Incidence and prevalence of recognised and unrecognised myocardial infarction in women. The Reykjavik Study

AIMS: The incidence and prevalence of recognised and unrecognised myocardial infarction were determined in the Icelandic cohort study of 13,000 women (the Reykjavik Study), followed for up to 29 years (mean 15 years). METHODS AND RESULTS: Women attending the Reykjavik Study, born between 1908 and 1935, were examined in five stages from 1968 to 1991. A health survey included history and ECG manifestations of coronary heart disease. Data retrieved from hospitals, autopsy records and death certificates identified 596 fatal and non-fatal myocardial infarctions to the end of 1992 (61 prior to examination, 320 non-fatal and 215 fatal). The incidence of recognised myocardial infarction ranged from 22 cases/100,000/year at 35-39 years to 1800 cases/100,000/year at 75-79 years. The incidence of unrecognised myocardial infarction ranged from 18 cases/100,000/year at 35 years to 219 cases/100,000/year at 75 years. Thirty-three percent of non-fatal myocardial infarctions were unrecognised. More occurred in the younger age groups (40%) than in the older (27%). The prevalence of recognised myocardial infarction was influenced by age and calendar year. In 1990, it was 1.3/1,000 at 35 years and 60/1000 at 75 years. Prevalence showed a time trend, tripling in all age groups from 1968-1992. Fore unrecognised myocardial infarction, prevalence rose from 0.9/1000 at 35 years to 19.2/1000 at 75 years, although there was no evident time trend. CONCLUSION: Myocardial infarction in women is very age-dependent with both incidence and prevalence increasing continuously and steeply with age. There was a significant trend for an increase in prevalence of recognised myocardial infarction from 1968 to 1992. The proportion of unrecognised non-fatal infarctions ranged from 27% in the oldest age group to 40% in the youngest. On average, this form of coronary heart disease is as common as in men.     

Prostate cancer in Denmark: a 50-year population-based study

OBJECTIVES: To review the trends in prostate cancer (PC) incidence and mortality rates in Denmark during a 50-year period. METHODS: A population-based register study was performed of all new cases of PC recorded in the Danish Cancer Registry from 1943 to 1992. RESULTS: The age-standardized incidence rate for PC increased from 11.5/100,000 in 1943 to 1947 to 30.9/100,000 in 1988 to 1992. Age-specific incidence rates increased in all age groups over 50 years of age. Mortality rates increased from 13.5/100,000 in 1953 to 1957 to 17.8/100,000 in 1988 to 1992. No major changes in the distribution of age, stage at the time of diagnosis, or in diagnostic procedures were found, indicating that the observed change in incidence rates was not caused by attempted early detection or changes in diagnostic strategy. CONCLUSIONS: Our data suggest that the increased PC incidence observed during the period of cancer registration in Denmark represents a true increase in the number of patients with clinical PC.     

Incidence and prevalence of juvenile chronic arthritis in East Berlin 1980-88

OBJECTIVE: To estimate the incidence and prevalence rates of juvenile chronic arthritis (JCA). METHODS: The study population was children under 16 years of age living in the East Berlin area (part of the former German Democratic Republic). By admission order that was effective up to 1990, all children with symptoms of a rheumatic disease living in the East Berlin area had to be referred to the 2nd Children's Hospital at Berlin-Buch. This specific condition allowed us to ascertain cases from the clinical records and to calculate population rates. Based upon this data, the results of surveys with different methods of case ascertainment are compared. RESULTS: An incidence rate of 3.5 per 100,000 and a prevalence rate of 2.0 per 10,000 children were calculated. The frequency of JCA is higher for girls, with an incidence of 4.3 per 100,000 and a prevalence of 2.3 per 10,000. The figures for boys are 2.7 per 100,000 and 1.7 per 10,000, respectively. CONCLUSION: Because of the specific prerequisites, the population rates of prevalence and incidence that were based on clinical records can be regarded as valid in this study. Deviant results of other surveys can be explained by differences in the study design or in the diagnostic procedures used.     

Epidemiology of multiple sclerosis in the county of Vestfold, eastern Norway: incidence and prevalence calculations

The county of Vestfold in the South-eastern part of Norway has undergone two incidence and prevalence surveys on multiple sclerosis. The prevalence of definite/probable MS on January 1, 1963 was 61.6/100,000. Based on the same diagnostic criteria, the present study reports a slight increase in prevalence to 86.4/100,000 on January 1st 1983. The average annual incidence was calculated for 5 years periods from 1953 to 1983. The time periods 1953-1962 and 1973-1977 showed age-adjusted incidence rates between 4.50 and 5.49/100,000 while the 10-year period 1963-1972 showed significantly lower rates. The fluctuating pattern of MS incidence and prevalence over time supports the view that MS is not a stable disease, and that exogenous factors are influencing the disease pattern.     

Prevention and control of hepatitis B virus infection in Singapore

Hepatitis B virus (HBV) accounted for 24% to 54% of the reported acute viral hepatitis cases in Singapore from 1982 to 1996. The prevalence of HBV infection, as indicated by the presence of markers of HBV, increased from 9.3% in children below 5 years of age to 54.6% in adults above 55 years. The overall hepatitis B surface antigen (HBsAg) prevalence was 5.7% for males and 3.4% for females, with the highest rate among the Chinese. About 39% of the HBsAg carriers were hepatitis B 'e' antigen positive. The main mode of transmission during the first year of life was perinatal, with 43% of the babies born to HBsAg-positive mothers developing the carrier state. Horizontal transmission within the infected household was significantly associated with sharing of personal and household articles. Based on the findings of seroprevalence surveys in various population groups and clinical trials on the safety, immunogenicity and efficacy of various doses and schedules with the plasma-based and yeast-derived hepatitis B vaccines in newborn babies, a national childhood hepatitis B vaccination programme was formulated and implemented in phases, starting with babies born to carrier mothers on 1 October 1985 and finally extending to all newborns on 1 September 1987. The hepatitis B prevention and control programme has been successful. During the period 1994 to 1996, more than 90% of children completed the full schedule of immunisation by below one year of age, and 85% had evidence of vaccination at school entry at age six. Follow-up of 2 cohorts of vaccinated children showed that perinatal transmission has been reduced by 80% to 100%. Horizontal transmission has also declined through other public health measures. The efficacy of the hepatitis B vaccine and the adequacy of reduced doses in the long-term protection of chronic carrier state have been shown in children and adults. The incidence of acute hepatitis B has declined from 10.4 per 100,000 in 1985 to 4.8 per 100,000 in 1996. There is a noticeable reduction in HBsAg prevalence in selected population (school children, national servicemen and antenatal women). The age-standardised incidence rate of primary liver cancer among males had also dropped from 27.8 per 100,000 per year during 1978 to 1982 to 19.0 per 100,000 per year during 1988 to 1992.     

Treatment of aggression and irritability after head injury

Epidemiological characteristics of colorectal cancer may differ by particular anatomical subsite, suggesting that the subsite-specific colorectal cancers may represent different disease entities. This study explored the time trends over a 23-year period in colorectal cancer incidence at various subsites by sex and age group. Data on the incidence of colorectal cancer were obtained from a population-based cancer registry in Shanghai, People's Republic of China. Between 1972 and 1994, 30,693 patients with colorectal cancer were registered at the Shanghai Cancer Registry. The overall age-adjusted colorectal cancer incidence rates increased > 50%, or 2% per year from 1972-1977 to 1990-1994, from 14 to 22 per 100,000 among men and from 12 to 19 per 100,000 among women. The increases in rates were considerably more rapid for colon cancer, with rates approximately doubling, than they were for rectal cancer. Proximal colon cancer was more common than distal colon cancer over the whole study period, whereas rates for both cancers rose with similar annual percentage changes (> 5% per year) and across virtually all age groups. The estimated annual increases rose from 2% at ages 35-44 years to 7% at ages 75-84 years for proximal colon cancer, but they were more uniform for distal colon cancer (5-6% per year). Age-adjusted and age-specific rectal cancer rates changed little. The male:female age-adjusted rate ratio for colorectal cancer was 1.19 in 1990-1994. The ratios increased over time and varied by subsites, with ratios increasing from the proximal colon to the distal colon and to the rectum. Furthermore, men had higher rates than women for distal colon and rectal cancers at ages 55 and older, whereas women had higher rates than men at younger ages for these two cancers. Male:female rate ratios for proximal colon cancer did not vary substantially with age. The findings from this study indicate that subsite-specific incidence rates of colorectal cancer differ by sex and age and in their time trends. Cancers arising in the proximal colon, distal colon, and rectum may have somewhat different disease etiologies.     

Age-specific incidence and prevalence rates of treated epilepsy in an unselected population of 2,052,922 and age-specific fertility rates of women with epilepsy

BACKGROUND: There are no data on prevalence or incidence of treated epilepsy, and no data on fertility of women with epilepsy from an unselected UK population. METHODS: We used the General Practice Research Database to ascertain the incidence and prevalence of people with treated epilepsy in an unselected population of 2,052,922 people in England and Wales, and also age-specific fertility rates. We defined period prevalence of treated epilepsy as the number of people with epilepsy taking an antiepileptic drug per 100,000 people during 1995. The incidence of treated epilepsy was defined as the number of new cases of treated epilepsy per 100,000 people during the same period. We calculated fertility rates among women with treated epilepsy between 1991 and 1995 and compared these rates with the population rates for England and Wales in 1993. FINDINGS: The period prevalence of treated epilepsy in 1995 was 5.15 per 1000 people (95% CI 5.05-5.25). The prevalence was lower in children (age 5-9 years 3.16 [2.86-3.48]; 10-14 years 4.05 [3.70-4.42]), and higher in older people (65-69 years 6.01 [5.50-6.57]; 70-74 years 6.53 [5.97-7.14]; 75-79 years 7.39 [6.73-8.11]); 80-84 years 7.54 [6.78-8.39]; 85 years and older 7.73 [6.98-8.66]). The incidence of treated epilepsy was 80.8 per 100,000 people (76.9-84.7). The incidence was lower in children (5-9 years 63.2 [50.5-79.1]; 10-14 years 53.8 [42.4-68.3]) and higher in older people (65-69 years 85.9 [68.5-107.3]; 70-74 years 82.8 [65.0-105.2]; 75-79 years 114.5 [116.9-179.2]; 80-84 years 159 [125.2-202.6]; > or = 85 years 135.4 [100.4-178.7]). Fertility was lower among women with treated epilepsy, with an overall rate of 47.1 livebirths per 1000 women aged 15-44 per year (42.3-52.2), compared with a national rate of 62.6 in the same age-group. The standardised fertility ratios were significantly lower between the ages of 25 and 39 years in women with epilepsy (p<0.001). INTERPRETATION: Compared with previous studies, we found that the incidence of epilepsy was higher in elderly people and lower in children. The prevalence rates also increase with age. Women aged 25-39 years with treated epilepsy have significantly lower fertility rates than those in the general population. Research is needed to identify any potentially preventable causes for the low fertility rates.     

Insulin-dependent diabetes in the county of Funen 1970-2020. An epidemiological description

We present an epidemiological model applicable to insulin-dependent diabetes mellitus (IDDM), based on which prevalence rates are estimated from assumed rates of incidence and mortality of diabetes. The model is illustrated by analysing epidemiological data on IDDM in Fyn County, Denmark for the period 1970-1990, with predictions of prevalence rates during 1990-2020. The epidemiological model assumes known prevalence rates as well as incidence rates and mortality at a given point of time. Under assumed rates of incidence and mortality of IDDM and its complications, the prevalence rate is the dependent variable which is estimated as a function of calendar time. We used epidemiological data on IDDM (operationally defined as insulin-treated diabetes with onset before age 30 years), blindness and nephropathy as well as mortality as reported for the years 1973 and 1987 in Fyn County, Denmark. During 1970-1990 the prevalence of IDDM increased steadily, due to increasing incidence and decreasing risk of complications and mortality. The relative prevalence of patients with nephropathy increased whereas that of blind patients decreased considerably. Under specified assumptions regarding the future levels of incidence of disease, complications and of mortality, it is estimated that the prevalence rate of IDDM in the year 2020 will be 45-60% higher than the level in 1990. The relative prevalence of patients with nephropathy will increase further, whereas the relative prevalence of blind patients will remain constant at a low level. We conclude that IDDM will represent an increasing public health problem in Denmark over the next decades, with increasing overall prevalence rates and a rising proportion of patients with nephropathy. The major determinants of this trend are increasing incidence, combined with declining mortality and declining risk of complications. It is recommended that epidemiological modelling techniques be further developed to provide improved data for the planning of the future diabetes care.     

Prevalence, incidence, and characteristics of multiple sclerosis in Westlock County, Alberta, Canada

We report a prevalence study of multiple sclerosis (MS) in the town of Westlock and surrounding county of Westlock, in Alberta, Canada. The prevalence rate for clinically definite MS on January 1, 1991, was 200/100,000. The average annual incidence rates for patients living in the area at onset were 1.91/100,000 for 1950-1959, 2.85/100,000 for 1960-1969, 3.82/100,000 for 1970-1979, and 7.26/100,000 for 1980-1989. Forty-eight percent of the patients were relapsing-remitting. Sixty percent were still walking without assistance. The female-to-male ratio was 1.4:1. Mean current age was 47, age at onset 30, and duration of illness 18 years. The majority of patients (40%) experienced multiple symptom onset. Forty percent were of single ethnic origin (primarily British); the remainder were predominantly north European combinations. Twenty-four percent of patients reported another MS relative, six first-degree and one second-degree relative.     

Incidence and hospitalization patterns of insulin-dependent diabetes mellitus

Data from a statewide insulin-dependent diabetes mellitus (IDDM) registry in Rhode Island show that IDDM affects young adults (20-29 yr) as frequently as adolescents and teenagers (10-19 yr). Overall incidence less than 30 yr was 14/100,000 population. Peak incidence occurred at 10-14 yr (19/100,000 population). Poor diabetic control and infection accounted for 46-62% of hospitalizations among 275 known diabetic persons. Despite a 10-yr mean duration of diabetes, only 31% of hospitalized diabetic persons less than 30 yr of age reported ever having received outpatient diabetes education of two or more hours. Readmissions 1 yr after initial registration were more frequent for known (43%) than new-onset (18%) IDDM cases. Increased risk of readmission for both groups was associated with a poverty socioeconomic status. Total direct hospitalization costs for IDDM in persons under 30 yr of age in Rhode Island was $530,000 per year of $2,245 per patient.     

Cervical cancer mortality in Belgium, 1955-1989. A descriptive study

This study describes trends in cervical cancer mortality among women in Belgium from 1954 to 1989. Data are analysed by means of the standardised mortality rate, age- and cohort-specific mortality rates and standardised cohort mortality ratios. The age-standardised mortality rate decreased progressively from 6.3/100,000 women-years in the first period (1955-1959) to 3.8/100,000 in 1985-1989, indicating a decline of 39.7% over the seven quinquennial periods. A decrease was observed in almost all age groups between 30 and 69 years. In the last 15 years, no further decline, but even a discrete increase, occurred for the age categories younger than 50 years. The successive cohorts born between 1915 and 1939 expressed a continuing lower risk of cervical cancer mortality. This trend was not observed for the most recent generations, for whom even a slight increase of the standardised cohort mortality ratio could be distinguished.     

The current neurologic burden of illness and injury in the United States

Estimates of the need for neurologists must be based ultimately on the frequency of neurologic disease. Community-based population surveys for diseases or injuries that have come to medical attention provide annual incidence rates per 100,000 population, point prevalence rates per 100,000, and average duration in years. For 61 disorders, including for 8 only those fractions that were thought to require neurologic attention, the annual incidence rates summed to 2500 per 100,000 or 2.5% of the population. For 55 of these conditions, including for 6 only the neurologic fraction and excluding all mental retardation, blindness, deafness, or psychosis, the point prevalence rates summed to 9500 per 100,000 population. Even if we also excluded all headache, all trauma, all alcoholism, and all vertebrogenic pain states, 3.6% of the general population at any one time should be under neurologic care. Substracting all these exclusions from the incidence rates similarly leaves more than 1 person in every 100 who each year will have a new neurologic disorder that requires the attention of a physician competent in clinical neurology.     

Stabilization of asthma mortality

BACKGROUND: Rates of death from asthma in the United States have increased since 1978. OBJECTIVE: To identify and evaluate recent trends in asthma mortality. METHODS: Analysis of data from the National Center for Health Statistics identifying asthma (ICD 493) as the underlying cause of death in the 50 United States and the District of Columbia with rates of death from asthma by age, race, and sex and age-adjusted rates of death by race. The Bureau of the Census provided population data by age, race, and sex that permitted calculation of rates of death at 5 through 34 years of age. The Departments of Health of Australia, Canada, Great Britain, and New Zealand provided numbers of deaths from asthma and population data from which we have calculated rates of death. RESULTS: Rates of death from asthma in the United States increased from .8 per 100,000 general population in 1977 and 1978 to 2.0 in 1989 and have been 1.9 or 2.0 since then until an increase to 2.1 in 1994. A significant difference in regression over groups indicates a difference in average rates between 1979 through 1987 compared with 1988 through 1994. Rates of death from asthma have been much higher for white females than white males with an increasing disparity. Rates of death from asthma at 5 through 34 years of age have been much greater in blacks than whites with no significant change in rates across time from 1980 through 1994. Age-adjusted rates for blacks over all ages increased from 1.5 in 1977 and 1978 to 3.5 in 1988 with rates no higher than that until an increase to 3.7 in 1994. Age-adjusted rates for whites increased from .5 in 1977 to 1.2 by 1989 with none higher than that since then through 1994. Comparison of slopes indicates a significantly greater increase for blacks than whites (F = 68.296, P < .0001). Equality of slopes tests indicate significantly greater age-adjusted rates of increase for each race separately for 1979 through 1987 compared with 1988 through 1994. CONCLUSION: Since 1988 rates of death from asthma in the United States for most ages have stabilized at rates more than 50% higher than those of 1979, but there has been only a suggestion of stabilization of rates at 5 through 34 years of age, ages at which certification of death as due to asthma is most accurate. Rates of death have been much higher for blacks than whites, and among whites rates have increased more for females than males. These differences might be due to difference in prevalence or severity of differences in accuracy of diagnosis. Improvements in management would reduce asthma mortality.     

Prospective study of bacterial meningitis in North East Thames region, 1991-3, during introduction of Haemophilus influenzae vaccine

OBJECTIVE: To describe the epidemiology of primary bacterial meningitis in the North East Thames region over a three year period before and during the introduction of the vaccine for Haemophilus influenzae type b. DESIGN: Analysis of information on cases of primary bacterial meningitis identified by microbiology laboratories in the region, with collection of case data by questionnaire. MAIN OUTCOME MEASURES: Annual incidence rates for types of meningitis according to age and ethnic group. RESULTS: The annual incidence rates for the three major causes of bacterial meningitis in the general population were 1.9/100,000 for Neisseria meningitidis, 1.6/100,000 for Haemophilus influenzae before vaccination, and 1.0/100,000 for Streptococcus pneumoniae. Higher rates of H influenzae meningitis were found in Asians compared with white people (3.6/100,000 v 1.5/100,000, P = 0.01). As a result of the vaccine programme introduced in October 1992 the number of cases of H influenzae meningitis in children under 5 years has fallen by 87%. CONCLUSIONS: Bacterial meningitis is a serious problem especially in preschool children. There are differences in the incidence of some causes of bacterial meningitis in different ethnic groups; with H influenzae type b being significantly more common among black and Asian people than among white people. The immunisation programme for H influenzae type b in the North East Thames region has been successful in reducing the incidence of this type of meningitis in Asian and white populations. The numbers were too small to evaluate in the black population.     

Descriptive epidemiology of IDDM in Hokkaido, Japan: the Childhood IDDM Hokkaido Registry

OBJECTIVE: To identify the incidence of IDDM with regard to sex, age, family history of diabetes, season, and 5-year period of childhood IDDM among children ages 0-14 years from a population-based epidemiological study in Hokkaido, Japan, from 1973 to 1992. RESEARCH DESIGN AND METHODS: Registration of all new IDDM cases in Hokkaido was conducted by the Childhood IDDM Hokkaido Registry Study Group from 1973 to 1992. The cases were selected from among 1) patients who were admitted to the member hospitals of the study group, 2) patients who answered a questionnaire distributed to hospitals and diabetic clinics throughout Hokkaido, and 3) patients whose cases were recorded in free-treatment medical records of urban and rural districts. The case ascertainment rate was estimated to be 100%. Differences in incidence with regard to sex, age, family history of diabetes, season, and year period were analyzed by the Poisson regression analysis by GENMOD. RESULTS: During the 20-year period studied, 396 cases (181 boys, 215 girls) of abrupt-onset IDDM were registered. Statistically significant differences in annual incidence were found according to sex (female), age (8-14 years), history (having no diabetes in family), season (spring), and 5-year period. CONCLUSIONS: This is the first population-based, long-term epidemiological study of childhood IDDM from Japan. We observed a significantly higher annual incidence (per 100,000/year) of IDDM in female subjects (1.81), older age-groups (2.25 for 8-14 years), subjects with no family history of diabetes (1.26), diabetes onset in the spring (2.20), and an increased trend over the 20 years. In addition, the heterogeneity of IDDM among Japanese children needs to be elucidated.     

Incorporating auxiliary variables into probability sampling designs

There have been few reports about the frequency of multiple sclerosis (MS) in Spain. We undertook a prevalence study in the province of Teruel, which is served by two hospitals as referral centres for a population of 143,680. We found a total of 46 patients who fulfilled Poser's criteria for clinically definite or probable MS with a prevalence rate of 32/100,000 [95% confidence interval (CI): 22.8-41.3]. The prevalence rates for males and females were 23.5 (95% CI: 12.3-34.7) and 40.6 (95% CI: 25.8-55.4) respectively. We found an incidence rate of 2.2/year per 100,000 in the last 5 years. The sex ratio (females/males) was 1.7. The mean age on prevalence day was 40.6 years (range: 15-76). The clinical course was relapsing-remitting in 82% of patients, progressive in 9% and secondary progressive in the other 9%. The mean EDSS score was 3.73 (range: 1-8.5). Our results confirm the hypothesis that Spain is an area at high risk for MS.     

Development of a multigenic plasmid vector for HCV DNA immunization

OBJECTIVES: The aim of this study was to determine the prevalence of multiple sclerosis in a population in South Hungary. METHODS: The diagnosis was established with the aid of the Poser diagnostic criteria and the degree of physical disability was determined on the Kurtzke expanded disability status scale (EDSS). The present medical state (EDSS score) was determined from outpatient clinical control tests. The prevalence, the average age at onset of the disease and the proportions of the various clinical forms were calculated, and the patients' disability status was estimated. RESULTS: In 1996, the prevalence was 65/100,000, and the incidence from January 1, 1995 through December 31, 1996 was 7/100,000/year. DISCUSSION: During a period of 2 years, the number of diagnosed patients has almost doubled. The disease can be recognized in an early stage with a minimal neurological deficit. The development of the diagnostics necessitates re-examinations with modern diagnostic procedures. During the last 3 years, the general practitioner system has been reorganized, and the working relationships between the clinic and family doctors have developed considerably. A comparison of the present findings with those in other countries with a similar climate revealed very similar prevalence data.     

The incidence and severity of rheumatoid arthritis, results from a county register in Oslo, Norway

OBJECTIVE: To examine the incidence of rheumatoid arthritis (RA) in the community of Oslo, Norway; and to link the incidence to measures of disease severity. METHODS: A register for RA in the county of Oslo was validated to be 85% complete for patients between 20 and 79 years of age. The incidence of RA was calculated from this register for patients with disease onset 1988-1993 (n=550). Data on health related quality of life [Modified Health Assessment Questionnaire (MHAQ), Arthritis Impact Measurement Scale 2 (AIMS2), pain, fatigue] were obtained from a postal survey (response rate 73%). RESULTS: The overall annual incidence of RA over a 6 year period was 25.7/100,000 (females 36.7, males 13.8). The incidence increased with age, from 7.8 in the age group 20-29 to 61.0 between 70 and 79 years. After 5 year followup a clinically important effect on physical function (MHAQ > 1.5) was seen in 38% of the patients, on social functioning (AIMS2 social > 4) in 50%, on mental distress (AIMS2 affect > 4) in 27%, on pain (VAS > 40 mm) in 35%, and on fatigue (VAS > 40 mm) in 41%. CONCLUSION: The incidence of RA was 25.7/100,000 in the population of Oslo. After 5 years, 40-50% had clinically important changes in health status. The annual disease incidence with clinically important effect on physical function after 5 years was 10/100,000 individuals at risk.     

In vitro and in vivo antibacterial activities of AM-1155 in the fields of obstetrics and gynecology

OBJECTIVES: Until relatively recently southern Europe was regarded as having a medium to low multiple sclerosis prevalence, of about 20 or less per 100,000. However, recent studies in Sardinia, Sicily, continental Italy, Cyprus and Spain have yielded higher MS prevalence rates, between 32 and 102.6 per 100,000. We present the results of a prevalence study of MS in the municipality of M6stoles, central Spain. MATERIAL AND METHODS: To ascertain the prevalence of multiple sclerosis in M6stoles (195,979 inhabitants), an intensive study was undertaken using several sources of information. We used the Poser criteria in diagnosis. RESULTS: There were 85 patients (53 women and 32 men) classified as definite or probable, prevalence 43.4/100,000 (95% CI, 34.7 to 53.7). The incidence rate was 3.8/100,000/year (95% CI, 2.7 to 5.3) in the last 5 years. Mean age on prevalence day was 38.8+/-10.9 years. Mean age at onset was 31.7+/-9.3 years. Mean interval between initial symptoms and diagnosis was 1.7 years. Mean duration of disease was 7.6+/-6.1 years. Overall, 70.6% had a relapsing-remitting course, 18.8% had a primary progressive and 10.5% had a secondary progressive. Mean EDSS score was 2.7+/-1.9. CONCLUSION: The M6stoles study confirms the conclusions of previous smaller population studies that Spain is a moderately high or medium MS risk zone.     

Paired pulse suppression and facilitation in human epileptogenic hippocampal formation

The most frequent major adverse effect of hormonal contraception is an increased risk of cardiovascular disease. The effect on the risk of venous thromboembolism (VTE), ischemic and hemorrhagic stroke, and myocardial infarction (MI) differs and is strongly influenced by smoking and the presence of other cardiovascular risks factors, such as hypertension and diabetes mellitus. The incidence of each disease rises with age and there are differences in risk among hormonal contraceptive preparations. This article provides a framework within which to assess the balance of risks among types of hormonal contraceptives according to individual circumstances. Data on cardiovascular disease mortality rates in women of reproductive age in different countries of the world were compiled from nationally reported statistics and supplemented where possible with reported disease incidence rates. Risks associated with current use of hormonal contraception were compiled from the most recent publications on the cardiovascular effects of steroid hormone contraception. These were combined to estimate the total cardiovascular incidence and mortality according to baseline cardiovascular risk and individual characteristics. Mortality rates for cardiovascular diseases are very low in women of reproductive age. Myocardial infarction mortality rates rise from < 0.4 per 100,000 woman-years at age 15-24 years to the range 2 to 7 per 100,000 woman-years at age 35-44 years. Stroke mortality rates similarly rise steeply with age and are between 3 and 5 times higher than those for MI. VTE mortality rates rise less steeply with age and are approximately one-tenth the MI mortality rates at age 35-44 years. The adverse effect of oral contraceptives (OC) on the risk of VTE is the most important contributor to the total number of cardiovascular cases attributable to OC use. The increased risk of stroke and MI dominate the patterns of mortality in OC users and smokers. The additional risks attributable to smoking are greater than the additional risks attributable to OC use. The risk attributable to OC use in women < 35 years of age is small, even if they smoke, but there are substantially increased risks in older women who both smoke and use OC. The additional mortality attributable to OC use can be reduced by screening users, as this results in lower relative risks of ischemic stroke and MI. Differences between OC types in the relative risk of VTE contribute little to the total cardiovascular mortality associated with OC use, even though the total number of cardiovascular events is increased. A potential reduction in the risk of MI with desogestrel and gestodene compared with levonorgestrel-containing OC would have little difference on overall mortality rates in women in their 20s and 30s, but may result in a net reduction in OC-attributable mortality in women aged 40-44 years who smoke. An overall quantification of the risks for different types of oral contraceptive users is necessary for an informed choice of contraceptive method, and any assessment of the balance of cardiovascular risks is complex. The model provides a tool to assess, at the level of the individual, the risks associated with use of different OC according to personal circumstances. It is important to consider the user's age and smoking status when determining OC attributable risks.