Short-term ozone exposure and cancer mortality in Brazil: A nationwide case-crossover study.

Exposure to ambient ozone (O3) is linked to increased mortality risks from various diseases, but epidemiological investigations delving into its potential implications for cancer mortality are limited. We aimed to examine the association between short-term O3 exposure and site-specific cancer mortality and investigate vulnerable subgroups in Brazil. In total 3,459,826 cancer death records from 5570 Brazilian municipalities between 2000 and 2019, were included. Municipal average daily O3 concentration was calculated from a global estimation at 0.25°×0.25° spatial resolution. The time-stratified case-crossover design was applied to assess the O3-cancer mortality association. Subgroup analyses by age, sex, season, time-period, region, urban hierarchy, climate classification, quantiles of GDP per capita and illiteracy rates were performed. A linear and non-threshold exposure-response relationship was observed for short-term exposure to O3 with cancer mortality, with a 1.00% (95% CI: 0.79%-1.20%) increase in all-cancer mortality risks for each 10-µg/m3 increment of three-day average O3. Kidney cancer was most strongly with O3 exposure, followed by cancers of the prostate, stomach, breast, lymphoma, brain and lung. The associated cancer risks were relatively higher in the warm season and in southern Brazil, with a decreasing trend over time. When restricting O3 concentration to the national minimum value during 2000-2019, a total of 147,074 (116,690-177,451) cancer deaths could be avoided in Brazil, which included 17,836 (7014-28,653) lung cancer deaths. Notably, these associations persisted despite observed adaptation within the Brazilian population, highlighting the need for a focus on incorporating specific measures to mitigate O3 exposure into cancer care recommendations.

Mortality risk and burden of aortic aneurysm and dissection attributable to low temperatures: A nationwide case-crossover analysis in Brazil, a predominantly tropical country.

BACKGROUND: Low temperatures are adverse contributors to cardiovascular diseases, but the associations between short-term exposure to cold and the risk of death from aortic dissection and aneurysm remain unclear, particularly in tropical regions. OBJECTIVE: This study was conducted based on 123,951 records of deaths caused by aortic dissection and aneurysms extracted from the national Mortality Information System in Brazil between 2000 and 2019. METHODS: Relative risks and 95 % confidence intervals (CI) for the aortic-related deaths associated with low ambient temperatures were estimated using the conditional logistic model combined with the distributed lag nonlinear model. Subgroup analyses were performed by age group, sex, race, education level, and residential region. Furthermore, this study calculated the number and fraction of aortic-related deaths attributed to temperatures below the temperature threshold to quantify the cold-related mortality burden of aortic diseases. RESULTS: During the study period, aortic-related deaths and mortality rates in Brazil exhibited a steady increase, rising from 4419 (2.66/100,000) in 2000 to 8152 (3.88/100,000) in 2019. Under the identified temperature threshold (26 °C), per 1 °C decrease in daily mean temperature was associated with a 4.77 % (95 % CI: 4.35, 5.19) increase in mortality risk of aortic-related diseases over lag 0-3 days. Females, individuals aged 50 years or older, Asian and Black race, and northern residents were more susceptible to low temperatures. Low temperatures were responsible for 19.10 % (95 % CI: 17.71, 20.45) of aortic-related deaths in Brazil. CONCLUSION: This study highlights that low temperatures were associated with an increased risk of aortic-related deaths, with a remarkable burden even in this predominantly tropical country.

Cancer mortality risk from short-term PM2.5 exposure and temporal variations in Brazil.

Although some studies have found that short-term PM2.5 exposure is associated with lung cancer deaths, its impact on other cancer sites is unclear. To answer this research question, this time-stratified case-crossover study used individual cancer death data between January 1, 2000, and December 31, 2019, extracted from the Brazilian mortality information system to quantify the associations between short-term PM2.5 exposure and cancer mortality from 25 common cancer sites. Daily PM2.5 concentration was aggregated at the municipality level as the key exposure. The study included a total of 34,516,120 individual death records, with the national daily mean PM2.5 exposure 15.3 (SD 4.3) µg/m3. For every 10-µg/m3 increase in three-day average PM2.5 exposure, the odds ratio (OR) for all-cancer mortality was 1.04 (95% CI 1.03-1.04). Apart from all-cancer deaths, PM2.5 exposure may impact cancers of oesophagus (1.04, 1.00-1.08), stomach (1.05, 1.02-1.08), colon-rectum (1.04, 1.01-1.06), lung (1.04, 1.02-1.06), breast (1.03, 1.00-1.06), prostate (1.07, 1.04-1.10), and leukaemia (1.05, 1.01-1.09). During the study period, acute PM2.5 exposure contributed to an estimated 1,917,994 cancer deaths, ranging from 0 to 6,054 cases in each municipality. Though there has been a consistent downward trend in PM2.5-related all-cancer mortality risks from 2000 to 2019, the impact remains significant, indicating the continued importance of cancer patients avoiding PM2.5 exposure. This nationwide study revealed a notable association between acute PM2.5 exposure and heightened overall and site-specific cancer mortality for the first time to our best knowledge. The findings suggest the importance of considering strategies to minimize such exposure in cancer care guidelines. ENVIRONMENTAL IMPLICATION: The 20-year analysis of nationwide death records in Brazil revealed that heightened short-term exposure to PM2.5 is associated with increased cancer mortality at various sites, although this association has gradually decreased over time. Despite the declining impact, the research highlights the persistent adverse effects of PM2.5 on cancer mortality, emphasizing the importance of continued research and preventive measures to address the ongoing public health challenges posed by air pollution.

Short-term exposure to PM2.5 and 1.5 million deaths: a time-stratified case-crossover analysis in the Mexico City Metropolitan Area.

BACKGROUND: Satellite-based PM2.5 predictions are being used to advance exposure science and air-pollution epidemiology in developed countries; including emerging evidence about the impacts of PM2.5 on acute health outcomes beyond the cardiovascular and respiratory systems, and the potential modifying effects from individual-level factors in these associations. Research on these topics is lacking in low and middle income countries. We aimed to explore the association between short-term exposure to PM2.5 with broad-category and cause-specific mortality outcomes in the Mexico City Metropolitan Area (MCMA), and potential effect modification by age, sex, and SES characteristics in such associations. METHODS: We used a time-stratified case-crossover study design with 1,479,950 non-accidental deaths from the MCMA for the period of 2004-2019. Daily 1 × 1 km PM2.5 (median = 23.4 µg/m3; IQR = 13.6 µg/m3) estimates from our satellite-based regional model were employed for exposure assessment at the sub-municipality level. Associations between PM2.5 with broad-category (organ-system) and cause-specific mortality outcomes were estimated with distributed lag conditional logistic models. We also fit models stratifying by potential individual-level effect modifiers including; age, sex, and individual SES-related characteristics namely: education, health insurance coverage, and job categories. Odds ratios were converted into percent increase for ease of interpretation. RESULTS: PM2.5 exposure was associated with broad-category mortality outcomes, including all non-accidental, cardiovascular, cerebrovascular, respiratory, and digestive mortality. A 10-µg/m3 PM2.5 higher cumulative exposure over one week (lag06) was associated with higher cause-specific mortality outcomes including hypertensive disease [2.28% (95%CI: 0.26%-4.33%)], acute ischemic heart disease [1.61% (95%CI: 0.59%-2.64%)], other forms of heart disease [2.39% (95%CI: -0.35%-5.20%)], hemorrhagic stroke [3.63% (95%CI: 0.79%-6.55%)], influenza and pneumonia [4.91% (95%CI: 2.84%-7.02%)], chronic respiratory disease [2.49% (95%CI: 0.71%-4.31%)], diseases of the liver [1.85% (95%CI: 0.31%-3.41%)], and renal failure [3.48% (95%CI: 0.79%-6.24%)]. No differences in effect size of associations were observed between age, sex and SES strata. CONCLUSIONS: Exposure to PM2.5 was associated with non-accidental, broad-category and cause-specific mortality outcomes beyond the cardiovascular and respiratory systems, including specific death-causes from the digestive and genitourinary systems, with no indication of effect modification by individual-level characteristics.

Daily exposure to PM2.5 and 1.5 million deaths: A time-stratified case-crossover analysis in the Mexico City Metropolitan Area.

Background: Satellite-based PM2.5 predictions are being used to advance exposure science and air-pollution epidemiology in developed countries; including emerging evidence about the impacts of PM2.5 on acute health outcomes beyond the cardiovascular and respiratory systems, and the potential modifying effects from individual-level factors in these associations. Research on these topics is lacking in Latin America. Methods: We used a time-stratified case-crossover study design with 1,479,950 non-accidental deaths from Mexico City Metropolitan Area for the period of 2004-2019. Daily 1×1 km PM2.5 (median=23.4 µg/m3; IQR=13.6 µg/m3) estimates from our satellite-based regional model were employed for exposure assessment at the sub-municipality level. Associations between PM2.5 with broad-category (organ-system) and cause-specific mortality outcomes were estimated with distributed lag conditional logistic models. We also fit models stratifying by potential individual-level effect modifiers including; age, sex, and individual SES-related characteristics namely: education, health insurance coverage, and job categories. Results: PM2.5 exposure was associated with higher total non-accidental, cardiovascular, cerebrovascular, respiratory, and digestive mortality. A 10-µg/m3 PM2.5 higher cumulative exposure over one week (lag06) was associated with higher cause-specific mortality outcomes including hypertensive disease [2.28% (95%CI: 0.26%-4.33%)], acute ischemic heart disease [1.61% (95%CI: 0.59%-2.64%)], other forms of heart disease [2.39% (95%CI: -0.35%-5.20%)], hemorrhagic stroke [3.63% (95%CI: 0.79%-6.55%)], influenza and pneumonia [4.91% (95%CI: 2.84%-7.02%)], chronic respiratory disease [2.49% (95%CI: 0.71%-4.31%)], diseases of the liver [1.85% (95%CI: 0.31%-3.41%)], and renal failure [3.48% (95%CI: 0.79%-6.24%)]. No differences in effect size of associations were observed between SES strata. Conclusions: Exposure to PM2.5 was associated with mortality outcomes beyond the cardiovascular and respiratory systems, including specific death-causes from the digestive and genitourinary systems, with no indications of effect modification by individual SES-related characteristics.

Association between ambient temperature and hospitalization for renal diseases in Brazil during 2000-2015: A nationwide case-crossover study.

Background: Climate change is increasing the risks of injuries, diseases, and deaths globally. However, the association between ambient temperature and renal diseases has not been fully characterized. This study aimed to quantify the risk and attributable burden for hospitalizations of renal diseases related to ambient temperature. Methods: Daily hospital admission data from 1816 cities in Brazil were collected during 2000 and 2015. A time-stratified case-crossover design was applied to evaluate the association between temperature and renal diseases. Relative risks (RRs), attributable fractions (AFs), and their confidence intervals (CIs) were calculated to estimate the associations and attributable burden. Findings: A total of 2,726,886 hospitalizations for renal diseases were recorded during the study period. For every 1°C increase in daily mean temperature, the estimated risk of hospitalization for renal diseases over lag 0-7 days increased by 0·9% (RR = 1·009, 95% CI: 1·008-1·010) at the national level. The associations between temperature and renal diseases were largest at lag 0 days but remained for lag 1-2 days. The risk was more prominent in females, children aged 0-4 years, and the elderly ≥ 80 years. 7·4% (95% CI: 5·2-9·6%) of hospitalizations for renal diseases could be attributable to the increase of temperature, equating to 202,093 (95% CI: 141,554-260,594) cases. Interpretation: This nationwide study provides robust evidence that more policies should be developed to prevent heat-related hospitalizations and mitigate climate change. Funding: China Scholarship Council, and the Australian National Health and Medical Research Council.

Alcohol and Road Traffic Injuries in Latin America and the Caribbean: A Case-Crossover Study.

BACKGROUND: This study reports dose-response estimates for the odds ratio (OR) and population attributable risk of acute alcohol use and road traffic injury (RTI). METHODS: Data were analyzed on 1,119 RTI patients arriving at 16 emergency departments (EDs) in Argentina, Brazil, Costa Rica, Dominican Republic, Guatemala, Guyana, Mexico, Nicaragua, Panama, and Trinidad and Tobago. Case-crossover analysis, pair-matching the number of standard drinks consumed within the 6 hours prior to the RTI with 2 control periods (prior d/wk), was performed using fractional polynomial analysis for dose-response. RESULTS: About 1 in 6 RTI patients in EDs were positive for self-reported alcohol 6 hours prior to the injury (country range 8.6 to 24.1%). The likelihood of an RTI with any drinking prior (compared to not drinking) was 5 times higher (country range OR 2.50 to 15.00) and the more a person drinks the higher the risk. Every drink (12.8 g alcohol) increased the risk of an RTI by 13%, even 1 to 2 drinks were associated with a sizable increase in risk of an RTI and a dose-response was found. Differences in ORs for drivers (OR = 3.51; 95% CI = 2.25 to 5.45), passengers (OR = 8.12; 95% CI = 4.22 to 15.61), and pedestrians (OR = 6.30; 95% CI = 3.14 to 12.64) and attributable fractions were noted. Acute use of alcohol was attributable to 14% of all RTIs, varying from 7% for females to 19% for being injured as a passenger. CONCLUSIONS: The finding that the presence of alcohol increases risk among drivers and nondrivers alike may further help to urge interventions targeting passengers and pedestrians. Routine screening and brief interventions in all health services could also have a beneficial impact in decreasing rates of RTIs. Higher priority should be given to alcohol as a risk factor for RTIs, particularly in Latin America and the Caribbean.

A meta-analysis of acute use of alcohol and the risk of suicide attempt.

BACKGROUND: No review has used a meta-analytic approach to estimate common odds ratios (ORs) for the effect of acute use of alcohol (AUA) on suicide attempts. We aim to report the results of the first meta-analysis of controlled epidemiological studies on AUA and suicide attempt. METHOD: The English-language literature on Medline, PsycINFO and Google Scholar was searched for original articles and critical review on AUA and suicide attempt (period 1996-2015). Studies had to report an OR estimate for this association. Common ORs and 95% confidence intervals (CIs) from random effects in meta-analyses for any AUA and two levels of alcohol use on suicide attempt were calculated. RESULTS: In all, seven studies provided OR estimates for the likelihood of suicide attempt by AUA, compared with those who did not drink alcohol. Studies used case-control (n 3) and case-crossover designs (n 4). Meta-analysis revealed a common OR of 6.97 (95% CI 4.77-10.17) for any AUA. Using four studies, 'low levels of acute drinking' resulted in an OR of 2.71 (95% CI 1.56-4.71) and 'high levels' had an OR of 37.18 (95% CI 17.38-79.53). CONCLUSIONS: AUA is associated with increased likelihood of a suicide attempt, particularly at high doses. Such data should be incorporated into estimates of the burden of disease associated with alcohol use, which are currently limited by a consideration of only alcohol's chronic effects. Future research should focus on the mechanisms through which AUA confers risk for attempt.

A dose-response estimate for acute alcohol use and risk of suicide attempt.

This study reports dose-response estimates for the relative risk and population attributable risk (PAR) between acute alcohol use and serious suicide attempt. Data were analyzed on 272 suicide attempters arriving at 38 emergency departments within 6 hours of the event in 17 countries. Case-crossover analysis, pair-matching the number of standard drinks consumed within the 6 hours prior to the suicide attempt with that consumed during the same 6-hour period of the previous week, was performed using fractional polynomial analysis for dose-response. Every drink increased the risk of a suicide attempt by 30 percent; even one-two drinks was associated with a sizable increase in the risk of a serious suicide attempt, and a dose-response was found for the relationship between drinking 6 hours prior and the risk of a suicide attempt up to 20 drinks. Acute use of alcohol was responsible for 35 percent PAR of all suicide attempts. While very high levels of drinking were associated with larger relative risk s of suicide attempt, the control and reduction of smaller quantities of acute alcohol use also had an impact on population levels of suicide attempt, as showed here for the first time with our PAR estimates. Interventions to stop drinking or at least decrease levels of consumption could reduce the risk of suicide attempt. Screening people more at risk to suffer these acute effects of ethanol and offering interventions that work to these high-risk groups are a matter of urgent new research in the area.

Características relacionadas con escaldaduras en menores de 5 años en un Hospital Pediátrico en la Ciudad de México, 2011 / Features related with scalds in children under 5 years old in a pediatric hospital in Mexico City, 2011.

Introducción: Las quemaduras son lesiones de los tejidos producidas por una agresión cutánea de energía térmica cuya clasificación varía de acuerdo a la gravedad. Representan un problema de salud pública especialmente en los niños por su elevada letalidad y los años de vida perdidos por discapacidad. Objetivo: Identificar las características relacionadas con la ocurrencia de escaldaduras en niños menores de 5 años, en un Hospital Pediátrico de la Ciudad de México, 2011. Material y Métodos: Se empleó un diseño de casos-autocontroles en 60 niños menores de 5 años que presentaron escaldadura. La evaluación de algunas variables se obtuvo mediante el diligenciamiento de un cuestionario estructurado por parte de los cuidadores. Se definieron dos periodos de estudio; el primero denominado "periodo de riesgo" que incluyó la evaluación de los eventos ocurridos 15 minutos previos a la escaldadura y el segundo, denominado "periodo de control" que evaluó las 24 horas previas a la ocurrencia del evento. Resultados: La muestra estuvo conformada por 60 menores, 70% (n=42) de los participantes fueron varones. El promedio de edad fue 2.2 años (ds=1.2). El 95% de las escaldaduras ocurrieron en el hogar, 61.4% se presentaron en la cocina y 15.8% en el baño. Cerca del 70% de los participantes tenía bajo nivel socioeconómico, 86.7% vivía en condiciones de hacinamiento. El rango horario en el cual se presentaron con mayor frecuencia fue entre las 12 a 18 horas. La única asociación encontrada se dio cuando el cuidador estaba cocinando (OR 6.8, IC95% 1.9-24.9) Conclusiones: Identificar las características relacionadas con las escaldaduras en menores de cinco años es fundamental para impulsar medidas preventivas que reduzcan el riesgo de vivir con secuelas derivados de estas lesiones. Los cuidadores deben mejorar la supervisión de los niños a su cargo, en especial al interior de las cocinas.

Introduction: Burns are injuries of tissues caused by skin aggression thermal energy. Their classification varies according to gravity. Such injuries are a public health problem especially in children because of its high fatality rate and years of life lost due to disability. Objective: Identify the characteristics associated with the occurrence of scalds in children under 5 years in a Pediatric Hospital in Mexico City, 2011 Methodology: We employed a case crossover design on a sample of 60 children under 5 years old with scalding, to whom we applied a structured questionnaire to their caregivers. We defined two study periods: risk period, 15 minutes pre-scald and control period 24 hours prior to the occurrence of the event. Results: Of the sample of 60 children, 70% (n:42) were male, mean age 2.2 years (sd:1.2); 95% of scalds occurred at home, 61.4% occurred in the kitchen and 15.8% in the bathroom. About 70% of them had low socioeconomic status, 86.7% were living in overcrowded conditions. The times of higher occurrence of events were between 12 to 18 hours. The only association found was when the caregiver was cooking (OR 6.8, CI 95% 1.9 - 24.9). Conclusions: To identify the risk factors and characterize the scald in children under than five years old are fundamentals aspects to promote promotion and preventive program to reduce risk of live with physical and psychological disability from these causes of injuries. The caregiver should to have more attention to the children they supervise, in special within kitchen.

Evaluating recall bias in a case-crossover design estimating risk of injury related to alcohol: data from six countries.

INTRODUCTION AND AIMS: Prior work suggests that recall bias may be a threat to the validity of relative risk estimation of injury due to alcohol consumption, when the case-crossover method is used based on drinking during the same six hours period the week prior to injury as the control period. This work explores the issue of alcohol recall bias used in the case-crossover design. DESIGN AND METHODS: Data were collected on injury patients from emergency room studies across six countries (Dominican Republic, Guatemala, Guyana, Nicaragua, Panama and Canada), conducted in 2009-2011, each with n ≈ 500 except Canada (n = 249). Recall bias was evaluated comparing drinking during two control periods: the same six hours period the day before versus the week before injury. RESULTS: A greater likelihood of drinking yesterday compared with last week was seen using data from the Dominican Republic, while lower likelihood of drinking yesterday was found in Guatemala and Nicaragua. When the data from all six countries were combined, no differential drinking between the two control periods was observed. DISCUSSION AND CONCLUSIONS: These findings are in contrast to earlier studies showing a downward recall bias of drinking, and suggest that it may be premature to dismiss the last week case-crossover method as a valid approach to estimating risk of injury related to drinking. However, the heterogeneity across countries suggests that there may be some unexplained measurement error beyond random sampling error.

Estudio epidemiológico de casos y autocontroles: una aproximación conceptual y metodológica / Case crossover studies: a conceptual and methodological approach

Los estudios de casos y autocontroles se clasifican como una variante de los estudios de casos y controles. Se han mencionado en la literatura científica desde hace aproximadamente 18 años, y son empleados en investigaciones epidemiológicas con exposiciones agudas o transitorias que pueden generar un evento en salud (infarto agudo del miocardio, asma, lesiones, enfermedades infectocontagiosas, entre otras). Para su manejo se requiere definir conceptos tales como disparadores, tiempo de inducción, periodo de caso, periodo de control. Su uso es limitado en la evaluación de exposiciones crónicas o no intermitentes. Por otro lado, este diseño reduce sesgos de selección, de información, de confusión y el sobrepareamiento. Una de sus ventajas es que requieren menor tamaño de muestra que un estudio clásico de casos y controles, donde los periodos de control se pueden obtener del mismo sujeto, sin la necesidad de entrevistar a otro tipo de controles. No obstante, para el cálculo del tamaño de la muestra se debe tener encuenta el enfoque de diseños pareados. Éste es un diseño donde los principios teóricos de homogeneidad, simultaneidad y representatividad se cumplen de manera singular.

Case crossover studies are considered as a variant of case control studies, and they have been included in the scientific literature since approximately eighteen years ago. They have also been used in epidemiological research on acute or intermittent exposures that may lead to a number of events including heart attack or cardiac arrest, injuries, asthma, etc. Application of this particular study design requires defining concepts such as: triggers, induction time, case period and control period. Its use is limited in studies on chronic exposures. On the other hand, this type of design may reduce selection and misclassification bias, confounding, and overmatching. Another advantage is that it requires a small sample size because the same case can be used as its own control in one or several periods. Nevertheless, sample size calculation must be assessed as a matched case-control study. This is a type of study in which theoretical principles are accomplished in a sui generis manner.

Estudo da influência de fatores ambientais sobre o desencadeamento de crise álgica em crianças e adolescentes portadores de anemia falciforme na cidade de São Paulo / Study of the influence of environmental factors in the development of pain crisis in children and adolescents with sickle cell disease in the city of São Paulo

Objetivo: Esse estudo foi desenvolvido para avaliar o impacto dos poluentes do ar na morbidade nas crianças e adolescentes portadoras de anemia falciforme. Métodos: Foram utilizadas as associações entre as concentrações diárias entre as concentrações dos poluentes do ar (PM10, SO2, NO2, CO, e O3) e os atendimentos no Pronto Socorro de anemia falciforme (CID 10 - D57) no período de setembro de 1999 até dezembro de 2004. Foi utilizado o desenho de case - crossover com dias de exposição de referencia escolhidos utilizando-se uma abordagem estratificada por tempo onde as exposições no dia índice foram comparadas a exposições com dias do mesmo mês com o mesmo valor de temperatura como o caso índice, controlando-se para o dia da semana. Estação do ano, clima e covariantes variáveis lentas foram controladas por pareamento. Também foram adotados modelos onde as exposições do caso índice foram comparadas às exposições para o mesmo dia da semana ou a cada três dias. Os efeitos estimados também foram estratificados para as duas causas principais de atendimento no pronto socorro de pacientes falciformes, dor e infecção respiratória. Resultados: As variações de interquartile aumentaram nas médias móveis de PM10 (25.9 mg/m3), NO2 (64.8 mg/m3), SO2 (8.1 mg/m3), CO (1.2 ppm), e O3 (57.23 mg/m3) foram associadas com aumento de 19.2% (95% CI: 11.2 - 27.8), 15.6% (95% CI: 6.3 - 25.8), 14.5% (95% CI: 6.6 - 23.0), 15,1% (95% CI: 7.7 -23.1), e 10% (95% CI: 1,3 - 18,6) nos atendimentos totais dos pacientes falciformes no pronto socorro, respectivamente. Na análise estratificada para dor, que é a manifestação cardinal dos processos de vaso-oclusão, os aumentos nos atendimentos dos pacientes falciformes com dor (23.1%, 95%CI: 11.0 - 36.5) devido a um aumento na variação interquartile da média móvel de 3 dias do PM10 foi 43% maior que nos pacientes falciformes sem dor. Conclusão: esse estudo mostra que o efeito da poluição do ar na saúde da população pediátrica não se restringe...

Objective: This study was developed to assess the impact of air pollutants on sickle cell morbidity in children and adolescents. Methods we examined the associations between daily air pollutants concentrations (PM10, SO2, NO2, CO, and O3) and sickle cell (ICD10th revision: D57) emergency room visits, from September 1999 to December 2004. We applied a case-crossover design with referent exposure days chosen using the time-stratified approach such that exposures on the case day were compared to exposures on days of the same month with the same value of temperature as the case day, controlling for day of the week. Season, weather, and slowly varying covariates were controlled for by matching. We also adopted models where exposures on the case day were compared to exposures on the same day of the week or on every third day. Effects estimates were also stratified by the two main causes of sickle cell emergency room visits, pain and respiratory infections. Results: interquartile range increases of the 3-day moving averages of PM10 (25.9 mg/m3), NO2 (64.8 mg/m3), SO2 (8.1 mg/m3), CO (1.2 ppm), and O3 (57.23 mg/m3) were associated with increases of 19.2% (95% CI: 11.2 - 27.8), 15.6% (95% CI: 6.3 - 25.8), 14.5% (95% CI: 6.6 - 23.0), 15,1% (95% CI: 7.7 - 23.1), and 10% (95% CI: 1,3 - 18,6) in total sickle cell emergency room visits, respectively. When the analyses were stratified by pain, the main clinical manifestation of vase-occlusion process, increases in visits of sickle cell patients with pain (23.1%, 95%CI:11.0 -36.5) due to an interquartile range increase of the 3-day moving averages of PM10 were 43% higher than in sickle cell patients without pain. Conclusions: this study found that the effects of air pollutants on children's health are not limited to respiratory diseases. Also, among sickle cell patients, the main manifestation of adverse effect was associated with inflammatory process of vases, reproducing results already observed among healthy...

El lugar donde ocurren las lesiones y su relación con el uso de alcohol. Estudio en sala de urgencias

Resumen Aunque en la bibliografía se ha reportado la relación entre el consumo de alcohol y los accidentes, se ha estudiado poco la asociación entre el lugar de ocurrencia de las lesiones y el consumo de alcohol. Por esta razón, nuestro objetivo es estimar la asociación entre los lugares de ocurrencia de la lesión y el consumo de alcohol. Los datos usados en este estudio provienen de una sala de urgencias de la Ciudad de México y son parte de un estudio epidemiológico multinacional (Estudio Colaborativo de Alcohol y Lesiones) coordinado por la Organización Mundial de la Salud. La muestra se conformó por 705 pacientes mayores de 18 años admitidos para tratamiento por lesión por primera vez. Los datos fueron recolectados por entrevistadores entrenados usando un cuestionario estructurado y con el consentimiento informado de los participantes. Los resultados que se presentan se basan en un diseño case-crossover, que se caracteriza por usar a los sujetos como sus propios controles pero en un periodo de tiempo diferente. Se calcularon razones de momios (RM) e intervalos de confianza al 95% (IC), para cada lugar de ocurrencia de lesiones (casa propia, casa de otra persona, calle/carretera, escuela, bar/lugar para beber y lugar de trabajo). Se analizaron como posibles modificadores de efecto el sexo, la edad y el consumo de alcohol seis horas antes de la lesión, y se calculó una prueba de heterogeneidad para detectar diferencias estadísticamente significativas entre éstos. Además -y sólo para las lesiones en calle/carretera-, se obtuvieron estimadores por tipo de accidente (de tránsito, violencia o caídas/otro), consumo de alcohol antes (número de copas) y autopercepción de embriaguez. La calle/carretera fue el único lugar en que el riesgo relativo de sufrir una lesión era elevado y estadísticamente significativo (RM=12.11; IC95%=7.5-19.6). Por otro lado, la casa propia (RM=0.25; IC95%=0.19-0.34) y el lugar de trabajo tuvieron un riesgo bajo. No se encontraron diferencias significativas en modificadores de efecto como el sexo o la edad. Sin embargo, el consumo de alcohol incrementó el riesgo de sufrir una lesión en la calle/carretera RM=21.33, que contrasta con una RM de 10.27 para aquellos que no lo hicieron. No obstante, la prueba de heterogeneidad (p=0.260) sugiere que estas RM no son estadísticamente diferentes entre sí. El riesgo de sufrir lesiones en casa de otra persona también aumentó con el uso de alcohol (RM=2.60; IC95%=0.93-7.29), y la prueba de heterogeneidad (p=0.017) muestra que dicho estimador sí difiere de aquel obtenido sin consumo (RM=0.63; IC95%=0.04-0.19). Si se profundiza en el contexto de las lesiones en calle/carretera, el consumo de alcohol incrementó el riesgo de una lesión debida a la violencia (RM=40.0; IC95%=5.5-290.9), además de que el riego aumentó en función del número de copas y de la percepción de embriaguez del sujeto. Estos resultados son los primeros en cuantificar el riesgo asociado a los lugares en que ocurren las lesiones, el consumo de alcohol y algunas otras variables asociadas usando un diseño de case-crossover. Se espera que éstos ayuden a entender el contexto del uso de alcohol y los problemas relacionados con la intención de informar a las personas y apoyar políticas públicas destinadas a reducir las consecuencias negativas del mismo.

Summary The relationship between alcohol use and injuries (fatal and non-fatal) is well documented. Through the years, new methodological approaches have been developed, looking for validity in measurements and control groups in order to quantify this relationship. The case-crossover designs use the same subjects as cases and controls but in a different time period, overcoming the selection bias of case-control studies. The risk associated to alcohol use and injuries using this design has been estimated at 4.0 and at 10.0 for alcohol and violence-related injuries. However, it is not well known the rol played by the context of drinking in this risk like companions, places of injury, places, frequency and quantity of drinking. In this paper we will estimate the relationship between places of injury and alcohol use before the event, as well as other relevant variables. Data presented here comes from a Mexico City emergency department (ED) in the multi-country epidemiological study (Collaborative Study on Alcohol and Injuries) coordinated by the World Health Organization. The sample consisted of all eligible patients (adults 18 years and older) who entered the ED for an injury and first treatment. The final sample totalled 705 respondents and was collected with informed consent by trained interviewers using a structured questionnaire lasting about 25 minutes. Among other items, respondents were asked questions about demographics, injury details (type, place, violence involvement), alcohol use prior to injury, typical drinking, place, and alcohol use during the previous week. Case-crossover analyses were performed using STATA's conditional logistic regression. Odds ratios (OR) and 95% confidence intervals (CI) were estimated for each of the six injury places revised: own home, someone else's home, street/highway, school, drinking place, and workplace. Sex, age, and alcohol use were analyzed as effect modifiers. OR's and CI's were estimated for each one, as well as a heterogeneity test. In addition -and only for street/highway-, estimates were obtained for injury type (traffic accident, violence, or falls/other), alcohol consumption before event (number of drinks), and drunkenness self-perception. The most common injury places were street/highway (n=254; 36.1%) and own home (n=213; 30.3%). Also, there was a relatively high number of injuries at work places (15%). Likewise, the most common place where this patients were the same day of the week, same time, one week before, was their own home (n=378; 53.8%) and work place (n=164; 23.3%). Street/highway was the place with higher injury risk (OR=12.11; CI95%=7.49-19.59). Own home (OR=0.25; CI95%=0.19-0.34) and work place had both a low injury risk. No significant differences were found in effect modifiers as gender or age group. However, alcohol use before accident increased the risk for street/highway (OR=21.33). Although the OR for not drinking in the event was 10.27, the heterogeneity test (p=0.260) suggested no differences between them. Risk for someone else's home was also increased with alcohol use (OR=2.60; CI95%=0.93-7.29). Although the null value is within the CI, the heterogeneity test showed significant differences (p=0.017) between this risk and non-alcohol associated risks (OR=0.63; CI95%=0.37-1.07). In addition, alcohol related injuries at own home had an even lower risk (OR=0.08; CI95%=0.04-0.19). Accident type in the street was also analyzed. It was not possible to estimate the OR for vehicle-related accidents (as a pedestrian, driver, or passenger) due to zero cell in our data. Violence related injuries (by a gun, knife, punch, etc.) (OR=10.22; CI95%=5.16-20.27) were more likely to occur in the street than non-violent injuries (such as falls) (OR=8.67; CI95%=4.35-17.28). In this context, alcohol use greatly increased the risk of violence-related injury (OR=40.0; CI95%=5.5-290.9) while non-alcohol related injuries risk decreases (OR=6.5; CI=3.09-13.68). For alcohol-related injuries in the street/highway, estimates for drunkenness self-perception and quantity of alcohol consumed six hours before injury increased; however, these estimates were not statically significant. These results are the first to quantify risks associated to injury places, alcohol use, and some others variables linked to it, using a case-crossover design. It is clear that being injured at home (OR=0.25) or the workplace (OR=0.27) is less likely to occur than being injured in the street or highway (OR=12.11), and alcohol use usually increased this difference, especially in someone else's home or in the street. Due to our small sample size many CI's were extremely wide or it was not possible to estimate really important risks like traffic-related injuries. Future research may consider this, as well as asking for several control periods according to this design. It is expected that this findings will help to understand alcohol use context and its related problems in order to inform people and support public policies addressed to reduce the negative consequences derived of episodic and acute alcohol use.