International trends in mortality from stroke, 1968 to 1994.

BACKGROUND AND PURPOSE: The World Health Organization data bank is an invaluable source of information for international comparison of mortality trends. We present rates and trends in mortality from stroke up to 1994, with a particular emphasis on the last 10-year period. Data are presented for men and women in 51 industrialized and developing countries from different parts of the world. METHODS: We included all deaths from cerebrovascular disease for the population aged 35 to 84 years from all the countries in which death certificates were estimated to be available for at least 80% for the period from 1968 to 1994. Age-standardized mortality rates from stroke were calculated for each country for the last available 5 years. Time trends were calculated by using ordinary linear regression and are presented for the entire study period and for 3 separate time periods: 1968 to 1974, 1975 to 1984, and 1985 to 1994. The last 10-year period was further subdivided into 2 parts of 5 years each. We analyzed data separately for men and women and for groups aged 35 to 74 years and 75 to 84 years. RESULTS: The highest rates at the end of the study period for the population aged 35 to 74 years were observed in eastern Europe and previous Soviet Union countries (309 to 156/100 000 per year among men and 222 to 101/100 000 per year among women), Mauritius (268/100 000 per year among men and 138/100 000 per year among women), and Trinidad and Tobago (185/100 000 per year among men and 134/100 000 per year among women). Relatively low to average rates (<100/100 000 per year among men and <70/100 000 per year among women) were reported for Western Europe, with an exception of Portugal (162/100 000 per year among men and 95/100 000 per year among women). The countries with lowest stroke mortality rates at the end of the study period, such as the United States, Canada, Switzerland, France, and Australia, experienced steep declining trends. However, the slope of the decline was substantially reduced during the last 5 years in these countries. Mortality from stroke increased most in the eastern European countries, especially during the last 5 years. Among other high-risk populations, no change in stroke mortality trends was observed in Mauritius, whereas somewhat declining trends were seen in Trinidad and Tobago. CONCLUSIONS: We observed large differences in mortality rates from stroke around the world together with a wide variation in mortality trends. A widening gap was observed between 2 groups of nations, those with low and declining stroke mortality rates and those with high and increasing mortality, in particular, between western and eastern Europe. Eastern European countries should initiate actions aiming at the reduction of stroke risk, perhaps by looking at the examples of Japan and Finland and the other countries that have been the most successful in reducing previously very high mortality from stroke.

International trends in mortality from stroke, 1968 to 1994

BACKGROUND AND PURPOSE: The World Health Organization data bank is an invaluable source of information for international comparison of mortality trends. We present rates and trends in mortality from stroke up to 1994, with a particular emphasis on the last 10-year period. Data are presented for men and women in 51 industrialized and developing countries from different parts of the world. METHODS: We included all deaths from cerebrovascular disease for the population aged 35 to 84 years from all the countries in which death certificates were estimated to be available for at least 80% for the period from 1968 to 1994. Age-standardized mortality rates from stroke were calculated for each country for the last available 5 years. Time trends were calculated by using ordinary linear regression and are presented for the entire study period and for 3 separate time periods: 1968 to 1974, 1975 to 1984, and 1985 to 1994. The last 10-year period was further subdivided into 2 parts of 5 years each. We analyzed data separately for men and women and for groups aged 35 to 74 years and 75 to 84 years. RESULTS: The highest rates at the end of the study period for the population aged 35 to 74 years were observed in eastern Europe and previous Soviet Union countries (309 to 156/100 000 per year among men and 222 to 101/100 000 per year among women), Mauritius (268/100 000 per year among men and 138/100 000 per year among women), and Trinidad and Tobago (185/100 000 per year among men and 134/100 000 per year among women). Relatively low to average rates (<100/100 000 per year among men and <70/100 000 per year among women) were reported for Western Europe, with an exception of Portugal (162/100 000 per year among men and 95/100 000 per year among women). The countries with lowest stroke mortality rates at the end of the study period, such as the United States, Canada, Switzerland, France, and Australia, experienced steep declining trends. However, the slope of the decline was substantially reduced during the last 5 years in these countries. Mortality from stroke increased most in the eastern European countries, especially during the last 5 years. Among other high-risk populations, no change in stroke mortality trends was observed in Mauritius, whereas somewhat declining trends were seen in Trinidad and Tobago. CONCLUSIONS: We observed large differences in mortality rates from stroke around the world together with a wide variation in mortality trends. A widening gap was observed between 2 groups of nations, those with low and declining stroke mortality rates and those with high and increasing mortality, in particular, between western and eastern Europe. Eastern European countries should initiate actions aiming at the reduction of stroke risk, perhaps by looking at the examples of Japan and Finland and the other countries that have been the most successful in reducing previously very high mortality from stroke.

Estimation of contribution of changes in coronary care to improving survival, event rates, and coronary heart disease mortality across the WHO MONICA Project populations.

BACKGROUND: The revolution in coronary care in the mid-1980s to mid-1990s corresponded with monitoring of coronary heart disease (CHD) in 31 populations of the WHO MONICA Project. We studied the impact of this revolution on coronary endpoints. METHODS: Case fatality, coronary-event rates, and CHD mortality were monitored in men and women aged 35-64 years in two separate 3-4-year periods. In each period, we recorded percentage use of eight treatments: coronary-artery reperfusion before, thrombolytics during, and beta-blockers, antiplatelet drugs, and angiotensin-converting-enzyme (ACE) inhibitors before and during non-fatal myocardial infarction. Values were averaged to produce treatment scores. We correlated changes across populations, and regressed changes in coronary endpoints on changes in treatment scores. FINDINGS: Treatment changes correlated positively with each other but inversely with change in coronary endpoints. By regression, for the common average treatment change of 20, case fatality fell by 19% (95% CI 12-26) in men and 16% (5-27) in women; coronary-event rates fell by 25% (16-35) and 23% (7-39); and CHD mortality rates fell by 42% (31-53) and 34% (17-50). The regression model explained an estimated 61% and 41% of variance for men and women in trends for case fatality, 52% and 30% for coronary-event rates, and 72% and 56% for CHD mortality. INTERPRETATION: Changes in coronary care and secondary prevention were strongly linked with declining coronary endpoints. Scores and benefits followed a geographical east-to-west gradient. The apparent effects of the treatment might be exaggerated by other changes in economically successful populations, so their specificity needs further assessment.

Seasonal variation in the incidence of Type 1 diabetes mellitus during 1983 to 1992 in the countries around the Baltic Sea.

AIM: To examine seasonal patterns of incidence of Type 1 diabetes mellitus incidence in children aged 0-14 years in Finland, Sweden, Estonia, Latvia and Lithuania during 1983-1992 (1987-1992 for Finland). METHODS: The study used a method that models incidence data using combinations of sine waves to model seasonal variation around a possible linear trend. RESULTS: In Finland, a significant pattern was found for combined sexes and age groups 0-9 and 10-14 years. A significant pattern was also confirmed for 10-14 year-old boys. In Sweden, the best model with significant pattern was found separately for boys and girls and age groups 0-9 and 10-14 years, however, a significant pattern was confirmed for older girls only. A seasonal pattern in older boys in Finland and girls in Sweden was characterized by two cycles with decreased incidence in June and November-December. The pattern among younger children (0-9 or 5-9 years) had one cycle with a decreased incidence in May-June. In Estonia, a significant pattern was found for the age group 0-14 years and combined sexes. No significant seasonal patterns were found in Latvia and Lithuania. CONCLUSIONS: The seasonal pattern with two cycles among older children and one cycle only among younger children may indicate different triggers of Type 1 diabetes mellitus for different age groups.

Association between type 1 diabetes and Haemophilus influenzae type b vaccination: birth cohort study.

OBJECTIVES: To determine the effect of Haemophilus influenzae type b vaccination and its timing on the risk of type 1 diabetes in Finnish children. DESIGN: Cumulative incidence and relative risk of type 1 diabetes was compared among three birth cohorts of Finnish children: those born during the 24 months before the H influenzae type b vaccination trial, those in the trial cohort who were vaccinated at 3 months of age and later with a booster vaccine, and those in the trial cohort who were vaccinated at 24 months of age only. The probability of type 1 diabetes was estimated using regression analysis assuming that there were no losses to 10 year follow up and no competing risks. SETTING: Finland (total population 5 million and annual birth rate 1.3%). SUBJECTS: 128 936 children born from 1 October 1983 to 1 September 1985, and 116 352 children born from 1 October 1985 to 31 August 1987. MAIN OUTCOME MEASURES: Probability of type 1 diabetes among children vaccinated with H influenzae type b and non-vaccinated children. RESULTS: No statistically significant difference was found at any time during the 10 year follow up in the risk of type 1 diabetes between the children born before the vaccination period and those vaccinated at the age of 24 months only (relative risk 1.01). The difference in the risk between the cohort vaccinated first at the age of 3 months and the cohort vaccinated at the age of 24 months only was not statistically significant either (1.06). CONCLUSION: It is unlikely that H influenzae type b vaccination or its timing cause type 1 diabetes in children.

Blood pressure levels in the 41 populations of the WHO MONICA Project.

In the early to mid 1980s, the WHO MONICA Project conducted cardiovascular risk factor surveys in 41 study populations in 22 countries. Study populations aged 35-64 years comprised 32,422 men and 32,554 women. Blood pressures (BP) and body mass index (BMI) were measured according to a standard protocol. Participants were asked about antihypertensive medication. In men, the average age-standardized BPs ranged among the populations from 124 to 148 mm Hg for systolic (SBP) and from 75 to 93 mm Hg for diastolic (DBP). The corresponding values in women were 118-145 mm Hg for SBP and 74-90 mm Hg for DBP. In all populations, women had lower SBP than men in the age group 35-44. However, SBP in women rose more steeply with age so that in 34 of 41 populations women had higher SBP than men in the age group 55-64. The proportion of participants with untreated major elevation of BP ranged from 4.5% to 33.7% in men and from 1.9% to 22.3% in women. The proportions of participants receiving antihypertensive medication were 4.3-17.7% for men and 6.0-22.0% for women. These proportions were not correlated with the prevalence of untreated hypertensives. Age-adjusted BMI was associated with SBP and accounted for 14% of the SBP variance in men and 32% in women. We found a large difference in SBP among the MONICA study populations and conclude that the results represent a valid estimate of the public health problem posed by elevated BP. We also have shown that almost universally the problem of elevated BP is more prevalent in women than in men, especially in the older age groups.

Risk factors for death from stroke in middle-aged Lithuanian men: results from a 20-year prospective study.

BACKGROUND AND PURPOSE: Although in eastern Europe, mortality from stroke at present is the highest in the world, no previous prospective study of the risk factors for stroke has been reported from this part of the world. The aim of our study, therefore, was to evaluate the relations between blood pressure, serum total cholesterol, glucose intolerance, body mass index, and cigarette smoking and the risk of death from stroke in middle-aged men in Kaunas, Lithuania. METHODS: We conducted a prospective study with an average follow-up of 17.5 years of 2295 men who had participated in risk factor surveys within the framework of the world Health Organization Kaunas-Rotterdam Intervention Study from 1972 to 1974. Risk factors included in the current analyses were smoking, blood pressure, serum total cholesterol, glucose intolerance, diabetes, and body mass index. Age-and risk factor adjusted relative risks (RR) for death of stroke were determined by use of the Cox proportional hazards model. RESULTS: The strongest risk factors for death from stroke in middle-age men were systolic blood pressure (RR=1.02; P=.0001), diabetes (RR=4.17; P=.02), and smoking (RR=2.01; P=.004). Serum cholesterol, impaired glucose tolerance, and body mass index were not related to the risk of death from stroke. Twenty-five percent and 19% of stroke deaths were attributed to hypertension and smoking, respectively. CONCLUSIONS: Prevention and effective control of hypertension, smoking, and diabetes are the key elements in primary prevention of stroke in eastern Europe, where stroke mortality remains high.

Epidemiology of stroke in Kaunas, Lithuania. First results from the Kaunas Stroke Register.

BACKGROUND AND PURPOSE: In Lithuania, only routine mortality statistics have thus far provided data on the epidemiology of stroke. This study aims to assess the mortality, incidence, and case-fatality rate of stroke in the city of Kaunas, Lithuania, during 1986 to 1988. METHODS: A community-based stroke register was set up in 1986 to collect data on all suspected events of acute stroke that occurred in the population aged 35 to 64 years permanently residing in Kaunas. Crude and age-standardized attack rates, incidence, mortality, and case-fatality rates were calculated for the period studied. RESULTS: Among men, the average age-standardized incidence of stroke (referring to first-ever events) was 230/100,000, the attack rate (all events) was 300/100,000, and the mortality from all strokes was 68/100,000. Among women, the corresponding rates were 131/100,000, 154/100,000, and 35/100,000, respectively. Of 973 acute stroke events registered, 80% were first-ever strokes. The age-adjusted 28-day overall case-fatality rate and the case-fatality rate of first-ever stroke were 23.3% and 19.8% in men and 21.8% and 21.3% in women, respectively. CONCLUSIONS: The findings from this first assessment of the incidence and mortality of stroke show that in the mid-1980s both were high in Kaunas compared with other countries. The case-fatality rate was similar to that reported for most other European countries. Further investigations are being carried out to assess the trends in mortality, incidence, and risk factors of stroke in the Kaunas population.

Comparison of trends in ischaemic heart disease between North Karelia, Finland, and Kaunas, Lithuania, from 1971 to 1987.

OBJECTIVE: To compare the long-term trends in mortality and attack rate of ischaemic heart disease in North Karelia, Finland, and in Kaunas, Lithuania, from 1971 to 1987. DESIGN: Data on routine mortality statistics were obtained from the Central Statistical Office of Finland and from the Central City Archives of Kaunas. In addition, data from the community based myocardial infarction registers were used. The registers used similar diagnostic criteria and had operated in both areas during the entire study period. SETTING: The province of North Karelia in Finland and the city of Kaunas in Lithuania. SUBJECTS: The target populations were the people of North Karelia and Kaunas aged 35-64 years. MAIN OUTCOME MEASURES: Mortality from ischaemic heart disease and the attack rate of acute myocardial infarction. RESULTS: In North Karelia mortality from ischaemic heart disease and the attack rate of acute myocardial infarction declined steeply both in men and women. This decline was accompanied by a decrease in total mortality. In Kaunas, both mortality and the attack rate increased in men but remained unchanged in women. In 1985 to 1987, age standardised total mortality per 100,000 inhabitants was similar in the two populations in men (1081 (95% confidence interval (CI) 1013 to 1149), in North Karelia; 1082 (95% CI 1032 to 1132), in Kaunas). The proportional mortality from ischaemic heart disease was considerably higher in North Karelia (40%) than in Kaunas (28%). In women, age standardised total mortality was lower in North Karelia (350 (95% CI 312-388)) than in Kaunas (440 (95% CI 413 to 467)). The proportional mortality from ischaemic heart disease in women was also higher in North Karelia (28%) than in Kaunas (13%). CONCLUSIONS: Despite the remarkable decline in the occurrence of ischaemic heart disease, it still remains the most important cause of premature mortality in North Karelia. In Kaunas ischaemic heart disease mortality and attack rate increased in men. Experiences from successful cardiovascular disease prevention programmes in western countries, such as the North Karelia Project, should be exploited to prevent an increasing epidemic of ischaemic heart disease in eastern Europe.

Comparison of the incidence of insulin-dependent diabetes mellitus in childhood among five Baltic populations during 1983-1988.

We have carried out a comparison of the incidence of childhood onset insulin-dependent diabetes mellitus (IDDM) between five populations around the Baltic Sea. These were Finland, Estonia, Latvia, Lithuania and Poland. The risk of IDDM is highest in the world in Finland and also very high in Sweden, on the western and northern side of the Baltic Sea. The risk of IDDM in children on the eastern side of the Baltic Sea has not been known before. The data collection period covered the years 1983-1988. A marked variation in incidence was seen within this relatively small geographical area. Among these five populations, the incidence increased with the latitude. Our present results confirmed the very high incidence of IDDM in Finland. The average age-standardized yearly incidence of IDDM/100,000 was in males under 15 years of age 36.9 in Finland, 10.7 in Estonia, 6.4 in Latvia, 6.5 in Lithuania and 6.0 in Poland. In females the incidence was 31.6, 10.0, 6.9, 7.0 and 6.4 in these five populations, respectively. The differential in incidence in Estonia as compared with Latvia, Lithuania and Poland was statistically significant (P = 0.0002). A slight male excess in incidence was found in countries with higher incidence--Finland and Estonia, but in lower incidence countries the sex ratio was opposite (P = 0.019 for the interaction sex-population). During 1983-1988 the incidence increased significantly in Finland but not in other populations although a large year-to-year variation in incidence was observed in each country, particularly in males. We recorded a peak in IDDM incidence in most of these populations around 1986.

New susceptibility haplotype for type 1 diabetes. DIME Study Group.

In a prospective family study in Finland HLA genotyping was carried out for 1610 individuals from 422 consecutively registered families of children aged 14 years or younger with newly diagnosed insulin-dependent diabetes mellitus (IDDM). A haplotype (A2, Cw1, Bw56, w6, DR4) that has not been identified previously was the third most common (5.5%) among 746 haplotypes found in the probands. Only the haplotypes A1, Cw7, B8, w6, DR3 and A2, Cw3, Bw62, w6, DR4, which are well known to occur with high frequency in IDDM, were more frequent (10.7% and 9.7%, respectively). Among the 30 families in which a parent had IDDM, the newly identified haplotype was the most common haplotype transmitted from the diabetic parent to the proband (16.7%). Among 642 "non-diabetic" haplotypes (parental haplotypes not found in probands, or siblings or parents with IDDM), this haplotype was found only twice. This haplotype may partially explain the high incidence of IDDM in Finland.