Modelling the burden of stroke in Finland until 2030.

BACKGROUND: It is well known that increasing age is the strongest risk factor of stroke. Therefore, it has been a common belief in many countries including Finland that the numbers of stroke patients will increase considerably during the next two decades because the population is rapidly ageing. METHODS: The FINMONICA and FINSTROKE registers operated in Finland in the Kuopio area and city of Turku from 1983 to 1997. The results showed that the incidence, mortality and case fatality of stroke declined significantly during that period. Importantly, it was established that the trends in incidence and mortality were also declining among the elderly (>74 years). We used these results to create a model for the entire country. The model was based on the trends present in these registers from Turku and Kuopio area and age-specific population projections up to the year 2030 that were obtained from Statistics Finland. RESULTS: In the year 2000, the number of new first stroke cases was estimated to be 11 500. If the declining trend were to level off totally after the year 2000, the number of new strokes would be 20 100 in the year 2030 due to the ageing of the population. It would be 12 100 if the trend continued as favourable as during the years 1983-1997. CONCLUSIONS: Ageing of the population will not inevitably increase the burden of stroke in Finland if the present declining trends are maintained, but the annual number of cases will almost double if the incidence remains at the level of the year 2000.

Long-term prognosis after coronary artery bypass surgery.

OBJECTIVE: To analyse the risk of coronary heart disease (CHD) events and total mortality among patients who had coronary artery bypass graft (CABG) surgery during 1988-1992. METHODS: A population-based myocardial infarction (MI) register included data on invasive cardiac procedures among residents of the study area. The subjects aged 35-64 years were followed-up for 12 years for non-fatal and fatal CHD events and all-cause mortality, excluding events within 30 days of the CABG operation. CABG was performed on 1158 men and 215 women. RESULTS: The overall survival of men who underwent CABG was similar to the survival of the corresponding background population for about ten years but started to worsen after that. At twelve years of follow-up, 23% (n=266, 95% CI 234-298) of the men who had undergone the operation had died, while the expected proportion, based on mortality in the background population, was 20% (n=231, 95% CI 226-237). The CHD mortality of men who had undergone the operation was clearly higher than in the background population. Among women, the mortality after CABG was about twice the expected mortality in the corresponding background population. In Cox proportional hazards models age, smoking, history of MI, body mass index and diabetes were significant predictors of mortality. CONCLUSIONS: The prognosis of male CABG patients did not differ from the prognosis of the corresponding background population for about ten years, but started to deteriorate after that. History of MI prior to CABG and major cardiovascular risk factors was a predictor of an adverse outcome.

Five-year risk of developing clinical diabetes after first myocardial infarction; the FINAMI study.

AIM: To investigate the incidence of clinical diabetes as determined by the incidence of diabetes drug reimbursements within a 5-year period after the first myocardial infarction (MI) in patients who were non-diabetic at the time of their first MI. RESEARCH DESIGN AND METHODS: A population-based MI register, FINMONICA/FINAMI, recorded all coronary events in persons of 35-64 years of age between 1988 and 2002 in four study areas in Finland. These records were used to identify subjects sustaining their first MI (n = 2632). Participants of the population-based risk factor survey FINRISK (surveys 1987, 1992, 1997 and 2002), who did not have diabetes or a history of MI, served as the control group (n = 7774). The FINMONICA/FINAMI study records were linked with the National Social Security Institute's drug reimbursement records, which include diabetes medications, using personal identification codes. The records were used to identify subjects who developed diabetes during the 5-year follow-up period (n = 98 in the MI group and n = 79 in the control group). RESULTS: Sixteen per cent of men and 20% of women sustaining their first MI were known to have diabetes and thus were excluded from this analysis. Non-diabetic men having a first MI were at more than twofold {hazard ratio (HR) 2.3 [95% confidence interval (CI) 1.6-3.4]}, and women fourfold [HR 4.3 (95% CI 2.4-7.5)], risk of developing diabetes mellitus during the next 5 years compared with the control population without MI. CONCLUSIONS: Many patients who do not have diabetes at the time of their first MI develop diabetes in the following 5 years.

Current smoking and the risk of non-fatal myocardial infarction in the WHO MONICA Project populations.

BACKGROUND: Cohort studies have shown that smoking has a substantial influence on coronary heart disease mortality in young people. Population based data on non-fatal events have been sparse, however. OBJECTIVE: To study the impact of smoking on the risk of non-fatal acute myocardial infarction (MI) in young middle age people. METHODS: From 1985 to 1994 all non-fatal MI events in the age group 35-64 were registered in men and women in the WHO MONICA (multinational monitoring of trends and determinants in cardiovascular disease) project populations (18,762 events in men and 4047 in women from 32 populations from 21 countries). In the same populations and age groups 65,741 men and 66,717 women participated in the surveys of risk factors (overall response rate 72%). The relative risk of non-fatal MI for current smokers was compared with non-smokers, by sex and five year age group. RESULTS: The prevalence of smoking in people aged 35-39 years who experienced non-fatal MI events was 81% in men and 77% in women. It declined with increasing age to 45% in men aged 60-64 years and 36% in women, respectively. In the 35-39 years age group the relative risk of non-fatal MI for smokers was 4.9 (95% confidence interval (CI) 3.9 to 6.1) in men and 5.3 (95% CI 3.2 to 8.7) in women, and the population attributable fractions were 65% and 55%, respectively. CONCLUSIONS: During the study period more than half of the non-fatal MIs occurring in young middle age people can be attributed to smoking.

Decline in out-of-hospital coronary heart disease deaths has contributed the main part to the overall decline in coronary heart disease mortality rates among persons 35 to 64 years of age in Finland: the FINAMI study.

BACKGROUND: Out-of-hospital deaths constitute the majority of all coronary heart disease (CHD) deaths and are therefore of considerable public health significance. METHODS AND RESULTS: We used population-based myocardial infarction register data to examine trends in out-of-hospital CHD deaths in Finland during 1983 to 1997. We included in out-of-hospital deaths also deaths in the emergency room and all deaths within 1 hour after the onset of symptoms. Altogether, 3494 such events were included in the analyses. The proportion of out-of-hospital deaths of all CHD deaths depended on age and gender. In the age group 35 to 64 years, it was 73% among men and 60% among women. These proportions did not change during the study. The annual average decline in the age-standardized out-of-hospital CHD death rate was 6.1% (95% CI, -7.3, -5.0%) among men and 7.0% (-10.0, -4.0%) among women. These declines contributed among men 70% and among women 58% to the overall decline in CHD mortality rate. In all, 58% of the male and 52% of the female victims of out-of-hospital CHD death had a history of symptomatic CHD. Among men with a prior history of myocardial infarction, the annual average decline in out-of-hospital CHD deaths was 5.3% (-7.2, -3.2%), and among men without such history the decline was 2.9% (-4.4, -1.5%). Among women, the corresponding changes were -7.8% (-14.2, -1.5%) and -4.5% (-8.0, -1.0%). CONCLUSIONS: The decline in out-of-hospital CHD deaths has contributed the main part to the overall decline in CHD mortality rates among persons 35 to 64 years of age in Finland.

Trends in coronary events in Finland during 1983-1997. The FINAMI study.

AIMS: To analyse the trends in incidence, recurrence, case fatality, and treatments of acute coronary events in Finland during the 15-year period 1983-97. METHODS AND RESULTS: Population-based MI registration has been carried out in defined geographical areas, first as a part of the FINMONICA Project and then continued as the FINAMI register. During the study period, 6501 coronary heart disease (CHD) events were recorded among men and 1778 among women aged 35-64 years. The CHD mortality declined on average 6.4%/year (95% confidence interval -5.4, -7.4%) among men and 7.0%/year (-4.7, -9.3%) among women. The mortality from recurrent events declined even more steeply, 9.9%/year (-8.3, -11.4%) among men and 9.3%/year (-5.1, -13.4%) among women. The proportion of recurrent events of all CHD events also declined significantly in both sexes. Of all coronary deaths, 74% among men and 61% among women took place out-of-hospital. The decline in 28-day case fatality was 1.3%/year (-0.3, -2.3%) among men and 3.1%/year (-0.7, -5.5%) among women. CONCLUSIONS: The study period was characterized by a marked reduction in the occurrence of recurrent CHD events and a relatively modest reduction in the 28-day case fatality. The findings suggest that primary and secondary prevention have played the main roles in the decline in CHD mortality in Finland.

Short-term functional outcome of hospitalised first-ever strokes in Finnmark, Norway in 1998-1999. Results from the Finnmark Stroke Register.

Data on the functional outcome, prevalence of risk factors and comorbidity of stroke were collected in the population-based Finnmark Stroke Register in northern Norway. Findings for hospitalised first-ever strokes (n = 125) during the first registration year (1998-1999) are presented here. The median age of the patients was 70 years for men and 79 years for women. Cerebral infarctions comprised 81.6% of the strokes. Patients were severely handicapped: at discharge from hospital about 46% of those 75 years or older and about 21% of those younger than 75 years had severe disability by Rankin Scale. Women were more impaired than men. After hospitalisation, 45% of those 75 years or older and 21% of those younger than 75 years were sent to nursing home. The prevalence of risk factors and comorbidity was high: 29% of men (52% of women) had high blood pressure, 22% of men (25% of women) had atrial fibrillation, 22% of both men and women had diabetes, and 50% of men and 33% of women were current smokers. In conclusion, stroke victims in Finnmark were left with severe disability and need intensive rehabilitation. The prevalence of treatable risk factors was high; thus, primary and secondary prevention is the key to reduce the individual and social burden of stroke.

Socioeconomic status and ischemic stroke: The FINMONICA Stroke Register.

BACKGROUND AND PURPOSE: It has been shown that low socioeconomic status is associated with death from stroke. More-detailed data have, however, remained scanty. The purpose of the present study was to examine the association of socioeconomic status with ischemic stroke. Besides mortality, we analyzed the incidence, case-fatality ratio, and prognosis of ischemic stroke events. METHODS: Our population-based study included 6903 first stroke events registered by the FINMONICA Stroke Register in 3 areas of Finland during 1983 to 1992. Indicators of socioeconomic status, such as taxable income and education, were obtained by record linkage of the stroke register data with files of Statistics Finland. RESULTS: Incidence, case-fatality ratio, and mortality rates for ischemic stroke were all inversely related to income. Furthermore, 28 days after the onset of symptoms, a greater proportion of patients with low income than of those with high income was still in institutionalized care and/or in need of help for their activities of daily living. Population-attributable risk of the incidence of first ischemic stroke due to low socioeconomic status was 36% for both sexes. For the death from first ischemic stroke, it was 56% for both sexes. CONCLUSIONS: Persons with low socioeconomic status have considerable excess rates of morbidity and mortality from ischemic stroke in Finland. A reduction in this excess could markedly decrease the burden of ischemic stroke to the society and thus constitute an important public health improvement.

Socioeconomic inequalities in the incidence, mortality and prognosis of subarachnoid hemorrhage: the FINMONICA Stroke Register.

Low socioeconomic status (SES) is associated with increased mortality from stroke, but usually no distinction is made between stroke subtypes. We analyzed the relationship of SES with mortality and morbidity of subarachnoid hemorrhage (SAH). In the FINMONICA Stroke Register, 956 consecutive SAH events were recorded during 1983-1992 in patients aged 25-74 years. We used taxable income stratified into three categories, low, middle, and high, as an indicator of SES. The age-standardized incidence of SAH among men and women aged 25-44 years was approximately three times higher in the low-income group than in the high-income group. In older individuals, differences between the income groups were less pronounced. Among survivors of the acute stage, a poorer prognosis was observed in patients with low income than in those with high income. In conclusion, there is a clear excess mortality and morbidity of SAH in young individuals with low income, particularly among men.

Relation of socioeconomic position to the case fatality, prognosis and treatment of myocardial infarction events; the FINMONICA MI Register Study.

OBJECTIVE: To examine socioeconomic differences in case fatality and prognosis of myocardial infarction (MI) events, and to estimate the contributions of incidence and case fatality to socioeconomic differences in coronary heart disease (CHD) mortality. DESIGN: A population-based MI register study. METHODS: The FINMONICA MI Register recorded all MI events among persons aged 35-64 years in three areas of Finland during 1983-1992. A record linkage of the MI Register data with the files of Statistics Finland was performed to obtain information on socioeconomic indicators for each individual registered. First MI events (n=8427) were included in the analyses. MAIN RESULTS: The adjusted risk ratio of prehospital coronary death was 2.11 (95% CI 1.82, 2.46) among men and 1.68 (1.14, 2.48) among women with low income compared with those with high income. Even among persons hospitalised alive the risk of death during the next 12 months was markedly higher in the low income group than in the high income group. Case fatality explained 51% of the CHD mortality difference between the low and the high income groups among men and 38% among women. Incidence contributed 49% and 62%, respectively. CONCLUSIONS: Considerable socioeconomic differences were observed in the case fatality of first coronary events both before hospitalisation and among patients hospitalised alive. Case fatality explained a half of the CHD mortality difference between the low and the high income groups among men and more than a third among women.

Gender differences in recurrent coronary events; the FINMONICA MI register.

BACKGROUND: Male gender is an established risk factor for first myocardial infarction, but some studies have suggested that among myocardial infarction survivors, women fare worse than men. Therefore, we examined the long-term prognosis of incident myocardial infarction survivors in a large, population-based MI register, addressing gender differences in mortality as well as the number of events and time intervals between recurrent events. METHODS AND RESULTS: Study subjects included 4900 men and women, aged 25-64 years, with definite or probable first myocardial infarctions who were alive 28 days after the onset of symptoms. At first myocardial infarction, women were older and more likely to be hypertensive or diabetic than men, and had a greater proportion of probable vs definite events. After adjustment for age and geographic region, men had 1.74 times the risk of fatal coronary heart disease relative to women (hazard ratio=1.63 and 1.55 for cardiovascular disease and all-cause mortality, respectively) over an average of 5.9 years of follow-up. Number and time intervals between any recurrent event--fatal and non-fatal--did not differ by gender. CONCLUSION: These data suggest that men are far more likely to have a fatal recurrent event than women despite comparable numbers of events.

Socioeconomic differences in the incidence, mortality and prognosis of intracerebral hemorrhage in Finnish Adult Population. The FINMONICA Stroke Register.

We examined the association of socioeconomic status (SES) with the incidence, mortality and case fatality of intracerebral hemorrhage (ICH). During 1982-1992, 909 ICH events were registered among persons aged 25-74 years. Taxable income was used as an indicator of SES. It was stratified into three categories: low, middle and high. The age-standardized incidence and mortality of ICH were significantly higher in the low- than in the high-income group in both genders. Among men aged 25-59 years, the adjusted odds ratio (OR) of ICH death within 1 year after the onset of the event was twice as high in the low-income group as in the high-income group (OR = 2.12, 95% confidence interval 1.02-4.40). In conclusion, marked socioeconomic differences were found in the incidence and mortality of ICH, in particular among working aged men.

A multinational comparison of subarachnoid hemorrhage epidemiology in the WHO MONICA stroke study.

BACKGROUND AND PURPOSE: By official, mostly unvalidated statistics, mortality from subarachnoid hemorrhage (SAH) show large variations between countries. Using uniform criteria for case ascertainment and diagnosis, a multinational comparison of attack rates and case fatality rates of SAH has been performed within the framework of the WHO MONICA Project. METHODS: In 25- to 64-year-old men and women, a total of 3368 SAH events were recorded during 35.9 million person-years of observation in 11 populations in Europe and China. Strict MONICA criteria were used for case ascertainment and diagnosis of stroke subtype. Case fatality was based on follow-up at 28 days after onset. RESULTS: Age-adjusted average annual SAH attack rates varied 10-fold among the 11 populations studied, from 2.0 (95% CI 1.6 to 2.4) per 100 000 population per year in China-Beijing to 22.5 (95% CI 20.9 to 24.1) per 100 000 population per year in Finland. No consistent pattern was observed in the sex ratio of attack rates in the different populations. The overall 28-day case fatality rate was 42%, with 2-fold differences in age-adjusted rates between populations but little difference between men and women. Case fatality rates were consistently higher in Eastern than in Western Europe. CONCLUSIONS: Using a uniform methodology, the WHO MONICA Project has shown very large variations in attack rates of SAH across 11 populations in Europe and China. The generally accepted view that women have a higher risk of SAH than men does not apply to all populations. Marked differences in outcome of SAH add to the wide gap in the burden of stroke between East and West Europe.

Relationship of socioeconomic status to the incidence and prehospital, 28-day, and 1-year mortality rates of acute coronary events in the FINMONICA myocardial infarction register study.

BACKGROUND: Low socioeconomic status (SES) is associated with increased coronary heart disease mortality rates. There are, however, very little data on the relation of SES to the incidence, recurrence, and prognosis of myocardial infarction (MI) events. METHODS AND RESULTS: The FINMONICA MI Register recorded detailed information on all MI events among men and women aged 35 to 64 years in 3 areas of Finland during the period of 1983 to 1992. We carried out a record linkage of the MI register data with files of Statistics Finland to obtain information on indicators of SES, such as taxable income and education, for each individual who is registered. In the analyses, income was grouped into 3 categories (low, middle, and high), and education was grouped into 2 categories (basic and secondary or higher). Among men with their first MI event (n=6485), the adjusted incidence rate ratios were 1.67 (95% CI 1.57 to 1.78) and 1.84 (95% CI 1.73 to 1.95) in the low- and middle-income categories compared with the high-income category. For 28-day mortality rates, the corresponding rate ratios were 3.18 (95% CI 2.82 to 3.58) and 2.33 (95% CI 2.03 to 2.68). Significant differentials were observed for prehospital mortality rates, and they remained similar up to 1 year after the MI. Findings among the women were consistent with those among the men. CONCLUSIONS: The excess coronary heart disease mortality and morbidity rates among persons with low SES are considerable in Finland. To bring the mortality rates of low- and middle-SES groups down to the level of that of the high-SES group constitutes a major public health challenge.

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.

The feasibility of routine mortality and morbidity register data linkage to study the occurrence of acute coronary heart disease events in Finland. The Finnish Cardiovascular Diseases Registers (CVDR) Project.

Validated population-based data on the occurrence of coronary heart disease in Finland have previously been obtained from myocardial infarction (MI) registers. Such registers cannot, however, cover large areas. Therefore, the Finnish Cardiovascular Diseases Registers (CVDR) Project was set up to obtain data for the whole of Finland. The CVDR Project is based on routine mortality and morbidity data linkage. We report here the overall approach used in the project, the results of the feasibility study and the first main results. In Finland, data on all hospitalizations are registered in the nationwide Hospital Discharge Register. Also, data on all deaths are collected in the nationwide Causes of Death Register. The unique personal identification number assigned to all persons residing in Finland was used for data linkage. Data have been validated using the FINMONICA MI registers. Sensitivity analyses showed that the data were robust and consistent between different geographical areas. Coronary heart disease (CHD) mortality as well as the incidence and event rates showed the same very clear geographical pattern, dividing Finland to a southwest area with a lower occurrence and a northeast area with nearly twice higher occurrence. Case fatality did not differ much between the areas and did not follow this Southwest-Northeast division. The differences between northeast and southwest Finland may be related to differences in risk factor levels but also to socioeconomic and genetic differences. The CVDR Project data will be instrumental in further research addressing these issues.

The feasibility of combining data from routine Hospital Discharge and Causes-of-Death Registers for epidemiological studies on stroke.

We assessed the validity of hospital discharge data on stroke in Finland and the feasibility of linked hospital discharge and causes-of-death data for epidemiological studies using the FINMONICA Stroke Register as the reference. The results showed that such data can, with some caution, be used for incidence studies and for identifying first stroke events. They cannot, however, be used for assessing secular trends in all stroke events.

Decreasing mortality from acute myocardial infarction: effect of incidence and prognosis.

Coronary heart disease (CHD) mortality rates have declined for the past 25 years in most western countries. During the 1970s and early 1980s, a decline in incidence was the main factor in the decline in mortality, but more recently, improvements in treatment and prognosis have played a larger role. Most of the change is a result of improvements in the treatment of risk factors among patients with chronic CHD, while the treatment of acute myocardial infarction has contributed a smaller part. CHD mortality has consistently decreased more than incidence, which may have led to an increased prevalence of CHD. Simultaneously, the treatment practice patterns and possibly also clinical presentation of CHD has changed so that hospitalizations as a result of CHD diagnoses other than myocardial infarction have increased, while definite myocardial infarctions have decreased. Furthermore, the stabilizing rates of incident myocardial infarction combined with the aging population tend to increase the numbers of CHD patients. Therefore, the total burden of CHD to the community has decreased less than one would expect on the basis of age-standardized mortality rates. There is a need to re-emphasize primary prevention, since heavy reliance on expensive treatments for the post-war baby-boom generation presents a major concern for public health resources.

Contribution of trends in survival and coronary-event rates to changes in coronary heart disease mortality: 10-year results from 37 WHO MONICA project populations. Monitoring trends and determinants in cardiovascular disease.

BACKGROUND: The WHO MONICA (monitoring trends and determinants in cardiovascular disease) Project monitored, from the early 1980s, trends over 10 years in coronary heart disease (CHD) across 37 populations in 21 countries. We aimed to validate trends in mortality, partitioning responsibility between changing coronary-event rates and changing survival. METHODS: Registers identified non-fatal definite myocardial infarction and definite, possible, or unclassifiable coronary deaths in men and women aged 35-64 years, followed up for 28 days in or out of hospital. We calculated rates from population denominators to estimate trends in age-standardised rates and case fatality (percentage of 28-day fatalities=[100-survival percentage]). FINDINGS: During 371 population-years, 166,000 events were registered. Official CHD mortality rates, based on death certification, fell (annual changes: men -4.0% [range -10.8 to 3.2]; women -4.0% [-12.7 to 3.0]). By MONICA criteria, CHD mortality rates were higher, but fell less (-2.7% [-8.0 to 4.2] and -2.1% [-8.5 to 4.1]). Changes in non-fatal rates were smaller (-2.1%, [-6.9 to 2.8] and -0.8% [-9.8 to 6.8]). MONICA coronary-event rates (fatal and non-fatal combined) fell more (-2.1% [-6.5 to 2.8] and -1.4% [-6.7 to 2.8]) than case fatality (-0.6% [-4.2 to 3.1] and -0.8% [-4.8 to 2.9]). Contribution to changing CHD mortality varied, but in populations in which mortality decreased, coronary-event rates contributed two thirds and case fatality one third. INTERPRETATION: Over the decade studied, the 37 populations in the WHO MONICA Project showed substantial contributions from changes in survival, but the major determinant of decline in CHD mortality is whatever drives changing coronary-event rates.