no DMD in the <55-year-olds was associated with a 23% lower hazard of hospitalization (adjusted hazard ratio, aHR0.77; 95%CI 0.72-0.82), but not in the ≥55-year-olds (aHR0.95; 95%CI 0.87-1.04). Similar patterns were observed for the first and second generation DMDs. Exposure to any (versus no) DMD was not associated with rates of physician visits in either age group (<55 years: adjusted rate ratio, aRR1.02; 95%CI 1.00-1.04 and ≥55 years: aRR1.00; 95%CI 0.96-1.03), but variation in aRR was observed across the individual DMDs. Conclusion: Our study showed beneficial effects of the DMDs used to treat MS on hospitalizations for those aged <55 at the time of exposure. In contrast, for individuals ≥55 years of age exposed to a DMD, the hazard of hospitalization was not significantly lowered. Our study contributes to the broader understanding of the potential benefits and risks of DMD use in the ageing MS population.

Adherence to laboratory monitoring among people taking oral drugs for multiple sclerosis: A Canadian population-based study.

OBJECTIVE: To examine laboratory testing adherence by persons initiating an oral disease-modifying therapy (DMT) for multiple sclerosis (MS). METHODS: Population-based health administrative and laboratory data were accessed in British Columbia, Canada, to identify everyone filling their first prescription for dimethyl fumarate (DMF), fingolimod or teriflunomide (2011-2015). The proportion of people adherent to each drug monograph's recommended laboratory monitoring schedule, pre- and on-DMT, was estimated. The association between patient characteristics and adherence was examined using multivariable logistic regression. RESULTS: A total of 1016 people were included (DMF 567, fingolimod 253 and teriflunomide 196). The proportions of people adherent to pre-DMT liver and lymphocyte tests ranged from 88% to 91% and 91% to 94%, respectively, while 77% adhered to pre-DMF urinalysis. Adherence to the first on-DMT liver test was 89% for DMF (within 6 months), 61% for fingolimod (within 3 months) and 40% for teriflunomide (within 1 month). Men were less likely than women to have pre-DMF urinalysis (adjusted odds ratio (aOR); 95% confidence interval (CI): 0.40-0.95) or on-DMF liver (aOR: 0.46; 95% CI: 0.23-0.95) or lymphocyte (aOR: 0.47; 95% CI: 0.22-0.98) tests. CONCLUSIONS: Adherence to recommended laboratory testing was high (>77%) before oral DMT initiation, but lower once on drug. There is a need to understand the long-term consequences of suboptimal laboratory monitoring and sex differences in the DMT-treated MS population.

Fatigue, sleep disorders, anaemia and pain in the multiple sclerosis prodrome.

BACKGROUND: There is increasing evidence of prodromal multiple sclerosis (MS). OBJECTIVE: The aim of this study was to determine whether fatigue, sleep disorders, anaemia or pain form part of the MS prodrome. METHODS: This population-based matched cohort study used linked administrative and clinical databases in British Columbia, Canada. The odds of fatigue, sleep disorders, anaemia and pain in the 5 years preceding the MS cases' first demyelinating claim or MS symptom onset were compared with general population controls. The frequencies of physician visits for these conditions were also compared. Modifying effects of age and sex were evaluated. RESULTS: MS cases/controls were assessed before the first demyelinating event (6863/31,865) or MS symptom onset (966/4534). Fatigue (adj.OR: 3.37; 95% CI: 2.76-4.10), sleep disorders (adj.OR: 2.61; 95% CI: 2.34-2.91), anaemia (adj.OR: 1.53; 95% CI: 1.32-1.78) and pain (adj.OR: 2.15; 95% CI: 2.03-2.27) during the 5 years preceding the first demyelinating event were more frequent among cases, and physician visits increased for cases relative to controls. The association between MS and anaemia was greater for men; that between MS and pain increased with age. Pre-MS symptom onset, sleep disorders (adj.OR: 1.72; 95% CI: 1.12-2.56) and pain (adj.OR: 1.53; 95% CI: 1.32-1.76) were more prevalent among cases. CONCLUSION: Fatigue, sleep disorders, anaemia and pain were elevated before the recognition of MS. The relative anaemia burden was higher in men and pain more evident among older adults.

Accurate classification of secondary progression in multiple sclerosis using a decision tree.

BACKGROUND: The absence of reliable imaging or biological markers of phenotype transition in multiple sclerosis (MS) makes assignment of current phenotype status difficult. OBJECTIVE: The authors sought to determine whether clinical information can be used to accurately assign current disease phenotypes. METHODS: Data from the clinical visits of 14,387 MS patients in Sweden were collected. Classifying algorithms based on several demographic and clinical factors were examined. Results obtained from the best classifier when predicting neurologist recorded disease classification were replicated in an independent cohort from British Columbia and were compared to a previously published algorithm and clinical judgment of three neurologists. RESULTS: A decision tree (the classifier) containing only most recently available expanded disability scale status score and age obtained 89.3% (95% confidence intervals (CIs): 88.8-89.8) classification accuracy, defined as concordance with the latest reported status. Validation in the independent cohort resulted in 82.0% (95% CI: 81.0-83.1) accuracy. A previously published classification algorithm with slight modifications achieved 77.8% (95% CI: 77.1-78.4) accuracy. With complete patient history of 100 patients, three neurologists obtained 84.3% accuracy compared with 85% for the classifier using the same data. CONCLUSION: The classifier can be used to standardize definitions of disease phenotype across different cohorts. Clinically, this model could assist neurologists by providing additional information.

Short-term laboratory and related safety outcomes for the multiple sclerosis oral disease-modifying therapies: an observational study.

BACKGROUND: Real-world safety data for the oral multiple sclerosis (MS) disease-modifying therapies (DMTs), dimethyl fumarate (DMF), fingolimod, and teriflunomide are important. We examined laboratory test abnormalities and adverse health conditions in new users. METHODS: Linked laboratory and administrative health data were accessed for all persons with MS (PwMS) filling their first oral DMT prescription in two Canadian provinces. PwMS were followed from first prescription fill until discontinuation, death, emigration or study end. Proportions of PwMS, and incidence rates (IR)/100 person-years, were calculated for ≥1 event of elevated alanine aminotransferase (ALT) (>the upper limit of normal [ULN]; all DMTs), liver toxicity (ALT>3xULN; fingolimod); lymphopenia and proteinuria (DMF), and cardiac arrhythmia, hypertension and pneumonia (all DMTs). RESULTS: Overall, 1,140 PwMS were followed for up to 2 years. De novo elevated alanine aminotransferase affected 13.2% (DMF), 12.4% (teriflunomide), and 30.0% (fingolimod) of users. Liver toxicity affected 2.8% of fingolimod, lymphopenia 3.1% of DMF, and proteinuria 2.9% of DMF users. The incidences of cardiac arrhythmia, pneumonia and hypertension ranged from <1 to 1.86/100 person-years depending on the DMT. CONCLUSIONS: The short-term, real-world incidences of abnormal laboratory results or adverse events were consistent with the pivotal clinical trial findings. Longer-term safety data are still needed.

Characteristics of a population-based multiple sclerosis cohort treated with disease-modifying drugs in a universal healthcare setting.

Background: Relatively little is known about the use of disease-modifying drugs (DMDs) for multiple sclerosis (MS) in the population-based universal healthcare setting. This study aimed to describe the characteristics of a population-based cohort with MS and their DMD exposure in four Canadian provinces. Methods: We identified all adults (aged ≥18 years) with MS using linked population-based health administrative data. Individuals were followed from the most recent of their first MS or demyelinating event or 1 January 1996(study entry), to the earliest of death, emigration, or 31 March 2018(study end). Cohort characteristics examined included sex, age, socioeconomic status, and comorbidity burden. Results: Overall, 10,418/35,894 (29%) of MS cases filled a DMD prescription during the 22-year study period. Most were women (n = 7,683/10,418;74%), and 17% (n = 1,745/10,418) had some comorbidity (Charlson Comorbidity Index≥1) at study entry. Nearly 20% (n = 1,745/10,418) were aged ≥50 when filling their first DMD; the mean age was 39.6 years. Conclusions: Almost 1 in 6 people with MS had at least some comorbidity, and nearly 1 in 6 were ≥50 years old at the time of their first DMD. As these individuals are typically excluded from clinical trials, findings illustrate the need to understand the harms and benefits of DMD use in these understudied groups.

Dealing With Treatment-Confounder Feedback and Sparse Follow-up in Longitudinal Studies: Application of a Marginal Structural Model in a Multiple Sclerosis Cohort.

The beta-interferons are widely prescribed platform therapies for patients with multiple sclerosis (MS). We accessed a cohort of patients with relapsing-onset MS from British Columbia, Canada (1995-2013), to examine the potential survival advantage associated with beta-interferon exposure using a marginal structural model. Accounting for potential treatment-confounder feedback between comorbidity, MS disease progression, and beta-interferon exposure, we found an association between beta-interferon exposure of at least 6 contiguous months and improved survival (hazard ratio (HR) = 0.63, 95% confidence interval 0.47, 0.86). We also assessed potential effect modifications by sex, baseline age, or baseline disease duration, and found these factors to be important effect modifiers. Sparse follow-up due to variability in patient contact with the health system is one of the biggest challenges in longitudinal analyses. We considered several single-level and multilevel multiple imputation approaches to deal with sparse follow-up and disease progression information; both types of approach produced similar estimates. Compared to ad hoc imputation approaches, such as linear interpolation (HR = 0.63), and last observation carried forward (HR = 0.65), all multiple imputation approaches produced a smaller hazard ratio (HR = 0.53), although the direction of effect and conclusions drawn concerning the survival advantage remained the same.

Alemtuzumab and prescription medication use in the MS population.

Medications are indicated to minimize adverse reactions with alemtuzumab treatment for multiple sclerosis, but polypharmacy can be problematic. We characterized prescriptions filled by 160 individuals before, during and after first infusion of alemtuzumab (Dec/2013-Jun/2017). Ninety-five percent of individuals filled ≥1 prescription(s) before alemtuzumab across 87 unique drug classes, averaging 5.3 prescriptions/person over 47 weeks. During the infusion period, 90% filled ≥1 prescription(s) for 40 new drug classes, averaging 2.2 prescriptions/person over 5 weeks. Twenty-four percent refilled ≥1 of these prescription(s) after alemtuzumab across 17 drug classes, averaging 0.3 refills/person over 24 weeks. There was substantial medication burden throughout the study.

A systematic review of morbidities suggestive of the multiple sclerosis prodrome.

INTRODUCTION: The identification of a prodromal phase in multiple sclerosis (MS) could have major implications for earlier recognition and management of MS. The authors conducted a systematic review assessing studies of morbidities before, or at, MS onset or diagnosis.Areas covered: Two independent reviewers searched Medline, Embase, Psycinfo and CINAHL from inception to February 8th, 2019. To be eligible, studies had to be published in English and report the relative occurrence of at least one morbidity or symptom before, or at, MS onset or diagnosis among MS cases in comparison to a control group not known to have MS. Findings were narratively synthesized. Study quality was assessed using the Newcastle-Ottawa scale (NOS, maximum score 9).Expert opinion: Twenty-nine studies were included, which comprised 83,590 MS cases and 396,343 controls. Most were case-control studies (25/29), 8/29 were of high quality (NOS≥8) and 19/29 examined the period before MS symptom onset. Most studies assessing anxiety, depression, migraine and lower cognitive performance found these conditions to be more prevalent before MS onset or diagnosis relative to controls. There was limited evidence to implicate other conditions. Thus, there is evidence that anxiety, depression, migraine and lower cognitive performance form part of the MS prodrome.

Interrogation of the Multiple Sclerosis Prodrome Using High-Dimensional Health Data.

BACKGROUND: There is growing evidence of a prodromal period in multiple sclerosis (MS). A better understanding of the prodrome may facilitate prompt recognition and treatment of MS as well as narrowing of the etiologically relevant -period when searching for MS risk factors. OBJECTIVES: To explore and further delineate the MS prodrome, we used statistical learning techniques to examine associations of physician-generated diagnostic codes and prescription medication classes in the 5 years before the first demyelinating-related claim for MS cases and matched population controls. METHODS: In this matched cohort study, we accessed data from linked health administrative hospital, physician, and prescription databases from British Columbia, Canada, between 1996 and 2013. We focused on 7 medication classes previously identified as associated with the MS prodrome: urinary anti-spasmodics, glucocorticoids, muscle relaxants, anti-epileptics, dopa-derivatives, benzodiazepine, and antivertigo preparations. Diagnostic codes associated with the use of each medication class were first identified using LASSO logistic regression analyses in two-thirds of the cohort and then validated using multivariate logistic regressions in the remaining cohort. RESULTS: Our analyses included 4,862 MS cases and 22,649 controls. Although the identified diagnostic codes showed fair to good predictive performance in 6 medication classes (C-index = 0.712-0.858), these codes failed to fully explain the higher usage of these medications by the MS cases. Compared to controls of the same age, sex, and diagnostic codes, MS cases had higher odds of filling a prescription for antivertigo preparations (adjusted OR [aOR] 2.48; 95% CI 1.92-3.19), anti-epileptics (aOR 2.34; 1.90-2.90), glucocorticoids (aOR 1.76; 1.52-2.03), urinary anti-spasmodics (aOR 1.72; 1.20-2.46), and muscle relaxants (aOR 1.33; 1.13-1.56). CONCLUSIONS: We observed markedly higher use of specific medications in MS cases in the 5 years before the first demyelinating claim. The overrepresentation of specific medications in MS cases, which was not fully explained by the physician diagnoses, may represent a signature of the MS prodrome.

Multiple cause of death analysis in multiple sclerosis: A population-based study.

OBJECTIVE: To gain a better understanding of the complex patterns of causes that contribute to death due to multiple sclerosis (MS) by assessing the relationship between MS and other causes of death listed on death certificates. METHODS: Multiple cause of death data for all adult deaths (aged ≥18 years) in British Columbia, Canada, between 1986 and 2013 were accessed. All causes, as listed on the death certificate, whether underlying or contributing, were considered "any mention" causes. The associations between mention of MS on the death certificate and mention of other causes of death were examined by logistic regression, adjusted for age, sex, and calendar year (Bonferroni-corrected α level = 0.002). Findings were also sex-stratified. RESULTS: Among 771,288 deaths, MS was mentioned on 2,153 certificates. If MS was mentioned (versus not mentioned), there was a greater chance that specific conditions contributed to the death: respiratory infection (adjusted odds ratio [aOR], 3.03 [95% confidence interval (CI), 2.73-3.36]), aspiration pneumonia (aOR, 7.15 [95% CI, 6.23-8.22]), urinary tract infection (UTI) (aOR, 10.2 [95% CI, 8.7-12.0]), other infection including sepsis (aOR, 1.34 [95% CI, 1.15-1.56]), and skin disease (aOR, 5.06 [95% CI, 3.96-6.46]). Sex differences existed for urinary tract infection (men: aOR, 14.9 [95% CI, 11.5-19.3]; women: aOR, 8.00 [95% CI, 6.53-9.81]) and chronic respiratory disease (men = aOR, 1.36 [95% CI, 1.14-1.63]; women = aOR, 0.97 [95% CI, 0.84-1.13]). CONCLUSIONS: Deaths attributed to MS were commonly caused by infection (especially respiratory and urinary tract-related); conditions associated with advanced disability and immobility, such as aspiration pneumonia; and chronic respiratory disease in men. All are potentially modifiable; interventions that reduce the frequency or severity of these complications could improve survival in MS.

Informing Medication Discontinuation Decisions among Older Adults with Relapsing-Onset Multiple Sclerosis.

BACKGROUND: For older adults with relapsing-onset multiple sclerosis (MS), limited information is available to inform if, or when, disease-modifying drugs (DMDs) may be safely discontinued. OBJECTIVE: The aim of this study was to project the outcomes of DMD discontinuation among older adults with relapsing-onset MS. METHODS: We projected the 10-year outcomes of discontinuation of a DMD (interferon-ß, fingolimod, or natalizumab) among older adults (aged 55 or 70 years) who were relapse-free for 5 or more years and had not reached an Expanded Disability Status Scale (EDSS) score of 6. Outcomes included the percentage of people who had at least one relapse or reached EDSS 6, and quality-adjusted life-years (QALYs), which incorporated both relapses and disability. We used a simulation modeling approach. With increased age, relapses decreased and the effectiveness of DMDs for disability outcomes also decreased. RESULTS: We found lower projected benefits for DMD continuation at 70 years of age than at 55 years of age. Compared with discontinuation, the projected benefit of DMD continuation ranged from 0.007 to 0.017 QALYs at 55 years of age and dropped to 0.002-0.006 at 70 years of age. The annual projected benefits of DMD continuation (0.1-3.0 quality-adjusted life-days) were very low compared with typical patient preferences regarding treatment burden. CONCLUSION: The benefits of DMDs may not be substantial among older adults with relapsing-onset MS. Direct clinical evidence remains limited and the decision of whether to discontinue a DMD should also take into account patient preferences. It is important to gain a better understanding of how age-related changes in the trajectory of relapsing-onset MS affect treatment effectiveness among older adults.