[Eccema herpético en una paciente con dermatitis atópica].

Background: Eczema herpeticum is an infection caused by herpes simplex virus in patients with atopic dermatitis, among its complications we can find meningitis, encephalitis, acute liver failure, and Staphylococcus aureus infection. Case report: We report the case of a female patient of 5 years of age, with a history of atopic dermatitis complicated by eczema herpeticum, who was treated initially without relief. Her hospital stay was complicated with cross infections, which prolonged her course. Dermatology diagnosed eczema herpeticum. Immediately after the start of treatment, the patient showed improvement. Conclusions: Eczema herpeticum is a rare complication of atopic dermatitis, it must be suspected based on patient history and physical examination. Therefore, early recognition and diagnosis are of clinical importance. Without an appropriate approach, these patients can present shock, sepsis, and death.

Antecedentes: El eccema herpético es una infección causada por el virus del herpes simple, que afecta a pacientes con dermatitis atópica. Las principales complicaciones son meningitis, encefalitis, insuficiencia hepática aguda e infección por Staphylococcus aureus. Reporte de caso: Paciente pediátrica de 5 años, con antecedente de dermatitis atópica complicada con eccema herpético, que recibió tratamiento sin reacción satisfactoria. Durante la hospitalización tuvo infecciones nosocomiales que prolongaron su estancia. Luego de la evaluación por personal del servicio de Dermatología se estableció el diagnóstico de eccema herpético, con adecuado tratamiento, seguimiento y egreso sin complicaciones. Conclusiones: El eccema herpético es una complicación rara de la dermatitis atópica, que debe diagnosticarse con base en los antecedentes personales patológicos y la exploración física adecuada. La atención oportuna es de relevancia clínica, pues los pacientes pueden tener complicación serias (choque, sepsis, incluso la muerte). Palabras clave: Eccema herpético; dermatitis atópica; infección nosocomial; Staphylococcus aureus.

The Bangor Gambling Task: Computerized replication and reappraisal of an emotion-based decision task.

Emotion-based decision making (EBDM) is the capacity to make decisions based on prior emotional consequences of actions. Several neuropsychological tasks, using different gambling paradigms and with different levels of complexity, have been designed to assess EBDM. The Bangor Gambling Task (BGT) was created as a brief and simple card gambling-task to assess EBDM. BGT contains a single-card deck and requires participants to decide whether to gamble or not, which can result in wins or losses. Unknown to the participant, the winning probabilities decrease throughout the task (from 0.75 in the first block to 0.25 in the fifth block), requiring participants to reduce their gambling probability to avoid long-term losses. A few studies have offered evidence regarding the BGT convergent validity. However, there are no computerized versions of BGT available, thus slowing the process of gathering information to explore the EBDM mechanisms behind the task, its validity, and clinical usefulness. In this article, we present a computerized version of the BGT using the Matlab environment and make all our code available. We explore BGT's replicability and analyze its probabilistic structure, providing trial-level and block-level analyses. Eighty-one participants performed the computerized version, which followed the same structure as the original version. It took participants 8.5 ± 3.3 minutes to complete the task, which is faster than the paper version. Replicating previous studies, participants diminished their gambling probability throughout the task, learning to inhibit the initially rewarded gambling behavior. This change in gambling probability could be considered a proxy for EBDM. Our analyses suggest that the last blocks are especially sensitive to capturing deficits in EBDM, and we propose some modifications to BGT's original version to enhance the initial exploratory and learning phase. Our results show that the BGT constitutes a quick and simple task to evaluate EBDM capacities.

Urinary Arsenic Concentration and Its Relationship with Bronchial Asthma in Children from Arica, Chile.

In the city of Arica, northern Chile, the population has been involuntarily exposed to arsenic of natural and anthropogenic origin. This study aims to evaluate the association between urinary arsenic concentration and bronchial asthma diagnosis in the children of Arica. A cross-sectional analysis of a database of 1892 subjects under 18 years of age enrolled in the Environmental Health Centre between 2009 and 2021 was carried out. Arsenic exposure was obtained from a urine sample and bronchial asthma diagnosis from the database of the system for the management of explicit health guarantees. Logistic regression models were used to assess the association between inorganic arsenic and asthma. The median inorganic arsenic was 15 µg/L, and the prevalence of asthma was 7.4%. After adjusting for sex, age, ethnicity, and urinary creatinine, children with the highest tertile of urinary arsenic concentration (≥21.4 µg/L) had a greater chance of developing asthma (odds ratio (OR) 1.90; 95% confidence interval (CI) [1.13-3.18]). When exploring the modifying effect of ethnicity, the association increased among children belonging to any ethnic group (OR 3.51, 95%CI [1.43-8.65]). These findings suggest a relationship between arsenic exposure and bronchial asthma in children. While further studies are needed to assess the impact of arsenic on respiratory health, mitigation efforts to reduce arsenic exposure should be maintained.

Effect of periodontal treatment in patients with periodontitis and diabetes: systematic review and meta-analysis.

OBJECTIVE: The evidence is inconclusive regarding the effect of periodontal treatment on glycemic control and systemic inflammation in patients with type 2 diabetes (T2D) and periodontitis. To evaluate the effect of scaling and root planing (SRP) on the metabolic control and systemic inflammation of patients with type 2 diabetes (T2D). METHODOLOGY: A literature search was conducted using the MEDLINE database via PubMed and the Cochrane Central Register of Controlled Trials, from their oldest records up to July 2018. Only randomized clinical trials (RCT) were considered eligible for evaluating the effect of periodontal treatment on markers of metabolic control [glycated hemoglobin (HbA1C)] and systemic inflammation [C-reactive protein (CRP)] in patients with T2D. The quality of the studies was evaluated using the Cochrane Collaboration risk assessment tool. Meta-analyses were performed for HbA1c and CRP using random effects models. The size of the overall intervention effect was estimated by calculating the weighted average of the differences in means (DM) between the groups in each study. Heterogeneity was assessed using the Q-statistic method (x2 and I²). The level of significance was established at p<0.05. RESULTS: Nine RCT were included. SRP was effective in reducing HbA1c [DM=0.56 (0.36-0.75); p<0.01] and CRP [DM=1.89 (1.70-2.08); p<0.01]. No heterogeneity was detected (I2=0%, p>0.05). CONCLUSIONS: SRP has an impact on metabolic control and reduction of systemic inflammation of patients with T2D.

Effect of periodontal treatment in patients with periodontitis and diabetes: systematic review and meta-analysis

Abstract The evidence is inconclusive regarding the effect of periodontal treatment on glycemic control and systemic inflammation in patients with type 2 diabetes (T2D) and periodontitis Objective: To evaluate the effect of scaling and root planing (SRP) on the metabolic control and systemic inflammation of patients with type 2 diabetes (T2D). Methodology: A literature search was conducted using the MEDLINE database via PubMed and the Cochrane Central Register of Controlled Trials, from their oldest records up to July 2018. Only randomized clinical trials (RCT) were considered eligible for evaluating the effect of periodontal treatment on markers of metabolic control [glycated hemoglobin (HbA1C)] and systemic inflammation [C-reactive protein (CRP)] in patients with T2D. The quality of the studies was evaluated using the Cochrane Collaboration risk assessment tool. Meta-analyses were performed for HbA1c and CRP using random effects models. The size of the overall intervention effect was estimated by calculating the weighted average of the differences in means (DM) between the groups in each study. Heterogeneity was assessed using the Q-statistic method (x2 and I²). The level of significance was established at p<0.05. Results: Nine RCT were included. SRP was effective in reducing HbA1c [DM=0.56 (0.36-0.75); p<0.01] and CRP [DM=1.89 (1.70-2.08); p<0.01]. No heterogeneity was detected (I2=0%, p>0.05). Conclusions: SRP has an impact on metabolic control and reduction of systemic inflammation of patients with T2D.

Structural Equation Modelling in the exploration and analysis of intrauterine environmental exposures with infant health effects.

INTRODUCTION: In epidemiology, generalized linear models are the main statistical methods used to explore associations. However, the use of other methods such as Structural Equation Modelling (SEM) is gradually increasing. OBJECTIVE: The aim of the study was to illustrate the use of SEM in the assessment of salivary cortisol concentration in infants as a biomarker of perinatal exposure to inorganic arsenic. MATERIAL AND METHODS: This was a cohort study of pregnant women recruited from public health care centres in Arica, Chile, in 2013. Socio-demographic information and urine samples to assess inorganic arsenic were collected during the second trimester of pregnancy. Saliva samples were collected to assess cortisol in infants between 18-24 months of age. Four linear regression models (LRMs) and two SEMs were run to estimate the effect of prenatal exposure to inorganic arsenic on cortisol concentration in infants. RESULTS: According to LRMs and SEMs, prenatal exposure to inorganic arsenic and salivary cortisol were not associated. However, the association between maternal cortisol and cortisol in infants was statistically significant in all models; for each increase in standard deviation of the covariate Ln(maternal cortisol), the outcome Ln(cortisol in infant) increased by 0.49 units of variance in both SEMs. CONCLUSIONS: LRMs and SEMs were useful to assess the effect of prenatal exposure to inorganic arsenic on cortisol in infants. However, SEM allowed the adjustment of estimations by an estimated latent that obtained the information about income, occupation, education and ethnicity in a more comprehensive way than achieved by LRM.

Is prenatal arsenic exposure associated with salivary cortisol in infants in Arica, Chile? An exploratory cohort study.

INTRODUCTION: In animal models, gestational exposure to inorganic arsenic has been associated with higher corticosterone concentration and consequent impairment of stress control in offspring. An equivalent association relating cortisol, a glucocorticoid hormone, in humans has not been previously studied. OBJECTIVE: The aim of the study was to explore the association between prenatal inorganic arsenic exposure and salivary cortisol in infants from Arica, Chile. MATERIAL AND METHODS: A cohort study of 168 mother-child dyads was recruited. In the 2nd trimester of pregnancy, urinary inorganic arsenic was assessed; 18-24 months after delivery, salivary cortisol was measured in the children. Maternal cortisol, maternal depression, stress, and socio-economic status were also evaluated. RESULTS: The adjusted association was estimated with multiple linear regression after evaluating confounding through a directed acyclic graph. Median urinary inorganic arsenic in pregnant women was 14.1 µg/L (IQR: 10.4-21.7) while salivary cortisol in the children was 0.17 µg/L (IQR: 0.11-0.38). Among children from the highest income families (> 614 USD/month), arsenic exposure was associated with salivary cortisol. Children in the third quartile of arsenic exposure had -0.769 units of the logarithm of salivary cortiso, compared with those in the first quartile (p = 0.045). CONCLUSIONS: In this sample, prenatal exposure to arsenic was associated with salivary cortisol (third quartile of inorganic arsenic), only in infants belonging the highest income strata (> 614 USD). More studies are needed to confirm these preliminary results.

Urinary Inorganic Arsenic Concentration and Gestational Diabetes Mellitus in Pregnant Women from Arica, Chile.

Introduction: The association of total arsenic exposure with impaired glucose tolerance and gestational diabetes has been shown; however, evidence regarding urinary inorganic arsenic in pregnant women is still limited. Our aim was to evaluate the association between urinary inorganic arsenic concentration and gestational diabetes among pregnant women living in Arica, Chile. Methods: Cross-sectional study of pregnant women receiving care at primary health centers in urban Arica. The exposure was urinary inorganic arsenic concentration, while gestational diabetes was the outcome. The association was evaluated using multiple logistic regression models adjusted by age, education level, ethnicity, and pre-pregnancy body mass index. Results: 244 pregnant women were surveyed. The median urinary inorganic arsenic was 14.95 μg/L, and the prevalence of gestational diabetes was 8.6%. After adjusting, we did not find a significant association between gestational diabetes and inorganic arsenic exposure tertiles (Odds ratio (OR) 2.98, 95% CI = 0.87⁻10.18), (OR 1.07, 95% CI = 0.26⁻4.33). Conclusion: This study did not provide evidence on the relationship between urinary inorganic arsenic concentration and gestational diabetes. Further research is needed to elucidate the factors underlying this association.

[Cleft lip/palate and flour fortification with folic acid in Chile]. / Fisuras labio-palatinas y fortificación de la harina con ácido fólico en Chile: An exploratory study.

BACKGROUND: The effect of food fortification with folic acid on the incidence of lip-palate fissures (FLP) is under discussion. AIM: To calculate the rate of hospital discharges due to cleft lip and palate (CLP) and explore whether they decreased after the start of folic acid fortification in Chile. MATERIAL AND METHODS: The hospital discharge databases published by the Chilean Ministry of Health were analyzed. The trends of discharge rates due to CLP of children of less than one year of life (ICD-10 Q350-379 code) and live births (lb) were calculated from 1986 to 2012. Variables such as incidence of rubella, poverty rate, obesity in pregnant women, and percentage of women who smoked or drank alcohol in the last month were included. The relative risk (RR) of CLP pre-fortification (1986-1999) and post-fortification (2000-2010) was calculated. Mixed and Prais-Winsten models were used to adjust other variables. RESULTS: The hospital discharge rate due to CLP decreased from 1.88 x 1,000 lb during 1986-1996 to 1.68 x 1,000 lb (RR = 1.09 (95% CI 1.05-1.14, p < 0.001). Prais-Winsten and Mixed models, determined that folic acid fortification is the variable explaining this decrease. During 2004-2011, hospital discharge rates for cleft lip decreased but there was an increase in the figures for cleft lip and palate. CONCLUSIONS: The 9% decrease in hospital discharge rates for CLP is concomitant with wheat folic acid fortification.

Contaminación intradomiciliaria por material particulado fino (MP2, 5) en hogares de recién nacidos / Indoor air pollution by fine particulate matter in the homes of newborns

Introducción: La contaminación de aire por material particulado (MP) es un importante problema de salud pública. En Chile se ha estudiado la contaminación atmosférica y MP10, y escasamente aire interior y MP2,5. Como los recién nacidos y los lactantes pasan la mayoría del tiempo en el hogar, es necesario evaluar la exposición a la contaminación intradomiciliaria en esta población susceptible. Objetivo: Determinar la concentración de MP2,5 en hogares de recién nacidos e identificar las fuentes de emisión contaminante. Pacientes y método: En 207 hogares se recolectó la concentración de MP2,5 ([MP2,5]) por 24 h y se evaluó la información sociodemográfica y los factores ambientales (calefacción, ventilación, tabaquismo intradomiciliario y aseo del hogar). Resultados: La [MP2,5] mediana fue 107,5 μg/m³. El antecedente «asma familiar¼ se asoció a menor [MP2,5] (p = 0,0495). Hogares sin uso de calefacción mostraron la menor [MP2,5] mediana, 58,6 μg/m³, mientras los que usaron leña, parafina, electricidad entre 112,5 y 114,9 μg/m³ y brasero 162,9 μg/m³. Hogares que usaron leña tuvieron diferencias significativas en [MP2,5] mediana (p = 0,0164) al usar estufa de combustión completa (98,2 μg/m³) versus cocina a leña (112,6 μg/m³) y salamandra (140,6 μg/m³). En el 8,7% de los hogares se reportó consumo de cigarrillos, no asociándose a [MP2,5]. La ventilación se asoció a mayor [MP2,5] mediana (120,6 vs. 99,1 μg/m³; p = 0,0039). Conclusión: Hubo hogares con [MP2,5] elevada, siendo el consumo residencial de leña casi universal y asociado a [MP2,5]. La ventilación natural incrementó el MP2,5 interior, probablemente por infiltración desde el exterior.

Introduction: Air pollution by particulate matter (PM) is a major public health problem. In Chile, the study has focused on outdoor air and PM10, rather than indoor air and PM2.5. Because newborns and infants spend most of their time at home, it is necessary to evaluate the exposure to indoor air pollution in this susceptible population. Objective: To determine concentration of PM2.5 in the homes of newborns and identify the emission sources of the pollutants. Patients and Method: The PM2.5 concentration ([PM2.5]) was collected over a 24 hour period in 207 households. Baseline sociodemographic information and environmental factors (heating, ventilation, smoking and house cleaning), were collected. Results: The median [PM2.5] was 107.5 μg/m³. Family history of asthma was associated with lower [PM2.5] (P = .0495). Homes without heating showed a lower median [PM2.5], 58.6 μg/m³, while those using firewood, kerosene, and electricity ranged between 112.5 and 114.9, and coal users’ homes reached 162.9 μg/m³. Wood using homes had significant differences (P = .0164) in median [PM2.5] whether the stove had complete combustion (98.2 μg/m³) vs. incomplete (112.6 μg/m³), or a salamander stove (140.6 μg/m³). Cigarette smoking was reported in 8.7% of the households, but was not associated with the [PM2.5]. Ventilation was associated with a higher median [PM2.5] (120.6 vs. 99.1 μg/m³, P = .0039). Conclusion: We found homes with high [PM2.5]. Residential wood consumption was almost universal, and it is associated with the [PM2.5]. Natural ventilation increased MP2.5, probably due to infiltration from outside.

Fisuras labio-palatinas y fortificación de la harina con ácido fólico en Chile: an exploratory study / Cleft lip/palate and flour fortification with folic acid in Chile

Background: The effect of food fortification with folic acid on the incidence of lip-palate fissures (FLP) is under discussion. Aim: To calculate the rate of hospital discharges due to cleft lip and palate (CLP) and explore whether they decreased after the start of folic acid fortification in Chile. Material and Methods: The hospital discharge databases published by the Chilean Ministry of Health were analyzed. The trends of discharge rates due to CLP of children of less than one year of life (ICD-10 Q350-379 code) and live births (lb) were calculated from 1986 to 2012. Variables such as incidence of rubella, poverty rate, obesity in pregnant women, and percentage of women who smoked or drank alcohol in the last month were included. The relative risk (RR) of CLP pre-fortification (1986-1999) and post-fortification (2000-2010) was calculated. Mixed and Prais-Winsten models were used to adjust other variables. Results: The hospital discharge rate due to CLP decreased from 1.88 x 1,000 lb during 1986-1996 to 1.68 x 1,000 lb (RR = 1.09 (95% CI 1.05-1.14, p < 0.001). Prais-Winsten and Mixed models, determined that folic acid fortification is the variable explaining this decrease. During 2004-2011, hospital discharge rates for cleft lip decreased but there was an increase in the figures for cleft lip and palate. Conclusions: The 9% decrease in hospital discharge rates for CLP is concomitant with wheat folic acid fortification.

[Indoor air pollution by fine particulate matter in the homes of newborns]. / Contaminación intradomiciliaria por material particulado fino (MP2,5) en hogares de recién nacidos.

INTRODUCTION: Air pollution by particulate matter (PM) is a major public health problem. In Chile, the study has focused on outdoor air and PM10, rather than indoor air and PM2.5. Because newborns and infants spend most of their time at home, it is necessary to evaluate the exposure to indoor air pollution in this susceptible population. OBJECTIVE: To determine concentration of PM2.5 in the homes of newborns and identify the emission sources of the pollutants. PATIENTS AND METHOD: The PM2.5 concentration ([PM2.5]) was collected over a 24hour period in 207 households. Baseline sociodemographic information and environmental factors (heating, ventilation, smoking and house cleaning), were collected. RESULTS: The median [PM2.5] was 107.5µg/m3. Family history of asthma was associated with lower [PM2.5] (P=.0495). Homes without heating showed a lower median [PM2.5], 58.6µg/m3, while those using firewood, kerosene, and electricity ranged between 112.5 and 114.9, and coal users' homes reached 162.9µg/m3. Wood using homes had significant differences (P=.0164) in median [PM2.5] whether the stove had complete combustion (98.2µg/m3) vs. incomplete (112.6µg/m3), or a salamander stove (140.6µg/m3). Cigarette smoking was reported in 8.7% of the households, but was not associated with the [PM2.5]. Ventilation was associated with a higher median [PM2.5] (120.6 vs. 99.1µg/m3, P=.0039). CONCLUSION: We found homes with high [PM2.5]. Residential wood consumption was almost universal, and it is associated with the [PM2.5]. Natural ventilation increased MP2.5, probably due to infiltration from outside.

Chile Confronts its Environmental Health Future After 25 Years of Accelerated Growth.

BACKGROUND: Chile has recently been reclassified by the World Bank from an upper-middle-income country to a high-income country. There has been great progress in the last 20 to 30 years in relation to air and water pollution in Chile. Yet after 25 years of unrestrained growth, there remain clear challenges posed by air and water pollution, as well as climate change. OBJECTIVE: The aim of this study was to review environmental health in Chile. METHODS: In late 2013, a 3-day workshop on environmental health was held in Santiago, Chile, bringing together researchers and government policymakers. As a follow-up to that workshop, here we review the progress made in environmental health in the past 20 to 30 years and discuss the challenges of the future. We focus on air and water pollution and climate change, which we believe are among the most important areas of environmental health in Chile. RESULTS: Air pollution in some cities remains among the highest in the continent. Potable water is generally available, but weak state supervision has led to serious outbreaks of infectious disease and ongoing issues with arsenic exposure in some regions. Climate change modeling in Chile is quite sophisticated, and a number of the impacts of climate change can be reasonably predicted in terms of which areas of the country are most likely to be affected by increased temperature and decreased availability of water, as well as expansion of vector territory. Some health effects, including changes in vector-borne diseases and excess heat mortality, can be predicted. However, there has yet to be an integration of such research with government planning. CONCLUSIONS: Although great progress has been made, currently there are a number of problems. We suspect that the Chilean experience in environmental health may be of some use for other Latin American countries with rapid economic development.

Geographical distribution of alcohol-attributable mortality in Chile: a Bayesian spatial analysis.

OBJECTIVE: To describe the distribution of alcohol-attributable mortality (AAM) at the local level (345 municipalities) in Chile, including fully and partially attributable causes in 2009. METHODS: AAM was estimated for the population 15years of age and older using per capita alcohol consumption combined with survey estimates. The effect of alcohol on each cause of death was extracted from the published scientific literature. We used Bayesian hierarchical models to smooth the Standardized Mortality Ratio for each municipality for six groups of causes related to alcohol consumption (total, neuro-psychiatric, cardiovascular, cancer, injuries and other causes). RESULTS: The percentage of municipalities with high risk for any group of causes in each region ranges from 0% to 87.0%. Municipalities with high risk were concentrated in south-central and southern Chile for all groups of causes related to alcohol. CONCLUSIONS: AAM risk shows marked geographic concentrations, mainly in south-central and southern regions of Chile. This combination of methods for small-area estimates of AAM is a powerful tool to identify high risk regions and associated factors, and may be used to inform local policies and programs.

Small area associations between social context and alcohol-attributable mortality in a middle income country.

BACKGROUND: Little is known about the association between alcohol-attributable mortality and small area socioeconomic variables when considering causes both wholly and partially attributable to alcohol. METHODS: An ecological study was conducted of the entire Chilean population aged 15 and older in 345 municipalities nationwide between 2004 and 2009. Deaths were attributed to alcohol consumption either wholly or partially, along with the estimated attributable fractions for each specified cause. Each municipality was characterized according to its average income and educational attainment. Estimates of the ecological associations were produced using a hierarchical Bayesian model, separating out deaths caused by alcohol and dividing them into seven groups of causes. RESULTS: Alcohol-attributable mortality risk showed an inverse association with income and education at the ecological level. A one-quintile increase in income was associated with an average decrease in risk of 10% (CI 95%: 10-20%) for cardiovascular deaths, 8% (6-10%) for intentional injuries and 7% (3-11%) for unintentional injuries. No associations were found between deaths due to cancers and other causes with income and education. CONCLUSIONS: Municipalities with lower income and education have higher risk of alcohol-attributable mortality in Chile.

Interacción, sinergia y antagonismo en estudios prospectivos en Epidemiología / Interaction, synergy and antagonism in prospective Epidemiological studies

En Salud Pública existe una creciente conciencia sobre las ventajas de las escalas aditivas para una mejor comprensión del impacto de los factores involucrados en un evento de salud. Es necesario siempre recordar que el concepto de interacción estadística es escala dependiente. En la relación causal entre una respuesta y la presencia de dos o más factores de exposición los conceptos de interacción, sinergia y antagonismo cobran protagonismo. El objetivo de este documento es mostrar una aplicación de los conceptos interacción, sinergia y antagonismo en estudios prospectivos con una mirada de la salud pública. Se presentan tres situaciones que ilustran dichos conceptos. Se utiliza Stata 12 para el ajuste de modelos (log-binomial y Poisson) y estimación de parámetros. Se aportan anexos con conceptos y comandos de Stata usados en los procesos de simulación y estimación de parámetros.

In public health there is a growing appreciation for the advantage of the additive scale to better understand the impacts of factors involved in a health event. It is necessary to always remember that the concept of statistical interaction is scale dependent. In the causal relationship between a response and the presence of two or more factors, the concepts interaction, synergy and antagonism are the key ideas. The aim of this note is to show an application of the concepts interaction, synergy and antagonism in prospective studies from a public health perspective. We present three scenarios that illustrate analyses of interaction, independence, synergy and antagonism. Stata 12 software was used for fitting models (log-binomial model and Poisson) and estimating parameters. Appendixes are provided with concepts and Stata commands used in the processes of simulation and parameter estimation.

Alcohol-attributable mortality and years of potential life lost in Chile in 2009.

AIMS: The aim of the study was to estimate mortality and years of potential life lost (YPLL) attributable to alcohol consumption in 2009 in Chile. METHODS: The population considered for this study included those 15 years and over. Exposure to alcohol in the population was estimated by triangulating the records of alcohol per capita consumption in Chile with information from the Eighth National Study of Drugs in the General Population (2008). The effect of alcohol consumption on each cause of death (relative risk) was extracted from previously published meta-analyses. With this information we estimated the alcohol-attributable fraction (AAF) and deaths and YPLL due to alcohol consumption. The confidence intervals for the AAF were estimated with Monte Carlo sampling using the estimated variances of the exposure prevalence and relative effect. RESULTS: The estimated total number of deaths attributable to alcohol consumption was 8753 (95% CI: 6257, 11,584) corresponding to 9.8% (95% CI: 7.01%, 12.98%) of all deaths in Chile in 2009. The total estimated YPLL attributable to alcohol were 195,475 (95% CI: 164,287, 227,726), corresponding to 21.5% (95% CI: 18.1%, 25.0%) of total YPLL for that year in Chile. CONCLUSION: Alcohol consumption is a major risk factor and accounts for nearly one of ten deaths in Chile. These results may be used to guide the design of public health policies and evaluations.

[Interaction, synergy and antagonism in prospective epidemiological studies]. / Interacción, sinergia y antagonismo en estudios prospectivos en Epidemiología.

In public health there is a growing appreciation for the advantage of the additive scale to better understand the impacts of factors involved in a health event. It is necessary to always remember that the concept of statistical interaction is scale dependent. In the causal relationship between a response and the presence of two or more factors, the concepts interaction, synergy and antagonism are the key ideas. The aim of this note is to show an application of the concepts interaction, synergy and antagonism in prospective studies from a public health perspective. We present three scenarios that illustrate analyses of interaction, independence, synergy and antagonism. Stata 12 software was used for fitting models (log-binomial model and Poisson) and estimating parameters. Appendixes are provided with concepts and Stata commands used in the processes of simulation and parameter estimation.

Exposure to lead from a storage site associated with intellectual impairment in Chilean children living nearby.

This study assesses the degree of impairment of children's IQ scores due to exposure to lead from a storage site. In 2005, we studied 192 children in Antofagasta, Chile, age 7-16 years who had been exposed to a lead storage site from birth until its removal in 1998. We used past (1998) and current (2005) blood lead levels as explanatory variables for IQ, which was measured once in 2005 using the WISC-r test. Multilevel mixed-effects linear regression models were constructed, adjusting for potential confounders. Current blood lead level (BPb, 2005) was associated with a significant decrease in full-scale IQ (P value = 0.03), whereas blood lead level measured in 1998 (BPb, 1998) showed an inverse but not significant association with full-scale IQ (P value = 0.35). The findings provide evidence that exposure to an open source of environmental lead can exert an effect on IQ. Policy efforts should be targeted to prevent lead exposure to avoid children's intellectual impairment.