Cohort-specific trends in stroke mortality in seven European countries were related to infant mortality rates

Area-Level Infant Mortality Exposure in Early Life and Alzheimer's Disease Mortality: Examining Variation Based on Age, Sex, and Place of Birth

BACKGROUND

Growing evidence suggests that critical periods in early life may contribute to one's risk of Alzheimer's disease and related dementias (ADRD) in later life. In this paper we explore the role that exposure to infant mortality plays in later life ADRD.

OBJECTIVE

To determine if exposure to early life infant mortality is associated with later mortality from ADRD. Also, we explore how these associations differ by sex and age group, along with the role of state of birth and competing risks of death.

METHODS

We use a sample of over 400,000 individuals aged 50 and above with the NIH-AARP Diet and Health Study with mortality follow-up, allowing us to examine how early life infant mortality rates along with other risk factors play in one's individual mortality risk.

RESULTS

We show that infant mortality rates are associated with death from ADRD among those under 65 years of age, but not those over 65 at baseline interview. Moreover, when factoring in competing risks of death, the associations are relatively unchanged.

CONCLUSION

These results suggest that those exposed to worse adverse conditions during critical periods increase their likelihood of death from ADRD earlier than average, due to that exposure increasing their susceptibility to develop illness later on in life.

Birth in High Infant Mortality States and Dementia Risk in a Cohort of Elderly African American and White Health Care Members

IMPORTANCE

Birth in areas with high infant mortality rates (IMRs) has been linked to worse long-term health outcomes, yet it is completely unknown if it impacts dementia risk.

METHODS

In total 6268 health care members were followed for dementia diagnosis from 1996 to 2015. Birth state IMRs from 1928 were ranked into quartile (worst IMRs quartile range, whites: 69 to 129 deaths/1000 live births, Non-whites: 129 to 277 deaths/1000 live births). Cox proportional hazard models estimated the dementia risk associated with birth state IMR quartile adjusting for demographics and lifecourse health indicators.

RESULTS

Compared with whites born outside of states in the worst IMR quartile, African Americans born in states in the worst IMR quartile had 92% increased dementia risk (HR=1.92; 95% CI: 1.42, 2.59), and African Americans born outside those states had 36% increased risk (HR=1.36; 95% CI: 1.20, 1.53). There was no association between birth state IMR and dementia risk among whites.

CONCLUSIONS

Birth in states with the highest rates of infant mortality was associated with elevated dementia risk among African Americans but not whites. The large absolute difference in IMRs likely reflects harsher early childhood conditions experienced by African Americans. These findings suggest that childhood conditions may play a role in racial disparities in dementia rates.

Age-Period-Cohort Analysis of Stroke Mortality in China: Data From the Global Burden of Disease Study 2013

BACKGROUND AND PURPOSE

Stroke has been the leading cause of death in China. The aim of this study is to assess the long-term trends of stroke mortality in China between 1994 and 2013.

METHODS

The mortality data were obtained from the GBD 2013 (Global Burden of Disease Study 2013) and were analyzed with the age-period-cohort framework.

RESULTS

We found that the net drift was -2.665% (95% confidence interval, -2.854% to -2.474%) per year for men and -4.064% (95% confidence interval, -4.279% to -3.849%) per year for women, and the local drift values were below 0 in all age groups (P<0.05 for all) in both sexes during the period of 1994 to 2013. In the same birth cohort, the risk of death from stroke rose exponentially with age for both sexes after controlling for period deviations. The estimated period and cohort relative risks were found in similar monotonic downward patterns (significantly with P<0.05 for all) for both sexes, with more quickly decreasing for women than for men during the whole period (significantly with P<0.05 for both).

CONCLUSIONS

The decreased mortality rates of stroke in China are likely to be related to improvements in medical care and techniques, spectacular economic growth and fast urbanization, and better early life nutrition conditions of Chinese people. Besides, better education and better awareness of stroke-related knowledge in successive generations could also probably play a role.

The effect of adherence to statin therapy on cardiovascular mortality: quantification of unmeasured bias using falsification end-points

BACKGROUND

To determine the clinical effectiveness of statins on cardiovascular mortality in practice, observational studies are needed. Control for confounding is essential in any observational study. Falsification end-points may be useful to determine if bias is present after adjustment has taken place.

METHODS

We followed starters on statin therapy in the Netherlands aged 46 to 100 years over the period 1996 to 2012, from initiation of statin therapy until cardiovascular mortality or censoring. Within this group (n = 49,688, up to 16 years of follow-up), we estimated the effect of adherence to statin therapy (0 = completely non-adherent, 1 = fully adherent) on ischemic heart diseases and cerebrovascular disease (ICD10-codes I20-I25 and I60-I69) as well as respiratory and endocrine disease mortality (ICD10-codes J00-J99 and E00-E90) as falsification end points, controlling for demographic factors, socio-economic factors, birth cohort, adherence to other cardiovascular medications, and diabetes using time-varying Cox regression models.

RESULTS

Falsification end-points indicated that a simpler model was less biased than a model with more controls. Adherence to statins appeared to be protective against cardiovascular mortality (HR: 0.70, 95 % CI 0.61 to 0.81).

CONCLUSIONS

Falsification end-points helped detect overadjustment bias or bias due to competing risks, and thereby proved to be a useful technique in such a complex setting.

Birth cohort appeared to confound effect estimates of guideline changes on statin utilization

OBJECTIVES

To investigate how birth cohorts can confound population-based intervention effect estimates.

STUDY DESIGN AND SETTING

Interrupted time series design was applied to study the prevalence of statin use in Dutch diabetes patients over the period 1998-2011. Effects of guideline changes on the outcome were estimated using a Poisson regression model with and without the birth cohort dimension modeled through random intercepts.

RESULTS

Both models estimated a stronger increase in prevalence of statin use after influential studies were published in 2003 for patients aged below 50 and above 70 years. The model that controlled for birth cohort also estimated an effect for patients aged 50-70 years from 2003 onward. The magnitude of the intervention effect for patients aged above 70 years when we controlled for birth cohort was reduced from 0.078 [95% confidence interval (CI): 0.065, 0.091] to 0.027 (95% CI: 0.013, 0.041). Similarly, for patients aged below 50 years, the estimated guideline effect was reduced from 0.070 (95% CI: 0.048, 0.092) to 0.055 (95% CI: 0.035, 0.075).

CONCLUSION

In this case study, the birth cohort dimension appeared to confound population-level effect estimates of guideline changes on prevalence of statin use in patients with diabetes.

Effect of fresh orange juice intake on physiological characteristics in healthy volunteers

Background. Impaired endothelial function is a predictor of cardiovascular events. Orange juice (OJ) is rich in dietary flavonoids and could inhibit oxidative stress and inflammatory responses. We examined the effects of commercial (COJ) and fresh orange juice (FOJ) on endothelial function and physiological characteristics in healthy humans. Materials and Methods. Twenty-two healthy volunteers years were enrolled in a single blind randomized crossover controlled trial. The two groups consumed either COJ for the first 4 weeks and then FOJ (CFOJ, 4 weeks), or FOJ for the first 4 weeks and then COJ (FCOJ, 4 weeks). We assessed endothelial function by measuring flow-mediated dilation, serum concentrations of lipids, apolipoproteins A and B (apo A-1 and apo B), and inflammatory markers such as vascular endothelial adhesion molecule 1 (VCAM-1), E-selectin, high-sensitivity C-reactive protein (hs-CRP), and interleukin-6. Results. Consumption of both juices decreased VCAM, hs-CRP, and E-selectin but increased apo A-1. A decline in LDL occurred in the FOJ group. There were no differences between the characteristics of two groups, with the exception of apo A-1 levels that were increased with both forms of OJ. The largest variations occurred with hs-CRP, VCAM in both groups. Conclusion. Consumption of COJ and FOJ produced beneficial effects on the physiological characteristics of healthy volunteers. Although these results could encourage the consumption of OJ, intervention studies are needed to determine the long-term effects of these types of OJ on metabolic and cardiovascular endpoints.

Remarkable decline in ischemic stroke mortality is not matched by changes in incidence

BACKGROUND AND PURPOSE

In Western Europe, mortality from ischemic stroke (IS) has declined over several decades. Age-sex-specific IS mortality, IS incidence, 30-day case fatality, and 1-year mortality after hospital admission are essential for explaining recent trends in IS mortality in the new millennium.

METHODS

Data for all IS deaths (1980-2010) in the Netherlands were grouped by year, sex, and age. A joinpoint regression was fitted to detect points in time at which significant changes in the trends occur. By linking nationwide registers, a cohort of patients first admitted for IS between 1997 and 2005 was constructed and age-sex-specific 30-day case fatality and 1-year mortality were computed. IS incidence (admitted IS patients and out-of-hospital IS deaths) was computed by age and sex. Mann-Kendall tests were used for trend evaluation.

RESULTS

IS mortality declined continuously between 1980 and 2000 with an attenuation of decline in the 1990s in some of the age-sex groups. A remarkable decline in IS mortality after 2000 was observed in all age-sex groups, except for young men. An improved decline in 30-day case fatality and in 1-year mortality was also observed in almost all age-sex groups. In contrast, IS incidence remained stable between 1997 and 2005 or even increased slightly.

CONCLUSIONS

The recent remarkable decline in IS mortality was not matched by a decline in the number of incident nonfatal IS events. This is worrying, because IS is already a leading cause of adult disability, claiming a heavy human and economic burden. Prevention of IS is therefore now of the greatest importance.

Inclusion of the birth cohort dimension improved description and explanation of trends in statin use

OBJECTIVE

Including the birth cohort dimension improves trend studies of mortality and health. We investigated the effect of including the birth cohort dimension in trend studies of prescription drug use by studying prevalence of statin use among adults.

STUDY DESIGN AND SETTING

Data from a drug prescription database in the Netherlands (IADB.nl) were used to obtain the number of users of statin per 1,000 population (prevalence) in the age range 18-85 years from 1994 to 2008. We applied descriptive graphs and standard age-period-cohort (APC) models.

RESULTS

From 1994 to 2008, the prevalence increased from ∼10 to ∼90 users per 1,000 population, with the peak in prevalence shifting from age 63 to 78 years. The APC model shows patterns that were masked in the age-period (AP) model. The prevalence rate ratio increased from the 1911 birth cohort to the 1930 birth cohort and then declined. Similar for both sexes, adding nonlinear period effects contributed ∼4.4% to reductions in deviance, whereas adding nonlinear birth cohort effects contributed ∼12.9%.

CONCLUSION

Adding the birth cohort dimension to AP analysis is valuable for academic and professional practice as trends can be more accurately described and explained and it can help improve projections of future trends.

Shorter adult stature increases the impact of risk factors for cognitive impairment: a comparison of two Nordic twin cohorts

We analyzed the association between mean height and old age cognition in two Nordic twin cohorts with different childhood living conditions. The cognitive performance of 4720 twin individuals from Denmark (mean age 81.6 years, SD = 4.59) and Finland (mean age 74.4 years, SD = 5.26) was measured using validated cognitive screens. Taller height was associated with better cognitive performance in Finland (beta-estimates 0.18 SD/10cm, p value < .001, for men and 0.13 SD, p = .008, for women), but this association was not significant in Denmark (beta-estimates 0.0093 SD, p value = .16, for men and 0.0075 SD, p value = .016, for women) when adjusted for age and education/social class. Among Finnish participants higher variability of cognitive performance within shorter height quintiles was observed. Analysis using gene-environment interaction models showed that environmental factors exerted a greater impact on cognitive performance in shorter participants, whereas in taller participants' it was explained mainly by genetic factors. Our results suggest that shorter participants with childhood adversity are more vulnerable to environmental risk factors for cognitive impairment.

Cause-specific mortality time series analysis: a general method to detect and correct for abrupt data production changes

BACKGROUND

Monitoring the time course of mortality by cause is a key public health issue. However, several mortality data production changes may affect cause-specific time trends, thus altering the interpretation. This paper proposes a statistical method that detects abrupt changes ("jumps") and estimates correction factors that may be used for further analysis.

METHODS

The method was applied to a subset of the AMIEHS (Avoidable Mortality in the European Union, toward better Indicators for the Effectiveness of Health Systems) project mortality database and considered for six European countries and 13 selected causes of deaths. For each country and cause of death, an automated jump detection method called Polydect was applied to the log mortality rate time series. The plausibility of a data production change associated with each detected jump was evaluated through literature search or feedback obtained from the national data producers.For each plausible jump position, the statistical significance of the between-age and between-gender jump amplitude heterogeneity was evaluated by means of a generalized additive regression model, and correction factors were deduced from the results.

RESULTS

Forty-nine jumps were detected by the Polydect method from 1970 to 2005. Most of the detected jumps were found to be plausible. The age- and gender-specific amplitudes of the jumps were estimated when they were statistically heterogeneous, and they showed greater by-age heterogeneity than by-gender heterogeneity.

CONCLUSION

The method presented in this paper was successfully applied to a large set of causes of death and countries. The method appears to be an alternative to bridge coding methods when the latter are not systematically implemented because they are time- and resource-consuming.

The decline in stroke mortality: exploration of future trends in 7 Western European countries

BACKGROUND AND PURPOSE

This article aims to make projections of future trends in stroke mortality in the Year 2030 based on recent trends in stroke mortality in 7 Western European countries.

METHODS

Mortality data were obtained from national cause of death registries. Annual rates of decline in stroke mortality of 1980 to 2005 were determined for men and women in the United Kingdom, France, the Netherlands, and 4 Nordic countries on the basis of regression analysis. Estimated rates of decline were extrapolated until 2030. Cause-elimination life tables were used to determine the effect of stroke in 2030 in terms of potential gain in life expectancy. The absolute numbers of stroke deaths in 2030 were estimated using national population projections of Eurostat.

RESULTS

In all countries, stroke mortality rates declined incessantly until 2005 among both men and women. If these trends were to continue, age-adjusted mortality rates would decline by approximately half between 2005 and 2030 with larger declines in France (approximately two thirds) and smaller declines in the Netherlands, Denmark, and Sweden (approximately one fourth). Similar rates of decline would be observed in terms of potential gain in life expectancy. Because of population aging, the absolute number of stroke deaths would decline slowly in the United Kingdom and France and stabilize or even increase in other countries.

CONCLUSIONS

In the near future, stroke may lose much of its effects on life expectancy but remain a frequent cause of death among elderly populations. The prevention of stroke-related disability instead of mortality may become increasingly more important.

Quality of life in Lithuanian population: the impact of country residence and socio-economic status

Quality of life (QoL) and individual perception of health has become a subject of great interest in Lithuania. The relationships between country residence, socio-economic status (SES), and QoL have not been well characterized among the Lithuanian urban and rural populations. The aim of the study was to assess the influence of country residence and SES on QoL in Lithuanian urban and rural population adjusting for the influence of other known determinants of QoL. The study population was randomly selected from 1193 urban and 264 rural men and women aged 45–72 years and have been filled in the self-administered the WHOQOL-100 questionnaire. The survey participation rate was 62.8%. Psychometric evaluation of the WHOQOL-100 showed good internal reliability of Cronbach’s α from 0.78 to 0.94. Multiple linear regression models were used to study the influence of country residence and SES on the WHOQOL-100 scores while adjusting for the influence of other determinants of QoL. After adjusting for the influence of these factors, country residence and SES independently influenced QoL. Rural residence negatively affected the overall QoL, psychological domain, level of independence and spirituality. Higher education level and income directly and positively influenced the WHOQOL-100 scores, while retired, unemployed and residents with chronic medical conditions had negative influence WHOQOL-100 scores. The study results conclude that country residence and SES are associated with differences in QoL among urban and rural Lithuanian population.

Effects of age, period and cohort on stroke mortality among a middle-aged Lithuanian urban population from 1980 to 2004

AIMS

The main purpose of this paper was to assess the effect of age, period, and cohort on stroke mortality rates among a Lithuanian urban population aged 25-64 years (1041 men and 724 women) between 1980 and 2004.

METHODS

Routine stroke mortality data were obtained from official Kaunas region mortality register by codes 430-438 and I60-I69 in the 9th and in the 10th revisions of the International Classifications of Diseases (ICD), respectively. Mortality rates per 100,000 persons for men and women were age-adjusted using the age distribution of the European Standard Population. Age-specific mortality rates were analysed by sex, period, and birth cohort in eight 5-year age groups and five 5-year age groups. Goodness of fit of the Poisson regression models were evaluated using Pearson and Freeman-Tukey residuals. The age-period and age-period-cohort models provided a significantly better fit than a model with the factors "age'' and "cohort''.

RESULTS

During the study period, mortality rates decreased from 46.8 to 33.0 per 100,000 for men, and from 20.2 to 18.1 per 100,000 for women (average annual decrease of -1.3%, p<0.1 for men, and -1.6%, p<0.03 for women). An age effect was present in both sexes. The definite upward period effect was observed from 1990 to 1994 both among men and women, and was followed by a sharp fall during 2000-4. Cohort and period effects have contained relevant information which partially explained trends in stroke mortality among a 25-64 year-old Lithuanian urban population.

CONCLUSIONS

During the period of 1980-2004, the mortality trend declined among women only. The period effect contains relevant information for the explanation of increasing mortality rates during 2000-4 among men and women. The Poisson regression models could be applied for the examination and explanation of the different causes of the population mortality.

Effects of age, period, and cohort on stroke mortality among the Lithuanian urban population during the 24-year follow-up period

The main purpose of this paper was to assess the effects of age, period, and cohort on stroke mortality among the urban Lithuanian population. Routine stroke mortality data among the Lithuanian urban population aged 25–64 years (1041 men and 724 women) between 1980 and 2004 were obtained from the official Kaunas region mortality register and classified by codes 430–438 and 160–169 in the 9th and 10th revisions of the International Classifications of Diseases (ICD), respectively. Mortality rates per 100,000 persons for men and women were age-adjusted using the age distribution of the European Standard Population. Goodness of fit of the Poisson regression models was evaluated using the Pearson and Freeman-Tukey residuals. During the study period, mortality rates decreased from 46.8 to 33.0 per 100,000 for men, and from 20.2 to 18.1 per 100,000 for women (average annual decrease of −1.3%, p<0.1 for men, and −1.6%, p<0.03 for women). An age effect was present in both sexes. The definite upward period effect was observed from 1990 to 1994 both among men and women, and was followed by a sharp fall during 2000–2004. Cohort and period effects have contained relevant information that partially explained trends in stroke mortality among 25–64 year-olds in the Lithuanian urban population. The Poisson regression models could be applied for the examination and explanation of the different causes of the population mortality.