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Kari Kuulasmaa

Publications and source records attributed to Kari Kuulasmaa.

13 recordsLinked to original sources
PubMed2006

Pattern of declining blood pressure across replicate population surveys of the WHO MONICA project, mid-1980s to mid-1990s, and the role of medication.

OBJECTIVE: Declining mean systolic and diastolic blood pressures were observed in most populations of the World Health Organization MONICA (monitoring trends and determinants in cardiovascular disease) project from the mid-1980s to mid-1990s. We tested whether pooled results would show mean change associated with decline in high readings only, resulting from better antihypertensive medication, or with similar falls in low, middle, and high readings, implying other causes. DESIGN: Independent, random sample, cross sectional population surveys, each end of the MONICA decade. SETTING: 38 populations in 21 countries across four continents. PARTICIPANTS: Design target in each survey of 200 participants in each 10 year age and sex group from age 35 to 64 MAIN OUTCOME MEASURES: Changes in the population in mean systolic and diastolic blood pressure, and in low, middle, and high readings-the 20th, 50th, and 80th centiles-and the differences between these changes. RESULTS: Individual populations differed considerably, but pooling the 38 population results gave mean changes in systolic blood pressure of -2.2 mm Hg in men, -3.3 mm Hg in women, and in diastolic blood pressure of -1.4 mm Hg in men and -2.2 mm Hg in women (overall average -2.26 mm Hg, population median -1.55 mm Hg). Antihypertensive medication, associated with high readings, rose by 0.5% to 11.4%. However, average falls in low and middle blood pressure readings were so similar to those in high readings and in the mean that no effect from improving treatment of hypertension was detected. Results in contrasted subgroups were consistent. CONCLUSIONS: Blood pressure fell across 38 MONICA populations at all levels of readings, with no differential fall in high readings attributable to better control of hypertension. Despite the importance of medication to individuals, in that decade other determinants of blood pressure lowering must have been more pervasive and powerful in whole populations.

Adult↗
PubMed2005

Effect of sampling frames on response rates in the WHO MONICA risk factor surveys.

Sample surveys are used to investigate occurrence and determinants of diseases in populations. Their reliability is influenced by quality of sampling frame and response rate. We investigated relationship between sampling frame type and response rates and assessed their impact on non-response bias, using data from the WHO MONICA Project, where 37 centres in 20 countries conducted sample surveys, employing the best locally available sampling frame. Sampling frames fell into three categories: Population registers (PR), electoral registers (ER), and health care registers (HR). Response rate (rrs) was factored into components reflecting quality of sampling frame (contact rate cr) and characterizing willingness of sample members to participate (enrolment rate er). The mean quality score for the sampling frames was 92% for PR, 87% for HR and 85% for ER; they contributed on average 23, 20, and 26% to the respective non-response rates. For all frame types and both sexes the lowest quality score occurred in the age group 35 - 44, suggesting a reduced ability to track migration of a highly mobile population group. The patterns in the age/sex distribution of er indicate at least for males in PR and females in HR a potential for non-response bias. Estimation of non-response bias through an abbreviated questionnaire failed because of low item response. We found that contact rate characterizes sampling frame quality. For all frame types it had a major influence on response rate. It is likely that low er and low cr cause different kind of bias, requiring different measures to minimize their effects.

Adult↗
PubMed2005

Myocardial infarction occurrence in Jerusalem: a Mediterranean anomaly.

BACKGROUND: The Jewish population of Israel consumes a diet rich in polyunsaturated fatty acids with a relatively low proportion of saturated fat, has a small alcohol intake and a lipid profile characterized by low HDL-cholesterol and high lipoprotein(a) (Lp(a)). It is therefore of interest to compare occurrence rates of coronary heart disease (CHD) with those elsewhere. METHODS: The community-based event rate of CHD [comprising acute myocardial infarction (AMI) and CHD death] and case-fatality was determined in 1995-1997 by active surveillance among Jewish residents of the Jerusalem District aged 25-64 according to standardized WHO-MONICA criteria. We compared our findings with rates among MONICA populations in 21 countries. Twelve hundred and six events occurred in Jerusalem during approximately 399,000 [correction] person-years (930 non-fatal AMI and 276 CHD deaths). RESULTS: The age-adjusted incidence of CHD ranked high compared with the 21 countries (men third highest, women eighth highest), far exceeding the Mediterranean countries. In contrast, the pre-hospital mortality rate was low, similar to countries in the Mediterranean basin, and the 28-day case fatality was remarkably low, far lower than for any MONICA population in men, and second lowest in women. Correspondingly, the incidence of non-fatal AMI ranked extraordinarily high (men first, women third). The low case-fatality ranking persisted upon adjustment for treatment differences between populations. CONCLUSIONS: We report an unusual combination of a high incidence of CHD among Jewish residents of Jerusalem accompanied by extraordinarily low case fatality, the latter suggesting reduced susceptibility to lethal arrhythmias. Determinants of this anomaly require clarification.

Adult↗
PubMed2005

The validity of the Finnish Hospital Discharge Register and Causes of Death Register data on coronary heart disease.

BACKGROUND AND DESIGN: The recent introduction of sensitive markers of myocardial injury is likely to affect the epidemiology of coronary heart disease (CHD). The American Heart Association together with other societies and research agencies have recently published a new definition on acute CHD to improve consistency in epidemiological and clinical studies (referred here as the '2003 definition'). METHODS: In this study we compare the data on CHD events in the Finnish National Hospital Discharge Register (HDR) and the Causes of Death Register (CDR) with the population-based myocardial infarction (MI) register, FINMONICA/FINAMI. The FINMONICA/FINAMI events were classified according to the 2003 definition. The relevant International Classification of Diseases (ICD) codes from the HDR and CDR were used. RESULTS: Using the 2003 definition as the reference, the overall sensitivity of the ICD codes for MI in the combined HDR and CDR was 83% and the positive predictive value (PPV) was 90%. When the ICD codes for unstable angina were added to the analyses, the sensitivity improved to 85% and the PPV declined to 83%. In the age group 35-74 the sensitivity of the MI codes improved over time, in men from 64% in 1988-1992 to 81% in 1998-2002, and in women from 61 to 78%, respectively. The oldest age group, 75 years or older, had sensitivity and PPV values comparable to those of the younger. CONCLUSION: Diagnoses of fatal and non-fatal CHD events in the Finnish HDR and Causes of Death register were reasonably valid indicators for hard CHD events when compared with the FINMONICA/FINAMI register data.

Adult↗
PubMed2005

Standardization of total cholesterol measurement in population surveys--pre-analytic sources of variation and their effect on the prevalence of hypercholesterolaemia.

BACKGROUND: The estimation of population distribution of total cholesterol, as well as other blood lipids requires population surveys. Comparability of the estimates over time or between populations requires a predefined, standardized measurement protocol. This paper will assess the effect of variation in the pre-analytic procedures, on the estimation of population distribution of total cholesterol and the prevalence of hypercholesterolaemia. Implications of variation to real survey results are demonstrated on data collected during the WHO MONICA Project. DESIGN AND METHODS: The extent (%) of pre-analytic variations were determined by literature review. Simulations were then used to estimate the effect of these variations on the distribution of total cholesterol values. Three populations were selected as examples for different population distributions of total cholesterol levels and variations resulting from seasonal and postural changes, use of tourniquet, and serum versus plasma collection were simulated both individually and in combinations. RESULTS: Depending on the population distribution of total cholesterol, differences in pre-analytic procedures can explain a difference of up to 1.12 mmol/l in the mean total cholesterol between populations, and a difference up to 41% in the prevalence of hypercholesterolaemia (> or =6.5 mmol/l). CONCLUSIONS: Variation in results on measured total cholesterol levels due to differences in procedures during the pre-analytic stage can diminish substantially the reliability and comparability of measurements among surveys over time and between populations. The effect of pre-analytic variation in the population estimates of total cholesterol can be extensively reduced by standardization and training.

Adult↗
PubMed2005

Total and cause specific mortality among participants and non-participants of population based health surveys: a comprehensive follow up of 54 372 Finnish men and women.

STUDY OBJECTIVE: To assess total and cause specific mortality among participants and non-participants of large population based health surveys. DESIGN: A prospective follow up study. Baseline surveys were conducted in 1972, 1977, 1982, 1987, and 1992. Study end points were overall, cardiovascular, cancer and violent mortality, and deaths related to smoking and alcohol. Study cohorts were followed up until the end of 2000 through computerised record linkage. All analyses were adjusted for age. SETTING: Finland. PARTICIPANTS: Participants and non-participants of five population based risk factor surveys. The samples included 54 372 men and women aged 25 to 64 years at baseline. MAIN RESULTS: The average participation rate was 81.7% among men and 87% among women. At eight year follow up, the non-participating men had twice and non-participating women 2.5-fold higher overall mortality than the participating men and women. Non-participants had also significantly higher cause specific mortality, except cancer and smoking related mortality among women. Relative differences in mortality were largest in violent and alcohol related deaths. Non-participants had considerably higher overall mortality than smoking participants, and their mortality was threefold compared with non-smoking participants. CONCLUSIONS: Observed differences in mortality show that health behaviour and health status substantially differ between non-participants and participants. Low participation rate may considerably bias the results of population based health surveys.

Adult↗
PubMed2005

Cold periods and coronary events: an analysis of populations worldwide.

STUDY OBJECTIVE: To investigate the association between cold periods and coronary events, and the extent to which climate, sex, age, and previous cardiac history increase risk during cold weather. DESIGN: A hierarchical analyses of populations from the World Health Organisation's MONICA project. SETTING: Twenty four populations from the WHO's MONICA project, a 21 country register made between 1980 and 1995. PATIENTS: People aged 35-64 years who had a coronary event. MAIN RESULTS: Daily rates of coronary events were correlated with the average temperature over the current and previous three days. In cold periods, coronary event rates increased more in populations living in warm climates than in populations living in cold climates, where the increases were slight. The increase was greater in women than in men, especially in warm climates. On average, the odds for women having an event in the cold periods were 1.07 higher than the odds for men (95% posterior interval: 1.03 to 1.11). The effects of cold periods were similar in those with and without a history of a previous myocardial infarction. CONCLUSIONS: Rates of coronary events increased during comparatively cold periods, especially in warm climates. The smaller increases in colder climates suggest that some events in warmer climates are preventable. It is suggested that people living in warm climates, particularly women, should keep warm on cold days.

Adult↗
PubMed2005

Evaluating whole genome amplification via multiply-primed rolling circle amplification for SNP genotyping of samples with low DNA yield.

The amount of available DNA is often a limiting factor in pursuing genetic analyses of large-scale population cohorts. An association between higher DNA yield from blood and several phenotypes associated with inflammatory states has recently been demonstrated, suggesting that exclusion of samples with very low DNA yield may lead to biased results in statistical analyses. Whole genome amplification (WGA) could present a solution to the DNA concentration-dependent sample selection. The aim was to thoroughly assess WGA for samples with low DNA yield, using the multiply-primed rolling circle amplification method. Fifty-nine samples were selected with the lowest DNA yield (less than 7.5 microg) among 799 samples obtained for one population cohort. The genotypes obtained from two replicate WGA samples and the original genomic DNA were compared by typing 24 single nucleotide polymorphisms (SNPs). Multiple genotype discrepancies were identified for 13 of the 59 samples. The largest portion of discrepancies was due to allele dropout in heterozygous genotypes in WGA samples. Pooling the WGA DNA replicates prior to genotyping markedly improved genotyping reproducibility for the samples, with only 7 discrepancies identified in 4 samples. The nature of discrepancies was mostly homozygote genotypes in the genomic DNA and heterozygote genotypes in the WGA sample, suggesting possible allele dropout in the genomic DNA sample due to very low amounts of DNA template. Thus, WGA is applicable for low DNA yield samples, especially if using pooled WGA samples. A higher rate of genotyping errors requires that increased attention be paid to genotyping quality control, and caution when interpreting results.

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PubMed2004

Use of oral contraceptives and hormone replacement therapy in the WHO MONICA project.

AIMS: To compare menopausal age and the use of oral contraceptives (OC) and hormonal replacement therapy (HRT) between the 32 populations of the WHO MONICA Project, representing 20 different countries. METHODS: Using a uniform protocol, age at menopause and the use of OC and HRT was recorded in a random sample of 25-64 year-old women attending the final MONICA population cardiovascular risk factor survey between 1989 and 1997. A total of 39,120 women were included. RESULTS: There were wide variations between the populations in the use of OC and HRT. The use of OC varied between 0 and 52% in pre-menopausal women aged 35-44 years, Central and East Europe and North America having the lowest and West Europe and Australasia the highest prevalence rates. Among post-menopausal women between 45 and 64 years, the prevalence of HRT use varied from 0 to 42%. In general, the use of HRT was high in Western and Northern Europe, North America and Australasia and low in Central, Eastern and Southern Europe and China. With the exception of Canada (45 years), the mean age at menopause differed only little (ranging from 48 to 50 years) between the populations. CONCLUSION: The use of OC and HRT varies markedly between populations, in general following a regional pattern. Whereas, the prevalence rates are mostly similar within a country, there are remarkable differences even between neighbouring countries, reflecting nation-specific medical practice and public attitudes that are not necessarily based on scientific evidence.

Adult↗
PubMed2004

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.

Adult↗
PubMed2002

Estimation of an errors-in-variables regression model when the variances of the measurement errors vary between the observations.

It is common in the analysis of aggregate data in epidemiology that the variances of the aggregate observations are available. The analysis of such data leads to a measurement error situation, where the known variances of the measurement errors vary between the observations. Assuming multivariate normal distribution for the 'true' observations and normal distributions for the measurement errors, we derive a simple EM algorithm for obtaining maximum likelihood estimates of the parameters of the multivariate normal distributions. The results also facilitate the estimation of regression parameters between the variables as well as the 'true' values of the observations. The approach is applied to re-estimate recent results of the WHO MONICA Project on cardiovascular disease and its risk factors, where the original estimation of the regression coefficients did not adjust for the regression attenuation caused by the measurement errors.

Algorithms↗
PubMed2002

Do trends in population levels of blood pressure and other cardiovascular risk factors explain trends in stroke event rates? Comparisons of 15 populations in 9 countries within the WHO MONICA Stroke Project. World Health Organization Monitoring of Trends and Determinants in Cardiovascular Disease.

BACKGROUND AND PURPOSE: Previous studies have indicated a reasonably strong relationship between secular trends in classic cardiovascular risk factors and stroke incidence within single populations. To what extent variations in stroke trends between populations can be attributed to differences in classic cardiovascular risk factor trends is unknown. METHODS: In the World Health Organization Monitoring of Trends and Determinants in Cardiovascular Disease (WHO MONICA) Project, repeated population surveys of cardiovascular risk factors and continuous monitoring of stroke events have been conducted in 35- to 64-year-old people over a 7- to 13-year period in 15 populations in 9 countries. Stroke trends were compared with trends in individual risk factors and their combinations. A 3- to 4-year time lag between changes in risk factors and change in stroke rates was considered. RESULTS: Population-level trends in systolic blood pressure showed a strong association with stroke event trends in women, but there was no association in men. In women, 38% of the variation in stroke event trends was explained by changes in systolic blood pressure when the 3- to 4-year time lag was taken into account. Combining trends in systolic blood pressure, daily cigarette smoking, serum cholesterol, and body mass index into a risk score explained only a small fraction of the variation in stroke event trends. CONCLUSIONS: In this study, it appears that variations in stroke trends between populations can be explained only in part by changes in classic cardiovascular risk factors. The associations between risk factor trends and stroke trends are stronger for women than for men.

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