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.     

Sex differences in short- and long-term case-fatality of myocardial infarction

Declining trends in case fatality (CF) of MI events have been generally reported in western countries. It is, however, not clear whether the development has been equally beneficial in both sexes. Data from two large population based registers, FINAMI and the Finnish National Cardiovascular Disease Register (CVDR) were used to determine whether the CF of incident MI events has declined less in women than in men. All patients aged 35 and over were included. CF was calculated for different time periods after the onset of the MI event, the main emphasis was in pre-hospital, 28-day, and 1-year CF. Figures were compared between two study periods: 1994–1996 and 2000–2002. A total of 6,342 incident MI events were recorded in FINAMI and 117,632 events in CVDR during the study periods. Comparison between the two study periods showed that the CF was generally declining. However, a slower decline in short-term CF was seen among young (aged < 55 years) women (P for sex by study period interaction in pre-hospital CF = 0.028 in FINAMI and 0.003 in CVDR, and for 28-day CF P = 0.016 in FINAMI and <0.0001 in CVDR). In conclusion, the short and long-term prognosis of MI events has improved in both sexes. Pre-hospital CF has declined less among younger women than among men and among older women. This slower decline in early CF was responsible for the slower improvement in 28-day and 1-year prognosis in young women.     

How did the recent increase in the supply of coronary operations in Finland affect socioeconomic and gender equity in their use?

STUDY OBJECTIVE: To explore how the increased supply of coronary bypass operations and angioplasties from 1988 to 1996 influenced socioeconomic and gender equity in their use. DESIGN: Register based linkage study; information on coronary procedures from the Finnish Hospital Discharge Register in 1988 and 1996 was individually linked to national population censuses in 1970-1995 to obtain patients' socioeconomic data. Data on both hospitalisations and mortality attributable to coronary heart disease obtained from similar linkage schemes were used to approximate the relative need of procedures in socioeconomic groups. SETTING: Finland, 2,094,846 inhabitants in 1988 and 2,401,027 in 1996 aged 40 years and older, and Discharge Register data from all Finnish hospitals offering coronary procedures in 1988 and 1996. MAIN RESULTS: The overall rate of coronary revascularisations in Finland increased by about 140% for men and 250% for women from 1988 to 1996. Over the same period, socioeconomic and gender disparities in operation rates diminished, as did the influence of regional supply of procedures on the extent of these differences. However, men, and better off groups in terms of occupation, education, and family income, continued to receive more operations than women and the worse off with the same level of need. CONCLUSIONS: Although revascularisations in Finland increased 2.5-fold overall, some socioeconomic and gender inequities persisted in the use of cardiac operations relative to need. To improve equity, a further increase of resources may be needed, and practices taking socioeconomic and gender equity into account should be developed for the referral of coronary heart disease patients to hospital investigations.     

The validity of hospital discharge register data on coronary heart disease in Finland

We studied the validity of the Finnish hospital discharge register data on coronary heart disease (CHD) for the purposes of epidemiologic studies and health services research. The Finnish nationwide hospital discharge register (HDR) was linked with the FINMONICA acute myocardial infarction (AMI) register for the years 1983–1990. The frequency of errors in the HDR was assessed separately. Between 8% and 13% of hospitalized AMI events registered in the AMI Register were not found in the HDR with an ICD code for CHD. Problems with the register linkage and the use of some ICD code other than one of the codes for CHD explained these missing events. The frequency of errors in the personal identification number was about 5% in the early 1980s. After 1986 errors were found only occasionally. The diagnosis recorded in the HDR was the same as that in the discharge sheet in about 95% of hospitalizations. The positive predictive value of the ICD code 410 (AMI), compared with the FINMONICA definite+possible AMI category, was very high and stable, about 90% in all areas and all hospitals, but it sensitivity varied from 50% at local hospitals to 80% at central hospitals. In summary, data on CHD obtained from the Finnish hospital discharge register give, on average, a correct picture on changes in the occurrence of AMI in Finland and can, with necessary caution, be used in epidemiological studies and health services research. However, the classification of individual cases is not standardized in the HDR, but varies over time, between geographical areas and the levels of care. Therefore, these data should not be used without confirmation in studies where correct classification of individual outcomes is of crucial importance, such as follow-up studies and case-control studies.     

Health registers as a feasible means of measuring health status in childhood – a 7-year follow-up of the 1987 Finnish birth cohort

Follow-up studies on health have usually been based on ad hoc cohort studies in which detailed information is collected specifically for research purposes on a certain group of people. The increasing collection of routine health data provides an alternative method of gathering follow-up data. In this study, the feasibility of using routinely collected health-register data and data linkages to follow up children's health was investigated. Five nationwide registers, 18 regional registers of intellectually disabled children and school administration data in one county were found to be of use for our follow-up and were combined with the 1987 Finnish Medical Birth Register ( n  = 60 254 births). In the follow-up, 62 children were untraced (0.1%), 327 were stillborn (0.5%), 440 died after birth (0.7%) and 287 emigrated (0.5%) before the age of 7 years. The cumulative incidences for all diseases (8.9% of all children living in Finland at the age of 7 years), for diabetes (3.0/1000), for epilepsy (6.8/1000) and for asthma (34.2/1000) correspond to the estim-ates of other studies, but our estimate for intellectual disabilities (18.0/1000, of whom 18% were reported to have an IQ of 70 or less) seems to be an underestimate. Our data collection did not provide reliable information on institutionalised children or children taken into care. Data collec-tion conducted by using health registers is a feasible method, and it saves both time and financial resources compared with cohort studies. Poten-tial problems with data linkage studies are variation in the content of data and in data quality of different registers and data protection issues.     

What underlies the high alcohol related mortality of the disadvantaged: high morbidity or poor survival?

STUDY OBJECTIVE: To investigate whether the large socioeconomic differences in alcohol related mortality can be explained by differences in morbidity or differences in survival. DESIGN: Register linkage study. A nationwide hospital discharge register was linked to population censuses for socioeconomic data and to the cause of death register for mortality follow up. SETTING: Finland. PARTICIPANTS: Men and women aged 15 years and older discharged from hospitals with an alcohol related diagnosis in 1991-1996. MEASUREMENTS: Mortality hazard up to the end of 1997 by socioeconomic category was estimated with Cox's regression model. MAIN RESULTS: Socioeconomic differences in alcohol related hospitalisation rates were almost as large as those that have been observed for alcohol related mortality. For example, the rate ratio among male unspecialized workers for any alcohol related hospitalisations was 3.6 as compared with upper white collar workers; among women the rate ratio was 2.7. Depending on gender, age, hospitalisation diagnosis, and cause of death, survival after discharge either showed no socioeconomic differences or it was worse among better off groups. CONCLUSIONS: The study suggests that differences in survival after hospitalisation do not cause the high socioeconomic differences in alcohol related mortality.     

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. Finnish multinational MONItoring of trends and determinants in CArdiovascular disease

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.     

1991-2010年中国女性乳腺癌的死亡分布特征

目的 分析中国1991-2010年女性乳腺癌死亡的分布特征,为女性乳腺癌的防治提供科学依据.方法 采集1991-2010年中国女性乳腺癌死亡资料,分析标化死亡率的动态变化、城乡差异和年龄分布差异等流行病学特征,通过趋势面分析方法研究其地理分布特征.结果 女性乳腺癌死亡率呈逐年上升趋势,城市高于农村;近10年来死亡高峰年龄延后,城乡妇女在55～岁段达到第1个死亡高峰;地理分布上,乳腺癌死亡率呈现由西南向东北、西部向东部增加的趋势.结论 我国女性乳腺癌死亡率呈上升趋势;东北、东部和东南地区是我国女性乳腺癌的重点防治区域;城市妇女是重点防治对象.     

Social class differences in health until the age of seven years among the Finnish 1987 birth cohort

Studies on social class differences in childhood health are controversial partly because of different data collection methods, limited sample sizes and the use of limited numbers of health indicators. The increasing collection of health register data enables the use of such data in social class studies. Our purpose was to investigate social class differences in mortality and morbidity among all children born in Finland in 1987 (N=59,865 liveborns) until the age of seven by using several national health registers, and to study whether perinatal health explains these differences. The follow-up was based on data linkage with six national health registers, with 18 regional registers of mentally disabled children, covering the whole country, and with 38 educational registers of the largest county. Morbidity was measured in terms of a cumulative disease index, the cumulative incidence of asthma, diabetes, epilepsy and intellectual disability, hospitalisations, disease-related welfare benefits and special education. Social class, divided in four groups (I–III, Others) was defined by using the mother's occupation at the time the child was seven years old. Our study showed that register-based data collection is a feasible method for studying social class differences in health. In the unadjusted analysis, social class differences were found for all indicators except mortality after the age of one year and for the cumulative incidence of asthma and diabetes. After adjusting for confounders, the children in the lowest social class had the highest risk for poor health outcome both in the perinatal period and in childhood, and had the most intellectual disabilities, the highest mean of hospitalisation days, and received the most special education. The differences were not explained by perinatal health. The health of the children in the lowest social class was poorer, especially regarding mental indicators.     

Validation of stroke diagnosis in the National Hospital Discharge Register and the Register of Causes of Death in Finland

The validity of stroke diagnosis in the National Hospital Discharge Register and the Register of Causes of Death was examined among 546 middle-aged men in Finland. The subjects were cases of cerebrovascular diseases of the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study and identified by record linkage to the registers. In all, 375 events with cerebrovascular disease as hospital discharge diagnosis and 218 events with cerebrovascular disease as the underlying cause of death were reviewed using specific criteria modified from the classifications of the National Survey of Stroke and the WHO MONICA Study. For hospital stroke diagnoses, there was agreement on diagnosis for all strokes in 90%, for subarachnoid hemorrhage in 79%, intracerebral hemorrhage in 82%, and cerebral infarction in 90%. The respective agreement rates for stroke as the underlying cause of death were 97%, 95%, 91%, and 92%. The data were insufficient for review in 1% and 3% of the stroke events, respectively. Age, observation year and trial supplementation with alpha-tocopherol or beta-carotene had no effect on validity. In conclusion, the validity of stroke diagnosis was good in registers of hospital diagnoses and causes of death justifying their use for endpoint assessment in epidemiological studies.     

Are there socioeconomic differences in myocardial infarction event rates and fatality among patients with angina pectoris?

BACKGROUND: Systematic socioeconomic differences in mortality have been reported among myocardial infarction (MI) patients in many countries, including Finland. The findings have been similar irrespective of country, study period, age group, or length of follow up, but few studies have examined the disparities among other groups of coronary patients. This study examined whether similar socioeconomic differences in outcomes exist among patients with angina pectoris (AP). METHODS: The data were based on individual register linkages among a population based 40-79 year-old cohort of 61,350 patients with incident AP or MI during 1995-1998 in Finland. Two year coronary heart disease mortality and one year MI incidence and its 28 day case fatality was studied among AP patients using Cox's and logistic regression analysis, and the results compared with those of the MI patient group. RESULTS: A clear socioeconomic pattern was found in two year coronary heart disease (CHD) mortality: the lower the socioeconomic group the higher the mortality risk. The socioeconomic patterning of mortality was similar to that found among MI patients. Controlling for comorbidity or disease severity did not change the results. Among AP patients a similar pattern was also found in MI incidence during the follow up, but no systematic socioeconomic differences were detected in its 28 day case fatality. CONCLUSIONS: Socioeconomic differences in CHD outcomes also exist among angina patients. These results suggest that targeted measures of secondary prevention are needed among CHD patients with lower socioeconomic status to reduce socioeconomic disparities in fatal and non-fatal coronary events.     

Methods for identifying pregnancy-associated deaths: population-based data from Finland 1987-2000

To find maternal and pregnancy-related deaths, it is important that all pregnancy-associated deaths are identified. This article examines the effect of data linkages between national health care registers and complete death certificate data on pregnancy-associated deaths. All deaths among women of reproductive age (15-49 years) in Finland during the period 1987-2000 (n = 15 823) were identified from the Cause-of-Death Register and linked to the Medical Birth Register (n = 865 988 births), the Register on Induced Abortions (n = 156 789 induced abortions), and the Hospital Discharge Register (n = 118 490 spontaneous abortions) to determine whether women had been pregnant within 1 year before death. The death certificates of the 419 women thus identified were reviewed to find whether the pregnancy or its termination was coded or mentioned. In total, 405 deaths (96.7%) were identified in registers other than the Cause-of-Death Register. Without data linkages, 73% of all pregnancy-associated deaths would have been missed; the percentage after induced and spontaneous abortions was even higher. Data linkages to national health care registers provide better information on maternal deaths and pregnancy-associated deaths than death certificates alone. If possible, pregnancies not ending in a live birth should be included in the data linkages.     

Socioeconomic inequities in invasive cardiac procedures after first myocardial infarction in Finland in 1995

OBJECTIVE: We examined socioeconomic disparities in coronary procedure rates after first events among hospitalized myocardial infarction (MI) patients. STUDY DESIGN AND SETTING: Information on MI patients in 1995 in Finland was obtained from the Finnish Cardiovascular Disease Register Project. Data on comorbidity, invasive treatments, hospitalizations, mortality, and socioeconomic status were obtained by linking data from the Finnish Hospital Discharge Register, cause of death register, population census, and the health insurance register using personal identity numbers. RESULTS: In 1995, 5172 patients aged 40 to 74 years were hospitalized for first MI. This corresponds to age-standardized event rates of 354/100,000 for men and 152/100,000 for women. Within 2 years, 33% of men and 21% of women underwent an invasive coronary procedure. Men in the lowest income third underwent 25% (95% confidence interval [CI] 12-36) fewer procedures than men in the highest third. Among women, the corresponding difference was 43% (95% CI 24-57). These disparities persisted throughout the 2-year follow-up, and they were not reduced by adjustment for comorbidity or hospital district. CONCLUSION: Socioeconomic disparities were observed in receipt of invasive cardiac procedures. More attention should be paid to equitable distribution of scarce health care resources.     

Trends in the incidence of and mortality from coronary heart disease in Finland, 1983-1988.

Trends in the incidence of and mortality from coronary heart disease during the period 1983-1988 were assessed in the population aged 35-64 years in three areas of Finland. The official mortality statistics and the FINMONICA (Finnish portion of the World Health Organization MONICA (Monitoring of Trends and Determinants in Cardiovascular Disease) project) Acute Myocardial Infarction Register were used as data sources. They both showed that coronary heart disease mortality declined steeply in Finnish men and women. This marked decline in coronary heart disease mortality was associated with a decline in the number of out-of-hospital coronary deaths. The changes in the incidence of acute myocardial infarction in men did not parallel the changes in mortality. No decline in incidence was seen in women in any of the study areas. These results suggest that the routine mortality statistics alone may give an overly favorable picture of coronary heart disease trends. Data on incidence are necessary to assess the need for the treatment and prevention of coronary heart disease.     

Regional equity in childhood health--register-based follow-up of the Finnish 1987 birth cohort

Our objective was to investigate regional health differences among Finnish children using a population-based longitudinal register data. All live births born in 1987 were included in the study (N=59,546) and followed-up until the age of seven years. Statistically significant regional variation was found for all health indicators but diabetes. Background variables, such as maternal age and social class, explained only the difference in mortality. Various indicators gave different geographical patterns. Regional equity in childhood health has not been achieved in Finland. Existing health registers were feasible in studying regional variation in health, but a set of comprehensive morbidity indicators - preferably derived from different data sources - should be developed to monitor equity in health.     

Socioeconomic equity in amenable mortality in Finland 1992-2008

This study presents an approach to assess socioeconomic equity in the effectiveness of health services. As an indicator of health system performance we use amenable mortality which captures premature deaths that should not occur in the presence of effective and timely health care. Data on amenable deaths by income groups in Finland in 1992-2008 came from the National Causes of Death Register which was linked to sociodemographic data in population registers. We evaluate the extent of and trends in socioeconomic differences with two widely used inequity indices, the concentration index and the slope index of inequality, and also for different categories of amenable mortality. By categorizing conditions according to the level of intervention associated with the conditions it is possible to evaluate the effect of types of health interventions. Causes of death attributable to specialized and primary care interventions comprise the main groups. By this approach of decomposing equity in amenable mortality in Finland we detected major and increasing socioeconomic inequities and also greater inequity among deaths amenable to specialized health care interventions. Moreover, we saw that inequity increased at a faster pace among deaths amenable to specialized health care interventions yet primary health care interventions made a greater contribution to overall inequity. Although the overall rate of amenable mortality decreased notably during the follow-up, the time trends of socioeconomic differences in amenable health care indicate a substantial increase in inequities in health care in Finland.     

Ethnic differences in being overweight and obesity among male military conscripts born in Sweden between 1973 and 1975

Background: Ethnic differences in being overweight and obesitywere studied among 18 year old males in Sweden. Methods. Thisnationwide study was based on a record linkage between the MedicalBirth Register, the Register of Military Induction Examinationsand the Register of the Total Population. For 140,766 (87.8%)of the 160,247 males information was available on body massindex (BMI) and on their mothers' nationality. Results. Afteradjustment for education and geographical region the odds ratiofor being overweight was found to be higher among 18 year oldsons of immigrants from Finland (1.38 and 95% Cl: 1.26–1.52)than among sons of Swedish mothers. Similarly, the odds ratiofor being overweight was higher among the sons of immigrantsfrom former Eastern Europe (1.68 and 96% Cl: 1.46–1.94)than among sons of Swedish mothers. Conclusions: The risks ofbeing overweight and obesity were increased among the sons ofimmigrants from Finland and former Eastern Europe compared tosons of Swedish mothers.     

A strategy for delineating risks due to exposure to neurotoxic chemicals.

A method for delineating the risks due to exposure to neurotoxic chemicals based upon the linkage of four national computer-based registers is described. The four registers are: the Danish Product Register database, PROBAS; Register of air pollution measurements in Danish workplaces, ATABAS; Register of notified occupational diseases; and Register of work force. Based on the information from the four registers, risk profiles for neurotoxic chemicals in 69 industrial groups were generated. The risk profiles describe the number of neurotoxic chemicals, their potency, the number of exposure measurements exceeding the occupational exposure limit (OEL), and the total and relative number of diseases caused by the chemicals in each group. Based on this linkage, twelve industries are noted to be potentially at high risk due to exposure to neurotoxic chemicals; therein, 18 chemicals are identified as "risk chemicals," primarily used in 8 main groups of products. The goal of the evaluation is to develop a tool for priority setting of preventive measures. The evaluation may also serve as a tool for assessing improvements and selecting areas for further epidemiological studies.     

Airway obstruction and the risk of myocardial infarction and death from coronary heart disease: a national health examination survey with a 33-year follow-up period

Chronic obstructive pulmonary disease (COPD) has been associated with coronary mortality. Yet, data about the association between COPD and acute myocardial infarction (MI) remain scarce. We aimed to study airway obstruction as a predictor of MI and coronary mortality among 5576 Finnish adults who participated in a national health examination survey between 1978 and 1980. Subjects underwent spirometry, had all necessary data, showed no indications of cardiovascular disease at baseline, and were followed up through record linkage with national registers through 2011. The primary outcome consisted of a major coronary event—that is, hospitalization for MI or coronary death, whichever occurred first. We specified obstruction using the lower limit of normal categorization. Through multivariate analysis adjusted for potential confounding factors for coronary heart disease, hazard ratios (HRs) (with the 95% confidence intervals in parentheses) of a major coronary event, MI, and coronary death reached 1.06 (0.79–1.42), 0.84 (0.54–1.31), and 1.40 (1.04–1.88), respectively, in those with obstruction compared to others. However, in women aged 30–49 obstruction appeared to predict a major coronary event, where the adjusted HR reached 4.21 (1.73–10.28). In conclusion, obstruction appears to predict a major coronary event in younger women only, whereas obstruction closely associates with the risk of coronary death independent of sex and age.     

Regional equity in childhood health — register-based follow-up of the Finnish 1987 birth cohort

Our objective was to investigate regional health differences among Finnish children using a population-based longitudinal register data. All live births born in 1987 were included in the study (N=59,546) and followed-up until the age of seven years. Statistically significant regional variation was found for all health indicators but diabetes. Background variables, such as maternal age and social class, explained only the difference in mortality. Various indicators gave different geographical patterns. Regional equity in childhood health has not been achieved in Finland. Existing health registers were feasible in studying regional variation in health, but a set of comprehensive morbidity indicators — preferably derived from different data sources — should be developed to monitor equity in health.