Pirjo Immonen-Räihä

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.

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.

Continuous 15-Year Decrease in Incidence and Mortality of Stroke in Finland. The FINSTROKE Study

Background and Purpose— The purpose of this study was to analyze the incidence and mortality trends in stroke events among persons 25 to 74 years of age in Finland during 1983 to 1997. Methods— The population-based FINSTROKE register recorded 5650 new strokes among persons 25 to 74 years of age in 2 geographical areas of Finland: 2770 in the Kuopio area (east central Finland) and 2880 in Turku (southwestern Finland). Of these, 3065 were men and 2585 were women. Results— The rates of acute stroke events fell during the whole study period in both men and women. In both FINSTROKE areas combined, the average annual decline in the age-standardized incidence of first stroke events was 2.0% (95% confidence interval [CI], −2.8 to −1.2; P <0.001) among men and 1.7% (95% CI, −2.6 to −0.8; P <0.001) among women. The decline in the incidence of ischemic stroke was even steeper, 2.9%/y (95% CI, −4.9 to −1.1; P <0.001) among men and 3.1%/y (95% CI, −5.0 to −1.1; P <0.001) among women, whereas the incidence of intracerebral hemorrhage and subarachnoid hemorrhage did not change. Mortality from all stroke events declined in the FINSTROKE areas by 3.7%/y (95% CI, −5.3 to −2.0; P <0.001) among men and by 4.1%/y (95% CI, −5.9 to −2.4; P <0.001) among women. The 28-day case fatality of all stroke events also tended to decline, but the decline was of borderline statistical significance only (P =0.07 among men, P =0.05 among women). Conclusions— Incidence and mortality of stroke events declined significantly in these 2 register areas in Finland during the 15-year period of 1983 to 1997.

Ten-Year Trends in Stroke Incidence and Mortality in the FINMONICA Stroke Study

BACKGROUND AND PURPOSE The trends in stroke incidence reported so far have not been entirely consistent, although declining trends in mortality from stroke have been reported from a number of studies around the world. This study aims to evaluate the 10-year trends (from 1983 through 1992) in incidence, attack rate, and mortality of stroke in the Finnish population. METHODS A population-based stroke register was set up in the early 1980s to collect data on all suspected events of acute stroke that occurred in the population aged 25 to 74 years permanently residing in three geographic areas of Finland: the provinces of Kuopio and North Karelia in eastern Finland and the Turku-Loimaa area in southwestern Finland. Trends in age-standardized attack rates, incidence, and mortality were calculated for the period studied. RESULTS During the 10-year study period, 11 392 acute stroke events occurred in the monitored populations. A statistically significant decline was observed in the pooled FINMONICA data, both in the incidence of stroke (-1.7% with 95% confidence interval [CI], -3.0% to -0.5% per year in men; -2.2% with 95% CI, -3.6% to -0.7% per year in women) and in mortality from stroke (-5.2% with 95% CI, -8.2% to -2.2% per year; -4.7% with 95% CI, -8.2% to -1.2% per year). The attack rate of stroke also declined significantly in both sexes. When the areas were considered separately, the declining trends were observed within each area. The decline in incidence of stroke was, however, statistically significant only among men and women in Kuopio and among women in Turku/Loimaa. Mortality declined significantly in all three areas among men but among women only in Kuopio. The incidence to mortality rate ratio increased during the study period, indicating a steeper fall in mortality than in incidence. CONCLUSIONS A substantial decline in both stroke incidence and mortality was observed in the adult and elderly population in the FINMONICA study areas. Part but not all of the decline in stroke mortality, observed also in the official mortality statistics, can be attributed to the decline in stroke incidence during this 10-year period.

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.

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.

The Validity of the Routine Mortality Statistics on Coronary Heart Disease in Finland: Comparison with the FINMONICA MI Register Data for the Years 1983–1992

We compared the diagnoses obtained from the routine mortality statistics with the standardized World Health Organization (WHO) MONICA (multinational MONItoring of trends and determinants in CArdiovascular disease) classification in suspect coronary heart disease (CHD) deaths registered in the FINMONICA myocardial infarction (MI) register during 1983-1992. All CHD deaths from routine mortality statistics (International Classification of Diseases codes 410-414) were registered in the MI register. Of the CHD deaths in routine mortality statistics 1.7% in men and 4.8% in women did not fulfill the MONICA criteria for CHD death (P<0.001 for the difference between the sexes). In men 4.7% and in women 7.3% (P=0.004) of the deaths registered in the MI Register and classified as CHD deaths by MONICA criteria had another underlying cause of death than CHD in routine mortality statistics; this proportion increased over time in both sexes (P=0.002 in men and P=0.77 in women). The CHD mortality trends obtained separately from the routine mortality statistics and from the FINMONICA MI Register were very similar. In conclusion, the high CHD mortality in Finland reported by the routine mortality statistics is real. It is possible that some CHD deaths have escaped registration, but the decline seen in the CHD mortality is also real.

Myocardial infarction in diabetic and non-diabetic persons with and without prior myocardial infarction: the FINAMI Study

Aims/hypothesisWe compared the risk of acute coronary events in diabetic and non-diabetic persons with and without prior myocardial infarction (MI), stratified by age and sex.MethodsA Finnish MI-register study known as FINAMI recorded incident MIs and coronary deaths (n=6988) among people aged 45 to 74 years in four areas of Finland between 1993 and 2002. The population-based FINRISK surveys were used to estimate the numbers of persons with prior diabetes and prior MI in the population.ResultsPersons with diabetes but no prior MI and persons with prior MI but no diabetes had a markedly greater risk of a coronary event than persons without diabetes and without prior MI. The rate of recurrent MI among non-diabetic men with prior MI was higher than the incidence of first MI among diabetic men aged 45 to 54 years. The rate ratio was 2.14 (95% CI 1.40–3.27) among men aged 50. Among elderly men, diabetes conferred a higher risk than prior MI. Diabetic women had a similar risk of suffering a first MI as non-diabetic women with a prior MI had for suffering a recurrent MI.Conclusions/interpretationBoth persons with diabetes but no prior MI, and persons with a prior MI but no diabetes are high-risk individuals. Among men, a prior MI conferred a higher risk of a coronary event than diabetes in the 45–54 year age group, but the situation was reversed in the elderly. Among diabetic women, the risk of suffering a first MI was similar to the risk that non-diabetic women with prior MI had of suffering a recurrent MI.

Trends in Case-Fatality of Stroke in Finland During 1983 to 1992

BACKGROUND AND PURPOSE Stroke mortality has been declining in Finland during the past 20 years. It is not known, however, whether this favorable development is attributable to the decline in the incidence or case-fatality of stroke. For this reason we examined the trends in case-fatality of stroke, including trends by subtype of stroke. METHODS The analyses were carried out using data of the community-based FINMONICA Stroke Register, which was operating in three geographic areas of Finland during 1983 to 1992. All stroke events (n = 11,171) in persons aged 35 to 74 years were included in this register. RESULTS The 28-day case-fatality of stroke fell yearly by 3.6% (P = .01) in men and by 2.6% (P = .2) in women. At the end of the study period, the average 28-day case-fatality of all strokes was 20% in men and 21% in women. Considerable differences by subtype of stroke were observed. The 28-day case-fatalities at the end of the study period were in men-56% for subarachnoid hemorrhage, 42% for intracerebral hemorrhage, and 14% for cerebral infarction. In women, the corresponding figures were 49%, 49%, and 14%. The 28-day case-fatality of subarachnoid hemorrhage did not change during the study period, but for intracerebral hemorrhage, a significant decline was observed in men and there was a declining trend also in women. The 28-day case-fatality of cerebral infarction declined significantly in both genders. CONCLUSIONS With the exception of subarachnoid hemorrhage, the 28-day case-fatality of stroke has fallen in Finland. It is likely that this fall has contributed to the decline in stroke mortality.

Socioeconomic Differences in the Incidence, Mortality and Prognosis of Intracerebral Hemorrhage in Finnish Adult Population

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.