Child mortality and cohort lifespan: a test of diminished entelechy

BACKGROUND: The literature implies a 'diminished entelechy' hypothesis in which birth cohorts subjected to relatively many or relatively virulent environmental insults early in life do not realize their otherwise expected lifespan. No direct test of this hypothesis appears in literature. METHODS: We test the hypothesis directly by measuring the association between mortality in the first 5 years and life expectancy at age 5 for male and female cohorts born in Sweden (1751-1912), Denmark (1835-1913), and England and Wales (1841-1912). The methods control for trends, seasonal cycles, and other forms of autocorrelation that could induce spurious associations. RESULTS: Our results support the hypothesis in that life expectancy at age 5 fell below the values expected from history in cohorts in which child mortality before age 5 increased over its expected value. We find no evidence for culling effects in which a cohort remaining after suffering relatively many environmental insults may be smaller but hardier than expected. CONCLUSIONS: These findings converge with individual-level studies and suggest that suffering relatively virulent or many environmental insults during childhood reduces the subsequent lifespan of birth cohorts.     

Association between gross domestic product throughout the life course and old-age mortality across birth cohorts: parallel analyses of seven European countries, 1950-1999

Mortality levels of national populations have often been studied in relation to levels of gross domestic product (GDP) at time of death. Following the life course perspective, we assessed whether old-age mortality levels for subsequent cohorts are differentially associated with GDP levels prevailing at different ages of the cohorts. We used all-cause and cause-specific mortality data by sex, age at death (65-99), year at death (1950-1999), and year of birth (1865-1924) for Denmark, England and Wales, Finland, France, the Netherlands, Norway, and Sweden. Trends in national GDP per capita between 1865 and 1999 were reconstructed from historical national accounts data. Through Poisson regression analyses, we determined for each country both univariate and multivariate associations across five-year birth cohorts between mortality and GDP levels prevailing at time of death, and at earlier ages of the cohorts (i.e. 0-5, 6-19, 20-49, and 50-64). For the subsequent cohorts, levels of GDP at time of death were strongly inversely associated with all-cause mortality, especially among women, and among men in England and Wales, Finland, and France. In most countries, stronger associations were observed with GDP levels prevailing at earlier ages of the cohorts. After control for GDP at time of death, these associations remained. An independent association of GDP at earlier ages of the cohort was also observed for cause-specific mortality. The associations were negative for ischaemic heart diseases, cerebrovascular diseases, and stomach cancer. They were positive for prostate cancer, breast cancer, COPD (women), and lung cancer (women). GDP prevailing at ages 20-49 (men) and ages 50-64 (women) had the largest associations with old-age mortality. These findings suggest an independent, mostly negative effect of GDP prevailing at earlier ages of subsequent cohorts on old-age mortality. Socio-economic circumstances during adulthood and middle age seem more important in determining old-age mortality trends than those during infancy or childhood.     

Variations in the pace of mortality decline in elderly in 7 Northwestern European countries between 1950-1999: the impact of smoking

OBJECTIVE: Examination of the variations in the pace of old-age (80+) mortality decline in 7 Northwestern European countries for the period 1950-1999, and the impact of smoking DESIGN: Retrospective. METHOD: The population mortality data of 7 Northwestern European countries were collated according to year of death for a 50 year period (1950-1999), single year of age (60+ and 80+) and sex. Both all-cause and non-smoking-related mortality were analysed. In addition, a comparison was made with the pace of mortality decline at younger age among the same cohorts. Regression and correlation analyses were used. RESULTS: Marked variations in the pace of old-age mortality decline were found between countries, periods and sexes. While mortality declines were constantly strong in France and England and Wales, modest declines or even increases in mortality rate were observed in the 1950s in the Nordic countries, and since the 1980s in Denmark, The Netherlands, and (for men only) Norway. For non-smoking-related mortality, a high and consistent pace ofmortality decline was observed. The declines showed a clear cohort pattern, with the smallest declines or even increases for men born between 1890 and 1899, compared to an increased pace of mortality decline among women born between 1847 and 1937. Among men, but not women, the pace of old-age mortality decline correlated with the pace of mortality decline at ages 60-69 among the same cohorts. CONCLUSIONS: Variations in the pace of old-age mortality decline are strongly influenced by smoking and probably also by other factors originating earlier in life. For future decades, substantial further declines in old-age mortality may be expected, even though rates of change in specific countries and periods would be difficult to predict.     

Infant and fetal mortality among a high fertility and mortality population in the Bolivian Amazon

Indigenous populations experience higher rates of poverty, disease and mortality than non-indigenous populations. To gauge current and future risks among Tsimane Amerindians of Bolivia, I assess mortality rates and growth early in life, and changes in risks due to modernization, based on demographic interviews conducted Sept. 2002–July 2005. Tsimane have high fertility (total fertility rate = 9) and infant mortality (13%). Infections are the leading cause of infant death (55%). Infant mortality is greatest among women who are young, monolingual, space births close together, and live far from town. Infant mortality declined during the period 1990–2002, and a higher rate of reported miscarriages occurred during the 1950–1989 period. Infant deaths are more frequent among those born in the wet season. Infant stunting, underweight and wasting are common (34%, 15% and 12%, respectively) and greatest for low-weight mothers and high parity infants. Regression analysis of infant growth shows minimal regional differences in anthropometrics but greater stunting and underweight during the first two years of life. Males are more likely to be underweight, wasted, and spontaneously aborted. Whereas morbidity and stunting are prevalent in infancy, greater food availability later in life has not yet resulted in chronic diseases (e.g. hypertension, atherosclerosis and diabetes) in adulthood due to the relatively traditional Tsimane lifestyle.     

Cohort patterns in mortality trends among the elderly in seven European countries, 1950-99

BACKGROUND: Secular trends in old-age mortality are of crucial importance to population ageing. For the understanding and prediction of these trends, it is important to determine whether birth cohort effects, i.e. long-lasting effects of exposures earlier in life, are important in determining mortality trends up to old age. This study aimed to identify and describe cohort patterns in trends in mortality among the elderly (>60 years of age) in seven European countries. METHODS: A standard age-period-cohort analysis was applied to all-cause and cause-specific mortality data by 5-year age groups and sex, for Denmark, England and Wales, Finland, France, The Netherlands, Norway, and Sweden, in the period 1950-99. RESULTS: Cohort patterns were identified in all countries, for both the sexes and virtually all causes of death. They strongly influenced the trends in all-cause mortality among Danish, Dutch, and Norwegian men, and the trends in mortality from infectious diseases, lung cancer (men only), prostate cancer, breast cancer, and chronic obstructive pulmonary disease (COPD). All-cause mortality decline stagnated among Danish, Dutch, and Norwegian male birth cohorts born between 1890 and 1915, among French men born after 1920, and among women from all countries born after 1920. Where all-cause mortality decline stagnated, cohort patterns in mortality from lung cancer, COPD, and to a lesser extent ischaemic heart diseases, were unfavourable as well. For infectious diseases, stomach cancer, and cerebrovascular diseases, mortality increased among cohorts born before 1890, and decreased strongly thereafter. CONCLUSIONS: Cohort effects related to factors such as living conditions in childhood and smoking in adulthood were important in determining the recent trends in mortality among the elderly in seven European countries.     

Born in Bradford,a cohort study of babies born in Bradford,and their parents: Protocol for the recruitment phase

Background  

Bradford, one of the most deprived cities in the United Kingdom, has a wide range of public health problems associated with socioeconomic deprivation, including an infant mortality rate almost double that for England and Wales. Infant mortality is highest for babies of Pakistani origin, who comprise almost half the babies born in Bradford. The Born in Bradford cohort study aims to examine environmental, psychological and genetic factors that impact on health and development perinatally, during childhood and subsequent adult life, and those that influence their parents' health and wellbeing. This protocol outlines methods for the recruitment phase of the study.     

Mortality consequences of the 1959–1961 Great Leap Forward famine in China: Debilitation,selection, and mortality crossovers

Using retrospective mortality records for three cohorts of newborns (1956–1958, 1959–1961, and 1962–1964) drawn from a large Chinese national fertility survey conducted in 1988, this article examines cohort mortality differences up to age 22, with the aim of identifying debilitating and selection effects of the 1959–1961 Great Leap Forward Famine. The results showed that the mortality level of the non-famine cohort caught up to and exceeded the level of the famine cohort between ages 11 and 12, suggesting both debilitating and selection effects. Multilevel multiprocess models further established a more direct connection between frailties in infancy and frailties at subsequent ages, revealing the underlying dynamics of mortality convergence between the famine and the non-famine cohorts caused by differential excess infant mortality. These results provide important new insights into the human mortality process.     

Occult HBV infection in anti-HBs-positive young adults after neonatal HB vaccination

Previous follow-up on our neonatal HB vaccination cohorts with 80,000 individuals in Qidong, China, showed significant protective efficacy of immunization against HBV infection in childhood. However, some vaccinees were found to be HBsAg negative, but anti-HBs positive and anti-HBc positive at age 10–11 years. To study this phenomenon, 2919 vaccinees at age 19–21 years were sampled from the cohort. HBsAg(−), anti-HBs(+) and anti-HBc(+) were found in 124/2919 (4.2%) of the vaccinees. HBV DNA was detectable in 81/106 sample sera by using nested PCR. The PreS-S regions of HBV were sequenced in 41 randomly sampled sera. All the HBV isolates were HBV genotype C. Twenty one isolates (21/41, 51.2%) were identical to an HBV isolated in this area (GU434374). Only 4/41 (9.8%) showed mutations at the “a” epitope and three of them were G145A. The other mutations were found outside of the “a” epitope. Most of the sera contained <10,000 HBV copies/ml. Occult HBV infection happened in the young adults with HBsAg(−), anti-HBs(+) and anti-HBc(+) status, who received neonatal vaccination in Qidong.     

Hepatitis B vaccination: the cost effectiveness of alternative strategies in England and Wales.

OBJECTIVE--To assess the cost effectiveness of adding universal hepatitis B vaccination in infancy or pre-adolescence to a policy of selective vaccination of at risk groups. DESIGN--Costs of a selective policy and additional costs of universal vaccination policies were estimated from costs of vaccine delivery and published data on target populations. Additional years of life gained were calculated for each policy by applying life tables to estimates of mortality attributable to hepatitis B. SETTING--England and Wales. RESULTS--Compared with no vaccination, vaccination in infancy was the most cost effective followed by vaccination in preadolescence. Selective vaccination was the least effective (cost per year of life gained 2568 pounds, 2824 pounds, and 8564 pounds respectively). Adding vaccination in infancy or at pre-adolescence to a selective policy cost 1537 pounds or 1658 pounds per year of life gained. Discounting years gained in the future at 6% per annum, however, made pre-adolescent vaccination more cost effective than infant or selective vaccination (51,817 pounds, 94,821 pounds, and 124,779 pounds per discounted year of life gained). Adding pre-adolescent vaccination to a selective policy cost 32,125 pounds per discounted year of life gained and infant vaccination, 77,085 pounds. CONCLUSIONS--Universal vaccination against hepatitis B was more cost effective than selective vaccination in a low prevalence country. Discounting future health gain, however, made universal infant vaccination lest cost effective than universal pre-adolescent vaccination. If future health gained is as important as present gain the addition of universal vaccination to a selective policy is equivalent to the cost per quality adjusted year of life from renal transplantation or breast cancer screening.     

The male–female health-survival paradox and sex differences in cohort life expectancy in Utah,Denmark, and Sweden 1850–1910

PurposeIn Utah, the prevalence of unhealthy male risk behaviors are lower than in most other male populations, whereas women experience higher mortality risk because of higher fertility rates. Therefore, we hypothesize that the Utah sex differential in mortality would be small and less than in Sweden and Denmark.MethodsLife tables from Utah, Denmark, and Sweden were used to calculate cohort life expectancies for men and women born in 1850–1910.ResultsThe sex difference in cohort life expectancy was similar or larger in Utah when compared with Denmark and Sweden. The change over time in the sex differences in cohort life expectancy was approximately 2 years smaller for active Mormons in Utah than for other groups suggesting lifestyle as an important component for the overall change seen in cohort life expectancy. Sex differences in cohort life expectancy at the age of 50 years were similar for individuals actively affiliated with the Church of Jesus Christ of Latter-day Saints and for Denmark and Sweden.ConclusionsThe hypothesis that a smaller sex difference in cohort life expectancies in Utah would be detected in relation to Denmark and Sweden was not supported. In Utah, the male–female differences in life expectancy remain substantial pointing toward biological mechanisms or other unmeasured risk factors.     

Testing a new health indicator: Using avoidable causes of death and life expectancy for Spain between 1975–1986

The concept of avoidable cause of death serves as the basis for measuring the quality and diversity of a health care system. In this study the authors propose a new way to use this kind of mortality by combining with the concept of life expectancy to obtain what they call life expectancy free of avoidable mortality (LEFAM).This indicator was 76.9 in 1986 in Spain while life expectancy was 75.83. If these deaths were avoidable there would be a gain of 1.09 years per person born. There is an important difference between the would-be male gain of 1.76 years and the would-be female gain of 0.6. In the ecological study, LEFAM would better explain the year to year changes of the resources in the health sector, measured in terms of the human resources (R = 0.96), the hospital beds per thousand persons (R = –0.86), and would also increase the relation with other health indicators such as infant mortality rate (R = –0.98) and mortality rate (R = 0.59) as compared with life expectancy alone.     

Do conditions in early life affect old-age mortality directly and indirectly? Evidence from 19th-century rural Sweden

Previous research has shown that the disease load experienced during the birth year, measured as the infant mortality rate, had a significant influence on old-age mortality in nineteenth-century rural Sweden. We know that children born in years with very high rates of infant mortality, due to outbreaks of smallpox or whooping cough, and who still survived to adulthood and married, faced a life length several years shorter than others. We do not know, however, whether this is a direct effect, caused by permanent physical damage leading to fatal outcomes later in life, or an indirect effect, via its influence on accumulation of wealth and obtained socio-economic status. The Scanian Demographic Database, with information on five rural parishes in southern Sweden between 1813 and 1894, contains the data needed to distinguish between the two mechanisms. First, the effects of conditions in childhood on obtained socio-economic status as an adult are analyzed, then the effects of both early-life conditions and socio-economic status at various stages of life on old-age mortality. By including random effects, we take into account possible dependencies in the data due to kinship and marriage. We find that a high disease load during the first year of life had a strong negative impact on a person's ability to acquire wealth, never before shown for a historical setting. This means that it is indeed possible that the effects of disease load in the first year of life indirectly affect mortality in old age through obtained socio-economic status. We find, however, no effects of obtained socio-economic status on old-age mortality. While the result is interesting per se, constituting a debatable issue, it means that the argument that early-life conditions indirectly affect old-age mortality is not supported. Instead, we find support for the conclusion that the effect of the disease load in early-life is direct or, in other words, that physiological damage from severe infections at the start of life leads to higher mortality at older ages. Taking random effects at family level into account did not alter this conclusion.     

Does exposure to infectious diseases in infancy affect old-age mortality? Evidence from a pre-industrial population

Many studies have shown that health conditions experienced in childhood play an important role on an individual's adult mortality. Recent research suggests that past reductions in early life exposure to infectious diseases have been a major contributor to the historical decline in old-age mortality. Drawing on French-Canadian data from cohorts born in the 17th and 18th centuries, we test whether a progressive deterioration in early life conditions (as revealed by an increasing infant mortality rate) translates into a decrease in survival prospects in late life. We use traditional demographic measures such as the age-specific probability of death, and a series of proportional hazard models to control for familial and environmental conditions. Results point toward little evidence of any early life effects. The trend of increasing infant mortality does not correlate with a general increase of mortality in older ages within the same cohorts. Period changes affecting survival at older ages (war, epidemics) as well as demographic and biological characteristics shared within families have a much larger role in old-age mortality than early life characteristics shared within the same cohorts.     

Pertussis in infancy and the association with respiratory and cognitive disorders at toddler age

Pertussis in unvaccinated infants can run a severe course and is often accompanied by complications. In this pilot study, we studied whether there is an association between pertussis hospitalisation in infancy and, respiratory symptoms, growth and cognitive development in early childhood. A group of 89 children aged 13-45 months and hospitalised for laboratory confirmed pertussis within the first six months of their life were compared with 172 children without a history of pertussis. Risk ratios (RR) with 95% confidence intervals (CI) of the association between health outcomes and pertussis in infancy were calculated. Weight-for-length and length-for-age z-scores were calculated to investigate growth. Van Wiechen scores were compared to study cognitive development.Children with a history of pertussis in infancy had a greater chance on “asthma symptoms” (RR 2.8 95%CI 1.1-7.0) on toddler age and were more likely to report “respiratory infections” (RR 3.3 95%CI 1.6-6.6). In addition, children with a history of pertussis in infancy had significantly lower weight-for-height in the first 40 months of life. No significant differences in cognitive development were found. We found an association between severe pertussis in infancy and respiratory symptoms on toddler age. The mechanisms that may underlie this association require further investigation.     

Young women facing multiple and intersecting stressors of modernity,gender orders and youth

This article aims to explore stressors experienced by Swedish adolescent girls and young women, specifically understood in relation to social context and gender theory. Interviews were conducted with 40 young Swedish women, aged 16–25 years, who had sought help at a youth health centre for stress problems. Using qualitative content analysis we identified three clusters of stressors: “the stressors of modernity”, “the stressors of gendered orders”, and “the stressors of youth”. The results revealed that multiple and intersecting discourse-shaped stressors and demands connected to essential life spheres contribute not only to experiences of distress but also to feelings of constraint. Gendered individualism and healthism proved to be essential in understanding the young women’s experienced stress. Failing social support from adults, gendered demands and responsibility taking were also illuminated. This calls for a broad contextualized and gender-sensitive approach to young women’s stress and health problems.     

Smoking and air pollution exposure and lung cancer mortality in Zhaoyuan County

Background

Simultaneous exposure to high levels of air pollution and high tobacco consumption at the same place is rare. The aim of the present study was to evaluate the impact of the two factors on the risk of developing lung cancer.

Methods

Data on the number of deaths due to lung cancer and on population from 1970 to 2009 were obtained from Zhaoyuan County. Data on the smoking populations were obtained at random sampling survey during the time in Zhaoyuan. Data on the components of atmospheric surveillance were obtained from the local environmental protection offices. Logarithmic linear regression and general log-linear Poisson age-period-cohort (APC) models were used to estimate age, period, cohort, gender, smoking, and air pollution effects on the risk of lung cancer mortality.

Results

The standardized mortality rates of lung cancer drastically increased from 8.43 in per 100 000 individuals in the 1970–1974 to 25.67 in per 100 000 individuals in the 2005–2009 death survey. The annual change of lung cancer mortality was 3.20%. In the log linear regression model, the age, proportion of smokers, gender, period, and air pollution are significantly associated with lung cancer mortality. The APC analysis shows that the relative risks (RRs) of gender, smoking, and air pollution are 2.29 (95% confidence interval (CI): 2.16–2.43), 3.05 (95% CI = 2.76–3.36), and 1.42 (95% CI = 1.19–1.69), respectively. Compared with the period 1970–1974, high RRs were found during 1995–2009. Compared with the birth cohort 1950–1954, the RRs increased in the birth cohorts of 1910 to the 1940. Compared the aged 35–59 and 60–84 in the1980–1984 death survey (not exposed to air pollution) with that in the 2005–2009 death survey (exposed to air pollution), The two age groups exposed to air pollution, 25 years later, had an increased mortality rates for lung cancer by 2.27 and 3.55 times for males and by 1.47 and 3.35 times for females.

Conclusion

The mortality rates of lung cancer drastically increased in the past 35 years. The trend of lung cancer mortality may be in a great extent possibly due to the effects of combined smoking and air pollution exposure.     

The cost-effectiveness of rotavirus vaccination in Armenia

The cost-effectiveness of introducing infant rotavirus vaccination in Armenia in 2012 using Rotarix(R) was evaluated using a multiple birth cohort model. The model considered the cost and health implications of hospitalisations, primary health care consultations and episodes not leading to medical care in children under five years old. Rotavirus vaccination is expected to cost the Ministry of Health $220,000 in 2012, rising to $830,000 in 2016 following termination of GAVI co-financing, then declining to $260,000 in 2025 due to vaccine price maturity. It may reduce health care costs by $34,000 in the first year, rising to $180,000 by 2019. By 2025, vaccination may be close to cost saving to the Ministry of Health if the vaccine purchase price declines as expected. Once coverage has reached high levels, vaccination may prevent 25,000 cases, 3000 primary care consultations, 1000 hospitalisations and 8 deaths per birth cohort vaccinated. The cost per disability-adjusted life year (DALY) saved is estimated to be about $650 from the perspective of the Ministry of Health, $850 including costs accrued to both the Ministry and to GAVI, $820 from a societal perspective excluding indirect costs and $44 from a societal perspective including indirect costs. Since the gross domestic product per capita of Armenia in 2008 was $3800, rotavirus vaccination is likely to be regarded as “very cost-effective” from a WHO standpoint. Vaccination may still be “very cost-effective” if less favourable assumptions are used regarding vaccine price and disease incidence, as long as DALYs are not age-weighted.     

Does reducing infant mortality depend on preventing low birthweight? An analysis of temporal trends in the Americas

Low birthweight (LBW) is highly associated with death during infancy, and countries with the highest LBW rates also have the highest infant mortality rates. We compared temporal trends in LBW with both overall and birthweight-specific infant mortality in United States, Canada, Argentina, Chile, and Uruguay over two time periods, using cohort and cross-sectional analysis of national population-based vital statistics for 1985-89 and 1995-98. Infant mortality diminished substantially (RR = 0.60-0.80 for the later vs. earlier periods) and to a similar degree in all birthweight categories in all five study countries, despite an increase in LBW in the US and Uruguay, minimal changes in Canada and Argentina, and a decrease in Chile. The strength of the (positive) association between LBW and overall infant mortality diminished over the two time periods (from r(s) = +0.80 to +0.25 and RR per SD increase in LBW rate from 2.13 [2.09, 2.17] to 1.76 [1.74, 1.79]). The proportion of infant deaths occurring among LBW infants was negatively correlated with overall infant mortality in both time periods (r(s) = -0.30 and -0.60, RR = 0.68 [0.67, 0.68] and 0.47 [0.46, 0.47]). Developed and less developed countries in the Americas have succeeded in reducing infant mortality in all birthweight groups despite inconsistent changes in LBW rates, and none has achieved this success primarily by reducing LBW. Although our results are not necessarily generalisable to the least developed countries in South Asia and sub-Saharan Africa, it is likely that all countries can substantially reduce their infant mortality rates by improving the care of infants at normal and low birthweights.     

Effect Of Maternal HIV Infection On Child Survival In Ghana

The purpose of this study was to measure the association between maternal HIV infection and infant mortality in Ghana. Using a censored synthetic cohort life table based on the birth history of 3,639 childbirths during 1999–2003 obtained from the interviews of a nationally representative sample of 5,691 women age 15–49 in 6,251 households in the 2003 Ghana Demographic and Health Survey. The survey collected demographic, socioeconomic, and health data of the respondents as well as obtained voluntary counseling test for HIV infection from all eligible women. The effects of maternal HIV status and other factors on infant mortality were estimated using multivariate survival regression analysis and the results are presented as Hazard Ratios (HR) with 95% confident interval (95% CI). Children born to HIV infected mothers were three times as likely to die during infancy as those born to uninfected mothers (HR=3.01; 95% CI: 1.64, 5.50). Controlling for other factors affecting infant mortality further sharpens this relationship (HR=3.51; 95% CI: 1.87, 6.61). Not receiving antenatal care, low birth weight, and living in households that use high pollution cooking fuels were associated with a higher risk of infant mortality. Maternal HIV status is a strong predictor of infant mortality in Ghana, independent of several other factors. The results of this study suggest that HIV/AIDS epidemic has had great impact on child well-being and child survival. This impact tends to increase as the HIV/AIDS epidemic matures and infection in adults increases.     

Comparison of cancer deaths in England and Wales and the Developed World by age and gender 1973–92, and, new malignancies in England and Wales 1971–88

Cancer deaths in England and Wales and the developed world were examined by age and gender between1973–1992. Whilst over-all mortality levels increased, this was mainly linked to extended longevity, as the rate fell substantially for people under 55 in the majority of countries, possibly as a result of improved treatment and prevention outcomes.Whilst England and Wales had above average reductions in cancer deaths, especially for children, there wereconsiderable rises in new malignancies, 1971–88, particularly amongst women under 35 years, and in certain selected sites.These over-all changes do not appear to be the result of improved diagnosis, thus, despite evidence of moreeffective therapeutic and preventative measures the incidence of new malignancies is increasing. The possible implications are briefly discussed, in the context of ‘medical audit’, which increasing uses mortatlity rates as ‘indicators of effectiveness’.