Accuracy of diagnosis on death certificates for underlying causes of death in a long-term autopsy-based population study in Hisayama, Japan; with special reference to cardiovascular diseases

An Automated Method of Causal Inference of the Underlying Cause of Death of Citizens

It is of great significance to correctly infer the underlying cause of death for citizens, especially under the current worldwide situation. The medical resources of all countries are overwhelmed under the impact of coronavirus disease 2019 (COVID-19) and countries need to allocate limited resources to the most suitable place. Traditionally, the cause-of-death inference relies on manual methods, which require a large resource cost and are not so efficient. To address the challenges, in this work, we present a mixed inference method named Sink-CF. The Sink-CF algorithm is based on confidence measurement and is used to automatically infer the underlying cause of death of citizens. The method proposed in this paper combines a mathematical statistics method and a collaborative filtering and analysis algorithm in machine learning. Thus, our method can not only effectively achieve a certain accuracy, but also does not rely on a large quantity of manually labeled data to continuously optimize the model, which can save computer computing power and time, and has the characteristics of being simple, easy and efficient. The experimental results show that our method generates a reasonable precision (93.82%) and recall (90.11%) and outperforms other state-of-the-art machine learning algorithms.

Impact of Body Mass Index on Obesity-Related Cancer and Cardiovascular Disease Mortality; The Japan Collaborative Cohort Study

AIM

We aimed to examine the association of obesity-related cancer and cardiovascular disease (CVD) with body mass index (BMI) and the estimated population attributable fraction in lean Asians.

METHODS

We studied 102,535 participants aged 40-79 years without histories of cancer or CVD at baseline between 1988 and 2009. The cause-specific hazard ratios (csHRs) of BMI categories (＜18.5, 18.5-20.9, 21.0-22.9 [reference], 23.0-24.9, 25.0-27.4, and ≥ 27.5 kg/m²) were estimated for each endpoint. The events considered were mortalities from obesity-related cancer (esophageal, colorectal, liver, pancreatic, kidney, female breast, and endometrial cancer) and those from CVD (coronary heart disease and stroke). Population attributable fractions (PAFs) were calculated for these endpoints.

RESULTS

During a 19.2-year median follow-up, 2906 died from obesity-related cancer and 4532 died from CVD. The multivariable-adjusted csHRs (95% confidence interval) of higher BMI categories (25-27.4 and ≥ 27.5 kg/m²) for obesity-related cancer mortality were 0.93 (0.78, 1.10) and 1.18 (0.92, 1.50) in men and 1.25 (1.04, 1.50) and 1.48 (1.19, 1.84) in women, respectively. The corresponding csHRs for CVD mortality were 1.27 (1.10, 1.46) and 1.59 (1.30, 1.95) in men and 1.10 (0.95, 1.28) and 1.44 (1.21, 1.72) in women, respectively. The PAF of a BMI ≥ 25 kg/m² for obesity-related cancer was -0.2% in men and 6.7% in women and that for CVD was 5.0% in men and 4.5% in women.

CONCLUSION

A BMI ≥ 25 kg/m² is associated with an increased risk of obesity-related cancer in women and CVD in both sexes.

Isolated systolic hypertension and 29-year cardiovascular mortality risk in Japanese adults aged 30--49 years

OBJECTIVE

The prognostic implication of isolated systolic hypertension (ISH), defined as SBP at least 140 mmHg and DBP less than 90 mmHg, among young-to-middle-aged adults remains controversial. We examined the association of ISH with cardiovascular disease (CVD) risk in adults aged 30-49 years.

METHODS

In a prospective cohort of representative Japanese general populations from the NIPPON DATA80 (1980-2009), we studied 4776 participants (mean age, 39.4 years; 55.4% women) without clinical CVD or antihypertensive medication. Participants were classified as follows: normal blood pressure (BP) (SBP/DBP, <120/<80 mmHg), high-normal BP (120-129/<80 mmHg), elevated BP (130-139/80-89 mmHg), ISH, isolated diastolic hypertension (IDH) (<140/≥90 mmHg), and systolic--diastolic hypertension (SDH) (≥140/≥90 mmHg).

RESULTS

ISH was observed in 389 (8.1%) participants. During the 29-year follow-up, 115 participants died of CVD, 28 of coronary heart disease, and 49 of stroke. Cox proportional hazards models adjusted for demographics and CVD risk factors showed that participants with ISH had higher risk of CVD mortality than those with normal BP [hazard ratio (confidence interval), 4.10 (1.87-9.03)]. The magnitude of CVD mortality risk related to ISH was comparable with that related to IDH [3.38 (1.31-8.72)] and not as great as that related to SDH [5.41 (2.63-11.14)]. We found significant associations of ISH with coronary and stroke mortality. The association of ISH with CVD mortality was consistent across men and women and those aged 30-39 and 40-49 years.

CONCLUSION

ISH among young-to-middle-aged Japanese adults was independently associated with higher risk of CVD mortality later in life.

An Automatic Approach Designed for Inference of the Underlying Cause-of-Death of Citizens

It is very important to have a comprehensive understanding of the health status of a country’s population, which helps to develop corresponding public health policies. Correct inference of the underlying cause-of-death for citizens is essential to achieve a comprehensive understanding of the health status of a country’s population. Traditionally, this relies mainly on manual methods based on medical staff’s experiences, which require a lot of resources and is not very efficient. In this work, we present our efforts to construct an automatic method to perform inferences of the underlying causes-of-death for citizens. A sink algorithm is introduced, which could perform automatic inference of the underlying cause-of-death for citizens. The results show that our sink algorithm could generate a reasonable output and outperforms other stat-of-the-art algorithms. We believe it would be very useful to greatly enhance the efficiency of correct inferences of the underlying causes-of-death for citizens.

Feasibility and validity of using death surveillance data and SmartVA for fact and cause of death in clinical trials in rural China: a substudy of the China salt substitute and stroke study (SSaSS)

BACKGROUND

In rural China, mortality surveillance data may be an alternative to primary data collection in clinical trials; SmartVA (verbal autopsy) is also a potential alternative for endpoint adjudication. The feasibility and validity of both need to be assessed.

METHODS

We used mortality data from the first 24 months of the China Salt Substitute and Stroke Study (SSaSS) trial and assessed the agreement between (1) mortality surveillance data and face-to-face visits for fact of death; (2) mortality surveillance data and SSaSS adjudication for causes of death; (3) SmartVA and SSaSS adjudication for causes of death; (4) cause-specific mortality fraction of different methods. Face-to-face visits and SSaSS adjudication were taken as reference methods. The agreement was measured by sensitivity, specificity and positive predictive value (PPV) across different 10th Revision of International Statistical Classification of Diseases chapters.

RESULTS

One thousand three hundred and sixty-five deaths were included. Mortality surveillance data had 82% sensitivity for fact of death and 81% sensitivity for causes of death, with substantial variances across different disease types and reasonable quality for circulatory death (91% sensitivity and 94% PPV). The sensitivity of SmartVA for causes of death was 61%, with reasonable quality for deaths of external causes of morbidity (90% sensitivity). The leading causes of death from different sources were the same with some variances in the fractions.

CONCLUSION

Using mortality surveillance data for fact of death in clinical trials need to account for under-reporting. A face-to-face visit to all participants at the completion of trials may be warranted. Neither mortality surveillance data nor SmartVA provided valid data source for endpoint events.

Blood pressure levels and risk of cardiovascular disease mortality among Japanese men and women: the Japan Collaborative Cohort Study for Evaluation of Cancer Risk (JACC Study)

OBJECTIVE

To examine the association of blood pressure (BP) with cardiovascular mortality in real-world settings and investigate whether that association varied by use of antihypertensive medication at baseline.

METHODS

Data from 27 728 Japanese men and women, aged 40-79 years, free of stroke, coronary heart disease, cancer, and kidney disease at entry (1988-1990) were used in this study. Mortality surveillance was completed through 2009, resulting in 449 800 person-years of follow-up. Hazard ratios for cardiovascular mortality were analysed by BP category (based on 2018 European guidelines) at admission.

RESULTS

There were 1477 deaths from cardiovascular diseases (CVDs). Relative to high-normal BP at admission, the multivariable hazard ratios (95% confidence intervals) of CVD were 0.85 (0.69-1.04) for optimal BP; 0.96 (0.81-1.15) for normal BP; 1.26 (1.09-1.46) for Grade 1 hypertension; and 1.55 (1.31-1.84) for Grade 2-3 hypertension. A similar linear association was observed among persons not taking antihypertensive medication at admission. Among patients treated for hypertension, a U-shaped association with CVD mortality was observed; hazard ratios = 2.31 (1.25-4.27), 1.68 (1.05-2.69), 1.56 (1.10-2.22), and 1.63 (1.13-2.36), respectively. Similar patterns were observed for stroke and coronary heart disease, although not always statistically significant.

CONCLUSION

BP categories at baseline were linearly and positively associated with CVD mortality overall and also among participants not taking antihypertensive medication. A higher risk of mortality from CVD was observed among patients already treated for hypertension with optimal and normal BPs than those with high-normal BP, suggesting the importance of careful monitoring of BP and comorbidities of such patients.

Association of Trajectories of Higher-Level Functional Capacity with Mortality and Medical and Long-Term Care Costs Among Community-Dwelling Older Japanese

Background

Higher-level functional capacity is crucial component for independent living in later life. We used repeated-measures analysis to identify aging trajectories in higher-level functional capacity. We then determined whether these trajectories were associated with all-cause mortality and examined differences in medical and long-term care costs between trajectories among community-dwelling older Japanese.

Methods

2,675 adults aged 65-90 years participated in annual geriatric health assessments and biennial health monitoring surveys during the period from October 2001 through August 2011. The average number of follow-up assessments was 4.0, and the total number of observations was 10,609. Higher-level functional capacity, which correspond to the fourth and fifth sublevels of Lawton's hierarchical model, was assessed with the Tokyo Metropolitan Institute of Gerontology-Index of Competence (TMIG-IC).

Results

We identified four distinct trajectory patterns (high-stable, late-onset decreasing, early-onset decreasing, and low-decreasing) on the TMIG-IC through age 65-90 years. As compared with the high-stable trajectory group, participants in the late-onset decreasing, early-onset decreasing, and low-decreasing TMIG-IC trajectory groups had adjusted hazard ratios for mortality of 1.22 (95% confidence interval: 1.01-1.47), 1.90 (1.53-2.36), and 2.87 (2.14-3.84), respectively. Participants with high-stable and late-onset decreasing higher-level functional capacity trajectories had lower mean monthly medical costs and long-term care costs. In contrast, mean total costs were higher for those with low-decreasing trajectories, after excluding the large increase in such costs at the end of life.

Conclusions

People with a low-decreasing aging trajectory in higher-level functional capacity had higher risks of death and had high monthly total costs.

The Circulatory Risk in Communities Study (CIRCS): A Long-Term Epidemiological Study for Lifestyle-Related Disease Among Japanese Men and Women Living in Communities

The Circulatory Risk in Communities Study (CIRCS) is an ongoing community-based epidemiological study of lifestyle-related disease involving dynamic prospective cohorts of approximately 12,000 adults from five communities of Japan: Ikawa, Ishizawa and Kita-Utetsu (Akita Prefecture), Minami-Takayasu (Osaka Prefecture), Noichi (Kochi Prefecture), and Kyowa (Ibaraki Prefecture). One of the most notable features of CIRCS is that it is not only an observational cohort study to identify risk factors for cardiovascular diseases (CVD), such as stroke, coronary heart disease, and sudden cardiac death, but it also involves prevention programs for CVD. Using basic, clinical, epidemiological, and statistical techniques, CIRCS has clarified characteristics of CVD and the related risk factors to develop specific methodologies towards CVD prevention in Japanese middle-aged or older adults for more than half a century.

Contribution of the clinical information to the accuracy of the minimally invasive and the complete diagnostic autopsy

Although autopsy diagnosis includes routinely, a thorough evaluation of all available pathological results and also of any available clinical data, the contribution of this clinical information to the diagnostic yield of the autopsy has not been analyzed. We aimed to determine to which degree the use of clinical data improves the diagnostic accuracy of the complete diagnostic autopsy (CDA) and the minimally invasive autopsy (MIA), a simplified pathological postmortem procedure designed for low-income sites. A total of 264 coupled MIA and CDA procedures (112 adults, 57 maternal deaths, 54 children, and 41 neonates) were performed at the Maputo Hospital, Mozambique. We compared the diagnoses obtained by the MIA blind to clinical data (MIAb), the MIA adding the clinical information (MIAc), and the CDA blind to clinical information (CDAb), with the results of the gold standard, the CDA with clinical data, by comparing the International Classification of Diseases, Tenth Revision codes and the main diagnostic classes obtained with each evaluation strategy (MIAb, MIAc, CDAb, CDAc). The clinical data increased diagnostic coincidence to the MIAb with the gold standard in 30 (11%) of 264 cases and modified the CDAb diagnosis in 20 (8%) of 264 cases. The increase in concordance between MIAb and MIAc with the gold standard was significant in neonatal deaths (κ increasing from 0.404 to 0.618, P = .0271), adult deaths (κ increasing from 0.732 to 0.813, P = .0221), and maternal deaths (κ increasing from 0.485 to 0.836, 0.;P < .0001). In conclusion, the use of clinical information increases the precision of MIA and CDA and may strengthen the performance of the MIA in resource-limited settings.

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The addition of clinical data increases the diagnostic accuracy of the minimally invasive autopsy (MIA) and complete diagnostic autopsy in 12% and 8% of the cases, respectively.

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The increase in concordance from MIA blind to clinical data to MIA enhanced with clinical data was significant in neonatal, adult, and maternal deaths and was also evident in children, although it did not reach statistical significance.

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The use of clinical data may improve the diagnostic precision of the MIA in resource-limited settings.

The Epidemic of Despair Among White Americans: Trends in the Leading Causes of Premature Death, 1999-2015

OBJECTIVES

To evaluate trends in premature death rates by cause of death, age, race, and urbanization level in the United States.

METHODS

We calculated cause-specific death rates using the Compressed Mortality File, National Center for Health Statistics data for adults aged 25 to 64 years in 2 time periods: 1999 to 2001 and 2013 to 2015. We defined 48 subpopulations by 10-year age groups, race/ethnicity, and county urbanization level (large urban, suburban, small or medium metropolitan, and rural).

RESULTS

The age-adjusted premature death rates for all adults declined by 8% between 1999 to 2001 and 2013 to 2015, with decreases in 39 of the 48 subpopulations. Most decreases in death rates were attributable to HIV, cardiovascular disease, and cancer. All 9 subpopulations with increased death rates were non-Hispanic Whites, largely outside large urban areas. Most increases in death rates were attributable to suicide, poisoning, and liver disease.

CONCLUSIONS

The unfavorable recent trends in premature death rate among non-Hispanic Whites outside large urban areas were primarily caused by self-destructive health behaviors likely related to underlying social and economic factors in these communities.

The ratio of serum eicosapentaenoic acid to arachidonic acid and risk of cancer death in a Japanese community: The Hisayama Study

Background

Whether the intake of eicosapentaenoic acid (EPA) or arachidonic acid (AA) affects the risk of cancer remains unclear, and the association between the serum EPA:AA ratio and cancer risk has not been fully evaluated in general populations.

Methods

A total of 3098 community-dwelling subjects aged ≥40 years were followed up for 9.6 years (2002–2012). The levels of the serum EPA:AA ratio were categorized into quartiles (<0.29, 0.29–0.41, 0.42–0.60, and >0.60). The risk estimates were computed using a Cox proportional hazards model. The same analyses were conducted for the serum docosahexaenoic acid to arachidonic acid (DHA:AA) ratio and individual fatty acid concentrations.

Results

During the follow-up period, 121 subjects died of cancer. Age- and sex-adjusted cancer mortality increased with lower serum EPA:AA ratio levels (P trend<0.05). In the multivariable-adjusted analysis, the subjects in the first quartile of the serum EPA:AA ratio had a 1.93-fold (95% confidence interval, 1.15–3.22) greater risk of cancer death than those in the fourth quartile. Lower serum EPA concentrations were marginally associated with higher cancer mortality (P trend<0.11), but the serum DHA or AA concentrations and the serum DHA:AA ratio were not (all P trend>0.37). With regard to site-specific cancers, lower serum EPA:AA ratio was associated with a higher risk of death from liver cancer. However, no such associations were detected for deaths from other cancers.

Conclusions

These findings suggest that decreased level of the serum EPA:AA ratio is a significant risk factor for cancer death in the general Japanese population.

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Lower serum EPA:AA ratio was significantly associated with higher cancer mortality.

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The risk of death from liver cancer increased with lower serum EPA:AA ratio.

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No significant association was found between serum DHA:AA ratio and cancer death.

Similarities and differences between coronary heart disease and stroke in the associations with cardiovascular risk factors: The Japan Collaborative Cohort Study

BACKGROUND AND AIMS

Coronary heart disease (CHD) and stroke have common risk factors, but some of these differ in the magnitude or direction of associations between CHD and stroke. We assessed whether the impact of each risk factor differed between CHD and stroke mortality in Asians.

METHODS

In total, 104 910 subjects aged 40-79 years without histories of cancer, CHD and stroke at baseline were followed between 1988 and 2009. Competing-risks analysis was used to test for differences in the associations of each risk factor with two endpoints (CHD and stroke). Population attributable fractions (PAFs) were also calculated for these endpoints to estimate the population impact of each risk factor.

RESULTS

During a median 19.1-year follow-up, 1554 died from CHD and 3163 from stroke. The association of hypertension with CHD was similar to that with stroke in terms of the magnitude and direction (multivariable-adjusted hazard ratio for CHD: 1.63 vs. stroke: 1.73 in men and 1.70 vs. 1.66 in women). Conversely, the magnitude of these associations differed for smoking (CHD: 1.95 vs. stroke: 1.23 in men and 2.45 vs. 1.35 in women) and diabetes (1.49 vs. 1.09 in men and 2.08 vs. 1.39 in women). The highest PAF for CHD was caused by smoking in men and by hypertension in women; that for stroke was caused by hypertension in both sexes.

CONCLUSIONS

Hypertension associations and PAFs were consistent between CHD and stroke, but not for other risk factors. These findings may be useful to optimize public health intervention strategies.

Validity of a Minimally Invasive Autopsy for Cause of Death Determination in Adults in Mozambique: An Observational Study

BACKGROUND

There is an urgent need to identify tools able to provide reliable information on the cause of death in low-income regions, since current methods (verbal autopsy, clinical records, and complete autopsies) are either inaccurate, not feasible, or poorly accepted. We aimed to compare the performance of a standardized minimally invasive autopsy (MIA) approach with that of the gold standard, the complete diagnostic autopsy (CDA), in a series of adults who died at Maputo Central Hospital in Mozambique.

METHODS AND FINDINGS

In this observational study, coupled MIAs and CDAs were performed in 112 deceased patients. The MIA analyses were done blindly, without knowledge of the clinical data or the results of the CDA. We compared the MIA diagnosis with the CDA diagnosis of cause of death. CDA diagnoses comprised infectious diseases (80; 71.4%), malignant tumors (16; 14.3%), and other diseases, including non-infectious cardiovascular, gastrointestinal, kidney, and lung diseases (16; 14.3%). A MIA diagnosis was obtained in 100/112 (89.2%) cases. The overall concordance between the MIA diagnosis and CDA diagnosis was 75.9% (85/112). The concordance was higher for infectious diseases and malignant tumors (63/80 [78.8%] and 13/16 [81.3%], respectively) than for other diseases (9/16; 56.2%). The specific microorganisms causing death were identified in the MIA in 62/74 (83.8%) of the infectious disease deaths with a recognized cause. The main limitation of the analysis is that both the MIA and the CDA include some degree of expert subjective interpretation.

CONCLUSIONS

A simple MIA procedure can identify the cause of death in many adult deaths in Mozambique. This tool could have a major role in improving the understanding and surveillance of causes of death in areas where infectious diseases are a common cause of mortality.

The importance of age groups in estimates of alcohol-attributable mortality: impact on trends in Switzerland between 1997 and 2011

BACKGROUND AND AIMS

Monitoring trends of alcohol-attributable mortality is an integral part of the global strategy to reduce the harmful use of alcohol. However, mortality estimates based on different age ranges come to different conclusions. This study examined the impact of including different age ranges in terms of directions of trends of alcohol-attributable mortality during 14 years in Switzerland.

METHOD

Alcohol-attributable mortality was estimated at four time-points between 1997 and 2011 using the Global Burden of Disease 2010 methodology. Estimates were obtained for two age groups: 15-64 years and the total adult population (15 years and older).

RESULTS

Alcohol-attributable mortality among 15-64-year-olds decreased [1997: 1334 deaths, confidence interval (CI) = 1237-1432; 2011: 1019 deaths, CI = 964-1073; trend per year odds ratio (OR) = 0.99, P < 0.001]. In contrast, alcohol-attributable mortality among those 65 and older increased in the same time-period (1997: 581 deaths, CI = -196 to 1357; 2011: 1664 deaths, CI = 957-2372; OR = 1.07, P< 0.001), resulting in an overall increase of alcohol-attributable mortality for 15+ year-olds (1997: 1915 deaths, CI = 1133-2697; 2011: 2683, CI = 1973-3393; OR = 1.02, P < 0.001). The main shift in trends was due to changes in the mixture (e.g. hypertension, ischaemic heart disease) of cardiovascular diseases over time among those 65+ years old.

CONCLUSIONS

Trends in alcohol-attributable mortality may yield qualitatively different results based on the upper age limit for deaths set for these estimates. Global trends of alcohol-attributable mortality between 1997 and 2011 were influenced heavily by changes in the mixture of deaths across cardiovascular diseases. Trends for alcohol-attributable mortality and cross-country comparisons should be reported separately for 15-64 and 65+ year-olds.

Validity of the European short list of respiratory diseases: a 40-year autopsy study

The predictors of autopsy and the accuracy of European short list (E) codes of respiratory diseases lack recent knowledge. A 10% random sample (n=6811) of inhabitants of Bergen, Norway, aged 20-70 years, was invited to participate in a survey in 1965-1971 (participation rate 83%). By December 31, 2005, 4387 (64%) participants had died and 1163 (27% of the deceased) had been given an autopsy. Causes of death were tuberculosis (E02, 0.2%), lung malignancy (E15, 3.5%), influenza (E38, 0.2%), pneumonia (E39, 6.5%) and chronic lower respiratory diseases (E40, 3.2%). Male sex, early deaths in the surveillance period and E15 were positive predictors of an autopsy examination, whereas old age and E39 were strong negative predictors. Among those referred for a post mortem examination, the cause of death was verified as tuberculosis in 0.3%, lung cancer in 8.1%, acute pneumonia in 2.0% and chronic obstructive lung diseases in 4.9%. Cohen's kappa coefficients (E codes versus autopsy) were 0.91 (95% CI 0.86-0.96) for E15, 0.37 (95% CI 0.20-0.54) for E39 and 0.65 (95% CI 0.54-0.76) for E40. These findings matter when deaths from respiratory diseases are used as end-points in epidemiological association studies and clinical trials.

Milk drinking and mortality: findings from the Japan collaborative cohort study

Background

Findings regarding the association between milk consumption and all-cause mortality reported by studies carried out in Western populations have been inconsistent. However, no studies have been conducted in Japan on this issue. The present study aimed to investigate the association of milk drinking with all-cause, cardiovascular, and cancer mortality in Japan.

Methods

The data were obtained from the Japan Collaborative Cohort (JACC) study. A total of 94 980 Japanese adults aged 40–79 years who had no history of cancer, stroke, or chronic cardiovascular diseases were followed between 1988 and 2009. Multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of mortalities were assessed using a Cox proportional hazard regression model and taking the lowest milk consumption group as the reference.

Results

During a median of 19 years of follow-up, there were 21 775 deaths (28.8% and 35.3% from cardiovascular diseases and cancer, respectively). Drinking milk 1–2 times a month was associated with lower all-cause mortality in men compared to those who never drank milk (multivariable-adjusted HR 0.92; 95% CI, 0.85–0.99). In women, those who drank 3–4 times a week also had a lower mortality risk compared with those who never drank milk (HR 0.91; 95% CI 0.85–0.98). Inverse associations between drinking milk and mortality from cardiovascular diseases and cancer were found only in men.

Conclusions

Drinking milk at least 1–2 times a month was associated with lower all-cause mortality in men compared to never drinking milk. An inverse association was also found between drinking milk and mortality from both cardiovascular diseases and cancer. However, lower all-cause mortality in women was found only in those who drank milk 3–4 times/week.

Death certificates underestimate infections as proximal causes of death in the U.S

Background

Death certificates are a primary data source for assessing the population burden of diseases; however, there are concerns regarding their accuracy. Diagnosis-Related Group (DRG) coding of a terminal hospitalization may provide an alternative view. We analyzed the rate and patterns of disagreement between death certificate data and hospital claims for patients who died during an inpatient hospitalization.

Methods

We studied respondents from the Health and Retirement Study (a nationally representative sample of older Americans who had an inpatient death documented in the linked Medicare claims from 1993–2007). Causes of death abstracted from death certificates were aggregated to the standard National Center for Health Statistics List of 50 Rankable Causes of Death. Centers for Medicare and Medicaid Services (CMS)-DRGs were manually aggregated into a parallel classification. We then compared the two systems via 2×2, focusing on concordance. Our primary analysis was agreement between the two data sources, assessed with percentages and Cohen's kappa statistic.

Results

2074 inpatient deaths were included in our analysis. 36.6% of death certificate cause-of-death codes agreed with the reason for the terminal hospitalization in the Medicare claims at the broad category level; when re-classifying DRGs without clear alignment as agreements, the concordance only increased to 61%. Overall Kappa was 0.21, or “fair.” Death certificates in this cohort redemonstrated the conventional top 3 causes of death as diseases of the heart, malignancy, and cerebrovascular disease. However, hospitalization claims data showed infections, diseases of the heart, and cerebrovascular disease as the most common diagnoses for the same terminal hospitalizations.

Conclusion

There are significant differences between Medicare claims and death certificate data in assigning cause of death for inpatients. The importance of infections as proximal causes of death is underestimated by current death certificate-based strategies.

High long-chain n-3 fatty acid intake attenuates the effect of high resting heart rate on cardiovascular mortality risk: a 24-year follow-up of Japanese general population

BACKGROUND

Increased resting heart rate (RHR) independently predicts cardiovascular mortality. Meanwhile, long-chain n-3 fatty acids (LCn3FAs) have a cardioprotective effect. Our aim was to evaluate whether higher LCn3FAs intake attenuates the elevated risk of cardiovascular mortality associated with increased RHR.

METHODS

We conducted a population-based 24-year prospective cohort study of Japanese, whose LCn3FAs intake is relatively high. Study participants included 8807 individuals aged 30-95 years from randomly selected areas across Japan without cardiovascular diseases and anti-hypertensive drugs at baseline. The primary endpoint was cardiovascular mortality, and the secondary endpoints were cardiac and stroke mortality during 24 years of follow-up. Individual dietary LCn3FAs intake was estimated from household-based 3-day weighed food records. RHR was obtained from 3 consecutive R-wave intervals on 12-lead electrocardiography. Cox models were used to estimate the multivariable hazard ratios (HRs) and 95% confidence intervals (95% CIs) adjusting for possible confounders.

RESULTS

During the follow-up period, 617 cardiovascular deaths were observed. The median daily intake of LCn3FAs was 0.37% kcal (0.86g/day). The interaction between dietary LCn3FAs intake and RHR in the risk of cardiovascular mortality was statistically significant (p=0.033). The risk of cardiovascular mortality was significantly higher in the low-intake group (<0.37%kcal) with an RHR >85beats/min (bpm) [hazard ratio (HR), 1.67; 95% confidence interval (CI), 1.15-2.43], but not in the high-intake group (≥0.37%kcal) with an RHR >85bpm (HR, 0.92; 95% CI, 0.61-1.38), compared with those in the high-intake group with an RHR <70bpm. Similar results were observed with stroke mortality, but not with cardiac mortality.

CONCLUSIONS

The risk of cardiovascular mortality associated with increased RHR is elevated in participants with low dietary LCn3FAs intake, but not in participants with high dietary LCn3FAs intake in a representative Japanese general population. These results suggest that high dietary LCn3FAs intake may prevent cardiovascular mortality associated with increased RHR.

Low serum LDL cholesterol levels are associated with elevated mortality from liver cancer in Japan: the Ibaraki Prefectural health study

Liver cancer a global public health concern and well known for poor prognosis. The association between low total cholesterol level and liver cancer has been reported. However, the association between low low-density lipoprotein (LDL) cholesterol levels and liver cancer is still unclear. The aim of this study was to examine the relationship between LDL cholesterol level and liver cancer mortality. A total of 16,217 persons (5,551 men and 10,666 women) aged 40-79 years in 1993 were followed until 2008. LDL cholesterol levels were divided into four categories (<80 mg/dl, 80-99 mg/dl, 100-119 mg/dl, and ≥120 mg/dl). Hazard ratio of LDL cholesterol level for liver cancer mortality was calculated using a multivariable Cox proportional hazards model. Covariates were age, sex, alanine transaminase, body mass index, alcohol intake and smoking status, all of which were correlated with LDL cholesterol levels. There were 51 deaths (32 men and 19 women) from liver cancer. Multivariable hazard ratios of liver cancer deaths for LDL cholesterol levels of <80 mg/dl was 4.33 (95% confident interval [CI]: 1.94, 9.68), for LDL cholesterol levels of 80-99 mg/dl was 1.03 (95% CI: 0.42, 2.53), and for LDL cholesterol levels of ≥120 mg/dl was 0.43 (95% CI: 0.20, 0.92) compared with LDL cholesterol levels of 100-199 mg/dl (p for trend<0.01). Therefore, low LDL cholesterol levels are associated with elevated risk of liver cancer mortality. Low LDL cholesterol may be a predictive marker for death due to liver cancer.

Secular trends in cardiovascular disease and its risk factors in Japanese: half-century data from the Hisayama Study (1961-2009)

BACKGROUND

Changes in lifestyle and advances in medical technology during the past half century are likely to have affected the incidence and mortality of cardiovascular disease and the prevalence of its risk factors in Japan.

METHODS AND RESULTS

We established 5 cohorts consisting of residents aged ≥40 years in a Japanese community, in 1961 (n=1618), 1974 (n=2038), 1983 (n=2459), 1993 (n=1983), and 2002 (n=3108), and followed up each cohort for 7 years. The age-adjusted incidence of stroke decreased greatly, by 51% in men and by 43% in women, from the 1960s to the 1970s, but this decreasing trend slowed from the 1970s to the 2000s. Among the stroke subtypes, ischemic stroke in both sexes and intracerebral hemorrhage in men showed a similar pattern. Stroke mortality decreased as a result of the decline in incidence and a significant improvement in survival rate. Although the incidence of acute myocardial infarction did not change in either sex, disease mortality declined slightly in women. From the 1960s to the 2000s, blood pressure control among hypertensive individuals improved significantly and the smoking rate decreased, but the prevalence of glucose intolerance, hypercholesterolemia, and obesity increased steeply.

CONCLUSIONS

Our findings suggest that in Japanese, the decreasing trends in the incidence of ischemic stroke have recently slowed down, and there has been no clear change in the incidence of acute myocardial infarction, probably because the benefits of hypertension control and smoking cessation have been negated by increasing metabolic risk factors.

Temporal trends in sudden unexpected death in a general population: the Hisayama study

BACKGROUND

Studies addressing the temporal trends in the prevalence of sudden unexpected death (SUD) and its underlying causes in the general population are limited.

METHODS

Among a total of 1934 residents aged ≥20 years of the town of Hisayama, Japan, who died of endogenous causes of death and underwent autopsy examination (autopsy rate 78.5%) from 1962 to 2009, 204 were determined to be cases of SUD within 24 hours.

RESULTS

The trend in the age- and sex-adjusted prevalence of SUD among all autopsy subjects was stable over four 12-year periods (13.1% in 1962-1973, 13.4% in 1974-1985, 15.0% in 1986-1997, and 14.6% in 1998-2009; P for trend = .80). Regarding causes of death, the prevalence of SUD from stroke significantly declined with time (8.0%, 5.0%, 2.3%, and 2.1%, respectively; P for trend < .001), whereas significant increments were observed in the prevalence of SUD from heart disease (4.0%, 6.2%, 8.6%, and 9.7%; P for trend = .02) and from aortic aneurysm and dissection (0.2%, 1.2%, 2.9%, and 2.8%; P for trend = .01). In particular, the prevalence of ischemic heart disease increased 3-fold from 2.1% in 1962-1973 to 6.6% in 1998-2009 (P = .04). Reflecting the increment of ischemic heart disease, SUD within 1 hour increased significantly from 2.5% to 7.6% during this period (P = .01).

CONCLUSIONS

The trend in the prevalence of SUD was stable across a half century in a general Japanese population. Despite the decrement in the prevalence of SUD from stroke, that from heart disease, especially ischemic heart disease, increased significantly with time.

Statistical Survey of Deaths from Nonmelanoma Skin Cancer in Japan during 54 Years

The author analyzed the annual trends in the number of deaths from nonmelanoma skin cancer (NMSC) from 1955 to 2008 in Japan on the basis of the data from the Vital Statistics of Japan. The general trends in the number of deaths from NMSC were downward between 1979 to 1994, but upward after 1995. The general trends in age-standardized death rates were roughly downward, although the death rates plateaued after 1995. The recent annual increased ratio of deaths from NMSC was 3.8% (95% confidence interval: 2.7 ∼ 4.9%). The number and proportion of deaths from NMSC among the elderly were increasing in Japan. For females, more than 50% of the deaths occurred recently at or after 85 years of age, whereas, for males, this proportion was at or after 75 years of age, nearly reaching at or after 80 years of age.

Hyperglycemia increases risk of gastric cancer posed by Helicobacter pylori infection: a population-based cohort study

BACKGROUND & AIMS

Although diabetes mellitus and hyperglycemia are considered to be possible risk factors for various types of malignancy, the epidemiologic evidence concerning gastric cancer is scarce. The aim of this study was to evaluate the impact of hemoglobin A1c (HbA1c) levels on gastric cancer occurrence and their interaction with Helicobacter pylori infection.

METHODS

A total of 2603 Japanese subjects aged>or=40 years were stratified into 4 groups according to baseline HbA1c levels (<or=4.9%, 5.0%-5.9%, 6.0%-6.9%, and >or=7.0%) and followed up prospectively for 14 years.

RESULTS

During the follow-up, 97 subjects developed gastric cancer. The age- and sex-adjusted incidence of gastric cancer significantly increased in the 6.0%-6.9% (5.1 per 1000 person-years; P<.05) and >or=7.0% groups (5.5 per 1000 person-years; P<.05) compared with the 5.0%-5.9% group (2.5 per 1000 person-years), whereas it was slightly but not significantly high in the <or=4.9% group (3.6 per 1000 person-years). This association remained substantially unchanged even after adjusting for the confounding factors including Helicobacter pylori seropositivity, (multivariate-adjusted hazard ratio [HR], 2.13; 95% confidence interval [CI]: 1.30-3.47 for the 6.0%-6.9% group and HR, 2.69; 95% CI: 1.24-5.85 for the >or=7.0% group). Among subjects who had both high HbA1c levels (>or=6.0%) and Helicobacter pylori infection, the risk of gastric cancer was dramatically elevated (interaction term, P=.004).

CONCLUSIONS

Our findings suggest that casual hyperglycemia is a risk factor for gastric cancer and is a possible cofactor increasing the risk posed by Helicobacter pylori infection.

Post-challenge blood glucose concentration and stroke mortality rates in non-diabetic men in London: 38-year follow-up of the original Whitehall prospective cohort study

AIMS/HYPOTHESIS

While individuals with diabetes have a raised risk of stroke, it is unclear whether hyperglycaemia in non-diabetic populations is related to the development of this disease.

METHODS

In this prospective cohort study of 19,019 men, capillary blood was drawn 2 h after consumption of a glucose preparation equivalent to 50 g of anhydrous dextrose. Study participants were then followed for mortality for a maximum of 38 years.

RESULTS

During follow-up of 18,406 non-diabetic men, 13,116 deaths occurred (1,189 by stroke). Plots of stroke mortality rates versus blood glucose identified an upward inflection in risk of death from stroke at about 4.6 mmol/l. This upward inflection in risk could be adequately described using a single linear term above this threshold. A 1 mmol/l increase in blood glucose after this point was associated with a 27% increase in risk of death from stroke (hazard ratio 1.27, 95% CI 1.14-1.42). This increase in risk was partially attenuated by adjustment for covariates (1.17, 1.04-1.31) but remained statistically significant at conventional levels. Similar observations were made when all-cause mortality was the outcome of interest, although the magnitude of the association with blood glucose was somewhat lower.

CONCLUSIONS/INTERPRETATION

An incremental elevation in stroke mortality rates occurs with increasing post-challenge blood glucose.

Cigarette smoking, systolic blood pressure, and cardiovascular diseases in the Asia-Pacific region

BACKGROUND AND PURPOSE

Smoking and increased levels of blood pressure (BP) substantially increase the risk of cardiovascular diseases (CVD). If these 2 risk factors have a synergistic impact on cardiovascular events, lowering BP and quitting smoking will contribute more to reducing CVD than would be expected from ignoring their interaction.

METHODS

Individual participant data were combined from 41 cohorts, involving 563 144 participants (82% Asian). During a median of 6.8 years follow-up, 4344 coronary heart disease (CHD) and 5906 stroke events were recorded. Repeat measures of systolic blood pressure (SBP) were used to adjust for regression dilution bias. Hazard ratios (HRs) and 95% confidence intervals (CIs) for SBP by cigarette smoking status were estimated from Cox proportional hazard models adjusted for age and stratified by study and sex.

RESULTS

Data suggested a log-linear relationship between SBP and all subtypes of CVD. The HRs relating SBP to both CHD and ischemic stroke were broadly similar irrespective of smoking status (P>/=0.1). For hemorrhagic stroke (intracerebral hemorrhage), the HRs (95% CIs) for an additional 10 mm Hg increment in SBP were 1.81 (1.73 to 1.90) for present smokers and 1.66 (1.59 to 1.73) for nonsmokers (P=0.003). For every subtype of cardiovascular events, similar results were found for analyses involving only fatal events.

CONCLUSIONS

Smoking exacerbated the impact of SBP on the risk of hemorrhagic stroke. Although quitting smoking and lowering BP are both crucial for prevention of CVD, combining the 2 could be expected to have extra beneficial effect on preventing hemorrhagic stroke.

Polymorphisms in pro- and anti-inflammatory cytokine genes and susceptibility to atherosclerosis: a pathological study of 1503 consecutive autopsy cases

Atherosclerosis is a chronic inflammatory disease in the intima of the arterial wall, where cytokines play a crucial role in the pathogenesis of this disease. However, the question of whether or not genetic variations in the cytokine genes could influence the development of atherosclerosis has been poorly investigated. We investigated the relationship of nine common single-nucleotide polymorphisms (SNPs) in tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta, IL-10, IL-4 and transforming growth factor (TGF)-beta1 with the atherosclerotic severity in 10 different arteries based on 1503 consecutive autopsies of elderly Japanese subjects registered in the Japanese SNPs for geriatric research (JG-SNP) study. The -1031C allele of TNF-alpha was a significant protective factor for atherogenesis in the carotid, femoral and intracranial arteries [odds ratio (OR): 0.72, 0.73 and 0.70, respectively]. The -511T of IL-1beta and the +29T of TGF-beta1 were significant risk factors for atherogenesis in the subclavian and intracranial arteries (OR: 1.35 and 1.48, respectively). In contrast, conventional risk factors for atherogenesis, such as hypertension and diabetes mellitus, conferred independent risks for almost all arteries. Functional SNPs in TNF-alpha, IL-1beta and TGF-beta1 genes play a role in atherogenesis, although their influences are less pronounced than those of conventional risk factors and appear to be limited to specific arteries in the Japanese elderly.

The relationship between serum total cholesterol and all-cause or cause-specific mortality in a 17.3-year study of a Japanese cohort

No study has shown a positive relationship between hypercholesterolemia and all-cause mortality in the Japanese population. Therefore, a cohort study of 17.3 years' duration was conducted on 9216 participants aged 30 years or older, selected randomly from throughout Japan. In both the lowest (<4.14mmol/L, 160mg/dl) and highest (>or=6.71mmol/L, 260mg/dl) total cholesterol (TC) groups, there was a positive association between TC and risk of all-cause mortality (hazard ratio (HR) 1.19; 95% confidence interval (CI), 1.03-1.37 and 1.36 (95% CI, 1.05-1.77), respectively). The lowest TC group had an increased risk of liver disease (HR 3.03; 95% CI, 1.70-5.43), whereas the highest TC group had an increased risk of coronary heart disease (HR 3.81; 95% CI, 1.70-5.43). After exclusion of deaths due to liver disease during the entire follow-up period and all-cause deaths within the first 5 years of follow-up, the increased HR in the lowest TC group disappeared (HR 1.05; 95% CI, 0.89-1.24). Although the cut-off point seemed to be higher than that for Western populations, hypercholesterolemia was shown to be positively associated with all-cause mortality in Japan.

Combined cardiovascular risk factors and outcome: NIPPON DATA80, 1980-1994

BACKGROUND

To examine the prognostic significance of the high-risk group with combined cardiovascular risk factors in the Japanese, we analyzed the relationship between the high-risk group with combined risks and coronary heart disease (CHD) and stroke mortality using the NIPPON DATA80 database.

METHODS AND RESULTS

At baseline in 1980, those of age>or=30 years were randomly selected and 4,144 men and 5,318 women without CHD and/or stroke at baseline were followed for 14 years. The cutoff values for risk components obtained heuristically by Cox analysis were hypertension (systolic>or=130, or diastolic>or=85 mmHg, or on antihypertensive drugs), hypercholesterolemia (total cholesterol>or=200 mg/dl), hyperglycemia (>or=130 mg/dl, or self-reported diabetes) and obesity (body mass index>or=27 kg/m2). Subjects were divided into 3 groups (0, 1-2 and 3-4 risks). Compared with those men in the risk 0 group, the hazard ratios in men in the risk 3-4 for CHD mortality was 8.04 (95% confidence interval: 1.03-62.6), and the stroke mortality was 5.06 (1.53-16.7). In women, no statistically significant difference was found due to a lesser number of events.

CONCLUSION

The high-risk group with combined risk factors is important risk for Japanese men.

Stroke incidence and prevalence in Europe: a review of available data

Reliable data on stroke incidence and prevalence are essential for calculating the burden of stroke and the planning of prevention and treatment of stroke patients. In the current study we have reviewed the published data from EU countries, Iceland, Norway, and Switzerland, and provide WHO estimates for stroke incidence and prevalence in these countries. Studies on stroke epidemiology published in peer-reviewed journals during the past 10 years were identified using Medline/PubMed searches, and reviewed using the structure of WHO's stroke component of the WHO InfoBase. WHO estimates for stroke incidence and prevalence for each country were calculated from routine mortality statistics. Rates from studies that met the 'ideal' criteria were compared with WHO's estimates. Forty-four incidence studies and 12 prevalence studies were identified. There were several methodological differences that hampered comparisons of data. WHO stroke estimates were in good agreement with results from 'ideal' stroke population studies. According to the WHO estimates the number of stroke events in these selected countries is likely to increase from 1.1 million per year in 2000 to more than 1.5 million per year in 2025 solely because of the demographic changes. Until better and more stroke studies are available, the WHO stroke estimates may provide the best data for understanding the stroke burden in countries where no stroke data currently exists. A standardized protocol for stroke surveillance is recommended.

Association between fish consumption and all-cause and cause-specific mortality in Japan: NIPPON DATA80, 1980-99

PURPOSE

Although high consumption of fish may be one of the contributing factors for Japanese longevity, no epidemiological study using Japanese data has tested this hypothesis.

SUBJECTS AND METHODS

The relationship between fish consumption and all-cause as well as cause-specific mortality was analyzed using the database of NIPPON DATA80. At baseline in 1980, history, physical, and blood biochemical measurement and a nutritional survey by the food-frequency method were performed in randomly selected community-based subjects aged 30 years and over in Japan. After exclusion of subjects with significant comorbidities at baseline, we followed 3945 men and 4934 women for 19 years. Men and women were analyzed comprehensively. Age- and sex-adjusted and multivariate adjusted relative risk for all-cause or cause-specific mortality was calculated using a Cox proportional hazards model with delayed entry.

RESULTS

During 19 years of followup, there were 1745 deaths. Subjects were divided into 5 groups according to fish consumption frequency. The multivariate Cox analyses showed that relative risks for subjects who ate fish more than twice daily compared with those of subjects who ate 1 to 2 times weekly were 0.99 (95% confidence intervals: 0.77-1.27) for all-cause, 1.26 (0.70-2.29) for stroke, 0.92 (0.20-4.23) for cerebral hemorrhage, 1.09 (0.48-2.43) for cerebral infarction, and 0.91 (0.35-2.35) for coronary heart disease mortality.

CONCLUSION

Our results did not provide evidence in support of the fish hypothesis, perhaps because the majority of the Japanese subjects in the study ate fish more than the threshold level shown to be beneficial in the previous studies.

Contributions of mortality changes by age group and selected causes of death to the increase in Japanese life expectancy at birth from 1950 to 2000

The purpose of this study is to analyze contributions of mortality change by age group and selected causes of death to the increase in life expectancy at birth from 1950 to 2000 in Japan, which has the longest longevity in the world. Using mortality data from Japanese vital statistics from 1950 to 2000, we analyzed contributions of mortality change by age group and selected causes of death to the increase in life expectancy at birth by the method of decomposition of changes and calculated age-adjusted death rates for selected causes of death. Gastroenteritis, tuberculosis and pneumonia largely contributed to an increase in life expectancy in childhood and in the young in the 1950s and 1960s. The largest contributing disease changed from tuberculosis and pneumonia in earlier decades to cerebrovascular diseases in the 1970s. The largest contributing age group also shifted to older age groups. Age-adjusted death rate for cerebrovascular diseases in 2000 was one fifth of the 1965 level. Cerebrovascular diseases contributed to an increase in life expectancy at birth of 2.9 years in males and 3.1 years in females from 1970 to 2000. In the 1990s, the largest contributing age group, both among males and among females, was the 75-84 age group. Of the selected causes of death, heart diseases other than ischemic heart disease became the largest contributor to the increase in life expectancy at birth. Unlike cerebrovascular diseases, cancer and ischemic heart disease contributed little to change in life expectancy at birth over the past 50 years. In conclusion, although mortality from ischemic heart disease has not increased since 1970 and remained low compared with levels in western countries, mortality from cerebrovascular diseases has dramatically decreased since the mid-1960s in Japan. This gave Japan the longest life expectancy at birth in the world. It is necessary to study future trends in life expectancy at birth in Japan.

Egg consumption, serum cholesterol, and cause-specific and all-cause mortality: the National Integrated Project for Prospective Observation of Non-communicable Disease and Its Trends in the Aged, 1980 (NIPPON DATA80)

BACKGROUND

Because egg yolk has a high cholesterol concentration, limited egg consumption is often suggested to help prevent ischemic heart disease (IHD).

OBJECTIVE

We epidemiologically examined the validity of this recommendation.

DESIGN

We analyzed the relations of egg consumption to serum cholesterol and cause-specific and all-cause mortality by using the NIPPON DATA80 (National Integrated Project for Prospective Observation of Non-communicable Disease And its Trends in the Aged, 1980) database. At the baseline examination in 1980, a nutritional survey was performed by using the food-frequency method in Japanese subjects aged > or =30 y. We followed 5186 women and 4077 men for 14 y.

RESULTS

The subjects were categorized into 5 egg consumption groups on the basis of their responses to a questionnaire (> or =2/d, 1/d, 1/2 d, 1-2/wk, and seldom). There were 69, 1396, 1667, 1742, and 315 women in each of the 5 groups, respectively. Age-adjusted total cholesterol (5.21, 5.04, 4.95, 4.91, and 4.92 mmol/L in the 5 egg consumption categories, respectively) was related to egg consumption (P < 0.0001, analysis of covariance). In women, unadjusted IHD mortality and all-cause mortality differed significantly between the groups [IHD mortality: 1.1, 0.5, 0.4, 0.5, and 2.0 per 1000 person-years, respectively (P = 0.008, chi-square test); all-cause mortality: 14.8, 8.0, 7.5, 7.5, and 14.5 per 1000 person-years, respectively (P < 0.0001, chi-square test)]. In men, egg consumption was not related to age-adjusted total cholesterol. Cox analysis found that, in women, all-cause mortality in the 1-2-eggs/wk group was significantly lower than that in the 1-egg/d group, whereas no such relations were noted in men.

CONCLUSION

Limiting egg consumption may have some health benefits, at least in women in geographic areas where egg consumption makes a relatively large contribution to total dietary cholesterol intake.

An update of cancer mortality among the French cohort of uranium miners: extended follow-up and new source of data for causes of death

The follow-up of the French cohort of uranium miners has been extended to 1994, and a new source of information for causes of death has been used. The paper presents the new results regarding the risk of death among the cohort, and analyses the impact of the methodological changes on these results. The extension of the follow-up results in a substantial increase in statistical power compared with previous analysis (+25% for person-years and +74% for the number of deaths). The use of the National Mortality Database as the principal source for causes of death allows to reduce the potential bias in the calculation of standardized mortality ratios (SMR). As a consequence, an excess risk of deaths from laryngeal cancer, suggested in the first analysis, is not confirmed. The analysis shows the existence of an excess risk of deaths from lung cancer among French uranium miners (85 observed deaths, SMR = 1.9, 95% confidence interval CI: 1.5-2.3), and an increase of this risk with cumulative exposure to radon (excess relative risk per 100 working level month = 0.6, 95% CI: 0.1-1.2). These results confirm the existence of a risk of death from lung cancer in a population chronically exposed to relatively low levels of radon.

Resting heart rate and cause-specific death in a 16.5-year cohort study of the Japanese general population

BACKGROUND

Several prospective studies have reported resting heart rate (HR) to be a risk factor for certain cause-specific death, together with sex- or age-specific differences in the effects of HR on death. However, there have been few prospective data from non-Western populations.

METHODS

Cohort study, over 16.5 years to date of death or end of follow-up (November 15, 1998) involving 8800 men and women > or =30 years of age randomly selected throughout Japan, who participated in the National Survey on Circulatory Disorders in 1980. Resting HR was determined from 3 consecutive intervals between R waves on the 12-lead electrocardiogram.

RESULTS

For middle-aged men (30 to 59 years of age), in the highest quartile of HR, there was a significant positive association with cardiovascular (RR, 2.55; 95% CI, 1.22 to 5.31) and all-cause death (RR, 1.45; 95% CI, 1.06 to 2.00). For middle-aged women, in the highest quartile, there was a significant positive association with noncancer, noncardiovascular (RR, 2.41; 95% CI, 1.04 to 5.59), and all-cause death (RR, 1.94; 95% CI, 1.26 to 3.01). Resting HR also showed a significant positive association with cardiac events but not to stroke. These relations were not evident for elderly subjects (> or =60 years of age). Results were not affected when deaths within the first 5 years of follow-up were excluded, except for noncancer, noncardiovascular death.

CONCLUSIONS

High resting HR is an independent predictor of long-term death in the Japanese general population.

Cigarette smoking as a risk factor for stroke death in Japan: NIPPON DATA80

BACKGROUND AND PURPOSE

Some previous Japanese cohort studies failed to show an association between smoking and stroke risk. Because such an association has been noted in other populations, this issue should be re-examined in a recent representative Japanese cohort with a higher total cholesterol level.

METHODS

A total of 9638 men and women aged 30 years and older without a history of cardiovascular disease (CVD) at baseline in 1980 were followed-up for 14 years.

RESULTS

We observed 203 stroke deaths (107 cerebral infarctions, 45 cerebral hemorrhages, and 51 others), 191 heart disease deaths, and 413 CVD deaths. The average serum total cholesterol level was approximately 4.91 mmol/L. Cox proportional hazard ratios were calculated adjusting for age, systolic blood pressure, and other conventional risk factors. The hazard ratios for men who smoked 1 to 20 cigarettes/day for all strokes, cerebral infarction, and cerebral hemorrhage were 1.60 (95% CI, 0.91 to 2.79), 2.97 (CI, 1.27 to 6.98), and 0.42 (CI, 0.16 to 1.09), respectively, and for those who smoked > or =21 cigarettes/day, they were 2.17 (CI, 1.09 to 4.30), 3.26 (CI, 1.11 to 9.56), and 0.68 (CI, 0.20 to 2.33), respectively. For women who smoked > or =21 cigarettes/day, the hazard ratio for all strokes was 3.91 (CI, 1.18 to 12.90). For CVD, all heart disease, and ischemic heart disease, the hazard risks of smoking were significant (1.49 to 4.25) for men but not significant for women.

CONCLUSIONS

Smoking in a cohort with moderate serum total cholesterol level was a potent risk factor for stroke, especially cerebral infarction, for both men and women, and for CVD and ischemic heart disease for men.

Incidence and prognosis of gastric cancer in a population-based cohort survey: the Hisayama study

BACKGROUND

No population-based cohort studies have been undertaken to evaluate the incidence and prognosis of gastric cancer. The purpose of this investigation was to clarify the incidence and fatal prognosis of gastric cancer and to determine the factors that contribute to the prognosis in a general Japanese population in Hisayama using a prospective study design.

METHODS

From 1988 to 1998 a total of 2605 subjects aged 40 years or older with no history of gastrectomy or gastric cancer were followed-up prospectively after a health examination. The diagnosis of gastric cancer was based on clinical records or autopsy findings.

RESULTS

During the follow-up period, 76 subjects developed gastric cancer. The age-adjusted incidence of gastric cancer for men (4.9 per 1000 person-years) was 4-fold higher than that for women (1.2, P < 0.05). In men, the incidence of gastric cancer increased with advancing age, but this trend was not observed in women. The age- and sex-adjusted 5-year survival rate was significantly higher in cancers of the middle third of the stomach than in those of the upper third of the stomach. The survival rate was higher in cancers of well-differentiated adenocarcinoma than in those of the other histological types. There were no cases of cancer-related death among the early gastric cancers during the follow-up period.

CONCLUSIONS

Our data suggest that men are at higher risk of gastric cancer than women in the general Japanese population. Clinical stage, histological type, and site of cancer in the stomach contribute to a fatal prognosis.

Vegetable and Fruit Intake and Stroke Mortality in the Hiroshima/Nagasaki Life Span Study

BACKGROUND AND PURPOSE

Fruits and vegetables are known for their beneficial effects on chronic diseases. The purpose of the present study was to investigate the protective effect of a diet rich in fruits and vegetables on total stroke mortality and its 2 main subtypes in men and women separately.

METHODS

A prospective cohort study of 40 349 Japanese men and women was initiated in 1980-1981 and followed until 1998. Fruit and vegetable intake was assessed at baseline on the basis of the response to a food frequency questionnaire. During the 18-year follow-up period, deaths from stroke were registered.

RESULTS

A total of 1926 stroke deaths were identified during the follow-up period. An increasing frequency of intake of green-yellow vegetables and fruit was associated with a reduced risk of death from intracerebral hemorrhage and cerebral infarction. Daily intake of green-yellow vegetables was associated with a significant 26% reduction in the risk of death from total stroke in men and women compared with an intake of once or less per week. The protective effect associated with daily fruit and vegetable intake was observed for both cerebral infarction and intracerebral hemorrhage mortality but was slightly stronger and clearer for infarction than for hemorrhage, with a 32% reduction in men and a 30% reduction in women. Daily fruit intake was associated with a significant 35% reduction in risk of total stroke in men and a 25% reduction in women and was equally strong for both intracerebral hemorrhage and cerebral infarction.

CONCLUSIONS

Daily consumption of green-yellow vegetables and fruits is associated with a lower risk of total stroke, intracerebral hemorrhage, and cerebral infarction mortality. The protective effects are similar in both men and women.

Trends in the incidence, mortality, and survival rate of cardiovascular disease in a Japanese community: the Hisayama study

BACKGROUND AND PURPOSE

The slowdown of a steeply declining trend in cardiovascular mortality has been reported in Japan, but precise reasons for this trend are uncertain.

METHODS

We established 3 study cohorts of Hisayama residents aged > or =40 years without a history of stroke or myocardial infarction in 1961 (1618 subjects, first cohort), 1974 (2038 subjects, second cohort), and 1988 (2637 subjects, third cohort). We followed up with each cohort for 12 years, comparing the incidence, mortality, and survival rate of cardiovascular disease.

RESULTS

The age-adjusted incidence of cerebral infarction significantly declined by 37% for men and by 32% for women from the first to the second cohort. It continued to decline by 29% for men, but the decline decelerated for women in the third cohort. The incidence of cerebral hemorrhage steeply declined by 61% from the first to the second cohort in men only, while it was sustained for both sexes in the third cohort. Stroke mortality continuously declined as a result of these incidence changes and significant improvement of survival. In contrast, the incidence and mortality rate of coronary heart disease were unchanged except for the increasing incidence in the elderly. The prevalence of severe hypertension and current smoking significantly decreased, while that of glucose intolerance, hypercholesterolemia, and obesity greatly increased among the cohorts.

CONCLUSIONS

Our data suggest that the decline in stroke incidence is slowing down and that the incidence of coronary heart disease has been increasing in the elderly in recent years. Insufficient control of hypertension and the increase in metabolic disorders may contribute to these trends.

Trends in fatal coronary heart disease among people aged 25-74 years in Oita City, Japan, from 1987-1998

Serum cholesterol has been increasing in recent years in Japan. There is concern that risk of coronary heart disease (CHD) may be increasing too, but there is little information on validated fatal CHD trends in the Japanese population. We identified 1,056 deaths from heart disease and other deaths possibly hiding CHD from death certificates of residents aged 25-74 years in Oita City, Japan in 1987-1988, 1992-1993, and 1997-1998 (mean population, 273,000 in 1997-1998). We validated 994 of them by medical record review and physician interviews, classifying them into definite fatal acute myocardial infarction (AMI) and possible fatal AMI or CHD death based on Monitoring Trends and Determinants in Cardiovascular Disease project's criteria. Sudden death was defined to estimate the number of CHD sudden deaths. In men, age-adjusted mortality rates due to validated fatal CHD remained quite stable over 10 years (25.3 per 100,000 [95% CI, 15.0-35.5] in 1987-1988 to 24.2 per 100,000 [95% CI, 16.1-32.3] in 1997-1998). When 50% or all sudden deaths were included as fatal CHD, the rates for men tended to decline. This was due to decreasing out-of-hospital deaths in connection with a declining CHD death rate among men aged 65-74 years, whereas in-hospital CHD deaths were level. In women, the rate of validated fatal CHD was highest in 1992-1993, but the 1997-1998 rate was similar to the 1987-1988 rate. We did not find that fatal CHD rates increased in Oita men and women from 1987-1998. Rather, out-of-hospital fatal CHD tended to decline in Oita men.

[Prevalence and pattern of distribution of cerebrovascular diseases in 242 hospitalized elderly patients, in a general hospital, autopsied in Belo Horizonte, Minas Gerais, Brazil, from 1976 to 1997]

OBJECTIVE

To describe the prevalence and the types of cerebrovascular diseases (CVDs) in autopsied elderly individuals.

METHOD

Consecutive clinical charts and neuropathological reports of 242 patients aged 61 years or older were reviewed. The patients died in Hospital das Clínicas, Federal University of Minas Gerais, in Belo Horizonte, Minas Gerais, Brazil, from 1976 to 1997.

RESULTS

The prevalent diseases of the central nervous system (CNS) found in decreasing order were: CVDs (71.9%), infections (12.4%), neoplasms (7.1%), head trauma (3.7%), nutritional diseases (2.5%) and degenerative diseases (1.7%). The most common CVDs were cerebral atherosclerosis (61.2%), hypertensive cerebrovascular disease (25.6%) and cerebral infarct (14.9%). There was an increase in prevalence and severity of atherosclerosis and an increase in prevalence of hypertensive cerebrovascular disease with advancing age. A significant association between hypertensive cerebrovascular disease and atherosclerosis was found. The CVDs patients had clinical stroke and this was the direct cause of death in 42,7% and 17,3% of the cases, respectively.

CONCLUSION

The CVDs were the most prevalent group of diseases of the CNS in elderly patients. Atherosclerosis and hypertensive cerebrovascular disease were the most common CVDs, and its prevalence increased with advancing age. Hypertensive cerebrovascular disease was significantly associated with atherosclerosis.

A Utstein-style analysis of prognostic factors related to survival in out-of-hospital cardiac arrests in Akita-City, Japan

To analyze the epidemiology of out-of-hospital cardiac arrests and to elucidate modifiable factors affecting survival, we conducted a prospective cohort study in a middle-sized urban city served by a single emergency medical service (EMS) system in which emergency medical technicians use an automated external defibrillator. Data were collected from out-of-hospital cardiac arrests occurring between 1 January, 1994 and 31 December, 1998 by applying the Utstein style. The main outcome measure was survival at 1 year after hospital discharge. The overall incidence of out-of-hospital cardiac arrest was 71.7/100 000 inhabitants/year. Resuscitations were attempted in 762 of 1118 patients with confirmed cardiac arrest. Of the 762 patients, 37 (4.86%) survived. The cause of cardiac arrest was presumed to be cardiac in 340 (44.6%). Of the 340 cardiac arrests, 180 (52.9%) were witnessed by bystanders. Ventricular fibrillation (VF) was recorded as an initial rhythm in 56 (31.1%) of the 180 patients, and cardiopulmonary resuscitation (CPR) was performed by bystanders in 89 (49.4%). The survival rate was 39.2% (22/56) when cardiac arrest was bystander-witnessed and of cardiac origin with VF as an initial rhythm. VF as an initial rhythm, age of the patients and intervals of call-to-first CPR attempt and collapse-to-arrival at patient's side were major factors relating to survival in the witnessed cardiac arrests of cardiac origin. The age, and gender of the patients, place of collapse and intervals of collapse-to-first CPR and collapse-to-arrival at patient's side were representative factors affecting the incidence of VF as an initial rhythm. The survival rate in Akita-City from bystander-witnessed cardiac arrests of cardiac origin with VF as an initial rhythm was comparable to those in other regions with advanced EMS systems. However, the incidence of VF as an initial rhythm is extremely low. Reduction of intervals of call (collapse)-to-first CPR attempt and collapse-to-arrival at patient's side or authorization of use of automated external defibrillator in basic life support may increase the incidence of VF as an initial rhythm and improve the survival from witnessed cardiac arrests with cardiac origin.

Are coroners' necropsies necessary? A prospective study examining whether a "view and grant" system of death certification could be introduced into England and Wales

AIMS

To determine whether the cause of death could be accurately predicted without the need for a necropsy, and thus to consider whether a "view and grant" system of issuing a cause of death could be introduced into England and Wales.

METHOD

A one year prospective necropsy study was performed incorporating 568 deaths. Before necropsy, in each case the cause of death was predicted from the available history without examination of the body, and this cause was then compared with the cause of death found at necropsy.

RESULTS

The ability of the pathologist involved in the study to predict a cause of death before necropsy, either while in the mortuary or as a paper exercise, was shown to vary between 61% and 74% of cases. After the necropsy, the number of correct predicted causes of death ranged from 39% to 46%. Ischaemic heart disease was found to be the most common and most accurately predicted cause of death. Some natural diseases were frequently misdiagnosed, whereas certain types of unnatural disease were always identified correctly.

CONCLUSIONS

This study highlights the advantages and disadvantages of a view and grant system. Although it identifies a potential use of such a system, in some cases such as natural cardiac disease, because of the potentially high diagnostic error rate, the continuation of the present system of postmortem examination as part of the coroner's enquiry is recommended.