Feasibility of Using a Nationally Representative Telephone Survey to Monitor Multiple Sclerosis Prevalence in the United States.

BACKGROUND: Multiple sclerosis (MS) is the most common chronic neurologic disease of young adults, placing a heavy burden on patients, families, and the healthcare system. Ongoing surveillance of the incidence and prevalence of MS is critical for health policy and research, but feasible options are limited in the United States and many other countries. We investigated the feasibility of monitoring the prevalence of MS using a large national telephone survey of the adult US population. METHODS: We developed questions to estimate the lifetime prevalence and age of onset of MS using the US-based Behavioral Risk Factor Surveillance System (BRFSS) and piloted these questions in 4 states (MN, RI, MD, and TX). There was a total of 45,198 respondents aged 18 years and above. Analyses investigated individual state and combined prevalence estimates along with health-related comorbidities and limitations. MS prevalence estimates from the BRFSS were compared to estimates from multi-source administrative claims and traditional population-based methods. RESULTS: The estimated lifetime prevalence of self-reported MS (per 100,000 adults) was 682 (95% CI 528-836); 384 (95% CI 239-529) among males and 957 (95% CI 694-1,220) among females. Estimates were consistent across the 4 states but much higher than recently published estimates using population-based administrative claims data. This was observed for both national results and for MS prevalence estimates from other studies within specific states (MN, RI, and TX). Prevalence estimates for Caucasian, African American, and Hispanic respondents were 824, 741, and 349 per 100,000 respectively. Age and sex distributions were consistent with prior epidemiologic reports. Comorbidity and functional limitations were more pronounced among female than male respondents. CONCLUSIONS: While yielding higher overall MS prevalence estimates compared to recent studies, this large-scale self-report telephone method yielded relative prevalence estimates (e.g., prevalence patterns of MS by sex, age, and race-ethnicity) that were generally comparable to other surveillance approaches. With certain caveats, population-based telephone surveys may eventually offer the ability to investigate novel disease correlates and are relatively feasible, and affordable. Further work is needed to create a valid question set and methodology for case ascertainment before this approach could be adopted to accurately estimate MS prevalence.

Symbol Digit Modalities Test: A valid clinical trial endpoint for measuring cognition in multiple sclerosis.

BACKGROUND: The need for more robust outcomes in multiple sclerosis (MS) clinical trials has been a main priority of the field for decades. Dissatisfaction with existing measures has led to several consensus meetings and initiatives over the past few decades in hopes of defining and gaining acceptance of measures that are valid, reliable, sensitive to change and progression, and most importantly, relevant to those living with MS. The Multiple Sclerosis Outcome Assessments Consortium (MSOAC) was formed for this purpose. OBJECTIVE: The objective of this paper is to describe the results of the MSOAC plan to obtain qualification for a cognitive performance measure that meets these requirements. METHODS: Using data from 14 MS disease-modifying registration trials, we completed a comprehensive examination of the psychometric qualities of the Symbol Digit Modalities Test (SDMT) and the Paced Auditory Serial Addition Test (PASAT) with the goal of compiling evidence to support the utilization of one of these measures in future clinical trials. RESULTS AND CONCLUSION: Consistent with the published literature, the SDMT proved superior to the PASAT. The SDMT should be considered the measure of choice for MS trials in assessing cognitive processing speed.

Computerized neuropsychological assessment devices in multiple sclerosis: A systematic review.

BACKGROUND: The proliferation of computerized neuropsychological assessment devices (CNADs) for screening and monitoring cognitive impairment is increasing exponentially. Previous reviews of computerized tests for multiple sclerosis (MS) were primarily qualitative and did not rigorously compare CNADs on psychometric properties. OBJECTIVE: We aimed to systematically review the literature on the use of CNADs in MS and identify test batteries and single tests with good evidence for reliability and validity. METHOD: A search of four major online databases was conducted for publications related to computerized testing and MS. Test-retest reliability and validity coefficients and effect sizes were recorded for each CNAD test, along with administration characteristics. RESULTS: We identified 11 batteries and 33 individual tests from 120 peer-reviewed articles meeting the inclusion criteria. CNADs with the strongest psychometric support include the CogState Brief Battery, Cognitive Drug Research Battery, NeuroTrax, CNS-Vital Signs, and computer-based administrations of the Symbol Digit Modalities Test. CONCLUSION: We identified several CNADs that are valid to screen for MS-related cognitive impairment, or to supplement full, conventional neuropsychological assessment. The necessity of testing with a technician, and in a controlled clinic/laboratory environment, remains uncertain.

Recommendations for cognitive screening and management in multiple sclerosis care.

PURPOSE: To promote understanding of cognitive impairment in multiple sclerosis (MS), recommend optimal screening, monitoring, and treatment strategies, and address barriers to optimal management. METHODS: The National MS Society ("Society") convened experts in cognitive dysfunction (clinicians, researchers, and lay people with MS) to review the published literature, reach consensus on optimal strategies for screening, monitoring, and treating cognitive changes, and propose strategies to address barriers to optimal care. RECOMMENDATIONS: Based on current evidence, the Society makes the following recommendations, endorsed by the Consortium of Multiple Sclerosis Centers and the International Multiple Sclerosis Cognition Society: Increased professional and patient awareness/education about the prevalence, impact, and appropriate management of cognitive symptoms. For adults and children (8+ years of age) with clinical or magnetic resonance imaging (MRI) evidence of neurologic damage consistent with MS: As a minimum, early baseline screening with the Symbol Digit Modalities Test (SDMT) or similarly validated test, when the patient is clinically stable; Annual re-assessment with the same instrument, or more often as needed to (1) detect acute disease activity; (2) assess for treatment effects (e.g. starting/changing a disease-modifying therapy) or for relapse recovery; (3) evaluate progression of cognitive impairment; and/or (4) screen for new-onset cognitive problems. For adults (18+ years): more comprehensive assessment for anyone who tests positive on initial cognitive screening or demonstrates significant cognitive decline, especially if there are concerns about comorbidities or the individual is applying for disability due to cognitive impairment. For children (<18 years): neuropsychological evaluation for any unexplained change in school functioning (academic or behavioral). Remedial interventions/accommodations for adults and children to improve functioning at home, work, or school.

Wellness and multiple sclerosis: The National MS Society establishes a Wellness Research Working Group and research priorities.

BACKGROUND: People with multiple sclerosis (MS) have identified "wellness" and associated behaviors as a high priority based on "social media listening" undertaken by the National MS Society (i.e. the Society). OBJECTIVE: The Society recently convened a group that consisted of researchers with experience in MS and wellness-related research, Society staff members, and an individual with MS for developing recommendations regarding a wellness research agenda. METHOD: The members of the group engaged in focal reviews and discussions involving the state of science within three approaches for promoting wellness in MS, namely diet, exercise, and emotional wellness. RESULTS: That process informed a group-mediated activity for developing and prioritizing research goals for wellness in MS. This served as a background for articulating the mission and objectives of the Society's Wellness Research Working Group. CONCLUSION: The primary mission of the Wellness Research Working Group is the provision of scientific evidence supporting the application of lifestyle, behavioral, and psychosocial approaches for promoting optimal health of mind, body, and spirit (i.e. wellness) in people with MS as well as managing the disease and its consequences.

The MSOAC approach to developing performance outcomes to measure and monitor multiple sclerosis disability.

BACKGROUND: The Multiple Sclerosis Outcome Assessments Consortium (MSOAC) was formed by the National MS Society to develop improved measures of multiple sclerosis (MS)-related disability. OBJECTIVES: (1) To assess the current literature and available data on functional performance outcome measures (PerfOs) and (2) to determine suitability of using PerfOs to quantify MS disability in MS clinical trials. METHODS: (1) Identify disability dimensions common in MS; (2) conduct a comprehensive literature review of measures for those dimensions; (3) develop an MS Clinical Data Interchange Standards Consortium (CDISC) data standard; (4) create a database of standardized, pooled clinical trial data; (5) analyze the pooled data to assess psychometric properties of candidate measures; and (6) work with regulatory agencies to use the measures as primary or secondary outcomes in MS clinical trials. CONCLUSION: Considerable data exist supporting measures of the functional domains ambulation, manual dexterity, vision, and cognition. A CDISC standard for MS ( http://www.cdisc.org/therapeutic#MS ) was published, allowing pooling of clinical trial data. MSOAC member organizations contributed clinical data from 16 trials, including 14,370 subjects. Data from placebo-arm subjects are available to qualified researchers. This integrated, standardized dataset is being analyzed to support qualification of disability endpoints by regulatory agencies.

Validity of the Symbol Digit Modalities Test as a cognition performance outcome measure for multiple sclerosis.

Cognitive and motor performance measures are commonly employed in multiple sclerosis (MS) research, particularly when the purpose is to determine the efficacy of treatment. The increasing focus of new therapies on slowing progression or reversing neurological disability makes the utilization of sensitive, reproducible, and valid measures essential. Processing speed is a basic elemental cognitive function that likely influences downstream processes such as memory. The Multiple Sclerosis Outcome Assessments Consortium (MSOAC) includes representatives from advocacy organizations, Food and Drug Administration (FDA), European Medicines Agency (EMA), National Institute of Neurological Disorders and Stroke (NINDS), academic institutions, and industry partners along with persons living with MS. Among the MSOAC goals is acceptance and qualification by regulators of performance outcomes that are highly reliable and valid, practical, cost-effective, and meaningful to persons with MS. A critical step for these neuroperformance metrics is elucidation of clinically relevant benchmarks, well-defined degrees of disability, and gradients of change that are deemed clinically meaningful. This topical review provides an overview of research on one particular cognitive measure, the Symbol Digit Modalities Test (SDMT), recognized as being particularly sensitive to slowed processing of information that is commonly seen in MS. The research in MS clearly supports the reliability and validity of this test and recently has supported a responder definition of SDMT change approximating 4 points or 10% in magnitude.

The Nine-Hole Peg Test as a manual dexterity performance measure for multiple sclerosis.

Impaired manual dexterity is a frequently reported disability in people with multiple sclerosis (MS) and is increasingly prevalent with worsening disease. While various tests and patient-reported outcome measures are available, the Nine-Hole Peg Test (NHPT) is considered as a gold standard measure of manual dexterity and most frequently used in MS research and clinical practice. The MS Outcome Assessments Consortium (MSOAC) includes representatives from advocacy organizations, Food and Drug Administration (FDA), European Medicines Agency (EMA), National Institute of Neurological Disorders and Stroke (NINDS), academic institutions, and industry partners along with persons living with MS. Among the MSOAC goals are acceptance and qualification by regulators of performance outcomes that are highly reliable and valid, practical, cost-effective, and meaningful to persons with MS. A critical step for these neuroperformance metrics is elucidation of clinically relevant benchmarks, well-defined degrees of disability, and gradients of change that are deemed clinically meaningful. This article addresses the NHPT, the proposed MSOAC measure for upper extremity function. We find that the NHPT is reliable within and between test sessions, discriminates between healthy subjects and MS patients with different levels of upper limb impairment, and shows high convergent validity with other manual dexterity as well as more comprehensive upper limb measures. Ecological validity is established by its relation to perceived upper limb use in daily life and perceived difficulty in performing activities of daily living. The NHPT is responsive to deterioration in longitudinal studies, and research suggests that a 20% change in test score is commonly used to define clinically meaningful worsening, a definition that needs further validation in all stages of the disease.

Validity of the timed 25-foot walk as an ambulatory performance outcome measure for multiple sclerosis.

The Multiple Sclerosis Outcome Assessments Consortium (MSOAC) includes representatives from advocacy organizations, Food and Drug Administration (FDA), European Medicines Agency (EMA), National Institute of Neurological Disorders and Stroke (NINDS), academic institutions, and industry partners along with persons living with multiple sclerosis (MS). One of the MSOAC goals is acceptance and qualification by regulators of performance outcomes that are highly reliable and valid, practical, cost-effective, and meaningful in MS. This article addresses the history, application, and psychometric properties of one such MSOAC metric of ambulation or walking namely, the timed 25-foot walk (T25FW). The T25FW has strong reliability over both brief and long periods of time in MS across a large range of disability levels. The outcome of walking speed from the T25FW has obvious real-world relevance and has correlated strongly with other measures of walking and lower extremity function. The T25FW is responsive for capturing intervention effects in pharmacological and rehabilitation trials and has an established value for capturing clinically meaningful change in ambulation. Directions for future research involve validating clinically meaningful improvements on the T25FW as well as determining whether 20% change is clinically meaningful across the disability spectrum. Researchers might further consider synchronizing accelerometers and motion sensors with the T25FW for capturing walking speed in everyday life and the patient's real environment.

Validity of low-contrast letter acuity as a visual performance outcome measure for multiple sclerosis.

Low-contrast letter acuity (LCLA) has emerged as the leading outcome measure to assess visual disability in multiple sclerosis (MS) research. As visual dysfunction is one of the most common manifestations of MS, sensitive visual outcome measures are important in examining the effect of treatment. Low-contrast acuity captures visual loss not seen in high-contrast visual acuity (HCVA) measurements. These issues are addressed by the MS Outcome Assessments Consortium (MSOAC), including representatives from advocacy organizations, Food and Drug Administration (FDA), European Medicines Agency (EMA), National Institute of Neurological Disorders and Stroke (NINDS), academic institutions, and industry partners along with persons living with MS. MSOAC goals are acceptance and qualification by regulators of performance outcomes that are highly reliable and valid, practical, cost-effective, and meaningful to persons with MS. A critical step is elucidation of clinically relevant benchmarks, well-defined degrees of disability, and gradients of change that are clinically meaningful. This review shows that MS and disease-free controls have similar median HCVA, while MS patients have significantly lower LCLA. Deficits in LCLA and vision-specific quality of life are found many years after an episode of acute optic neuritis, even when HCVA has recovered. Studies reveal correlations between LCLA and the Expanded Disability Status Score (EDSS), Multiple Sclerosis Functional Composite (MSFC), retinal nerve fiber layer (RNFL) and ganglion cell layer plus inner plexiform layer (GCL + IPL) thickness on optical coherence tomography (OCT), brain magnetic resonance imaging (MRI), visual evoked potential (VEP), electroretinogram (ERG), pupillary function, and King-Devick testing. This review also concludes that a 7-point change in LCLA is clinically meaningful. The overall goal of this review is to describe and characterize the LCLA metric for research and clinical use among persons with MS.

Multiple Sclerosis Outcome Assessments Consortium: Genesis and initial project plan.

The need for improved clinical outcome measures in multiple sclerosis trials has been recognized for two decades, but only recently has the Food and Drug Administration (FDA) created a pathway for qualification of new clinician-reported outcome (ClinRO) assessments. Additionally, drug development in multiple sclerosis (MS) has been extraordinarily active, with numerous disease-modifying drugs now on the market. This shifting therapeutic landscape, along with the unmet need for drugs to treat the progressive forms of MS and the changing expectations of clinicians, patients, and payers, have led to the call for more sensitive and meaningful disability progression measures. In response to these drivers, the Multiple Sclerosis Outcome Assessments Consortium (MSOAC) was launched. A public-private partnership, MSOAC aims to accelerate the development of new therapies for MS by generating new tools for measuring outcomes in clinical trials. At the first annual MSOAC/FDA meeting, a regulatory path was outlined for qualifying a new tool for assessing efficacy in registration trials of MS. The European Medicines Agency (EMA) and FDA will provide parallel consultation and review. The consensus approach with engagement by all of the stakeholders, prominently including patients with MS, should also increase acceptance of the measure by clinicians and patients.

Population-Based Estimates for the Prevalence of Multiple Sclerosis in the United States by Race, Ethnicity, Age, Sex, and Geographic Region.

Importance: Racial, ethnic, and geographic differences in multiple sclerosis (MS) are important factors to assess when determining the disease burden and allocating health care resources. Objective: To calculate the US prevalence of MS in Hispanic, non-Hispanic Black (hereafter referred to as Black), and non-Hispanic White individuals (hereafter referred to as White) stratified by age, sex, and region. Design, Setting, and Participants: A validated algorithm was applied to private, military, and public (Medicaid and Medicare) administrative health claims data sets to identify adult cases of MS between 2008 and 2010. Data analysis took place between 2019 and 2022. The 3-year cumulative prevalence overall was determined in each data set and stratified by age, sex, race, ethnicity, and geography. The insurance pools included 96 million persons from 2008 to 2010. Insurance and stratum-specific estimates were applied to the 2010 US Census data and the findings combined to calculate the 2010 prevalence of MS cumulated over 10 years. No exclusions were made if a person met the algorithm criteria. Main Outcomes and Measurements: Prevalence of MS per 100 000 US adults stratified by demographic group and geography. The 95% CIs were approximated using a binomial distribution. Results: A total of 744 781 persons 18 years and older were identified with MS with 564 426 cases (76%) in females and 180 355 (24%) in males. The median age group was 45 to 54 years, which included 229 216 individuals (31%), with 101 271 aged 18 to 24 years (14%), 158 997 aged 35 to 44 years (21%), 186 758 aged 55 to 64 years (25%), and 68 539 individuals (9%) who were 65 years or older. White individuals were the largest group, comprising 577 725 cases (77%), with 80 276 Black individuals (10%), 53 456 Hispanic individuals (7%), and 33 324 individuals (4%) in the non-Hispanic other category. The estimated 2010 prevalence of MS per 100 000 US adults cumulated over 10 years was 161.2 (95% CI, 159.8-162.5) for Hispanic individuals (regardless of race), 298.4 (95% CI, 296.4-300.5) for Black individuals, 374.8 (95% CI, 373.8-375.8) for White individuals, and 197.7 (95% CI, 195.6-199.9) for individuals from non-Hispanic other racial and ethnic groups. During the same time period, the female to male ratio was 2.9 overall. Age stratification in each of the racial and ethnic groups revealed the highest prevalence of MS in the 45- to 64-year-old age group, regardless of racial and ethnic classification. With each degree of latitude, MS prevalence increased by 16.3 cases per 100 000 (95% CI, 12.7-19.8; P < .001) in the unadjusted prevalence estimates, and 11.7 cases per 100 000 (95% CI, 7.4-16.1; P < .001) in the direct adjusted estimates. The association of latitude with prevalence was strongest in women, Black individuals, and older individuals. Conclusions and Relevance: This study found that White individuals had the highest MS prevalence followed by Black individuals, individuals from other non-Hispanic racial and ethnic groups, and Hispanic individuals. Inconsistent racial and ethnic classifications created heterogeneity within groups. In the United States, MS affects diverse racial and ethnic groups. Prevalence of MS increases significantly and nonuniformly with latitude in the United States, even when adjusted for race, ethnicity, age, and sex. These findings are important for clinicians, researchers, and policy makers.

The Economic Burden of Multiple Sclerosis in the United States: Estimate of Direct and Indirect Costs.

BACKGROUND AND OBJECTIVES: A recent report estimated that approximately 1 million adults were living with multiple sclerosis (MS) in the United States. Although MS is rarely the direct cause of death, its debilitating effects on normal body functions can result in considerable disruption to daily living and life roles including work, physical independence, mobility, social interaction, and participation in leisure activities. This study estimated the total economic burden of MS in the United States in 2019. METHODS: This study used a prevalence-based approach to estimate the national economic burden of MS. Claims from 3 sources (Medicare Current Beneficiary Survey, Medicare Standard Analytical File, and Optum de-identified Normative Health Information System) were used to obtain direct costs and a survey was developed to collect indirect costs (e.g., labor market productivity losses, costs of paid and unpaid caregivers, home modification) from 946 patients with MS (PwMS). Direct medical costs reflected the difference in the total average annual amount paid for PwMS vs matched controls without MS. Future earnings loss due to premature death attributable to MS was calculated using Centers for Disease Control and Prevention mortality data and Medicare claims data. RESULTS: The estimated total economic burden was $85.4 billion, with a direct medical cost of $63.3 billion and indirect and nonmedical costs of $22.1 billion. Retail prescription medication (54%); clinic-administered drugs, medication, and administration (12%); and outpatient care (9%) were the 3 largest components of the direct costs. The average excess per-person annual medical costs for PwMS was $65,612; at $35,154 per person, disease-modifying therapies (DMTs) accounted for the largest proportion of this cost. The cost per DMT user ranged from $57,202 to $92,719, depending on sex-age strata. The average indirect and nonmedical costs were $18,542 per PwMS and $22,875 per PwMS if caregivers' costs were included. Lost earnings due to premature death, presenteeism, and absenteeism losses were the largest indirect cost components. DISCUSSION: MS is a costly chronic disease, with direct costs of prescription drugs and indirect productivity loss being important cost drivers. Our findings suggested that the burden of MS in the United States has been underestimated.

Quality of life and experience with the national multiple sclerosis society strategic plan priorities for people with multiple sclerosis: Findings from a path analysis.

BACKGROUND: The National Multiple Sclerosis Society (NMSS) strives to ensure that people affected by multiple sclerosis (MS) can live their best lives. This mission is reflected in the Society's strategic plan, which establishes the roadmap for the Society's continued commitment to a world free of MS. OBJECTIVE: The purpose of this article is to add to the understanding of both the scope and complexity of the impact of MS and MS-related supports on quality of life (QOL). METHODS: A national sample of people with MS (n = 748) participated in the study by completing validated surveys assessing their QOL, physical and mental health, MS self-efficacy, resilience, participation in NMSS, perceived stress, emotional support, and social roles and activities. A path model was used to examine how the frequently identified MS QOL predictors, including demographic, MS, psychosocial, and physical functional status variables relate to each other and to QOL. RESULTS: The model exhibited reasonable model fit with hypothesized paths being statistically significant and in the hypothesized direction. CONCLUSION: Findings revealed that the relationships among mental health, demographic factors, overall MS experiences, QOL, NMSS participation, and resonance with the mission of the NMSS are complex, highly nuanced, and yet strongly correlated. More importantly, the study highlights the strong influence of variables that are more readily amenable to change through programmatic and clinical intervention, and active self-management and participation.

Multiple Sclerosis Adult Day Programs and Health-Related Quality of Life of Persons with Multiple Sclerosis and Informal Caregivers.

BACKGROUND: Multiple sclerosis adult day programs (MSADPs) offer life-enhancing services for individuals and informal caregivers affected by multiple sclerosis (MS), including medical care, rehabilitation therapies, nutrition therapy, cognitive training, tailored education, exercise programs, and social interaction. The purpose of this study was to examine the effects of MSADPs on health-related quality of life (HRQOL) and health care utilization of persons with MS and HRQOL and well-being of informal caregivers. METHODS: Using a quasi-experimental design, outcomes between baseline and 1-year follow-up in persons with MS and informal caregivers who used MSADP services and a comparison group of similar persons with MS and caregivers who did not use MSADP services were compared. For persons with MS, outcomes included standardized measures of physical and mental HRQOL and health care utilization. For caregivers, outcomes included physical and mental HRQOL and well-being. Changes in outcomes between baseline and follow-up were examined using propensity score-weighted difference-in-differences regression analysis. RESULTS: For persons with MS, MSADP use had a significant positive effect on 12-Item Short Form Health Survey physical component scores, although the difference was not clinically meaningful. Use of MSADPs did not have effects on any other outcomes for persons with MS or caregivers. CONCLUSIONS: Use of MSADPs did not show a clinically meaningful effect on HRQOL for persons with MS or informal caregivers. The MSADPs do not seem to offer sustained benefits to persons with MS or caregivers, but the possibility of initial short-term benefits cannot be ruled out.

Conducting dietary intervention trials in people with multiple sclerosis: Lessons learned and a path forward.

Disease course in people with multiple sclerosis (MS) is heterogeneous. The impact of dietary and nutritional factors on MS prognosis is of interest to both patients and clinicians; differences in diet are hypothesized to contribute to disease evolution over time. However, studying diet, especially in people with MS, introduces methodologic complexity that should be recognized. In this review, we focus on methodological aspects relevant to the conduct of dietary interventions in people with MS, given our experience in leading such studies and the challenges we encountered in the realization of this work. We summarize key aspects of study design and important considerations, regardless of the specifics of the actual study (e.g. the particular diet of interest, target MS population, etc.). We discuss strategies for the design of the intervention as well as the selection of appropriate study endpoints. Finally, we provide an overview of strategies to improve the rigor of conducting dietary studies in people with MS.

Achieving effective patient and public involvement in international clinical trials in neurology.

There is a growing need for patient and public involvement (PPI) to inform the way that research is developed and performed. International randomized controlled trials are particularly likely to benefit from PPI, but guidance is lacking on how or when it should be incorporated. In this article, we describe the PPI process that occurred during the design and initiation of an international treatment clinical trial in MS. PPI was incorporated using a structured approach, aiming to minimize bias and achieve equivalence in study design, implementation, and interpretation. Methods included PPI representation within the study research team, and the use of focus groups, analyzed using thematic framework analysis. We report the outcomes of PPI and make recommendations on its use in other neurology clinical trials. By sharing our model for PPI, we aim to maximize effectiveness of future public involvement and to allow its effect to be better evaluated.

A new way to estimate neurologic disease prevalence in the United States: Illustrated with MS.

OBJECTIVE: Considerable gaps exist in knowledge regarding the prevalence of neurologic diseases, such as multiple sclerosis (MS), in the United States. Therefore, the MS Prevalence Working Group sought to review and evaluate alternative methods for obtaining a scientifically valid estimate of national MS prevalence in the current health care era. METHODS: We carried out a strengths, weaknesses, opportunities, and threats (SWOT) analysis for 3 approaches to estimate MS prevalence: population-based MS registries, national probability health surveys, and analysis of administrative health claims databases. We reviewed MS prevalence studies conducted in the United States and critically examined possible methods for estimating national MS prevalence. RESULTS: We developed a new 4-step approach for estimating MS prevalence in the United States. First, identify administrative health claim databases covering publicly and privately insured populations in the United States. Second, develop and validate a highly accurate MS case-finding algorithm that can be standardly applied in all databases. Third, apply a case definition algorithm to estimate MS prevalence in each population. Fourth, combine MS prevalence estimates into a single estimate of US prevalence, weighted according to the number of insured persons in each health insurance segment. CONCLUSIONS: By addressing methodologic challenges and proposing a new approach for measuring the prevalence of MS in the United States, we hope that our work will benefit scientists who study neurologic and other chronic conditions for which national prevalence estimates do not exist.

The prevalence of MS in the United States: A population-based estimate using health claims data.

OBJECTIVE: To generate a national multiple sclerosis (MS) prevalence estimate for the United States by applying a validated algorithm to multiple administrative health claims (AHC) datasets. METHODS: A validated algorithm was applied to private, military, and public AHC datasets to identify adult cases of MS between 2008 and 2010. In each dataset, we determined the 3-year cumulative prevalence overall and stratified by age, sex, and census region. We applied insurance-specific and stratum-specific estimates to the 2010 US Census data and pooled the findings to calculate the 2010 prevalence of MS in the United States cumulated over 3 years. We also estimated the 2010 prevalence cumulated over 10 years using 2 models and extrapolated our estimate to 2017. RESULTS: The estimated 2010 prevalence of MS in the US adult population cumulated over 10 years was 309.2 per 100,000 (95% confidence interval [CI] 308.1-310.1), representing 727,344 cases. During the same time period, the MS prevalence was 450.1 per 100,000 (95% CI 448.1-451.6) for women and 159.7 (95% CI 158.7-160.6) for men (female:male ratio 2.8). The estimated 2010 prevalence of MS was highest in the 55- to 64-year age group. A US north-south decreasing prevalence gradient was identified. The estimated MS prevalence is also presented for 2017. CONCLUSION: The estimated US national MS prevalence for 2010 is the highest reported to date and provides evidence that the north-south gradient persists. Our rigorous algorithm-based approach to estimating prevalence is efficient and has the potential to be used for other chronic neurologic conditions.