The incidence and prevalence of reported multiple sclerosis

A national survey, sponsored by the National Institute of Neurological and Communicative Disorders and Stroke, to determine the incidence, prevalence, and economic impact of multiple sclerosis has just been completed. These data are the first report of the results. Based on the data gathered, it is estimated that on Januaryuary 1, 1976, there were a reported 123,000 multiple sclerosis patients in the conterminous United States (a rate of 58 per 100,000). The annual incidence for the period 1970–1975 was estimated to be 8,800 (a rate of 4.2 per 100,000). The pattern of the disease being more common among females, whites, persons aged 30 to 50 years, and individuals living above the 37th parallel was also demonstrated. In addition to demographic characteristics, selected disease characteristics of the incidence and prevalence populations were also examined.     

A prospective study of the incidence, prevalence and mortality of multiple sclerosis in Leeds

Objective: To establish the prospective incidence of multiple sclerosis and mortality rates of people with multiple sclerosis in Leeds Health Authority and an updated prevalence of multiple sclerosis on 31 October 1999. Methods A population based prevalence register established on 30 April 1996 was maintained by prospectively registering all new cases of multiple sclerosis, flagging all cases with the National Health Service Central Register for notification of deaths and by registering all new clinical events. General practitioners notified patients with multiple sclerosis moving into or out of the area. Results 136 incident cases were prospectively registered from 30 April 1996 living in Leeds Health Authority (with an estimated resident population of 728 840). 57 deaths were notified. 792 people with multiple sclerosis were identified living in Leeds on 31 October 1999. The mean annual incidence rate for the three-year period 1996–1998 was 6.1/10⁵ (95 % CI: 5.1–7.2). The sex ratio of incident cases was 2.3 to 1 women to men. On 31 October 1999 the prevalence of multiple sclerosis in the Leeds Health Authority was 108.7/10⁵ (95 % CI: 101.2–116.5). This compares with a prevalence of 97.3/10⁵ (95 % CI: 90.3 –104.7) on 30 April 1996. The prevalence of definite and probable multiple sclerosis was 93.3/10⁵ (95 % CI: 86.4–100.6) and of suspected multiple sclerosis was 15.4/10⁵ (95 % CI 12.7 –18.5). Crude annual mortality rates of people with multiple sclerosis for 1997 and 1998 were 1.9/10⁵ (95 % CI: 1.1 to 3.2) and 3.2/10⁵ (95 % CI: 2.0 to 4.7). Multiple sclerosis was noted as the underlying cause of death in 8 (14 %) cases. Conclusion The incidence of multiple sclerosis in the Leeds Health Authority is similar to that in the south of the United Kingdom. The difference in successive prevalence figures is less than that published in other serial studies. Multiple sclerosis was notified as the underlying cause of death in a minority of deaths in people with multiple sclerosis. Received: 5 December 2000, Received in revised form: 23 March 2001, Accepted: 10 July 2001     

A further prevalence study of multiple sclerosis in north-east Scotland.

A second epidemiological study of multiple sclerosis (MS) in north-east Scotland has confirmed that the area has the highest prevalence rate in the world for any population of comparable size. On 1 December 1973 the prevalence was 144 per 100000 population. The age and sex specific prevalence rates are the highest ever recorded, one in every 306 of the population aged 40 to 59 years being affected. All patients have been tabulated in the National Health Service Central Register to facilitate future studies. The MS mortality rate in north-east Scotland is similar to the rate for the whole of Scotland. Throughout most of Scotland, therefore, MS probably is as prevalent as it is in the north-east.     

Increasing prevalence and incidence of multiple sclerosis in northern Japan

BACKGROUND: We previously reported that prevalence of multiple sclerosis (MS) in Japan was 8.6/100,000 individuals in 2001. This was much higher than prevalence previously reported from Asian countries. A second epidemiologic survey was conducted to assess changes in MS prevalence and incidence over the last 30 years in Tokachi province of Hokkaido, the northernmost island of Japan. METHODS: The authors studied the frequency of MS in the community of Tokachi Province, where the population has stabilized between 350,000 and 360,000 over the last 30 years. The survey was conducted at the same institutions using the same methods as the first survey in 2001. RESULTS: On March 31, 2006, 47 subjects satisfied Poser's criteria for MS. The prevalence rate increased from 8.6 to 13.1/100,000 individuals between 2001 and 2006. The prevalence of conventional MS (C-MS) increased in five years although the prevalence of optic-spinal MS (OS-MS) did not increase. The mean annual incidence increased from 0.15 (1975-1989) to 0.68 (1990-2004). CONCLUSIONS: The results show the highest MS prevalence in Asia; the increase in MS prevalence in Tokachi Province may be due to increased incidence after 1990.     

Comparative epidemiological studies of multiple sclerosis in South Africa and Japan.

Evidence is presented pointing to an increased incidence of multiple sclerosis having taken place in South Africa during the period 1964 to 1970 and in Tokyo, Japan, during the period 1966 to 1972. There is a possibility that these changes in incidence point to the introduction during the years immediately after the second world war, of an infective element-probably from a high-risk area-to Tokyo and South Africa. If this is so, it lends support to the theory of an infective basis for multiple sclerosis and that the suspected infection in prepubertal susceptibles may produce the symptoms of multiple sclerosis years later. Other factors relevant to multiple sclerosis such as environmental changes, improved diagnostic techniques, and susceptibility are discussed.     

The prevalence of migraine in multiple sclerosis (MS): A systematic review and meta-analysis

ObjectivesWe designed this systematic review to estimate pooled prevalence of migraine in patients with multiple sclerosis (MS).MethodsWe searched PubMed, Scopus, EMBASE, CINAHL, Web of Science, google scholar and gray literature including references from identified studies, conference abstracts which were published up to December 2019.The search strategy included the MeSH and text words as ((Disorder, Migraine OR Disorders, Migraine Disorder OR Migraine OR Migraines, OR Migraine Headache OR Migraine Headaches) AND (Multiple Sclerosis OR Sclerosis, Multiple) OR Sclerosis, Disseminated) OR Disseminated Sclerosis) OR MS (Multiple Sclerosis)) OR Multiple Sclerosis, Acute Fulminating).ResultsThe literature search found 2100 articles. After eliminating duplicates, 1500 articles remained. Eleven articles and twelve abstract conference papers were included for final analysis.A total of 11,372 MS cases and 2627 MS patients with migraine included in the analysis. The prevalence of migraine ranged from 2% to 67%.The pooled prevalence of migraine in included studies was 31% (95%CI: 22%–40%) (I² = 99.3%, p < 0.001). The pooled prevalence of migraine in different continents were significantly different (p < 0.001).The pooled prevalence was 24% in Asian countries, 43% in American countries, 25% in European countries and 43% in African countries.ConclusionThe results of this systematic review shows that the prevalence of migraine in MS patients is 31% while the prevalence differs significantly among residents of different continents.     

A prevalence survey of multiple sclerosis in Sussex.

A first survey of the Brighton and Mid-Downs health districts in Sussex showed a prevalence of multiple sclerosis of 111 per 100,000 (95% confidence interval (95% CI) 103-120) in a population of 596,594 on prevalence day, 1 July 1991. Cases were notified by multiple sources and to maximise case notification patients were not contacted. Cases were classified by hospital and family practitioner notes. The Poser criteria were used for classification. These criteria are precise and exclude cases of isolated spinal cord syndrome. The Allison and Millar criteria used in the surveys in Scotland may lack specificity and it is concluded that the high prevalence of multiple sclerosis in Scotland needs to be reassessed with the more precise criteria. Until this is done, the latitude effect within the United Kingdom remains not proved.     

The accuracy of prevalence rates of multiple sclerosis: a critical review

Review of the recent medical literature raises doubts about the reliability of reported prevalence rates of multiple sclerosis (MS). Many published prevalence rates are inflated. Some studies have shown that relying on clinical information and MRI interpretation leads to one third of incorrect MS diagnoses. The most important error is failing to distinguish between the clinical and MRI characteristics of MS and of disseminated encephalomyelitis (DEM) in both their acute and relapsing forms. The diagnostic criteria in current usage, including those relating to imaging, do not differentiate between MS and other recurrent inflammatory demyelinating diseases of the central nervous system. Considering a second demyelinating episode following a clinically isolated symptom or acute DEM, as confirming MS, is another major source of error. Another is including cases with onset before they entered the study group or moved to the geographic area. Neuromyelitis optica (NMO) has long been considered an MS variant and in Far Eastern countries it is counted as the 'oriental' form of MS, falsely inflating prevalence rates of MS in those areas. Recent immunologic and radiologic evidence shows that at least some NMO cases represent instances of DEM.     

The incidence and prevalence of multiple sclerosis in Newfoundland and Labrador, 1960-1984

A study of the incidence and prevalence of multiple sclerosis on the island of Newfoundland between 1960 and 1984 has yielded a current overall prevalence rate of 55.2 per 100,000, but wide variation is noted in the rates for different parts of the island (range, 15.9 to 105.0 per 100,000). The annual incidence rates for St. John's and the Avalon region of Newfoundland show cyclical variation on an approximate five- or six-year cycle. Suggestive evidence for a temporal link between varying incidence rates in these areas and recurrent local outbreaks of canine distemper was obtained.     

Epidemiology of multiple sclerosis in Kuwait: new trends in incidence and prevalence

The epidemiology of multiple sclerosis (MS) is undergoing dramatic changes; MS is occurring with increased frequency in many parts of the world. In this retrospective study, we examined the changes in incidence and prevalence of MS in Kuwait in the period between 1993 and 2000. We analyzed the records of patients with clinically defined and laboratory supported MS. The total incidence rate increased from 1.05/100,000 population in 1993 to 2.62/100,000 in 2000. The increased incidence of MS was most pronounced among Kuwaiti women (from 2.26/100,000 in 1993 to 7.79/100,000 in 2000. The total prevalence rate increased from 6.68/100,000 in 1993 to 14.77/100,000 in 2000. It was much higher for Kuwaitis (31.15/100,000), as compared to non-Kuwaitis (5.55/ 100,000), in a complete reversal of the pattern observed before 1990. The prevalence was also higher among Kuwaiti women (35.54/100,000), as compared with Kuwaiti men (26.65/100,000). In conclusion, the incidence and prevalence of MS in Kuwait has increased between the early and late 1990s with no signs of leveling off. In a geographic area that was previously associated with low prevalence, local environmental factors may be responsible for these dramatic changes.     

A prevalence study of multiple sclerosis in L'Aquila, central Italy

We report the results of an epidemiologic study in the Municipality of L'Aquila, Abruzzo, Central Italy, undertaken to estimate the prevalence rate of Multiple Sclerosis (MS). On December 31, 1984, the prevalence was 33.2 per 100,000 (34.2 when age and sex is standardized to the Italian population). In agreement with recent intensive surveys from different regions in the North and South of Italy, our data indicate that the prevalence of MS in Italy is higher than 30 per 100,000, and emphasize the importance of small population studies in the epidemiology of MS. Our findings suggest that in Italy the risk for MS is higher than recorded before.     

The risk of multiple sclerosis in nurses: a population-based epidemiological study

The incidence of multiple sclerosis (MS) in nurses during the period 1980-1996 was calculated in a nationwide study. The cohort consisted of 69,428 nurses, 2185 men and 67,243 women. Sixty (two men and 58 women) with definite MS were observed, whereas 69.3 were expected. We found no significant difference between the observed and expected number of MS cases (standardized incidence ratio = 0.87; 95% confidence interval, 0.66-1.12).     

Epidemiology of multiple sclerosis: incidence and prevalence rates in Denmark 1948–64 based on the Danish Multiple Sclerosis Registry

The Danish Multiple Sclerosis Registry (DMSR) is a national register based upon the ethnically homogeneous Danish population of about 5 millions. The DMSR was founded in 1956 following a nationwide Danish prevalence survey of MS in 1949 and a continuous registration of incident cases of MS since January 1, 1948. Included in DMSR are all Danish cases of MS (or suspicion of MS) diagnosed by a neurologist or a department of neurology. The sources of notification are the 22 neurological departments in Denmark, the National Patient Registry, the neuropathological departments, the Registry of Causes of Death, and, up to 1975, the Disablement Insurance Court. Notified cases which do not comply with the standardized diagnostic criteria of the DMSR are excluded. An estimate of the completeness of the DMSR is 90-95% and the validity is around 94%. Age- and sex-specific incidence rates of MS for the interval 1948-64 are presented. The crude annual incidence rate of MS in Denmark was in the year 1948-64 4.42 per 100,000 population, 22% higher in females than males. There was a significant geographical variation of incidence rates and a significant downward trend in incidence rates during the interval, whereas the prevalence rates showed a slight increase.     

The prevalence of multiple sclerosis in south east Wales.

A population-based survey of multiple sclerosis in the county of South Glamorgan has demonstrated a prevalence of 441/376718 (117/10(5)). Eighty six per cent of the patients (101/10(5)) had definite or probable disease and 14% (16/10(5)) had suspected multiple sclerosis on 1 January 1985. The estimated average incidence is 5.41/10(5)/year for the period 1947-84 and it has risen significantly over four decades. The prevalence is similar to that found in a recent survey from the south east of England but significantly lower than revised figures from Scotland.     

Progressive increase in incidence and prevalence of multiple sclerosis in Newcastle,Australia: a 35-year study

The prevalence of multiple sclerosis (MS) in Newcastle, Australia increased significantly between 1961 and 1981 and the incidence of the disease also increased between the decades 1950-1959 and 1971-1981. The present study sought to determine whether there has been a further increase in the frequency of MS in the subsequent 15 years, and to examine the potential factors underlying this change. The incidence, prevalence and clinical profile of multiple sclerosis were therefore re-examined in Newcastle, Australia in 1996 using comparable diagnostic criteria and methods to those employed in studies in the same region in 1961 and 1981. There has been a significant progressive increase in prevalence from 19.6 to 59.1 per 100,000 population and a significant increase in incidence from 1.2 to 2.4 per 100,000 population from 1961 to 1996. The most pronounced increase in prevalence was in females and in the age-group over 60 years, and there was also an increased incidence in females aged 20-29 years. There was little change in the age of disease onset, but duration of disease in females had increased substantially. The significant increase in prevalence is attributed to increased incidence, particularly in females; and to increased survival. Although such trends in prevalence have been observed in the Northern Hemisphere, this is the first such study in the Southern Hemisphere to show a longitudinal increase in prevalence and incidence over a period of this duration.     

Immobilization and the risk of venous thromboembolism. A meta-analysis on epidemiological studies

Background

The thrombogenic burden of immobilization remains unknown especially in the medical setting. Most of epidemiological studies estimating the link between risk factors and venous thromboembolism (VTE) have not been designed to evaluate immobilization. The aim of this work was to estimate the risk of VTE in medical bedridden patients by a systematic review and a meta-analysis.

Methods

A research on PUBMED and EMBASE was carried out to retrieve case-control and cohort studies showing the proportion of bedridden patients with or without VTE. Included studies were assigned in six groups according to the following criteria: 1) their design (cohort or case-control), 2) the targeted population (with or without suspicion of VTE) and 3) the medical setting (ambulatory or hospital). Odd-Ratios and Relative Risk for case-control and cohort studies were calculated using a random effect method. Heterogeneity and publication bias were statistically assessed by the I² statistics and funnel plots with Egger's tests.

Results

43 studies were included (24181 patients). The pooled RR ranged from 1.46 to 2.77 in the subgroups of cohort studies (n = 36) with an overall RR of 1.86 (1.61-2.14; P < 0.001). The pooled OR were 2.79 and 2.47 in the two subgroups of case-control studies (n = 7), both statistically significant (overall OR: 2.52; 1.70-3.74; P < 0.001). Heterogeneity through studies was demonstrated in four subgroups. Publication bias was only observed in one subgroup.

Conclusions

Among medical patients, immobilization increases the risk of VTE. Nevertheless, a specific role of underlying conditions can not be excluded.