Prevalence of multiple sclerosis in Verona, Italy: an epidemiological and genetic study

Italian adaptation and psychometric validation of the Fatigue Impact Scale (FIS) and its modified versions in adults with multiple sclerosis: a Rasch analysis study

Purpose: Several outcome measures are available to assess the severity of fatigue in people with multiple sclerosis (MS). The aim of this study was to adapt the Italian version of the Fatigue Impact Scale (FIS-40) and its modified versions: a 21-item Modified scale (MFIS-21), its 5-item short version (MFIS-5), and an 8-item version for daily use (DFIS-8) and investigate their measurement properties through classical theory-test (CTT) and Rasch analysis (RA).Methods: 229 Italian-speaking adults with MS were included. Questionnaires were cross-culturally translated and subjected to CTT (i.e. internal consistency through Cronbach's alpha and unidimensionality through confirmatory factor analysis [CFA]) and RA. (i.e. internal construct validity, reliability, and targeting).Results: Internal consistency was high for all scales (>0.850). Final CFAs reported issues in the unidimensionality for all scales except for FIS-40. Baseline RA revealed a misfit for all scales. After adjusting for local dependency, FIS-40, MFIS-21, and MFIS-5 fitted the Rasch model (RM). MFIS-21 and D-FIS-8 required a structural modification, i.e. item deletions to satisfy the RM.Conclusion: The FIS-40, MFIS-21, MFIS-5, and DFIS-8 achieved the fit to the RM after statistical and structural modifications. The fit to the RM allowed for providing ordinal-to-interval measurement conversion tables for all the questionnaires.

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.

Rising prevalence of multiple sclerosis in Saudi Arabia, a descriptive study

BACKGROUND

In 2015, the first nationwide, multicenter Multiple Sclerosis (MS) registry was initiated in the Kingdom of Saudi Arabia (KSA) mainly with an objective to describe current epidemiology, disease patterns, and clinical characteristics of MS in Saudi Arabia. This article aimed to report initial findings of the registry and regional prevalence of MS.

METHOD

In 2015, a national MS registry was launched in KSA to register all MS patient with confirmed diagnosis according to the 2010 McDonald Criteria. The registry aimed to identify and recruit all healthcare facilities treating MS patients in the Kingdom, and collect data such as demographics, clinical characteristics (disease onset, diagnosis, presentation of symptoms at onset, disease course, relapse rate, and disability measures), family history, and treatments. All the included sites have obtained IRB/EC approvals for participating in the registry. Currently, the registry includes 20 hospitals from different regions across the Kingdom. The Projected prevalence was calculated based on the assumption that the number of diagnosed MS cases in participating hospitals (in each region) is similar to the number of cases in remaining nonparticipant hospitals in the same region.

RESULTS

As of September 2018, the registry has included 20 hospitals from the different regions across the Kingdom and has collected comprehensive data on 2516 patients from those hospitals, with median age 32 (Range: 11-63) and 66.5% being females. The reported prevalence of MS for those hospitals was estimated to be 7.70/100,000 population and 11.80/100,000 Saudi nationals. Based on the assumption made earlier, we projected the prevalence for each region and for the country as a whole. The overall prevalence of MS at the country level was reported to be 40.40/100,000 total population and 61.95/100,000 Saudi nationals. Around 3 out of every 4 patients (77.5%) were 40 years of age or younger. Female to male ratio was 2:1. The prevalence was higher among females, young and educated individuals across all five regions of Saudi Arabia.

CONCLUSION

The prevalence of MS has significantly increased in Saudi Arabia but is still much lower than that in the western and other neighboring countries like Kuwait, Qatar, and the UAE. However, compared to the past rates, Saudi Arabia's projected prevalence of MS through this national study is 40.40/100,000 population, putting the Kingdom above the low risk zone as per Kurtzke classification. The projected prevalence was estimated to be much higher among Saudi nationals (61.95/100,000 Saudi-nationals). The prevalence was higher among female, younger and educated individuals. Further studies are needed to assess the risk factors associated with increased prevalence in Saudi Arabia.

The Prevalence of Multiple Sclerosis in the Metropolitan Area of Rome: A Capture-Recapture Analysis

BACKGROUND

Limited data are available on the prevalence of multiple sclerosis (MS) in central Italy. The objective of this study is to estimate MS prevalence in the metropolitan area of Rome.

METHODS

We used the capture-recapture method to calculate prevalence estimates in the study area. The selected prevalence day was December 31, 2015. A total of 1,007 patients, with a definite diagnosis of MS according to the revised McDonald's criteria, were considered for crude, age- and sex-specific prevalence estimation.

RESULTS

The overall crude prevalence rate was 146.2 cases per 100,000 (95% CI 119.9-172.5). A higher prevalence rate was recorded in females (194.1, 95% CI 149.6-238.6) than in males (93.0, 95% CI 67.2-118.8) with a female to male ratio of 1.8. Age-specific prevalence peaked in the 25-34 , 35-44 and 45-54 years class; moreover, it was found to increase up to the 45-54 years age group in females and the 35-44 years age group in males, decreasing thereafter.

CONCLUSION

The results confirm that the metropolitan area of Rome is a high-risk area for MS.

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

Introduction:

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

Objectives and methods:

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

Results:

A total of 1010 patients (mean age = 45 years) participated in Italy. In total, 94% were below retirement age, and of these, 56% were employed. Employment was related to disability, and MS affected productivity at work in 77% of the patients. Overall, 96% and 65% of the patients experienced fatigue and cognitive difficulties as a problem, respectively. Mean utility and total annual costs were 0.735 and €22,900 at Expanded Disability Status Scale (EDSS) of 0–3, 0.534 and €40,100 at EDSS of 4–6.5, and 0.135 and €53,300 at EDSS of 7–9. The mean cost of a relapse was estimated to be €2600.

Conclusion:

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

Prevalence and mortality of patients with multiple sclerosis in France in 2012: a study based on French health insurance data

Data on the prevalence of multiple sclerosis (MS) in France are scarce. National and regional updated estimates are needed to better plan health policies. In this nationwide study, we provided estimates of the prevalence of MS in France in 2012 and mortality rate in 2013. MS cases were identified in the French national health insurance database (SNIIRAM-PMSI) using reimbursement data for disease-modifying treatment, long-term disease status for MS, disability pension for MS, and hospitalisation for MS (MS ICD-10 code: G35). We identified 99,123 MS cases, corresponding to an overall crude prevalence rate of 151.2 per 100,000 inhabitants [95% confidence interval (CI) 150.3-152.2]: 210.0 per 100,000 in women (95% CI 208.4-211.5) and 88.7 per 100,000 in men (95% CI 87.6-89.7). The overall prevalence rate was 155.6 per 100,000 inhabitants (95% CI 154.7-156.6) after standardization on the 2013-European population. We observed a prevalence gradient with a higher prevalence (190-200 per 100,000) in North-Eastern France and a lower prevalence in Southern and Western France (126-140). The crude mortality rate in 2013 was 13.7 per 1,000 MS cases (11.4 in women and 20.3 in men). The standardized mortality ratio was 2.56 (95% CI 2.41-2.72). Our results revise upwards the estimation of MS prevalence in France and confirm the excess mortality of MS patients compared to the general population.

Multiple Sclerosis Epidemiology in Europe

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

Estimated prevalence of multiple sclerosis in Italy in 2015

Italy is a high risk area for multiple sclerosis (MS) as confirmed by the numerous prevalence and incidence studies conducted in several regions/districts of the country. Nevertheless, there are no recent published epidemiological data, nor studies about the total prevalence of MS in Italy. Our aim was to update as of 2015 the prevalence rates of MS in different geographical areas using already published epidemiological studies, and to estimate the overall prevalence of the disease in Italy. We made a search in MEDLINE database of all published studies on epidemiology of MS in Italy. Then, we applied, to the already published prevalence data, the last published incidence and mortality rates to recalculate, as of 2015, the prevalence of MS. So, we calculated the mean prevalence rate from our extrapolations, and we applied it to the population in 2015 to estimate the number of MS patients in Italy. Our prevalence extrapolations ranged from 122 to 232 cases/100,000 in the mainland and Sicily, with an average of 176/100,000, and from 280 to 317 cases/100,000 in Sardinia with an average of 299/100,000. Applying these media to the Italian population in 2015, we obtained an estimate of more than 109,000 MS patients in Italy. Our estimates were higher than the latest published rates but consistent with the annual increase of prevalence due to incidence that exceeds mortality, with the increase of survival and, maybe, with the probable increase of incidence.

Prevalence of multiple sclerosis in the Lazio region, Italy: use of an algorithm based on health information systems

Compared with other areas of the country, very limited data are available on multiple sclerosis (MS) prevalence in Central Italy. We aimed to estimate MS prevalence in the Lazio region and its geographical distribution using regional health information systems (HIS). To identify MS cases we used data from drug prescription, hospital discharge and ticket exemption registries. Crude, age- and gender-specific prevalence estimates on December 31, 2011 were calculated. To compare MS prevalence between different areas within the region, we calculated age- and gender-adjusted prevalence and prevalence ratios using a multivariate Poisson regression model. Crude prevalence rate was 130.5/100,000 (95 % CI 127.5–133.5): 89.7/100,000 for males and 167.9/100,000 for females. The overall prevalence rate standardized to the European Standard Population was 119.6/100,000 (95 % CI 116.8–122.4). We observed significant differences in MS prevalence within the region, with estimates ranging from 96.3 (95 % CI 86.4–107.3) for Latina to 169.6 (95 % CI 147.6–194.9) for Rieti. Most districts close to the coast showed lower prevalence estimates compared to those situated in the eastern mountainous area of the region. In conclusion, this study produced a MS prevalence estimate at regional level using population-based health administrative databases. Our results showed the Lazio region is a high-risk area for MS, although with an uneven geographical distribution. While some limitations must be considered including possible prevalence underestimation, HIS represent a valuable source of information to measure the burden of SM, useful for epidemiological surveillance and healthcare planning.

The Role of HLA in MS Susceptibility and Phenotype

One of the most consistent findings in multiple sclerosis (MS) is that development of MS is linked with carriage of the class II human leucocyte antigen (HLA) molecule HLA-DRB1*15:01; around 60 % of Caucasian MS patients carry this allele compared to 25-30 % of ethnically matched healthy individuals. However, other HLA molecules have also been linked to the development of MS. In this chapter, the association between different HLA types and susceptibility to MS will be reviewed, and other linkages between the carriage of specific HLA molecules and clinical and experimental findings in MS will be considered.

Prevalence of multiple sclerosis in Csongrád County, Hungary

OBJECTIVE

Recent epidemiological studies were mainly based on the Poser or other diagnostic criteria. There have been no previous data from Hungary, which were assessed with the more up-to-date McDonald criteria and which give comparable standardized data from the region.

MATERIALS AND METHODS

Data were collected from the MS Register of the Department of Neurology at the University of Szeged. All possible and definitive patients with MS living in the county on the prevalence day were included in the study. Direct standardization was based on the European standard population.

RESULTS

On 1 January 2013, 379 registered patients with MS were alive in the county, that is, a crude MS prevalence of 89.8/100,000, 46.6/100,000 in males and 128.6/100,000 in females; standardized prevalence: 83.7/100,000 (42.3/100,000 for males, 122.6/100,000 for females). The distribution of the clinical forms: 11% clinically isolated syndrome, 69% relapsing-remitting form, 14% secondary progressive form, 6% primary progressive form. Patients with no or only mild symptoms comprised 91.9% of the relapsing-remitting population.

CONCLUSIONS

This is the first standardized epidemiological study based on the McDonald criteria in Central Europe. Hungary is a medium-risk country as concerns the prevalence of MS. The crude prevalence appears to have increased relative to previous reports from the county.

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.

Genetic burden of common variants in progressive and bout-onset multiple sclerosis

BACKGROUND

The contribution of genetic variants underlying the susceptibility to different clinical courses of multiple sclerosis (MS) is still unclear.

OBJECTIVE

The aim of the study is to evaluate and compare the proportion of liability explained by common SNPs and the genetic burden of MS-associated SNPs in progressive onset (PrMS) and bout-onset (BOMS) cases.

METHODS

We estimated the proportion of variance in disease liability explained by 296,391 autosomal SNPs in cohorts of Italian PrMS and BOMS patients using the genome-wide complex trait analysis (GCTA) tool, and we calculated a weighted genetic risk score (wGRS) based on the known MS-associated loci.

RESULTS

Our results identified that common SNPs explain a greater proportion of phenotypic variance in BOMS (36.5%±10.1%) than PrMS (20.8%±6.0%) cases, and a trend of decrease was observed when testing primary progressive (PPMS) without brain MRI inflammatory activity (p = 7.9 × 10(-3)). Similarly, the wGRS and the variance explained by MS-associated SNPs were higher in BOMS than PPMS in males (wGRS: 6.63 vs 6.51, p = 0.04; explained variance: 4.8%±1.5% vs 1.7%±0.6%; p = 0.05).

CONCLUSIONS

Our results suggest that the liability of disease is better captured by common genetic variants in BOMS than PrMS cases. The absence of inflammatory activity and male gender further raise the difference between clinical courses.

Increasing prevalence and incidence rates of multiple sclerosis in Kuwait

Background:

Kuwait was considered as low to intermediate risk area for MS.

Objectives:

To determine the prevalence and incidence rates of MS among Kuwaiti nationals based on 2011 population census.

Methods:

This cross-sectional study was conducted between October 2010 and April 2013 using the newly developed national MS registry in Kuwait. Patients with a diagnosis of MS according to 2010 revised McDonald criteria were identified. The crude, age- and sex-specific prevalence and incidence rates among Kuwaiti patients were calculated.

Results:

1176 MS patients were identified of which 927 (78.8%) were Kuwaitis and 249 (21.2%) were expatriates. Among Kuwaiti patients, female to male ratio was 1.8:1 with a mean age of 35.40 ± 10.99 years. The prevalence rate of MS was 85.05 per 100,000 persons (95% CI: 82.80 – 87.04). There was a peak in prevalence among patients aged 30–39 years. The incidence of MS was 6.88 per 100,000 persons (95% CI 5.52–8.55). Between 2003 and 2011, the incidence increased 3.22 and 2.54 times in women and men respectively.

Conclusion:

Kuwait is considered a high-risk area for MS. The significant increase in prevalence and incidence rates may represent a true increase despite the improvement in case ascertainment and case definition.