Socioeconomic inequalities in national transfers accounts in Ecuador 2006 and 2011: did a new socialist government make a difference?

Latin America is the least egalitarian region in the world. A neo-socialist government in Ecuador prioritized the reduction of socioeconomic status (SES) inequalities. The generational economy is a framework to understand the economic lifecycle and to link demographic change with people's well-being. This article aims to uncover SES-driven inequalities in the generational economy of Ecuador: did public transfers modify them from 2006 to 2011? National transfer accounts (NTA) were disaggregated by SES quartiles, which were defined by the highest level of education attainment in each household. The accounts within SES quartiles were estimated using standard NTA methods. A pseudo-Gini coefficient summarized SES-driven inequalities by age and generational account. This secondary analysis was based on existing micro databases from the Ecuadorian NTA.

Results

National averages do not represent well the generational economy of the low-SES population. The usual gradient of higher economic figures in higher SES strata shows up in almost all NTAs with the notable exceptions of reversal (progressive) gradients in conditional public cash transfers to low-SES households and public education at the elementary school level. Retirement pensions are extremely regressive public transfers, benefiting mostly high-SES strata.

Conclusions

Population aging might worsen the high levels of inequality already existing in Ecuador and Latin America. Some progressive public policies worked well to reduce inequality in Ecuador.

Contribution

This article demonstrates the importance of uncovering SES-driven inequalities existing in NTAs and their change through the lifecycle. It also identifies public policies that ameliorated inequality as well as public transfers that are regressive.

Centenarian clocks: epigenetic clocks for validating claims of exceptional longevity

Claims surrounding exceptional longevity are sometimes disputed or dismissed for lack of credible evidence. Here, we present three DNA methylation-based age estimators (epigenetic clocks) for verifying age claims of centenarians. The three centenarian clocks were developed based on n = 7039 blood and saliva samples from individuals older than 40, including n = 184 samples from centenarians, 122 samples from semi-supercentenarians (aged 105 +), and 25 samples from supercentenarians (aged 110 +). The oldest individual was 115 years old. Our most accurate centenarian clock resulted from applying a neural network model to a training set composed of individuals older than 40. An epigenome-wide association study of age in different age groups revealed that age effects in young individuals (age < 40) are correlated (r = 0.55) with age effects in old individuals (age > 90). We present a chromatin state analysis of age effects in centenarians. The centenarian clocks are expected to be useful for validating claims surrounding exceptional old age.

Vaccine effectiveness of Pfizer-BioNTech and Oxford-AstraZeneca to prevent severe COVID-19 in Costa Rica: A nationwide, ecological study of hospitalizations prevalence

Background

The Costa Rican COVID-19 vaccination program has used Pfizer-BioNTech and Oxford-AstraZeneca vaccines. Real-world estimates of the effectiveness of these vaccines to prevent hospitalizations range from 90%-98% for two doses and from 70%-91% for a single dose. Almost all of these estimates predate the Delta variant.

Objective

The aim of this study is to estimate the dose-dependent effectiveness of COVID-19 vaccines to prevent severe illness in real-world conditions in Costa Rica, after the Delta variant became dominant.

Methods

This observational study is a secondary analysis of hospitalization prevalence. The sample is all 3.67 million adult residents living in Costa Rica by mid-2021. The study is based on public aggregated data of 5978 COVID-19–related hospital records from September 14, 2021, to October 20, 2021, and 6.1 million vaccination doses administered to determine hospitalization prevalence by dose-specific vaccination status. The intervention retrospectively evaluated is vaccination with Pfizer-BioNTech (78%) and Oxford-AstraZeneca (22%). The main outcome studied is being hospitalized.

Results

Vaccine effectiveness against hospitalization (VEH) was estimated as 93.4% (95% CI 93.0-93.9) for complete vaccination and 76.7% (95% CI 75.0-78.3) for single-dose vaccination among adults of all ages. VEH was lower and more uncertain among older adults aged ≥58 years: 92% (95% CI 91%-93%) for those who had received full vaccination and 64% (95% CI 58%-69%) for those who had received partial vaccination. Single-dose VEH declined over time during the study period, especially in the older age group. Estimates were sensitive to possible errors in the population count used to determine the residual number of unvaccinated people when vaccine coverage is high.

Conclusions

The Costa Rican COVID-19 vaccination program that administered Pfizer-BioNTech and Oxford-AstraZeneca vaccines seems to be highly effective at preventing COVID-19–related hospitalization after the Delta variant became dominant. Even a single dose seems to provide some degree of protection, which is good news for people whose second dose of the Pfizer-BioNTech vaccine was postponed several weeks to more rapidly increase the number of people vaccinated with a first dose. Timely monitoring of vaccine effectiveness is important to detect eventual failures and motivate the public to get vaccinated by providing information regarding the effectiveness of the vaccines.

Epigenome-wide association study and epigenetic age acceleration associated with cigarette smoking among Costa Rican adults

Smoking-associated DNA methylation (DNAm) signatures are reproducible among studies of mostly European descent, with mixed evidence if smoking accelerates epigenetic aging and its relationship to longevity. We evaluated smoking-associated DNAm signatures in the Costa Rican Study on Longevity and Healthy Aging (CRELES), including participants from the high longevity region of Nicoya. We measured genome-wide DNAm in leukocytes, tested Epigenetic Age Acceleration (EAA) from five clocks and estimates of telomere length (DNAmTL), and examined effect modification by the high longevity region. 489 participants had a mean (SD) age of 79.4 (10.8) years, and 18% were from Nicoya. Overall, 7.6% reported currently smoking, 35% were former smokers, and 57.4% never smoked. 46 CpGs and five regions (e.g. AHRR, SCARNA6/SNORD39, SNORA20, and F2RL3) were differentially methylated for current smokers. Former smokers had increased Horvath’s EAA (1.69-years; 95% CI 0.72, 2.67), Hannum’s EAA (0.77-years; 95% CI 0.01, 1.52), GrimAge (2.34-years; 95% CI1.66, 3.02), extrinsic EAA (1.27-years; 95% CI 0.34, 2.21), intrinsic EAA (1.03-years; 95% CI 0.12, 1.94) and shorter DNAmTL (− 0.04-kb; 95% CI − 0.08, − 0.01) relative to non-smokers. There was no evidence of effect modification among residents of Nicoya. Our findings recapitulate previously reported and novel smoking-associated DNAm changes in a Latino cohort.

Diet and Leukocyte Telomere Length in a Population with Extended Longevity: The Costa Rican Longevity and Healthy Aging Study (CRELES)

Elderly Costa Ricans have lower mortality rates compared to their counterparts from developed countries. Reasons for this survival advantage are not completely known. In the present study, we aimed to identify dietary factors associated with leukocyte telomere length (LTL), a marker of biologic aging, in the elderly population of Costa Rica. We conducted prospective analysis in 909 participants aged 60+ years from the Costa Rican Longevity and Healthy Aging Study (CRELES). We used a food frequency questionnaire to assess usual diet. We calculated dietary patterns using Principal Component Analysis (PCA). We used generalized linear models to examine the association of dietary patterns and food groups with leukocyte telomere length. We found two major dietary patterns explaining 9.15% and 7.18% of the total variation of food intake, respectively. The first dietary pattern, which represents a traditional Costa Rican rice and beans pattern, was more frequent in rural parts of the country and was positively associated with baseline LTL: β (95% CI) = 42.0 base-pairs (bp) (9.9 bp, 74.1 bp) per one-unit increase of the traditional dietary pattern. In analysis of individual food groups, intake of grains was positively associated with baseline LTL: β (95% CI) = 43.6 bp (13.9 bp, 73.3 bp) per one-serving/day increase of consumption of grains. Our results suggest that dietary factors, in particular a traditional food pattern, are associated with telomere length and may contribute to the extended longevity of elderly Costa Ricans.

Diabetes epidemics: inequalities increase the burden on the healthcare system

Diabetes is a major cause of morbidity and mortality and represents a source of demands on already constrained healthcare systems in Latin America and the Caribbean. We estimate inequalities in diabetes incidence, prevalence and mortality and assess the economic burden on the healthcare system in Costa Rica. The main source of data is the Costa Rican Longevity and Healthy Aging Study, a longitudinal nationally representative survey of the elderly population (n = 2827). Data analyses include descriptive statistics, multiple regression models and survival analysis models. More than a fifth of Costa Rican elderly experience diabetes. Incidence is estimated at 5 per 1000 person-years in the population 30+. Gender and geographical inequalities were found. Men have a significantly lower prevalence (16.51% vs 24.02%, P < 0.05) and incidence (4.3 vs 6.0 per 1000 person-years, P < 0.05), but higher mortality (hazard ratio = 1.31, P < 0.01). Longer time to the closest facility translates into a lower probability of having the condition diagnosed [odds ratio (OR) = 0.77, P < 0.05]. The diabetic as compared to the non-diabetic population imposes a larger economic burden on the healthcare system with a higher probability of using outpatient care (OR = 3.08, P < 0.01), medications (OR = 3.44, P < 0.01) and hospitalizations (OR = 1.24, P > 0.05). Individuals living in the Metro Area have a significantly lower probability of being hospitalized (OR = 0.72, P < 0.05), which may be evidence of better access to primary care that prevents hospitalization. Along the same line, women have higher utilization rates of outpatient care (OR = 2.02, P < 0.01) and medications (OR = 1.73, P < 0.01), which may contribute to lower odds of hospitalization (OR = 0.61, P < 0.01). Aligned with the aim of attaining Sustainable Development Goals, this study highlights the importance of generating health policies focused on prevention of diabetes that take into consideration gender and geographical inequalities. Strategies should booster preventive healthcare utilization by men and aim to make healthcare services accessible to all, regardless of geographical location.

Estacionalidad de la mortalidad en los trópicos

El objetivo de esta investigación es determinar la existencia y magnitud de ciclos de variación estacional en la mortalidad de Costa Rica de 1970 a 2016. Metodológicamente, el estudio se basa en microdatos de 630,000 defunciones entre esos años. La naturaleza cíclica de la variación estacional se modela con regresión sinusoide y parámetros estimados con regresión de Poisson. Los resultados muestran que hay variación estacional significativa con un máximo en enero y un mínimo en mayo. La mortalidad tiende a ser 7 % mayor en su ápex que en su nadir. Este patrón está determinado por accidentes, especialmente de transporte, alcoholismo, enfermedades cardio- y cerebrovasculares, e infecciones respiratorias. La mortalidad por diarreas presenta un patrón diferente de estacionalidad. En conclusión, la mayor mortalidad de enero estaría asociada con la temperatura menor, ausencia de pluviosidad, menor luz solar y comportamiento durante días festivos. Algunos picos de mortalidad podrían deberse a fluctuaciones en la calidad de los servicios de salud y de atención de emergencias.

Education Gains Attributable to Fertility Decline: Patterns by Gender, Period, and Country in Latin America and Asia

We investigate the heterogeneity across countries and time in the relationship between mother's fertility and children's educational attainment-the quantity-quality (Q-Q) trade-off-by using census data from 17 countries in Asia and Latin America, with data from each country spanning multiple census years. For each country-year, we estimate micro-level instrumental variables models predicting secondary school attainment using number of siblings of the child, instrumented by the sex composition of the first two births in the family. We then analyze correlates of Q-Q trade-off patterns across countries. On average, one additional sibling in the family reduces the probability of secondary education by 6 percentage points for girls and 4 percentage points for boys. This Q-Q trade-off is significantly associated with the level of son preference, slightly decreasing over time and with fertility, but it does not significantly differ by educational level of the country.

Differential DNA methylation and lymphocyte proportions in a Costa Rican high longevity region

Background

The Nicoya Peninsula in Costa Rica has one of the highest old-age life expectancies in the world, but the underlying biological mechanisms of this longevity are not well understood. As DNA methylation is hypothesized to be a component of biological aging, we focused on this malleable epigenetic mark to determine its association with current residence in Nicoya versus elsewhere in Costa Rica. Examining a population’s unique DNA methylation pattern allows us to differentiate hallmarks of longevity from individual stochastic variation. These differences may be characteristic of a combination of social, biological, and environmental contexts.

Methods

In a cross-sectional subsample of the Costa Rican Longevity and Healthy Aging Study, we compared whole blood DNA methylation profiles of residents from Nicoya (n = 48) and non-Nicoya (other Costa Rican regions, n = 47) using the Infinium HumanMethylation450 microarray.

Results

We observed a number of differences that may be markers of delayed aging, such as bioinformatically derived differential CD8+ T cell proportions. Additionally, both site- and region-specific analyses revealed DNA methylation patterns unique to Nicoyans. We also observed lower overall variability in DNA methylation in the Nicoyan population, another hallmark of younger biological age.

Conclusions

Nicoyans represent an interesting group of individuals who may possess unique immune cell proportions as well as distinct differences in their epigenome, at the level of DNA methylation.

Electronic supplementary material

The online version of this article (doi:10.1186/s13072-017-0128-2) contains supplementary material, which is available to authorized users.

Predicting Survival from Telomere Length versus Conventional Predictors: A Multinational Population-Based Cohort Study

Telomere length has generated substantial interest as a potential predictor of aging-related diseases and mortality. Some studies have reported significant associations, but few have tested its ability to discriminate between decedents and survivors compared with a broad range of well-established predictors that include both biomarkers and commonly collected self-reported data. Our aim here was to quantify the prognostic value of leukocyte telomere length relative to age, sex, and 19 other variables for predicting five-year mortality among older persons in three countries. We used data from nationally representative surveys in Costa Rica (N = 923, aged 61+), Taiwan (N = 976, aged 54+), and the U.S. (N = 2672, aged 60+). Our study used a prospective cohort design with all-cause mortality during five years post-exam as the outcome. We fit Cox hazards models separately by country, and assessed the discriminatory ability of each predictor. Age was, by far, the single best predictor of all-cause mortality, whereas leukocyte telomere length was only somewhat better than random chance in terms of discriminating between decedents and survivors. After adjustment for age and sex, telomere length ranked between 15th and 17th (out of 20), and its incremental contribution was small; nine self-reported variables (e.g., mobility, global self-assessed health status, limitations with activities of daily living, smoking status), a cognitive assessment, and three biological markers (C-reactive protein, serum creatinine, and glycosylated hemoglobin) were more powerful predictors of mortality in all three countries. Results were similar for cause-specific models (i.e., mortality from cardiovascular disease, cancer, and all other causes combined). Leukocyte telomere length had a statistically discernible, but weak, association with mortality, but it did not predict survival as well as age or many other self-reported variables. Although telomere length may eventually help scientists understand aging, more powerful and more easily obtained tools are available for predicting survival.

Exploring why Costa Rica outperforms the United States in life expectancy: A tale of two inequality gradients

Mortality in the United States is 18% higher than in Costa Rica among adult men and 10% higher among middle-aged women, despite the several times higher income and health expenditures of the United States. This comparison simultaneously shows the potential for substantially lowering mortality in other middle-income countries and highlights the United States' poor health performance. The United States' underperformance is strongly linked to its much steeper socioeconomic (SES) gradients in health. Although the highest SES quartile in the United States has better mortality than the highest quartile in Costa Rica, US mortality in its lowest quartile is markedly worse than in Costa Rica's lowest quartile, providing powerful evidence that the US health inequality patterns are not inevitable. High SES-mortality gradients in the United States are apparent in all broad cause-of-death groups, but Costa Rica's overall mortality advantage can be explained largely by two causes of death: lung cancer and heart disease. Lung cancer mortality in the United States is four times higher among men and six times higher among women compared with Costa Rica. Mortality by heart disease is 54% and 12% higher in the United States than in Costa Rica for men and women, respectively. SES gradients for heart disease and diabetes mortality are also much steeper in the United States. These patterns may be partly explained by much steeper SES gradients in the United States compared with Costa Rica for behavioral and medical risk factors such as smoking, obesity, lack of health insurance, and uncontrolled dysglycemia and hypertension.

La situación demográfica en Costa Rica

El presente documento estudia la población de Costa Rica en tanto que conjunto de individuos sujetos a evolución, ciyos componentes fundamentales son la mortalidad y la fecundidad. El estudio centra su atención en el cambio ocurrido en estas dos variables, ocupándose especialmente de la evolición de causas de muerte y, en el caso de la evolución de las causa de muerte y , en el caso de la fecundidad, de la etapas de la formación de la familia, de la nupcialidad y de la práctica anticonceptiva. También se enumeran algunas de las consecuencias que han tenido los cambios en la mortalidad y en la fecundidad, discutiéndose además el posible comportamiento futuro de estas variables, con el riesgo que implica el hacer conjeturas de este tipo.

Disease and weight loss: a prospective study of middle-aged and older adults in Costa Rica and England

OBJECTIVE

To determine whether disease predicts weight loss in population-based studies, as this may confound the relationship between weight and mortality.

MATERIALS AND METHODS

We used longitudinal data from the Costa Rican Longevity and Healthy Aging Study (CRELES) and the English Longitudinal Study of Ageing (ELSA). We defined two overlapping outcomes of measured weight loss between waves: >1.0 point of body mass index (BMI) and >2.0 BMI points. Logistic regression models estimated the associations with disease, adjusting for age (range 52-79), sex, smoking, and initial BMI.

RESULTS

In ELSA, onset of diabetes, cancer, or lung disease is associated with loss >2.0 points (respectively, OR=2.25 [95%CI: 1.34-3.80]; OR=2.70 [95%CI: 1.49-4.89]; OR=1.82 [95%CI: 1.02-3.26]). In CRELES, disease-onset reports are not associated with weight loss at 5% significance, but statistical power to detect associations is poor.

CONCLUSION

Although it is known that some diseases cause weight loss, at the population level these associations vary considerably across samples.

Effects of Self-Rated Health and Self-Rated Economic Situation on Depressed Mood Via Life Satisfaction Among Older Adults in Costa Rica

Objective: The study examined the relationship of self-rated health and self-rated economic situation with depressed mood, and life satisfaction as mediator of this relationship among older adults in Costa Rica. Method: A longitudinal study was conducted with a subsample (N = 1,618) from the Costa Rican Longevity and Healthy Aging Study (CRELES). Self-rated health, self-rated economic situation, depressed mood, and life satisfaction were measured at baseline, and depressed mood was reassessed 18 months later. Putative mechanisms for changes in depressed mood were examined by means of conditional process analysis. Results: Self-rated health was negatively associated to depressed mood. This effect took place via life satisfaction. An interaction showed that better economic situation compensated the effect of a low self-rated health on life satisfaction. Discussion: This study suggests that subjective variables such as self-rated health, economic situation, and life satisfaction should be considered when addressing the onset of depressed mood.

Seasonal variation of peripheral blood leukocyte telomere length in Costa Rica: A population-based observational study

OBJECTIVES

Peripheral blood leukocyte telomere length (LTL) is increasingly being used as a biomarker of aging, but its natural variation in human populations is not well understood. Several other biomarkers show seasonal variation, as do several determinants of LTL. We examined whether there was monthly variation in LTL in Costa Rica, a country with strong seasonal differences in precipitation and infection.

METHODS

We examined a longitudinal population-based cohort of 581 Costa Rican adults age 60 and above, from which blood samples were drawn between October 2006 and July 2008. LTL was assayed from these samples using the quantitative PCR method. Multivariate regression models were used to examine correlations between month of blood draw and LTL.

RESULTS

Telomere length from peripheral blood leukocytes varied by as much as 200 base pairs depending on month of blood draw, and this difference is not likely to be due to random variation. A moderate proportion of this association is statistically accounted for by month and region specific average rainfall. We found shorter telomere length associated with greater rainfall.

CONCLUSIONS

There are two possible explanations of our findings. First, there could be relatively rapid month-to-month changes in LTL. This conclusion would have implications for understanding the natural population dynamics of telomere length. Second, there could be seasonal differences in constituent cell populations. This conclusion would suggest that future studies of LTL use methods to account for the potential impact of constituent cell type.

The Nicoya region of Costa Rica: a high longevity island for elderly males

Reliable data show that the Nicoyan region of Costa Rica is a hot spot of high longevity. A survival follow-up of 16,300 elderly Costa Ricans estimated a Nicoya death rate ratio (DRR) for males 1990-2011 of 0.80 (0.69-0.93 CI). For a 60-year-old Nicoyan male, the probability of becoming centenarian is seven times that of a Japanese male, and his life expectancy is 2.2 years greater. This Nicoya advantage does not occur in females, is independent of socio-economic conditions, disappears in out-migrants and comes from lower cardiovascular (CV) mortality (DRR = 0.65). Nicoyans have lower levels of biomarkers of CV risk; they are also leaner, taller and suffer fewer disabilities. Two markers of ageing and stress-telomere length and dehydroepiandrosterone sulphate-are also more favourable. The Nicoya diet is prosaic and abundant in traditional foods like rice, beans and animal protein, with low glycemic index and high fibre content.

Longer leukocyte telomere length in Costa Rica's Nicoya Peninsula: a population-based study

Studies in humans suggest that leukocyte telomere length may act as a marker of biological aging. We investigated whether individuals in the Nicoya region of Costa Rica, known for exceptional longevity, had longer telomere length than those in other parts of the country. After controlling for age, age squared, rurality, rainy season and gender, the mean leukocyte telomere length in Nicoya was substantially longer (81 base pairs, p<0.05) than in other areas of Costa Rica, providing evidence of a biological pathway to which this notable longevity may be related. This relationship remains unchanged (79 base pairs, p<0.05) after statistically controlling for nineteen potential biological, dietary and social and demographic mediators. Thus the difference in the mean leukocyte telomere length that characterizes this unique region does not appear to be explainable by traditional behavioral and biological risk factors. More detailed examination of mean leukocyte telomere length by age shows that the regional telomere length difference declines at older ages.

Predicting mortality with biomarkers: a population-based prospective cohort study for elderly Costa Ricans

Background

Little is known about adult health and mortality relationships outside high-income nations, partly because few datasets have contained biomarker data in representative populations. Our objective is to determine the prognostic value of biomarkers with respect to total and cardiovascular mortality in an elderly population of a middle-income country, as well as the extent to which they mediate the effects of age and sex on mortality.

Methods

This is a prospective population-based study in a nationally representative sample of elderly Costa Ricans. Baseline interviews occurred mostly in 2005 and mortality follow-up went through December 2010. Sample size after excluding observations with missing values: 2,313 individuals and 564 deaths. Main outcome: prospective death rate ratios for 22 baseline biomarkers, which were estimated with hazard regression models.

Results

Biomarkers significantly predict future death above and beyond demographic and self-reported health conditions. The studied biomarkers account for almost half of the effect of age on mortality. However, the sex gap in mortality became several times wider after controlling for biomarkers. The most powerful predictors were simple physical tests: handgrip strength, pulmonary peak flow, and walking speed. Three blood tests also predicted prospective mortality: C-reactive protein (CRP), glycated hemoglobin (HbA1c), and dehydroepiandrosterone sulfate (DHEAS). Strikingly, high blood pressure (BP) and high total cholesterol showed little or no predictive power. Anthropometric measures also failed to show significant mortality effects.

Conclusions

This study adds to the growing evidence that blood markers for CRP, HbA1c, and DHEAS, along with organ-specific functional reserve indicators (handgrip, walking speed, and pulmonary peak flow), are valuable tools for identifying vulnerable elderly. The results also highlight the need to better understand an anomaly noted previously in other settings: despite the continued medical focus on drugs for BP and cholesterol, high levels of BP and cholesterol have little predictive value of mortality in this elderly population.

Long-term association of economic inequality and mortality in adult Costa Ricans

Despite the large number of studies, mostly in developed economies, there is limited consensus on the health effects of inequality. Recently a related literature has examined the relationship between relative deprivation and health as a mechanism to explain the economic inequality and health relationship. This study evaluates the relationship between mortality and economic inequality, as measured by area-level Gini coefficients, as well as the relationship between mortality and relative deprivation, in the context of a middle-income country, Costa Rica. We followed a nationally representative prospective cohort of approximately 16,000 individuals aged 30 and over who were randomly selected from the 1984 census. These individuals were then linked to the Costa Rican National Death Registry until Dec. 31, 2007. Hazard models were used to estimate the relative risk of mortality for all-cause and cardiovascular disease mortality for two indicators: canton-level income inequality and relative deprivation based on asset ownership. Results indicate that there was an unexpectedly negative association between canton income inequality and mortality, but the relationship is not robust to the inclusion of canton fixed-effects. In contrast, we find a positive association between relative deprivation and mortality, which is robust to the inclusion of canton fixed-effects. Taken together, these results suggest that deprivation relative to those higher in a hierarchy is more detrimental to health than the overall dispersion of the hierarchy itself, within the Costa Rican context.

Do biological measures mediate the relationship between education and health: A comparative study

Despite a myriad of studies examining the relationship between socioeconomic status and health outcomes, few have assessed the extent to which biological markers of chronic disease account for social disparities in health. Studies that have examined this issue have generally been based on surveys in wealthy countries that include a small set of clinical markers of cardiovascular disease. The availability of recent data from nationally representative surveys of older adults in Costa Rica and Taiwan that collected a rich set of biomarkers comparable to those in a recent US survey permits us to explore these associations across diverse populations. Similar regression models were estimated on three data sets - the Social Environment and Biomarkers of Aging Study in Taiwan, the Costa Rican Study on Longevity and Healthy Aging, and the Health and Retirement Study in the USA - in order to assess (1) the strength of the associations between educational attainment and a broad range of biomarkers; and (2) the extent to which these biomarkers account for the relationships between education and two measures of health status (self-rated health, functional limitations) in older populations. The estimates suggest non-systematic and weak associations between education and high risk biomarker values in Taiwan and Costa Rica, in contrast to generally negative and significant associations in the US, especially among women. The results also reveal negligible or modest contributions of the biomarkers to educational disparities in the health outcomes. The findings are generally consistent with previous research suggesting stronger associations between socioeconomic status and health in wealthy countries than in middle-income countries and may reflect higher levels of social stratification in the US. With access to an increasing number of longitudinal biosocial surveys, researchers may be better able to distinguish true variations in the relationship between socioeconomic status and health across different settings from methodological differences.

Stressors over the life course and neuroendocrine system dysregulation in Costa Rica

OBJECTIVE

A key aspect of the increasingly popular allostatic load (AL) framework is that stressors experienced over the entire life course result in physiological dysregulation. Although core to AL theory, this idea has been little tested, and where it has been tested, the results have been mixed.

METHOD

The study analyzes the Costa Rican Study on Longevity and Healthy Aging (CRELES), a new, cross-sectional, and nationally representative survey of older Costa Rican men and women (aged between 60 and 109 years). The survey period is between 2004 and 2006, and the survey has a sample size of 2,827 individuals. This article focuses on the relationship between a variety of stressors experienced over the life course and cortisol, dehydroepiandrosterone sulfate (DHEAS), epinephrine, and norepinephrine analyzed separately and in an index.

RESULTS

There are some links between certain stressors and worse cortisol levels, but overall, almost all of the stressors examined are not associated with riskier neuroendocrine biomarker profiles.

DISCUSSION

More work is needed, in order to establish the connection between stressors experienced over the life course and resting levels of the neuroendocrine markers.

Differences in the association of cardiovascular risk factors with education: a comparison of Costa Rica (CRELES) and the USA (NHANES)

Background

Despite different levels of economic development, Costa Rica and the USA have similar mortalities among adults. However, in the USA there are substantial differences in mortality by educational attainment, and in Costa Rica there are only minor differences. This contrast motivates an examination of behavioural and biological correlates underlying this difference.

Methods

The authors used data on adults aged 60 and above from the Costa Rican Longevity and Healthy Ageing Study (CRELES) (n=2827) and from the US National Health and Nutrition Examination Survey (NHANES) (n=5607) to analyse the cross-sectional association between educational level and the following risk factors for cardiovascular disease (CVD): ever smoked, current smoker, sedentary, high saturated fat, high carbohydrates, high calorie diet, obesity, severe obesity, large waist circumference, HDL cholesterol, LDL cholesterol, triglycerides, hemoglobin A1c, fasting glucose, C-reactive protein, systolic blood pressure and BMI.

Results

There were significantly fewer hazardous levels of risk biomarkers at higher levels of education for more than half (10 out of 17) of the risk factors in the USA, but for less than a third of the outcomes in Costa Rica (five out of 17).

Conclusions

These results are consistent with the context-specific nature of educational differences in risk factors for CVD and with a non-uniform nature of association of CVD risk factors with education within countries. Our results also demonstrate that social equity in mortality is achieved without uniform equity in all risk factors.

Differentials by socioeconomic status and institutional characteristics in preventive service utilization by older persons in Costa Rica

Objective.The goals of this article are to assess the level of preventive service utilization by older persons in Costa Rica and to determine whether there are differentials in utilization across socioeconomic status (SES) and institutional characteristics. Method. Using data from the Costa Rican Study on Longevity and Healthy Aging (CRELES) project, a study of healthy aging in Costa Rica, the authors use self-reported information on preventive service utilization. The SES differentials are studied using logistic regressions. Results. Preventive services linked to cardiovascular disease prevention are frequently utilized; preventive services linked to cancer screening, vaccination, and sense impairments are not so widely used. Higher SES people are more likely to utilize most preventive services. Utilization rates among uninsured seniors are lower than among their insured peers. Home visits by community health workers are positively associated with higher utilization rates. Discussion. The SES disparities in preventive service utilization exist in Costa Rica, and institutional characteristics are positively associated with increasing utilization.

Surprising SES Gradients in mortality, health, and biomarkers in a Latin American population of adults

BACKGROUND

To determine socioeconomic status (SES) gradients in the different dimensions of health among elderly Costa Ricans.

HYPOTHESIS

SES disparities in adult health are minimal in Costa Rican society.

METHODS

Data from the Costa Rican Study on Longevity and Healthy Aging study: 8,000 elderly Costa Ricans to determine mortality in the period 2000-2007 and a subsample of 3,000 to determine prevalence of several health conditions and biomarkers from anthropometry and blood and urine specimens.

RESULTS

The ultimate health indicator, mortality, as well as the metabolic syndrome, reveals that better educated and wealthier individuals are worse off. In contrast, quality of life-related measures such as functional and cognitive disabilities, physical frailty, and depression all clearly worsen with lower SES. Overall self-reported health (SRH) also shows a strong positive SES gradient. Traditional cardiovascular risk factors such as diabetes and cholesterol are not significantly related to SES, but hypertension and obesity are worse among high-SES individuals. Reflecting mixed SES gradients in behaviors, smoking and lack of exercise are more common among low SES, but high calorie diets are more common among high SES.

CONCLUSIONS

Negative modern behaviors among high-SES groups may be reversing cardiovascular risks across SES groups, hence reversing mortality risks. But negative SES gradients in healthy years of life persist.

Factors associated with hypertension prevalence, unawareness and treatment among Costa Rican elderly

Background

Reliable information on the prevalence of hypertension is crucial in the development of health policies for prevention, control, and early diagnosis of this condition. This study describes the prevalence of hypertension among Costa Rican elderly, and identifies co-factors associated with its prevalence, unawareness and treatment.

Methods

The prevalence of hypertension is estimated for the Costa Rican elderly. Measurement error is assessed, and factors associated with high blood pressure are explored. Data for this study came from a nationally representative sample of about 2,800 individuals from CRELES (Costa Rica: Longevity and Healthy Aging Study). Two blood pressure measures were collected using digital monitors. Self reports of previous diagnosis, and medications taken were also recorded as part of the study.

Results

No evidence of information bias was found among interviewers, or over time. Hypertension prevalence in elderly Costa Ricans was found to be 65% (Males = 60%, Females = 69%). Twenty-five percent of the studied population did not report previous diagnoses of hypertension, but according to our measurement they had high blood pressure. The proportion of unaware men is higher than the proportion of unaware women (32% vs. 20%). The main factors associated with hypertension are: age, being overweight or obese, and family history of hypertension. For men, current smokers are 3 times more likely to be unaware of their condition than non smokers. Both men and women are less likely to be unaware of their condition if they have a family history of hypertension. Those women who are obese, diabetic, have suffered heart disease or stroke, or have been home visited by community health workers are less likely to be unaware of their hypertension. The odds of being treated are higher in educated individuals, those with a family history of hypertension, elderly with diabetes or those who have had heart disease.

Conclusion

Sex differences in terms of hypertension prevalence, unawareness, and treatment in elderly people have been found. Despite national programs for hypertension detection and education, unawareness of hypertension remains high, particularly among elderly men. Modifiable factors identified to be associated with prevalence such as obesity and alcohol intake could be used in educational programs aimed at the detection and treatment of those individuals who have the condition.

The exceptionally high life expectancy of Costa Rican nonagenarians

Robust data from a voter registry show that Costa Rican nonagenarians have an exceptionally high live expectancy. Mortality at age 90 in Costa Rica is at least 14% lower than an average of 13 high-income countries. This advantage increases with age by 1% per year Males have an additional 12% advantage. Age-90 life expectancy for males is 4.4 years, one-half year more than any other country in the world. These estimates do not use problematic data on reported ages, but ages are computed from birth dates in the Costa Rican birth-registration ledgers. Census data confirm the exceptionally high survival of elderly Costa Ricans, especially males. Comparisons with the United States and Sweden show that the Costa Rican advantage comes mostly from reduced incidence of cardiovascular diseases, coupled with a low prevalence of obesity, as the only available explanatory risk factor Costa Rican nonagenarians are survivors of cohorts that underwent extremely harsh health conditions when young, and their advantage might be just a heterogeneity in frailty effect that might disappear in more recent cohorts. The availability of reliable estimates for the oldest-old in low-income populations is extremely rare. These results may enlighten the debate over how harsh early-life health conditions affect older-age mortality.

Metabolic control in a nationally representative diabetic elderly sample in Costa Rica: patients at community health centers vs. patients at other health care settings

Background

Costa Rica, like other developing countries, is experiencing an increasing burden of chronic conditions such as diabetes mellitus (DM), especially among its elderly population. This article has two goals: (1) to assess the level of metabolic control among the diabetic population age ≥ 60 years old in Costa Rica, and (2) to test whether diabetic elderly patients of community health centers differ from patients in other health care settings in terms of the level of metabolic control.

Methods

Data come from the project CRELES, a nationally representative study of people aged 60 and over in Costa Rica. This article analyzes a subsample of 542 participants in CRELES with self-reported diagnosis of diabetes mellitus. Odds ratios of poor levels of metabolic control at different health care settings are computed using logistic regressions.

Results

Lack of metabolic control among elderly diabetic population in Costa Rica is described as follows: 37% have glycated hemoglobin ≥ 7%; 78% have systolic blood pressure ≥ 130 mmHg; 66% have diastolic blood pressure ≥ 80 mmHg; 48% have triglycerides ≥ 150 mg/dl; 78% have LDL ≥ 100 mg/dl; 70% have HDL ≤ 40 mg/dl. Elevated levels of triglycerides and LDL were higher in patients of community health centers than in patients of other clinical settings. There were no statistical differences in the other metabolic control indicators across health care settings.

Conclusion

Levels of metabolic control among elderly population with DM in Costa Rica are not that different from those observed in industrialized countries. Elevated levels of triglycerides and LDL at community health centers may indicate problems of dyslipidemia treatment among diabetic patients; these problems are not observed in other health care settings. The Costa Rican health care system should address this problem, given that community health centers constitute a means of democratizing access to primary health care to underserved and poor areas.

X-ray screening seems to reduce gastric cancer mortality by half in a community-controlled trial in Costa Rica

X-ray screening of gastric cancer is broadly used in Japan, although no controlled trial has proved its effectiveness. This study evaluates the impact of an X-ray screening demonstrative intervention to reduce gastric cancer mortality in a Costa Rican region. The evaluation follows a quasi-experimental, community-controlled design, with measures before and after. About 7000 individuals participated by invitation in the two-wave screening programme. X-ray screening was followed by videoendoscopy and gastric biopsies. Treatment included resection with or without lymph node dissection. Comparisons with two control groups estimate that gastric cancer mortality was halved in the period from 2 to 7 years after the first screening visit. Validity of X-rays as used in this intervention had 88% sensitivity, 80% specificity, and 3% predictive value for individuals with two screening visits. Incidence in the screened group increased up to four times. Case survival was 85% in the intervention group after 5 years, compared to 12% among the controls before the intervention and 35% among the controls in the same region after the intervention. Although X-ray mass screening seems able to reduce stomach cancer mortality, its high cost may be an obstacle for scaling up this intervention in a non-rich country like Costa Rica.

Insurance and other socioeconomic determinants of elderly longevity in a Costa Rican panel

Official figures show that life expectancy in Costa Rica is longer than in the United States (US), in spite of the fact that per capita health expenditure is only one-tenth that of the US. To check whether this is for real and to explore some of its determinants, 900 Costa Ricans aged 60+ were followed from 1984 to 2001. Follow-up household visits were made, deaths were tracked in the national death registry, and survival status in the voting registry was double-checked. In addition, the survivors were contacted in 2002. Two-thirds of the panel had died by December 2001. Kaplan-Meier curves, life tables and Cox regression were used to analyse the panel's survival. Mortality in the panel was slightly higher than the Costa Rican average and similar to that in the US, confirming the exceptional longevity of Costa Ricans. Survival was substantially lower among unmarried men and individuals with limited autonomy at the beginning of the study. The effect of socioeconomic status is weak. Insurance effects seem to be confounded by selection biases.

Spatial access to health care in Costa Rica and its equity: a GIS-based study

This study assembles a geographic information system (GIS) to relate the 2000 census population (demand) with an inventory of health facilities (supply). It assesses the equity in access to health care by Costa Ricans and the impact on it by the ongoing reform of the health sector. It uses traditional measurements of access based on the distance to the closest facility and proposes a more comprehensive index of accessibility that results from the aggregation of all facilities weighted by their size, proximity, and characteristics of both the population and the facility. The weighting factors of this index were determined with an econometric analysis of clinic choice in a national household sample. Half Costa Ricans reside less than 1 km away from an outpatient care outlet and 5 km away from a hospital. In equity terms, 12-14% of population are underserved according to three indicators: having an outpatient outlet within 4 km, a hospital within 25 km, and less than 0.2 MD yearly hours per person. The data show substantial improvements in access (and equity) to outpatient care between 1994 and 2000. These improvements are linked to the health sector reform implemented since 1995. The share of the population whose access to outpatient health care (density indicator) was inequitable declined from 30% to 22% in pioneering areas where reform began in 1995-96. By contrast, in areas where reform has not occurred by 2001, the proportion underserved has slightly increased from 7% to 9%. Similar results come from a simpler index based on the distance to the nearest facility. Access to hospital care has held steady in this period. The reform achieved this result by targeting the least privileged population first, and by including such measures as new community medical offices and Basic Teams for Integrated Health Care (EBAIS) to work with these populations. The GIS platform developed for this study allows pinpointing communities with inadequate access to health care, where interventions to improve access would have the greatest impact.

Alcohol, tobacco and breast cancer--collaborative reanalysis of individual data from 53 epidemiological studies, including 58,515 women with breast cancer and 95,067 women without the disease

Alcohol and tobacco consumption are closely correlated and published results on their association with breast cancer have not always allowed adequately for confounding between these exposures. Over 80% of the relevant information worldwide on alcohol and tobacco consumption and breast cancer were collated, checked and analysed centrally. Analyses included 58,515 women with invasive breast cancer and 95,067 controls from 53 studies. Relative risks of breast cancer were estimated, after stratifying by study, age, parity and, where appropriate, women's age when their first child was born and consumption of alcohol and tobacco. The average consumption of alcohol reported by controls from developed countries was 6.0 g per day, i.e. about half a unit/drink of alcohol per day, and was greater in ever-smokers than never-smokers, (8.4 g per day and 5.0 g per day, respectively). Compared with women who reported drinking no alcohol, the relative risk of breast cancer was 1.32 (1.19-1.45, P<0.00001) for an intake of 35-44 g per day alcohol, and 1.46 (1.33-1.61, P<0.00001) for >/=45 g per day alcohol. The relative risk of breast cancer increased by 7.1% (95% CI 5.5-8.7%; P<0.00001) for each additional 10 g per day intake of alcohol, i.e. for each extra unit or drink of alcohol consumed on a daily basis. This increase was the same in ever-smokers and never-smokers (7.1% per 10 g per day, P<0.00001, in each group). By contrast, the relationship between smoking and breast cancer was substantially confounded by the effect of alcohol. When analyses were restricted to 22 255 women with breast cancer and 40 832 controls who reported drinking no alcohol, smoking was not associated with breast cancer (compared to never-smokers, relative risk for ever-smokers=1.03, 95% CI 0.98-1.07, and for current smokers=0.99, 0.92-1.05). The results for alcohol and for tobacco did not vary substantially across studies, study designs, or according to 15 personal characteristics of the women; nor were the findings materially confounded by any of these factors. If the observed relationship for alcohol is causal, these results suggest that about 4% of the breast cancers in developed countries are attributable to alcohol. In developing countries, where alcohol consumption among controls averaged only 0.4 g per day, alcohol would have a negligible effect on the incidence of breast cancer. In conclusion, smoking has little or no independent effect on the risk of developing breast cancer; the effect of alcohol on breast cancer needs to be interpreted in the context of its beneficial effects, in moderation, on cardiovascular disease and its harmful effects on cirrhosis and cancers of the mouth, larynx, oesophagus and liver.

[Forest and population at Península de Osa, Costa Rica]

The research is focused on the relationship between population growth and conservation of the forest on the Osa Peninsula. Data of the geo-referenced censuses and information on land-use, derived from satellite images and aerial photography, were integrated into a GIS. We undertook an historical inventory of the changes in the population and the forest coverage, and the key events in the land tenure and economy of the region. Deforestation, reforestation, and fragmentation of the forest during the period 1980-1995 were analyzed. Relationships with the population potential, derived from the 1984 Costa Rican censuses, were identified, and the effects of third variables were controlled such as distances to the roads, rain, distances to the forest frontier, level of protection, etc. Both strong and significant associations between 1984 population potential and the three processes were detected. The probability of deforestation is null in unpopulated areas, 35% in areas with 25-30 potential farmers and to 65% in areas with 50 farmers and over. The probability of reforestation decreases from 100% to 28% and to 18% in these three categories. This kind of relationship persists in the multivariable analysis. An increase of 0.63% in the number of household, results in an increment of 1% in the risk of deforestation (elasticity). The elasticity in the chances of reforestation is -0.37 and 1% in fragmentation of the forest. An evaluation in the risk of deforestation for the period 1995-2005 was done. The most recent population data were used and it identifies several geographic areas with high deforestation risk.

Assessing and interpreting birth spacing goals in Costa Rica

A procedure for assessing birth spacing goals, an important component of fertility preferences, is proposed and applied to 1993 Costa Rican data. Based on a reverse or backward survival analysis, preferred birth intervals are estimated to range between 3.5 and 4.5 years (1.5 years for the interval union to first birth). These intervals are 2 or 3 years shorter than crude estimates from data on open or last closed intervals, which are upwardly biased by selection and left censoring effects. To achieve these spacing preferences, a cohort must spend about two-thirds of the time using contraception (one-third in the interval union to first birth). An inverse association between desired family size and desired birth interval is evident only in parity-specific analyses.

Breast cancer and hormonal contraceptives: further results. Collaborative Group on Hormonal Factors in Breast Cancer

The Collaborative Group on Hormonal Factors in Breast Cancer has brought together and reanalysed the worldwide epidemiological evidence on breast cancer risk and use of hormonal contraceptives. Original data from 54 studies, representing about 90% of the information available on the topic, were collected, checked and analysed centrally. The 54 studies were performed in 26 countries and include a total of 53,297 women with breast cancer and 100,239 women without breast cancer. The studies were varied in their design, setting and timing. Most information came from case-control studies with controls chosen from the general population; most women resided in Europe or North America and most cancers were diagnosed during the 1980s. Overall 41% of the women with breast cancer and 40% of the women without breast cancer had used oral contraceptives at some time; the median age at first use was 26 years, the median duration of use was 3 years, the median year of first use was 1968, the median time since first use was 16 years, and the median time since last use was 9 years. The main findings, summarised elsewhere, are that there is a small increase in the risk of having breast cancer diagnosed in current users of combined oral contraceptives and in women who had stopped use in the past 10 years but that there is no evidence of an increase in the risk more than 10 years after stopping use. In addition, the cancers diagnosed in women who had used oral contraceptives tended to be less advanced clinically than the cancers diagnosed in women who had not used them. Despite the large number of possibilities investigated, few factors appeared to modify the main findings either in recent or in past users. For recent users who began use before age 20 the relative risks are higher than for recent users who began at older ages. For women whose use of oral contraceptives ceased more than 10 years before there was some suggestion of a reduction in breast cancer risk in certain subgroups, with a deficit of tumors that had spread beyond the breast, especially among women who had used preparations containing the highest doses of oestrogen and progestogen. These findings are unexpected and need to be confirmed. Although these data represent most of the epidemiological evidence on the topic to date, there is still insufficient information to comment reliably about the effects of specific types of oestrogen or of progestogen. What evidence there is suggests, however, no major differences in the effects for specific types of oestrogen or of progestogen and that the pattern of risk associated with use of hormonal contraceptives containing progestogens alone may be similar to that observed for preparations containing both oestrogens and progestogens. On the basis of these results, there is little difference between women who have and have not used combined oral contraceptives in terms of the estimated cumulative number of breast cancers diagnosed during the period from starting use up to 20 years after stopping. The cancers diagnosed in women who have used oral contraceptives are, however, less advanced clinically than the cancers diagnosed in never users. Further research is needed to establish whether the associations described here are due to earlier diagnosis of breast cancer in women who have used oral contraceptives, to the biological effects of the hormonal contraceptives or to a combination of both. Little information is as yet available about the effects on breast cancer risk of oral contraceptive use that ceased more than 20 years before and as such data accumulate it will be necessary to re-examine the worldwide evidence.

Sexual behavior, sexually transmitted diseases, and risk of cervical cancer

To explore sexually transmitted diseases and sexual behavior as risk factors for cervical cancer, we analyzed data from a population-based case-control study of breast and cervical cancer in Costa Rica. Data from 415 cases of cervical carcinoma in situ, 149 cases of invasive cervical cancer, and 764 controls were included in the analysis. Multivariate analysis showed that lifetime number of sex partners, first intercourse before age 15 years, number of livebirths, herpes simplex virus type 2 seropositivity, and serologic evidence of previous chlamydial infection were predictors of carcinoma in situ. Serologic evidence of previous syphilis was not associated with carcinoma in situ. Predictors for invasive cervical cancer included lifetime number of sex partners, first intercourse before age 15 years, number of livebirths, serologic evidence of previous syphilis, herpes simplex type 2 infection, and chlamydial infection. Cigarette smoking, socioeconomic status, self-reported history of sexually transmitted diseases, and douching were not associated with either carcinoma in situ or invasive cervical cancer.

The effect of using different reference dates for control exposure measurement on relative risk estimates in a case-control study

In case-control studies in which case and control enrollment periods are not identical, exposure status for time-dependent variables is often measured relative to a reference date. Using data from a case-control study of the relation between cervical cancer and oral contraceptive (OC) use in which control enrollment began 6 months after the end of case enrollment, we evaluated the effect on odds ratios from using five different reference dates to determine the controls' exposure status. The choice of reference date had little effect on the odds ratios in this study. Reference dates for time-dependent exposure variables should be considered carefully in studies when case and control enrollment periods are not identical.