Multiple sclerosis in Móstoles, central Spain

Incidence and prevalence of multiple sclerosis in Spain: a systematic review

INTRODUCTION

Greater understanding of the prevalence and incidence of multiple sclerosis in Spain and their temporal trends is necessary to improve the allocation of healthcare resources and to study aetiological factors.

METHODS

We performed a systematic search of the MedLine database and reviewed the reference lists of the articles gathered. We collected studies reporting prevalence or incidence rates of multiple sclerosis in any geographical location in Spain, with no time limits. In 70% of cases, data were extracted by 2 researchers (FGL and EAC); any discrepancies were resolved by consensus.

RESULTS

We identified 51 prevalence and 33 incidence studies published between 1968 and 2018. In the adjusted analysis, the number of prevalent cases per 100 000 population increased by 26.6 (95% confidence interval [CI], 21.5-31.8) every 10 years. After adjusting for year and latitude, the number of incident cases per 100 000 population increased by 1.34 (95% CI, 0.98-1.69) every 10 years. We observed a trend toward higher prevalence and incidence rates at higher latitudes.

CONCLUSIONS

The prevalence of multiple sclerosis in Spain has increased in recent decades, although case ascertainment appears to be incomplete in many studies. Incidence rates have also increased, but this may be due to recent improvements in the detection of new cases.

Systematic literature review and meta-analysis of the prevalence of secondary progressive multiple sclerosis in the USA, Europe, Canada, Australia, and Brazil

Background

Secondary progressive multiple sclerosis (SPMS) is a subtype of multiple sclerosis (MS), which is a chronic neurological disease, characterised by inflammation of the central nervous system. Most of MS patients eventually progress to SPMS. This study estimates the prevalence of SPMS in the United States of America, Europe, Canada, Australia, and Brazil.

Methods

A systematic literature search of the Medline and Embase databases was performed using the OVID™ SP platform to identify MS epidemiological studies published in English from database inception to September 22, 2020. Studies reporting the prevalence of MS and proportion of SPMS patients in the included population were selected. The pooled prevalence of SPMS was calculated based on the proportion of SPMS patients. The Loney quality assessment checklist was used for quality grading. A meta-analysis of the proportions was conducted in RStudio.

Results

A total of 4754 articles were retrieved, and prevalence was calculated from 97 relevant studies. Overall, 86 medium- and high-quality studies were included in the meta-analysis. Most studies were conducted in European countries (84 studies). The estimated pooled prevalence of SPMS was 22.42 (99% confidence interval: 18.30, 26.95)/100,000. The prevalence of SPMS was more in the North European countries, highest in Sweden and lowest in Brazil. A decline in SPMS prevalence was observed since the availability of oral disease-modifying therapies. We also observed a regional variation of higher SPMS prevalence in urban areas compared with rural areas.

Conclusion

High variability was observed in the estimated SPMS prevalence, and the quality of the studies conducted. The influence of latitude and other factors known to affect overall MS prevalence did not fully explain the wide range of inter-country and intra-country variability identified in the results.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02820-0.

The Role of Fungi in the Etiology of Multiple Sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disorder of the central nervous system. Infectious triggers of MS are being actively investigated. Substantial evidence supports the involvement of the Epstein-Barr virus (EBV), though other viruses, bacteria, protists, and fungi are also being considered. Many links between fungi and diseases involving chronic inflammation have been found recently. Evidence linking MS and fungi is reviewed here. The HLA-DRB1*15 allele group is the most important genetic risk factor of MS, and is a risk factor in several other conditions linked to fungal infections. Many biomarkers of MS are consistent with fungal infections, such as IL-17, chitotriosidase, and antibodies against fungi. Dimethyl fumarate (DMF), first used as an industrial fungicide, was recently repurposed to reduce MS symptoms. Its mechanisms of action in MS have not been firmly established. The low risk of MS during childhood and its moderate association with herpes simplex virus type 2 suggest genital exposure to microbes (including fungi) should be investigated as a possible trigger. Molecular and epidemiological evidence support a role for infections such as EBV in MS. Though fungal infections have not been widely studied in MS, many lines of evidence are consistent with a fungal etiology. Future microbiome and serological studies should consider fungi as a possible risk factor for MS, and future clinical studies should consider the effect of fungicides other than DMF on MS symptoms.

Prevalence of multiple sclerosis in Santiago de Compostela (Galicia, Spain)

Introduction

Multiple sclerosis (MS) is the most common central nervous system disease in young adults, and one of the leading causes of disability in this age group.

Objectives

To establish the prevalence and incidence of MS in Santiago de Compostela (Spain).

Material and methods

We performed a prospective, case-finding study on >90188 inhabitants, from 1 January 1998 to 15 September 2003, selected as day of prevalence. Sources of information were the University Clinical Hospital of Santiago, the hospitals and private clinics of the city, rehabilitators, pediatricians, ophthalmologists, psychiatrists, neurosurgeons, specialists in internal medicine, primary care physicians, association of patients of MS, social services and nongovernmental and religious associations. Informative days were programmed for the susceptible population, and campaigns were carried out in the media. All patients with Poser diagnostic criteria for MS, on the census of Santiago de Compostela as of 15 September 2003, were included in the study.

Results

On the day of prevalence, 71 patients with MS were registered on the census of Santiago de Compostela, therefore, the prevalence was 79 cases per 100000 inhabitants. The incidence of the disease in the study period was 5.3 cases per 100000 inhabitants and year.

Conclusions

The prevalence and incidence rates of MS found in Santiago de Compostela are the highest reported, to date, in Spain. Multiple Sclerosis 2007; 13: 262–264. http://msj.sagepub.com

[Management of symptoms associated with spasticity in patients with multiple sclerosis]

OBJECTIVE

To describe the role of nurses in the management of symptoms related to spasticity in patients with multiple sclerosis (MS).

METHOD

A descriptive study was developed based on a questionnaire on spasticity in MS patients. The questionnarie was completed through an anonymous tele-voting system at a national meeting with nurses involved in the management of these patients.

RESULTS

Apart from fatigue, according to the opinion of the participants, the spasticity symptom associated with MS most notified by patients was difficulty in walking, followed by spasms and pain. Participants thought that it is important that nursing takes: 1) a role in identifying these symptoms, 2) should focus on the detection of the triggering or aggravating factors, and 3) on providing support in the assessment of the level of spasticity. It is important to inform about the correct use of anti-spasticity drugs, how to adjust the dosage and side effects of treatments, including cannabinoids via an oromucosal spray, titrating its doses according to each patient, and monitoring its tolerability, efficacy and adherence. Although there are usually resources to follow up these patients, there are still important gaps, including the lack of a specific follow-up protocol.

CONCLUSIONS

Although all the participants are experts in the management of patients with MS, there is still diversity in the functions they perform, and the available resources they have in their hospitals. Nurses act as a key element in the process of identification of symptoms, training and monitoring of these patients with spasticity in EM.

The Standards of Reporting of Neurological Disorders (STROND) checklist: Application to multiple sclerosis

Background:

Descriptive epidemiological studies documenting the incidence and prevalence of multiple sclerosis (MS) and studies that report morbidity, mortality, and economic burden provide essential information for patients, healthcare providers, and policymakers. However, the quality of reporting of observational studies is often poor, limiting the ability to evaluate the validity of the findings. The Standards of Reporting of Neurological Disorders (STROND) reporting guideline comprises recommendations and a 15-item checklist of reporting items to aid high-quality reporting of incidence and prevalence studies of neurological disorders.

Methods:

We explain the basic reporting items of the STROND checklist for the methods, results, and discussion sections in the context of the MS literature and searched for examples of good reporting of those items.

Results:

We identified examples of good reporting of the basic reporting items from previous systematic reviews of the descriptive epidemiologic literature in MS.

Conclusion:

The adoption of the STROND reporting guidelines should improve the quality of reporting of descriptive epidemiological studies in MS. Along with efforts to improve methodological aspects of epidemiological studies and harmonization of data collection efforts, improved reporting could contribute to furthering our understanding of the epidemiology of MS.

A systematic approach to analyse health-related quality of life in multiple sclerosis: the GEDMA study

Objective: To describe a holistic and comprehensive approach to the assessment of sufferer’s perceptio ns of health-related quality of life (HRQ oL) in a cohort of multiple sclerosis (MS) patients. Methods: The G EDMA (Grupo de Enfermedades Desmielinizantes de Madrid, in Spanish) study is an ongoing longitudinal survey using quantitative and qualitative methodologies. The baseline cohort consisted of a large sample of MS patients recruited from 13 hospitals in Madrid, Spain. Using a standardized protocol we collected data concerning the sociodemographic and health status characteristics of patients, as well as implementing a modified Spanish version of the Functio nal A ssessment of Multiple Sclerosis quality of life instrument. Primary caregivers were interviewed using a specific protocol combined with the Zarit Burden Interview. Results: The index cohort comprised 371 MS patients (68.7% female) of mean age 38.9 ± 0.9 years. A ge, sex and clinical form distribution were similar to other MS population-based surveys. There were 258 (69.5%) relapsing-remitting (RR) MS patients and 113 (30.5%) progressive MS patients. More than one-third of the married patients with progressive MS and almost a quarter of the RRMS patients separated or divorced following a diagnosis of MS; 71.3% of the progressive MS patients as well as 65.8% of the RRMS patients were unemployed as a consequence of the disease. Q ualitative analysis showed that friendship and family relationships and occupational status were the most significant dimensions influenced by MS. O n the other hand, the speech analysis of primary caregivers showed that emotional burden was related to patients’ physical disability. Furthermore, primary caregivers described the influence of MS on their own occupatio nal status, their nonacceptance of the disease, a perceptio n of a lack of support by other members of the family as well as a ‘selfish and intransigent’ attitude of the patients themselves. Conclusions: The analysis of the G EDMA cohort provides valuable information that helps clarify the impact of MS on patients’ HRQ oL.

Long-term epidemiology of multiple sclerosis in the Northern Seville District

OBJECTIVES

Comprehensive epidemiologic data for multiple sclerosis (MS) in Spain are limited. The aim of this study was to collect epidemiologic data on MS in the Northern Seville District of Spain.

MATERIALS AND METHODS

This longitudinal study identified possible MS cases every year from nine centres between 1 January 1991 and 31 December 2011. Patients with a confirmed diagnosis of MS were included. MS data prior to enrolment were collected retrospectively from clinical records and prospectively during quarterly follow-up clinic visits. Variables included age at onset, age at diagnosis, treatment, follow-up duration, number of visits, number of relapses, change in the number of relapses over time and Expanded Disability Status Scale score. The incidence and prevalence of MS rate were calculated.

RESULTS

Overall, 156 patients with MS were identified (111 females; mean follow-up 7.5 years). Most patients had relapsing-remitting MS (73.7%); primary progressive disease was less frequent than secondary disease (10.9% vs 15.4%). The yearly incidence of MS was 4.6 per 100,000, and the prevalence at 31 December 2011 was 90.2 per 100,000.

CONCLUSIONS

The annual MS incidence rate in this southern region of Spain was higher than previously reported rates in Spanish studies.

Miscellaneous adverse events with biologic agents (excludes infection and malignancy)

Anti-tumor necrosis factor-α (anti-TNF) agents are frequently used in the treatment of inflammatory bowel disease (IBD). Currently, there are 4 anti-TNF therapies that are Food and Drug Administration-approved for moderate to severe IBD: infliximab, adalimumab, golimumab, and certolizumab pegol. For most noninfectious, nonmalignant adverse events, cessation of anti-TNF therapy typically leads to improvement or resolution of drug-induced complications. In this article, the current knowledge regarding the noninfectious and nonmalignant toxicities associated with anti-TNF agents is summarized.

Gender-related protection from or vulnerability to severe CNS diseases: gonado-structural and/or gonado-activational? A meta-analysis of relevant epidemiological studies

BACKGROUND

A vast scientific literature has dealt with gender-specific risk for brain disorder. That field is evolving toward a consensus to the effect that the estrogen hormone family is outstandingly and uniquely neuroprotective. However, the epidemiology relevant to this general outlook remains piecemeal.

METHOD

The present investigation strategically formats the relevant epidemiological findings around the world in order to quantitatively meta-analyze gender ratio of risk for a variety of relevant severe central nervous system (CNS) diseases at all three gonadal stages of the life cycle, pre pubertal, post adolescent/pre menopausal, and post menopausal.

RESULTS

The data quantitatively establish that (1) no single epidemiological study should be cited as evidence of gender-specific neuroprotection against the most common severe CNS diseases because the gender-specific risk ratios are contradictory from one study to the other; (2) risk for severe CNS disease is indeed significantly gender-specific, but either gender can be protected: it depends on the disease, not at all on the age bracket.

CONCLUSION

Our assay of gender-specific risk for severe brain disease around the world has not been able to support the idea according to which any one gender-prevalent gonadal steroid hormone dominates as a neuroprotective agent at natural concentrations.

Is it time for a new global classification of multiple sclerosis?

BACKGROUND

The geographic distribution of multiple sclerosis (MS) is classically divided into three zones based on frequency that were established by Kurtzke in the early 1970s. In recent years, an increasing number of epidemiological studies have shown significantly higher MS prevalence and incidence rates.

OBJECTIVE

The aim of this study was to review and update the geographic distribution of MS using incidence, prevalence and disease duration from the latest epidemiology surveys.

METHODS

We conducted a systematic review of articles on MS epidemiology published between January 1, 1990 and December 31, 2012.

RESULTS

MS studies were grouped by continent: the Americas, Europe, Asia, Australia/New Zealand, and Africa. A total of 101 studies were identified according to the inclusion criteria, and 58 reported incidence estimates. Globally, the median estimated incidence of MS was 5.2 (range: 0.5-20.6) per 100,000 p-yrs, the median estimated prevalence of MS was 112.0 (with a range of 5.2-335) per 100,000 p-yrs, and the average disease duration was 20.2 years (range: 7.6-36.2).

CONCLUSION

In the past few decades, the global prevalence and incidence patterns of MS have changed dramatically. Regardless of the reason of increasing prevalence and incidence rate, we suggest the need for a novel classification system based on global MS disease burden. Adopting such a system would improve economic efficiency and prioritization in health policy planning for MS.

Cost-effectiveness of injectable disease-modifying therapies for the treatment of relapsing forms of multiple sclerosis in Spain

OBJECTIVE

To compare the cost-effectiveness of injectable disease-modifying therapies (DMTs) for the first-line treatment of relapsing-remitting multiple sclerosis (RRMS) in Spain.

METHODS

A Markov model was developed to estimate the cost-effectiveness of intramuscular interferon beta-1a (IM IFNβ-1a), subcutaneous interferon beta-1a (SC IFNβ-1a), interferon beta-1b (IFNβ-1b) and glatiramer acetate (GA) relative to best supportive care in a hypothetical cohort of 1,000 RRMS patients in Spain. The model was developed from a societal perspective with a time horizon of 30 years. Natural history and clinical trial data were used to model relapse rates and disease progression. Cost and utility data were obtained from a published survey of multiple sclerosis patients in Spain. The primary outcome measure was cost per quality-adjusted life year (QALY) gained. Univariate and probabilistic sensitivity analyses were performed.

RESULTS

Compared to best supportive care, the base case cost-effectiveness was <euro>168,629 per QALY gained for IM IFNβ-1a, <euro>231,853 per QALY gained for IFNβ-1b, <euro>295,638 per QALY gained for SC IFNβ-1a, and <euro>318,818 per QALY gained for GA. Results were most sensitive to changes in DMT cost, utility values and treatment effect.

CONCLUSIONS

In our cost-effectiveness analysis of first-line injectable DMTs in Spain, we found IM IFNβ-1a to be more cost-effective than SC IFNβ-1a, IFNβ-1b or GA. Sensitivity analyses confirmed the robustness of these results.

Incidence and prevalence of multiple sclerosis in Europe: a systematic review

BACKGROUND

Multiple sclerosis (MS) is the most common cause of neurological disability in young adults worldwide and approximately half of those affected are in Europe. The assessment of differential incidence and prevalence across populations can reveal spatial, temporal and demographic patterns which are important for identifying genetic and environmental factors contributing to MS. However, study methodologies vary and the quality of the methods can influence the estimates. This study aimed to systematically review European studies of incidence and prevalence of MS and to provide a quantitative assessment of their methodological quality.

METHODS

A comprehensive literature search was performed to obtain all original population-based studies of MS incidence and prevalence in European populations conducted and published between January 1985 and January 2011. Only peer-reviewed full-text articles published in English or French were included. All abstracts were screened for eligibility and two trained reviewers abstracted the data and graded the quality of each study using a tool specifically designed for this study.

RESULTS

There were 123 studies that met the inclusion criteria. The study estimates were highly heterogeneous, even within regions or countries. Quality was generally higher in the more recent studies, which also tended to use current diagnostic criteria. Prevalence and incidence estimates tended to be higher in the more recent studies and were higher in the Nordic countries and in northern regions of the British Isles. With rare exceptions, prevalence and incidence estimates were higher in women with ratios as high as 3:1. Few studies examined ethnicity. Epidemiological data at the national level was uncommon and there were marked geographical disparities in available data, with large areas of Europe unrepresented and other regions well-represented in the literature. Only 37% of the studies provided standardized estimates.

CONCLUSIONS

Despite the breadth of the literature on the epidemiology of MS in Europe, inter-study comparisons are hampered by the lack of standardization. Further research should focus on regions not yet studied and the evaluation of ethnic differences in MS prevalence and incidence. National-level studies using current diagnostic criteria, validated case definitions and similar age- and sex-standardization would allow better geographical comparisons.

A systematic review of randomized, double-blind, placebo-controlled trials examining the clinical efficacy of vitamin D in multiple sclerosis

BACKGROUND

An association between multiple sclerosis (MS) prevalence as well as MS mortality and vitamin D nutrition has led to the hypothesis that high levels of vitamin D could be beneficial for MS. The purpose of this systematic review is to establish whether there is evidence for or against vitamin D in the treatment of MS.

METHODS

Systematic literature searches were performed to locate randomized, placebo-controlled, double-blind trials measuring the clinical effect of vitamin D on MS in human participants. Data were extracted in a standardized manner, and methodological quality was assessed by the Jadad score.

RESULTS

Five trials were located that met the selection criteria. Of the 5 trials, 4 showed no effect of vitamin D on any outcome, and 1 showed a significant effect, namely by a reduction in the number of T1 enhancing lesions on brain magnetic resonance imaging. Three studies commented on adverse effects of vitamin D, with gastrointestinal adverse effects being the most frequently reported. The literature is limited by small study sizes (ranging from 23 to 68 patients), heterogeneity of dosing, form of vitamin D tested (vitamin D3 in 4 trials and vitamin D2 in 1) and clinical outcome measures. Therefore, a meta-analysis was not performed.

CONCLUSIONS

The evidence for vitamin D as a treatment for MS is inconclusive. Larger studies are warranted to assess the effect of vitamin D on clinical outcomes in patients with MS. We further encourage researchers to also test the effect of vitamin D on the health-related quality of life experienced by patients and their families.

Geomagnetic disturbances may be environmental risk factor for multiple sclerosis: an ecological study of 111 locations in 24 countries

BACKGROUND

We noticed that a hypothesis based on the effect of geomagnetic disturbances (GMD) has the ability to explain special features of multiple sclerosis (MS). Areas around geomagnetic 60 degree latitude (GM60L) experience the greatest amount of GMD. The easiest way to evaluate our hypothesis was to test the association of MS prevalence (MSP) with angular distance to geomagnetic 60 degree latitude (AMAG60) and compare it with the known association of MS with geographical latitude (GL). We did the same with angular distance to geographic 60 degree latitude (AGRAPH60) as a control.

METHODS

English written papers with MSP keywords, done in Europe (EUR), North America (NA) or Australasia (AUS) were retrieved from the PubMed. Geomagnetic coordinates were determined for each location and AMAG60 was calculated as absolute value of numerical difference between its geomagnetic latitude from GM60L. By an ecological study with using meta-regression analyses, the relationship of MSP with GL, AMAG60 and AGRAPH60 were evaluated separately. MSP data were weighted by square root of number of prevalent cases. Models were compared by their adjusted R square (AR2) and standard error of estimate (SEE).

RESULTS

111 MSP data were entered in the study. In each continent, AMAG60 had the best correlation with MSP, the largest AR2 (0.47, 0.42 and 0.84 for EUR, NA and AUS, respectively) and the least SEE. Merging both hemispheres data, AMAG60 explained 56% of MSP variations with the least SEE (R = 0.75, AR2 = 0.56, SEE = 57), while GL explained 17% (R = 0.41, AR2 = 0.17, SEE = 78.5) and AGRAPH60 explained 12% of that variations with the highest SEE (R = 0.35, AR2 = 0.12, SEE = 80.5).

CONCLUSIONS

Our results confirmed that AMAG60 is the best describer of MSP variations and has the strongest association with MSP distribution. They clarified that the well-known latitudinal gradient of MSP may be actually a gradient related to GM60L. Moreover, the location of GM60L can elucidate why MSP has parabolic and linear gradient in the north and south hemisphere, respectively. This preliminary evaluation supported that GMD can be the mysterious environmental risk factor for MS. We believe that this hypothesis deserves to be considered for further validation studies.

Understanding tremor in multiple sclerosis: prevalence, pathological anatomy, and pharmacological and surgical approaches to treatment

Background

Given that tremor is one of the most prevalent and disabling features of multiple sclerosis (MS), we will review the most significant milestones in tremor in this disease in recent years, focusing on prevalence, clinical features, anatomical basis, and treatment.

Methods

Data for this review were identified by searching MEDLINE with the search terms “multiple sclerosis” and “tremor”. References were also identified from relevant articles published between January 1966 and May 2012.

Results

The predominant type of MS tremor is a large-amplitude, postural, and kinetic tremor, which most commonly affects the arms, although tremor can also involve head, neck, vocal cords, and trunk. Involvement of the tongue, jaw, or palate has not been reported. Although the anatomical basis underlying tremor in MS is poorly understood, the link between the cerebellum and the MS-related tremor is supported by clinical and experimental studies. Currently available medication is often unsuccessful in most cases. Surgical treatment can be a satisfactory alternative to treat severe and disabling tremor.

Discussion

Tremor in MS patients could be considered as an advanced consequence of the disease and its presence suggests a more aggressive course. MS tremor can be severe and very disabling for a small group of patients. Treatment of MS tremor remains a great challenge. Recent studies suggest that dissociating tremor from cerebellar dysfunction using selected clinical tests would be the key issue to successful surgical treatment. Understanding the pathophysiology and biochemistry of tremor production in MS may lead to new therapeutic approaches.

Impaired health-related quality of life predicts progression of disability in multiple sclerosis

BACKGROUND AND PURPOSE

To determine the value of health-related quality of life (HRQOL) in predicting progression of disability in patients with multiple sclerosis (MS) over a period of 2 years.

METHODS

Patients with MS were recruited in 13 outpatient clinics in Madrid, Spain. Baseline HRQOL was quantified using the Functional Assessment of MS (FAMS) and disability with Kurtzke Expanded Disability Status (EDSS). A clinical meaningful deterioration of disability was defined as an increased of ≥1 point in baseline EDSS scores of ≤5.5 and an increase of ≥0.5 point in baseline EDSS scores of ≥6.0. We dichotomized the change in disability according to clinical meaningful deterioration (dependent variable) and performed a logistic regression analysis with the tertiles of the FAMS scores (the upper tertile [high HRQOL] was the reference) as independent variable, adjusting by socio-demographic and clinical variables.

RESULTS

Out of 371 enrolled patients, 61 patients with MS dropped out during the 2-year follow-up. Of the remaining 310, 94 (30.3%) had clinical meaningful deterioration of disability. The odds of clinical meaningful deterioration of disability were higher as HRQOL decreased with a significant dose-dependent effect. Adjusted odds ratios were 2.61 [95% confidence interval (CI) 95% = 1.12-6.09], [middle tertile vs. upper tertile (reference)]; and 3.27 (95% CI = 1.31-8.18), (lower tertile vs. upper tertile).

CONCLUSIONS

The identification of those patients with MS with poor HRQOL may be important in assessing the risk of future disability progression. Clearly, impaired HRQOL should be one of the primary concerns amongst clinicians who provide treatment to patients affected by MS.

Increasing frequency of multiple sclerosis in Catania, Sicily: a 30-year survey

Background and Objective: The objective of this study was to determine the prevalence and incidence of multiple sclerosis (MS) and its temporal profiles from 1975 to 2005 in the city of Catania.

Methods: The incidence of MS from 1975 to 31 December 1999 had been previously investigated by the same group. The frequency of MS in the community of Catania from 1 January 2000 to 31 December 2004 was studied in a population of 313,110 inhabitants (2001 census). All patients who satisfied Poser’s criteria were considered as prevalent and incident cases.

Results: Three hundred and ninety-eight patients with MS who had experienced the clinical onset of the disease before 31 December 2004 were found in a population of 313,110 inhabitants. The prevalence rate was 127.1/100,000 [95% confidence interval (CI) 115.1–140.4]. From 2000 to 2004, 108 patients with MS had clinical onset of the disease . The mean annual incidence was 7.0/100,000 (95% CI 5.7–13.7) and was higher in women (8.4/100,000; 95% CI 6.4–10.5) than in men (5.3/100,000; 95% CI 3.7–7.2). The mean length of time between the date of clinical onset and the date of the diagnosis was 1.4 ± 1.7 years. During the last 30 years the incidence of MS in this population increased from 1.3/100,000 during the first quinquennium (1975–9) to 7.0/100,000 during 2000–4.

Conclusions: Incidence rates have further increased in this population, suggesting that the risk of MS is still increasing.

The changing demographic pattern of multiple sclerosis epidemiology

The uneven distribution of multiple sclerosis (MS) across populations can be attributed to differences in genes and the environment and their interaction. Prevalence and incidence surveys could be affected by inaccuracy of diagnosis and ascertainment, and prevalence also depends on survival. These sources of error might play a part in the geographical and temporal variations. Our literature search and meta-regression analyses indicated an almost universal increase in prevalence and incidence of MS over time; they challenge the well accepted theory of a latitudinal gradient of incidence of MS in Europe and North America, while this gradient is still apparent for Australia and New Zealand; and suggest a general, although not ubiquitous, increase in incidence of MS in females. The latter observation should prompt epidemiological studies to focus on changes in lifestyle in females. New insights into gene-environment and gene-gene interactions complicate interpretations of demographic epidemiology and have made obsolete the idea of simple causative associations between genes or the environment and MS.

Burden and health-related quality of life of Spanish caregivers of persons with multiple sclerosis

Little information exists about caregivers of persons with multiple sclerosis (MS). Our aims were to describe the characteristics of a sample of caregivers of persons with MS, assess their perceived burden, health-related quality of life, and investigate factors influencing this burden. We studied 278 caregivers of persons with MS, recruited from a Spanish cross-sectional survey, measuring health-related quality of life by the 36-Item Short-Form Health Survey (SF-36) and burden by the Zarit Caregiver Burden Interview. Of the caregivers, 56.8% were female and their mean age was 50.1 ± 12.6 years. Their main relationship with the person with MS was spouse/partner (52.9%) and son or daughter (25.9%). Caregiver General Health, Mental Health, Bodily Pain, and Role-emotional Functioning were the most affected dimensions on the SF-36. Multiple regression analysis showed that independent and significant predictors of burden were Role-emotional Functioning and Vitality dimensions SF-36 scores of caregivers, and the Expanded Disability Status Scale scores. The total adjusted variance explained by these variables (adjusted R2) was 0.512. Emotional factors and the disability of the person with MS were major predictors of burden. Psychological and social support should be considered to reduce caregiver burden.

Costs and quality of life of multiple sclerosis in Spain

This cost-of-illness analysis is based on information from 1.848 patients in Spain and is part of a Europe-wide study on the costs of multiple sclerosis. The objective was to analyze the costs and quality of life (QOL) related to the level of disease severity and progression. Patients were identified by the Asociación Española de Esclerosis Múltiple (AEDEM) and participated in the survey by answering a mail questionnaire (response rate 31.8%). In addition to details on the disease (type of disease, relapses, level of functional disability), the questionnaire asked for information on all resource consumption, medical, non-medical, work absence and informal care, as well as utility (QOL). The mean age of the cohort was 45 years, and only 5.5% of patients were 65 years of age or more. Approximately 36% of patients had mild disease (Expanded Disability Status Scale [EDSS] score of 0-3), 44.8% had moderate disease (EDSS score of 4-6.5) and 17.7% had severe disease (EDSS score > or =7). The mean EDSS score in the sample was 4.5 (median 5.0), with a utility of 0.554. Costs and utility are highly correlated with disease severity. Workforce participation decreases from around 70% in early disease to less than 5% in the very late stages. Hospitalization is very infrequent in early disease, representing less than euro 1.300 per patient per year for patients at EDSS scores <6, but increases steeply for patients at scores > or =7. Ambulatory care increases fivefold between early and late disease, while investments and services increase from basically no cost to just over euro 6.000 at EDSS scores > or =7. Productivity losses increase more than eightfold, and informal care increases from euro 593 at EDSS scores of 0-1 to nearly euro 34.228 at scores of 8-9. Hence, total mean costs per patient are driven by the distribution of the severity levels in the sample, increasing from euro 10.425 at EDSS scores of 0-1 to euro 45.264 at a score of 7, and euro 65.693 at scores of 8-9. The same is true for utility, which decreases from 0.865 to 0.084 as patients progress from the mildest to the most severe disability levels. However, the utility loss compared to the age- and gender-matched general population is high at all levels of the disease ( approximately 0.25 in patients below 30 years of age with an EDSS score of 2-3, and approximately 0.4 in patients over 60 years of age and a score of > or =6), leading to an estimated annual loss of 0.276 quality-adjusted life-year per patient. Relapses for patients with an EDSS score below 5 are associated with a cost of approximately euro 2.750 and a utility loss of 0.1 during the quarter in which they occur.

The epidemiology of multiple sclerosis in Europe

Multiple sclerosis (MS) is a chronic and potentially highly disabling disorder with considerable social impact and economic consequences. It is the major cause of non-traumatic disability in young adults. The social costs associated with MS are high because of its long duration, the early loss of productivity, the need for assistance in activities of daily living and the use of immunomodulatory treatments and multidisciplinary health care. Available MS epidemiological estimates are aimed at providing a measure of the disease burden in Europe. The total estimated prevalence rate of MS for the past three decades is 83 per 100,000 with higher rates in northern countries and a female:male ratio around 2.0. Prevalence rates are higher for women for all countries considered. The highest prevalence rates have been estimated for the age group 35-64 years for both sexes and for all countries. The estimated European mean annual MS incidence rate is 4.3 cases per 100,000. The mean distribution by disease course and by disability is also reported. Despite the wealth of epidemiological data on MS, comparing epidemiological indices among European countries is a hard task and often leads only to approximate estimates. This represents a major methodological concern when evaluating the MS burden in Europe and when implementing specific cost-of-illness studies.

The prevalence of multiple sclerosis in the District of Santarém, Portugal

The prevalence of multiple sclerosis (MS) in Portugal is still unknown. Recent studies conducted in southern European countries showed higher than expected rates of MS prevalence. In an attempt to evaluate the MS prevalence in Santarém--a district with 62621 inhabitants (1991 census) located in the centre of Portugal--we have conducted a population survey in this district for five years. The crude prevalence rate found was 46.3/100,000. This figure is not different from findings recently reported in studies conducted at similar latitudes in neighbour southern European countries. This was the first population survey conducted in Portugal, and it is the first accurate contribution to the knowledge of the MS prevalence in this country.

[Prevalence of neuropathic pain in Spain: clinical, working and health care implications]

A narrative systematic medical literature review on prevalence of neuropathic pain (NP) in Spain from 1990 to 2004 was conducted. The average number of publications was 3 per year. Prevalence data varied depending on studied population, definition of pain/pathology and time of pain evolution. The most commonly studied pathologies included: mononeuropathies and polyneuropathies: 42%, multiple sclerosis: 35% and entrapment neuropathies: 16%. Some episodes of NP were left untreated. One third of patients with back pain receiving analgesic treatment still had high intensity pain. Future studies on the prevalence of NP should use work definitions and criteria reached by consensus. An awareness of the clinical presentation of NP and an appropriate and early treatment could minimize its clinical, working and health care implications. NP is a diverse and highly prevalent condition in Spain. Efforts should be conducted towards the achievement of diagnostic criteria consensus and higher rates of analgesic success.

Prevalence and incidence of multiple sclerosis in Las Palmas, Canary Islands, Spain

OBJECTIVES

To determine the prevalence and incidence of multiple sclerosis (MS) in the city of Las Palmas (Canary Islands, Spain), geographically belonging to north-western Africa, but with European ancestry.

METHODS

This population-based survey was conducted for a period of 5 years (1998-2002) in a Sanitary District of Las Palmas city (28 degrees 20' N), with a population of 82,623 inhabitants. Multiple sources were periodically investigated for case ascertainment. Patients with definite and probable MS were included.

RESULTS

Sixty-four patients with MS were identified on prevalence day, December 31, 2002. According to Poser's criteria the crude prevalence rate was 77.5 per 100,000 (95% CI: 59.7-98.9). This rate decreased to 73.8 (95% CI: 56.5-94.8) according to McDonald's criteria. Age-adjusted rates for the world and European standard populations were 61.6 (95% CI: 47.1-78.9) and 70.6 (95% CI: 55-89), respectively. Prevalence was higher for women aged 25-44 years. In 17 patients onset of MS occurred within the study period. Average annual incidence was 4.1 per 100,000 (95% CI: 2.4-6.6).

CONCLUSIONS

The prevalence and incidence rates in Las Palmas city are close to those reported from Continental Spain and other countries of southern Europe with similar social and ethnic background. These results highlight the role of racial-ethnic factors in the genesis of MS.

Trends in prevalence and incidence of multiple sclerosis in Bajo Aragón, Spain

OBJECTIVE

Recent reports provide consistent evidence that Spain is an area of high risk for multiple sclerosis (MS) according to prevalence surveys. However, the studies of incidence are scarce. The objective of the current work is to analyse whether the increased prevalence of MS is accompanied by increasing incidence in the area of Bajo Aragón, northeastern Spain.

METHODS

The data of both prevalence and incidence were retrieved from a prospective register created in 1994 and which included patients with probable or definite MS. Crude and age-standardised rates were calculated from 1994 to 2002 and compared with those found retrospectively in the previous period of 1984-1993.

RESULTS

In January 2003, we found a prevalence rate of 75/100,000 (95% CI: 52-97) whereas it was 35/100,000 (95% CI: 20-50) in 1994. In a period of 9 years, 25 new cases were diagnosed in the area with a mean annual incidence rate of 4.6/100,000 (95% CI: 2.8-6.5; range: 1.6-13.6) in comparison to 17 new cases from 1984 to 1993 with a mean incidence rate of 3/100,000 (95% CI: 1.6-4.5). The standardised ratio of incidences was 1.44 (95% CI: 0.95-2.17) and, therefore, the difference of rates was not significant.

CONCLUSION

We conclude that the increase in prevalence of MS is more likely to be due to improvement on case ascertainment than to increasing incidence. Nonetheless, further prospective incidence studies in larger populations are warranted in Spain to elucidate whether the frequency of this disease is truly increasing.

Incidence and prevalence of multiple sclerosis in Olmsted County, Minnesota, 1985-2000

BACKGROUND

Epidemiologic data for multiple sclerosis (MS) in Olmsted County, MN, have been recorded for almost 100 years and have indicated that the increasing prevalence rate was likely due in part to an increasing incidence rate.

METHODS

All cases of MS diagnosed from 1985 to 2000 were identified using the centralized diagnostic index at the Mayo Clinic and the Rochester Epidemiology Program Project, a shared database of all medical practitioners in the county. Patients were required to have established residency at least 1 year prior to diagnosis of MS. Results were also age- and sex-adjusted to control for shifts in the population structure.

RESULTS

The raw prevalence of MS was determined to be 177 per 100,000 on December 1, 2000, and the raw incidence rate was 7.5 per 100,000 person-years at risk from 1985 to 2000.

CONCLUSIONS

After age and sex adjustment to a common population, these prevalence and incidence rates of MS appear to have been stable rather than increasing over the past 20 years.

Informal caregiving in multiple sclerosis patients: data from the Madrid Demyelinating Disease Group study

PURPOSE

To describe the profile of Multiple Sclerosis (MS) patient caregivers and assess their caregiving burden.

METHODS

A total of 91 MS patients, recruited from a Spanish longitudinal survey, and their corresponding caregivers were studied. Caregivers were administered a questionnaire that collected social and demographic data, and a generic caregiver burden interview (the Zarit scale). Furthermore, MS patients were administered a specific health-related quality of life (HRQoL) instrument (the modified Spanish version of the Functional Assessment of Multiple Sclerosis).

RESULTS

24.5% of the sample required caregivers to perform activities of daily life. Caregiver profile was as follows: 67% female; mean age, 51.5 +/- 14.1 years; and mean daily time devoted to care, 11.5 +/- 8.2 h. Most caregivers had some type of support, 67% informal and 31.9% formal. The amount of time spent in caring for relatives was the main item determining the burden of MS-patient caregivers. Moreover, MS patient's HRQoL showed a moderate inverse correlation with caregiver burden.

CONCLUSIONS

In contrast to previous studies, most Spanish MS-patient caregivers are female, and there is a considerable percentage of parent caregivers. A greater degree of formal support and an improvement in MS patients' HRQoL may serve to reduce caregiver burden.

Increasing frequency of multiple sclerosis in Padova, Italy: a 30 year epidemiological survey

OBJECTIVE

To determine the incidence and prevalence rates of multiple sclerosis (MS) and their temporal profiles over the last 30 years in the province of Padova (northeast Italy).

BACKGROUND

In the early 1970s an epidemiological survey in the province of Padova showed a MS prevalence and incidence of 16/100 000 and 0.9/100 000 population, respectively; these figures are much lower than current estimates in other regions of Italy and Central Europe.

METHODS

The population of the study area was approximately 820 000 (422 028 women, 398 290 men) in the 1991 census. All possible sources of case collection were used, but only clinically definite/probable and laboratory-supported definite/probable MS were considered in the analysis of incidence and prevalence trends from 1971 to 1999.

RESULTS

On 31 December 1999, the crude prevalence rate was 80.5/100 000 (95% CI 70.3-90.7); prevalence was higher in women (111.1/100 000; 95% CI 99.0-123.1) than in men (49.7/100 000; 95% CI 41.3-58.1). This difference was significant (F/M = 2.43; z = 10.1, P < 0,00001); a rate adjusted for the European population was 81.4/100 000. On 31 December 1980 and on 31 December 1990 the estimated prevalence rates were 18/100 000 and 45.7/100 000, respectively. Thus, a fivefold increase in prevalence was observed from the 1970s. The mean annual incidence was 2.2/100 000 in the period 1980-89, 3.9 in the period 1990-94 and 4.2 in the period 1995 99. Thus, incidence increased more than fourfold from the 1970s through 1994 and remained quite stable in the last several years. Mean age at onset was 31.3 +/- 9.88 years. Mean diagnostic latency decreased significantly from 49.2 +/- 44.5 months in 1985 to 23.0 +/- 30.3 months in 1990, 12.9 +/- 15.61 in 1995 and 5.3 +/- 4.7 in 1999.

CONCLUSIONS

The actual prevalence (80.5/100 000) and incidence (4.2/100 000) of MS in the province of Padova agree with the most recent epidemiological estimates/trends observed in other Italian and European areas, except for Sardinia and Scotland. The increase in both incidence and prevalence rates observed in much of this region over the last 30 years parallels the introduction of more sensitive diagnostic techniques and a highly significant decrease in diagnostic latency. These findings probably do not support a real increase in the frequency of MS in northeast Italy because recent estimates of incidence have increased only slightly (3.9 to 4.2, which is < 10% in five years) and increase in the prevalence rate was almost completely due to the accumulation of new incidence cases.

Health-related quality of life and its relationship to cognitive and emotional functioning in multiple sclerosis patients

The existing knowledge about the health-related quality of life (HRQoL) and its relationship to cognitive and/or emotional functioning in multiple sclerosis (MS) is scarce. We assessed differences between subgroups of MS outpatients (n = 209) on one HRQoL instrument: a version of the Functional Assessment of Multiple Sclerosis quality of life instrument; on two cognitive functioning tests: the Mini-Mental State Examination and the clock drawing test; and on two emotional functioning tests: the Hamilton Rating Scale for Depression and the Hamilton Rating Scale for Anxiety. Three disease-related characteristics were assessed: physical disability, duration of the illness, and clinical course. The results showed that each of these has an effect on at least one dimension of HRQoL and on one mental functioning test. Thus, the more severe, the more progressive, and the longer the illness duration, the lower the HRQoL. Likewise, cognitive mean scores decreased and emotional mean scores increased with greater illness severity and progressive the MS. Furthermore, we also found significant correlations between cognitive and emotional functioning tests and HRQoL dimensions. Thus, the worse cognitive functioning and the higher depressive and anxiety symptoms score the lower the HRQoL.

Prevalence of multiple sclerosis in the L'Aquila district, central Italy

OBJECTIVE

To estimate the prevalence of multiple sclerosis in the L'Aquila district, central Italy.

METHODS

All available case sources were screened. Definite and probable cases of multiple sclerosis, classified according to the Poser criteria, were considered as prevalent cases.

RESULTS

On the prevalence day, 31 December 1996, 158 patients (105 women and 53 men; ratio 2:1) affected by definite (n=131) or probable (n=27) multiple sclerosis were alive and resident in the L'Aquila district. Mean (SD) age was 38.4 (11.9) years (38.9 (11.7) years for women and 38.5 (12.3) years for men, p=0.9). The overall crude prevalence was 53.0/100 000 (95% confidence interval (95% CI)=45.4-62.0); 68.4/100 000 (95% CI=56. 5-82.8) in women, and 36.7/100 000 (95% CI=28.1-48.0) in men. The prevalence was similar (55.9/100 000) when standardised to the 1996 European population. Mean (SD) age at onset of multiple sclerosis was 29.4 (9.6) years and mean (SD) duration of the disease was 9.4 (7.4) years, without any significant difference between sexes. Mean age at onset was significantly higher in patients with the primary progressive than in those with the relapsing-remitting course (p=0. 0002, Scheffé's test).

CONCLUSIONS

The prevalence found in the L'Aquila district gives support to the consideration of Italy as an area in which multiple sclerosis has been shown to have high prevalence at least in the populations that were surveyed recently.