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Objective To investigate the correlation between the concentration of air pollutants (PM10, SO2, NO2) and the number of outpatient and emergency visits for pediatric respiratory diseases in a general hospital in Shanghai. Methods Data including pediatric respiratory disease outpatient and emergency visits in a hospital in Pudong New Area of Shanghai from May 1, 2013 to March 20, 2022 were collected. Daily concentration of air pollutants including PM10, SO2 and NO2 and meteorological data in Pudong New Area during the same period were collected. A case-crossover study with distributed lag non-linear model was conducted to explore the correlation between air pollutants (PM10, SO2, NO2) and the number of outpatient and emergency visits for pediatric respiratory diseases. Results The concentrations of PM10, SO2 and NO2 were positively with the number of outpatient and emergency visits for pediatric respiratory diseases. The strongest cumulative effect was observed on six days lag (Lag0-5) for PM10. For a 10 μg/m3 increase of the concentrations of PM10, the corresponding increase of cumulative pediatric respiratory disease outpatients was 1.10% (95%CI:0.97%, 1.23%) in Lag0-5. The strongest cumulative effect was observed on eight days lag (Lag0-7) for SO2 and NO2. For a 10 μg /m3 increase of the concentrations of SO2 and NO2, the corresponding increase of cumulative pediatric respiratory disease outpatients was 5.64% (95%CI:5.16%, 6.13%) and 5.41% (95%CI:5.15%, 5.66%) in Lag 0-7, respectively. The association of PM10 and SO2 with the number of pediatric respiratory disease visits in males was significantly stronger than that in females. The impact of PM10 on the number of pediatric respiratory disease visits in children aged 0-6 was higher than that in children aged 7-14, while the impact of SO2 and NO2 on the number of pediatric respiratory disease visits in children aged 7-14 was higher than that in children aged 0-6. Conclusion The concentration of ambient PM10, SO2, and NO2 is positively correlated with outpatient and emergency visits for pediatric respiratory diseases, with obvious lag and cumulative effect. Boys and children aged 0-6 are more susceptible to the hazard of air pollution.
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Background Nitrogen dioxide (NO2), a crucial component of traffic pollutants, has been shown in studies to exert toxic effects on the nervous system. However, there is a limited body of research examining the relationship between NO2 exposure and neurological disorders in children. Objective To explore the impact of short-term NO2 exposure on the outpatient visits due to pediatric neurological diseases in Shijiazhuang. Methods From 2013 to 2021, we collected outpatient data related to neurological diseases at the Children's Hospital in Shijiazhuang, Hebei Province. We also collected air pollution data and meteorological data of the same city. The air pollution data included daily average concentrations of inhalable particles (PM10), fine particulate matter (PM2.5), sulfur dioxide (SO2), NO2, carbon monoxide (CO), and daily maximum 8-hour average concentration of ozone (O3). The meteorological data comprised daily average atmospheric pressure, temperature, relative humidity, wind speed, and sunshine duration. Employing a time-stratified case-crossover design, we used conditional logistic regression models to analyze the association between NO2 and pediatric outpatient visits for neurological diseases. Stratification analyses were conducted based on gender (male, female) and age groups (0-6 years, 7-14 years). Results The study included a total of 154348 valid pediatric outpatient visits for neurological diseases. The daily average concentration of NO2 was 49.3 μg·m−3 for the study period. The results from the single-pollutant model indicated that NO2 increased the risk of pediatric neurological outpatient visits, with the highest association observed at lag0. Specifically, for every 10 μg·m⁻³ increase in atmospheric NO2 exposure, there was a 1.40% increase (95%CI: 1.05%, 1.74%) in pediatric neurological outpatient visits. The stratification analyses revealed that increased atmospheric NO2 exposure was associated with an elevated risk of neurological outpatient visits for girls (ER=1.54, 95%CI: 1.01, 2.08) and children aged 7-14 years (ER=2.35, 95%CI: 1.68, 3.02). Even after introducing PM2.5 (ER=1.96, 95%CI: 1.49, 2.43), SO2 (ER=2.09, 95%CI: 1.62, 2.55), and O3 (ER=1.40, 95%CI: 1.06, 1.74) to the models, the impact of NO2 exposure on pediatric neurological outpatient visits remained statistically significant. The results of the multi-pollutant model also indicated a significant association (ER=2.53, 95%CI: 1.97, 3.08). Conclusion The effect of short-term exposure to atmospheric NO2 on the outpatient visits of children with neurological diseases in Shijiazhuang is acute and independent, especially for children aged 7-14.
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OBJECTIVES@#To study the effect of vaccination on the short-term risk of immunoglobulin A vasculitis (IgAV) in children.@*METHODS@#A retrospective analysis was conducted on the general data and the vaccination history within one year prior to onset in children with IgAV hospitalized in the Children's Hospital Affiliated to Zhengzhou University from November 2021 to January 2023. Vaccine exposure rates in the risk period (3 months prior to IgAV onset) and the control period were compared by autocontrol-case crossover analysis, and the odds ratio and 95% confidence interval (95%CI) were calculated. A sensitivity analysis for the one-month and two-month risk periods was conducted.@*RESULTS@#A total of 193 children with IgAV were included, with a median age of 7.0 years. Among the 193 children, 36 (18.7%) received at least one dose of the vaccine within 1 year prior to IgAV onset, and 14 (7.3%) received at least one dose of the vaccine during the 3-month risk period. Compared to the unvaccinated IgAV group, the vaccinated IgAV group had a significantly younger age of onset (P<0.05). There were no significant differences in the proportions of children with gastrointestinal involvement, renal involvement, and joint involvement between the two groups (P>0.05). The odds ratio for developing IgAV after receiving any type of vaccine within 3 months prior to IgAV onset was 2.08 (95%CI: 0.82-5.27, P>0.05). Further sensitivity analysis for the 1-month and 2-month risk periods demonstrated that the odds ratios for developing IgAV after receiving any type of vaccine were 2.74 (95%CI: 0.72-10.48, P>0.05) and 2.72 (95%CI: 0.95-7.77, P>0.05), respectively.@*CONCLUSIONS@#Vaccination dose not increase the risk of IgAV, nor does it exacerbate clinical symptoms in children with IgAV.
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Humans , Child , Retrospective Studies , Immunoglobulin A , IgA Vasculitis , Vaccination , VaccinesABSTRACT
Background Air pollution is a major public health concern. Air Quality Health Index (AQHI) is a very important air quality risk communication tool. However, AQHI is usually constructed by single-pollutant model, which has obvious disadvantages. Objective To construct an AQHI based on the joint effects of multiple air pollutants (J-AQHI), and to provide a scientific tool for health risk warning and risk communication of air pollution. Methods Data on non-accidental deaths in Yunnan, Guangdong, Hunan, Zhejiang, and Jilin provinces from January 1, 2013 to December 31, 2018 were obtained from the corresponding provincial disease surveillance points systems (DSPS), including date of death, age, gender, and cause of death. Daily meteorological (temperature and relative humidity) and air pollution data (SO2, NO2, CO, PM2.5, PM10, and maximum 8 h O3 concentrations) at the same period were respectively derived from China Meteorological Data Sharing Service System and National Urban Air Quality Real-time Publishing Platform. Lasso regression was first applied to select air pollutants, then a time-stratified case-crossover design was applied. Each case was matched to 3 or 4 control days which were selected on the same days of the week in the same calendar month. Then a distributed lag nonlinear model (DLNM) was used to estimate the exposure-response relationship between selected air pollutants and mortality, which was used to construct the AQHI. Finally, AQHI was classified into four levels according to the air pollutant guidance limit values from World Health Organization Global Air Quality Guidelines (AQG 2021), and the excess risks (ERs) were calculated to compare the AQHI based on single-pollutant model and the J-AQHI based on multi-pollutant model. Results PM2.5, NO2, SO2, and O3 were selected by Lasso regression to establish DLNM model. The ERs for an interquartile range (IQR) increase and 95% confidence intervals (CI) for PM2.5, NO2, SO2 and O3 were 0.71% (0.34%–1.09%), 2.46% (1.78%–3.15%), 1.25% (0.9%–1.6%), and 0.27% (−0.11%–0.65%) respectively. The distribution of J-AQHI was right-skewed, and it was divided into four levels, with ranges of 0-1 for low risk, 2-3 for moderate risk, 4-5 for high health risk, and ≥6 for severe risk, and the corresponding proportions were 11.25%, 64.61%, 19.33%, and 4.81%, respectively. The ER (95%CI) of mortality risk increased by 3.61% (2.93–4.29) for each IQR increase of the multi-pollutant based J-AQHI , while it was 3.39% (2.68–4.11) for the single-pollutant based AQHI . Conclusion The J-AQHI generated by multi-pollutant model demonstrates the actual exposure health risk of air pollution in the population and provides new ideas for further improvement of AQHI calculation methods.
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Background Under the background of global climate change, temperature has increased dramatically. Most studies about association between temperature and human health are conducted in low-altitude areas, but rarely focus on plateau areas. Objective To examine the association between temperature and non-accidental mortality risk in Tibet Plateau, China and to identify vulnerable populations for formulating targeted policies of climate change adaptation. Methods The mortality data, meteorological data, and pollutant data of Tibet area between 2013 to 2019 were collected. Based on time-stratified case-crossover design, conditional logistic regression models were used to analyze the exposure-response relationship between temperature and cause-specific mortality, which was linearized to obtain excess risk for 1 ℃ change; attributable fraction was calculated for assessing burden attributable to temperature; and stratified analyses were further conducted by gender, age (＜65 years old, ≥65 years old), and causes of death (cardiovascular diseases, cerebrovascular diseases, and respiratory diseases). Sensitivity analyses were conducted by adjusting model parameters and variables. Results A total of 26 045 non-accidental deaths were collected in Tibet during 2013 and 2019, and the P50 of temperature was 5.0 ℃. The non-accidental mortality risk increased as temperature become colder. A 1 ℃ decrease in temperature was associated with a 2.01% (95%CI: 0.94%-3.07%) increase in total non-accidental mortality, while the association changed to 2.05% (95%CI: 0.62%-3.47%) for male and 1.96% (95%CI: 0.34%-3.56%) for female, both of statistial significance; 1.45% (95%CI: −0.10%-2.98%) for the people <65 years old (not of significance) and 2.52% (95% CI : 1.04%-3.99%) for the people ≥65 years old (of significance); the excess risk for cardiovascular mortality was 2.65% (95%CI: 1.03%-4.24%), for cerebrovascular mortality was 3.70% (95%CI: 0.74%-6.57%), both of statistical significance, and for respiratory mortality was 2.18% (95%CI: −0.14%-4.44%), without significance. The total attribution number of non-accidental mortality was 5340 (95%CI: 2719-7528), and the total attributable fraction was 20.50% (95%CI: 10.44%-28.91%). The attributable fractions were higher in specific subgroups like male (20.72%), people ≥65 years (23.33%), and people with cardiovascular diseases (26.07%). Conclusion The exposure-response relationship between temperature and non-accidental mortality in Tibet showes that the non-accidental mortality risk increase as temperature become colder. The attributable burden of disease is heavy. Residents being male, ≥65 years, with cardiovascular diseases and respiratory diseases may be vulnerable to nonoptimal temperature.
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Objective To investigate the risk of fatal stroke mortality associated with short-term exposure to air pollution， and to determine the susceptible population. Methods In this study， daily stroke mortalities of adults between 2012 and 2014 in Songjiang District， Shanghai were collected. Time-stratified case-crossover approach was used to assess the association between daily concentrations of air pollutants and fatal stroke mortalities. Results This study included 514 patients who died from acute strokes. The average concentrations during the study period were 77.45 μg·m-3 for PM2.5， 21.22 μg·m-3 for SO2， and 57.59 μg·m-3 for NO2. The fatal stroke mortality of adults under the age of 65 was found to be significantly associated with NO2. At the time of a Lag of 2 d and 03 d， a significantly higher risk of fatal stroke mortality in relation to NO2 exposure was observed， and the OR values of ischemic stroke mortality for people were 3.86 （1.53-9.75） and 5.83 （1.40-24.34） respectively. People over the age of 65 were more sensitive to increased PM2.5 concentrations， at the time of a Lag of 03 d， fatal strokes increased by 28% when PM2.5 levels increased. A significantly higher risk of fatal stroke mortality in relation to increase of NO2 concentration was observed among people who were overweight or obese. Conclusion A significantly higher risk of fatal stroke mortality is associated with the increase of PM2.5 and NO2. The results also suggest that the susceptible population should take additional precautions to avoid or reduce the risk of fatal strokes.
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OBJECTIVES@#The association between concentrations of sulfur dioxide (SO), nitrogen dioxide (NO), carbon monoxide (CO), ozone (O), and emergency ambulance dispatches (EADs) for asthma was explored in the central Sichuan Basin of southwestern China for the first time.@*METHODS@#EADs for asthma were collected from the Chengdu First-Aid Command Center. Pollutant concentrations were collected from 24 municipal environmental monitoring centers and including SO, NO, CO, daily 8-h mean concentrations of O (O-8 h), and particulate matter less than 2.5 μm in aerodynamic diameter (PM). The climatic data were collected from the Chengdu Municipal Meteorological Bureau. All data were collected from years spanning 2013-2017. A time-stratified case-crossover design was used to analyze the data.@*RESULTS@#After controlling for temperature, relative humidity, and atmospheric pressure, IQR increases in SO (13 μg/m), NO (17 μg/m), and CO (498 μg/m) were associated with 18.8%, 11.5%, and 3.1% increases in EADs for asthma, respectively. The associations were strongest for EADs and SO, NO, and CO levels with 3-, 5-, and 1-day lags, respectively.@*CONCLUSIONS@#This study provides additional data to the limited body of literature for potential health risks arising from ambient gaseous pollutants. The results of the study suggest that increased concentrations of SO, NO, and CO were positively associated with emergency ambulance dispatches for asthma in Chengdu, China. Further studies are needed to investigate the effects of individual air pollutants on asthma.
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Humans , Air Pollutants , Toxicity , Asthma , Epidemiology , Carbon Monoxide , Toxicity , China , Epidemiology , Cities , Cross-Over Studies , Emergency Medical Dispatch , Environmental Monitoring , Nitrogen Dioxide , Toxicity , Ozone , Toxicity , Particle Size , Particulate Matter , Toxicity , Risk , Sulfur Dioxide , ToxicityABSTRACT
BACKGROUND: Despite its growing significance, studies on the burden of disease associated with natural disasters from the perspective of public health were few. This study aimed at estimating the national burden of disease associated with typhoons and torrential rains in Korea. METHODS: During the period of 2002–2012, 11 typhoons and five torrential rains were selected. Mortality and morbidities were defined as accentual death, injury and injury-related infection, and mental health. Their incidences were estimated from National Health Insurance Service. Case-crossover design was used to define the disaster-related excess mortality and morbidity. Disability-adjusted life years (DALYs) were directly assessed from excess mortality and morbidity. RESULTS: The burden of disease from typhoons increased with the intensity, with 107.7, 30.6, and 36.6 DALYs per 100,000 per event for strong, moderate, and weak typhoons, respectively. Burden of disease from torrential rains were 56.9, 52.8, and 26.4 DALYs per 100,000 per event for strong, moderate, and weak episodes, respectively. Mental disorders contributed more years lived with disability (YLDs) than did injuries in most cases, but the injury-induced YLDs associated with strong typhoon and torrential rain were higher than those of lower-intensity. The elderly was the most vulnerable to most types of disaster and storm intensities, and males younger than 65 years were more vulnerable to a strong torrential rain event. CONCLUSION: The intensity of torrential rain or typhoon was the strongest determinant of the burden of disease from natural disasters in Korea. Population vulnerable may vary depending on the nature and strength of the disasters.
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Aged , Humans , Male , Cyclonic Storms , Disasters , Incidence , Korea , Mental Disorders , Mental Health , Mortality , National Health Programs , Public Health , Rain , Vulnerable PopulationsABSTRACT
Objective To understand the levels of exposure to traffic-related air pollutants including nitrogen dioxide (NO2),PM10 and PM2.5,and the relationship between the exposure to air pollutants during pre-pregnancy or early pregnancy and birth defects.Methods Data on air pollution and birth defects from 2013 to 2015 was collected.A case-crossover design was employed to analyze the exposure-response relationship between traffic-related air pollutants and birth defects.Results A total of 4 235 pregnant women were studied.During the study period,the daily average concentrations of ambient NO2,PM10 and PM25 appeared as 60.83 μg/m3,104.94 μg/m3 and 103.88 μ.tg/m3,respectively,with the concentration of PM2.5 larger than the 2nd version of Standard National Ambient Air Quality Standard.In addition,there were strong correlations seen between each of the pollutants (P＜0.01).After adjustment for the influence of meteorological factors,it was found that the exposure to high level of NO2 and PM10 during pre-pregnancy or early pregnancy increased the risk on birth defects (P＜0.05).Conclusion Levels of exposure to adverse environmental factors during pre-pregnancy or early pregnancy could increase the risk of birth defects,suggesting that in these sensitive periods,women should try to avoid being exposed to high concentration of traffic-related air pollutants as NO2,PM10 etc.in order to reduce the risk of birth defects.
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Objective To understand the levels of exposure to traffic-related air pollutants including nitrogen dioxide (NO2),PM10 and PM2.5,and the relationship between the exposure to air pollutants during pre-pregnancy or early pregnancy and birth defects.Methods Data on air pollution and birth defects from 2013 to 2015 was collected.A case-crossover design was employed to analyze the exposure-response relationship between traffic-related air pollutants and birth defects.Results A total of 4 235 pregnant women were studied.During the study period,the daily average concentrations of ambient NO2,PM10 and PM25 appeared as 60.83 μg/m3,104.94 μg/m3 and 103.88 μ.tg/m3,respectively,with the concentration of PM2.5 larger than the 2nd version of Standard National Ambient Air Quality Standard.In addition,there were strong correlations seen between each of the pollutants (P＜0.01).After adjustment for the influence of meteorological factors,it was found that the exposure to high level of NO2 and PM10 during pre-pregnancy or early pregnancy increased the risk on birth defects (P＜0.05).Conclusion Levels of exposure to adverse environmental factors during pre-pregnancy or early pregnancy could increase the risk of birth defects,suggesting that in these sensitive periods,women should try to avoid being exposed to high concentration of traffic-related air pollutants as NO2,PM10 etc.in order to reduce the risk of birth defects.
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Objective To explore the association between atmospheric particulate matter (PM10/PM2.5) levels and hospital admissions due to lower respiratory tract infection in Shijiazhuang. Methods Data of air pollution, meteorologic data, and the data of patients admitted to hospital due to lower respiratory tract infection were retrospectively analyzed. Pearson's correlation coefficients were calculated to analyze correlations between atmospheric particulate matter and meteorologic factors. Data of hospital admission due to lower respiratory tract infection and of atmospheric air pollution levels in Shijiazhuang were obtained, a bidirectional case-crossover design was used to investigate the association between hospital admissions due to lower respiratory tract infection and levels of atmospheric particles. Stratified analyses of exposure based on age, gender, complications and season were performed to evaluate the effect. Results Pearson's correlation analysis showed positive correlations among PM2.5, PM10, SO2, NO2 and CO. The concentration of all these five pollutants were negatively correlated with O3 and daily mean temperature, while a positive correlation was found between concentrations of the 5 pollutants and daily average temperature and O3. In single-pollutant model, every 10μg/m3 increase in PM2.5 and PM10 at lag5 brought the corresponding OR values (95%CI) up to 1.010(1.005-1.015) and 1.006(1.003-1.009) respectively. In the multi-pollutant models, the observed effects of PM2.5 remained significant. Stratified analysis based on gender, age, season and comorbidities showed that the effect of PM2.5 exposure on lower respiratory tract infection admissions was stronger in males, persons younger than 60 years of age and persons without comorbidities, and even more stronger in cold season. The effect of PM10 exposure on lower respiratory tract infection admissions was stronger in females, persons older than 60 years of age and persons with comorbidities, and even more stronger in cold season. Conclusion Our study demonstrates that higher levels of atmospheric particulate matter (PM10/PM2.5) may increase the risk of hospital admissions due to lower respiratory tract infection.
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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.
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Objective To investigate the correlation between meteorological factors and the incidence of acute cardiovascular disease.Methods The number of calls for ambulance in case of cardiovascular disease between 2006 to 2010 was obtained from Beijing 120 emergency center and the data of meteorological factor during for the same period from Beijing Meteorological professional were collected,and then the impact of the weather factors of different seasons of weather factors on the incidence of cardiovascular disease was ere analyzed by time-stratified case-crossover design.Results The average daily incidence cases of cardiovascular disease in four seasons average daily were 5.61,4.55,5.05 and 6.03 respectively.The association between temperature Temperature and the incidence of acute cardiovascular disease was were non-linear relationship changes in spring and autumn seasons.Atmosphere Air pressure and the incidence were negatively correlated in the winter.The relative humidity of airand the incidence were related in the spring,summer,autumn.Wind and the incidence were related in the spring,summer,but negative correlation in the autumn,winter.Conclusions The incidences of acute cardiovascular disease are higher more in winter and spring than in summer and autumn.The incidences of cardiovascular disease are related with temperature,relative humidity,wind speed and other meteorological factors.,The influence of meteorological factors on the incidence of the disease delays to occur after changes in weather.
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Case-crossover study is research using only data from cases, patient with interested event. Getting control from own data, the case-crossover study is classified into self-controlled study. It has a lot of condition to be valid study. When study satisfies the conditions, the case-crossover has a lot of advantage in which it is not necessary to collect information of control group patients, and the control is to be matched genetic and other background. The paper is summarized the case-crossover study design. (Jpn J Pharmacoepidemiol 2013; 18(2): 90-94)
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Objective To analyze the association between the concentration of ambient inhalable particulate matter (PM10) and population mortality for cerebrovascular diseases and to explore the impact of PM10 on cerebrovascular diseases.Methods Data including meteorological factors,air pollutants (NO2,SO2 and PM10) and cerebrovascular disease mortality in one district of Beijing from 2004 to 2008 were collected and both symmetric bidirectional case-crossover design and conditional logistic regression model were used to analyze the associations among them.Results After adjusting the influence of meteorological factors as daily average temperature and relative humidity,the single pollutant model showed that there was no significant lag effect.In the multipollutant model,the effect of the every 105.43 μg/m3 increase of ambient PM10 had a larger impact on the daily death of the cerebrovascular diseases with statistically significant difference (P＜0.05).The effect of ambient PM10 pollution on daily death of cerebrovascular diseases was significant for females,65 year-olds and in winter season.Conclusion Our data showed that elevated levels of ambient PM10was positively associated with the increase of cerebrovascular disease mortality.The elevated levels of ambient PM10 could lead to thc increase of the daily mortality on cerebrovascular diseases for females,elderly who were 65 or older and in winter seasons.
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OBJECTIVES: To evaluate the risk of fractures related with zolpidem in elderly insomnia patients. METHODS: Health claims data on the entire South Korean elderly population from January 2005 to June 2006 were extracted from the Health Insurance Review and Assessment Service database. We applied a case-crossover design. Cases were defined as insomnia patients who had a fracture diagnosis. We set the hazard period of 1 day length prior to the fracture date and four control periods of the same length at 5, 10, 15, and 20 weeks prior to the fracture date. Time independent confounding factors such as age, gender, lifestyle, cognitive function level, mobility, socioeconomic status, residential environment, and comorbidity could be controlled using the casecrossover design. Time dependent confounding factors, especially co-medication of patients during the study period, were adjusted by conditional logistic regression analysis. The odds ratios and their 95% confidence intervals (CIs) were estimated for the risk of fracture related to zolpidem. RESULTS: One thousand five hundred and eight cases of fracture were detected in insomnia patients during the study period. In our data, the use of zolpidem increased the risk of fracture significantly (adjusted odds ratio [aOR], 1.72; 95% CI, 1.37 to 2.16). However, the association between benzodiazepine hypnotics and the risk of fracture was not statistically significant (aOR, 1.00; 95% CI, 0.83 to 1.21). Likewise, the results were not statistically significant in stratified analysis with each benzodiazepine generic subgroup. CONCLUSIONS: Zolpidem could increase the risk of fracture in elderly insomnia patients. Therefore zolpidem should be prescribed carefully and the elderly should be provided with sufficient patient education.
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Aged , Aged, 80 and over , Female , Humans , Male , Benzodiazepines/adverse effects , Cross-Over Studies , Fractures, Bone/chemically induced , Hypnotics and Sedatives/adverse effects , Odds Ratio , Pyridines/adverse effects , Republic of Korea/epidemiology , Risk Assessment , Risk Factors , Sleep Initiation and Maintenance Disorders/drug therapyABSTRACT
Objective To explore the effects of heat wave on daily deaths caused by acute myocardial infarction (AMI) in Beijing.Methods A case-crossover design was used to study the impact of 5 heat waves on the daily number of AMI deaths from Jan.1,1999 to Jun.30,2000.The effect of heat wave on death in different gender or age groups was also compared.The 7th day before and after death occurred was chosen as its own bi-directional self-control.The OR value and its corresponding risk period was used to reflect the impact of heat wave on daily number of AMI deaths,lag days and duration.Results There were five heat waves during the study period.The first heat wave sustained 9 days and the maximum temperature was 38.8 ℃ with average humidity as 46.7％.The OR value for the AMI death was 1.437 (95％CI:1.066-1.937).The second heat wave lasted 3 days,with the maximum temperature of 36.8 ℃ and average humidity of 61.0％.The OR value for the AM1 death was 1.846 (95％ CI:0.671-5.076).The third heat wave continued 7 days,with the maximum temperature of 41.5 ℃ with average humidity of 58.5％.The OR value for the daily death counts caused by AMI was 2.427 (95％ CI:1.825-3.229).The fourth lasted for 3 days,with the maximum temperature of 39.6 ℃ and average humidity as 3 1.9％.The OR value for the AMI deaths was 2.857 (95％ CI:1.088-7.506).The fifth heat wave lasted for 4 days,with the maximum temperature as 37.4 ℃,and average humidity as 42.0％ during this period.The OR value for daily death counts caused by AMI was 1.500(95％CI:0.632-3.560).The OR value of the first heat wave for daily death counts of men and women caused by AMI were 1.153 (95％CI:0.756-1.758 ) and 1.818 (95％CI:1.185-2.790) respectively.The OR value for daily death counts of under 65 age was 1.200 (95％ CI:0.669-2.153),with the OR value for the older than 64 age group was 1.534 (95％ CI:1.083-2.173).The OR value for daily death counts of older than 64 age women was 1.818 (95％CI:1.109-2.981 ).The OR values of the third heat wave for daily death counts of men and women caused by AMI were 2.392 (95％CI:1.649-3.470) and 2.514 (95％CI:1.613-3.919) respectively.The OR value for daily death counts of under 65 age group was 2.000 (95％CI:1.149-3.482 ) and the OR value for the older than 64 age group was 2.623 (95％CI:1.880-3.660).The OR value for daily death counts of older than 64 age group women was 2.800 (95％CI:1.676-4.678).Conclusion (1) Significant increase for daily death counts of AMI in Beijing was noticed during the heat wave and usually causing hysteretic effect.The lag phase was 0-2 days in general.(2)The increase of maximum temperature was greater at the beginning day when the heat wave occurred in the previous day,with shorter lag time and greater risk of AMI death.(3)The risk of AMI death in women was greater than in men during the heat wave period.(4)The risk of AMI death among those older than 64 age group was greater than the under 65 year olds.(5)The impact of heat wave to the elderly female was greater.
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Objective:It is well known that the use of benzodiazepines is associated with falling in elderly people, but there have been few researches focused on changes in the dose of benzodiazepines and falls. If the association between changes in the dose of benzodiazepines and falling becomes clear, we may take an action to prevent falling.In this study, we investigated the association between changes in the dose of benzodiazepines and falling among elderly inpatients in an acute-care hospital.<br>Design:Falling generally results from an interaction of multiple and diverse risk factors and situations, and medication history of each subject must be considered in this study. We conducted a case-crossover study in which a case was used as his/her own control at different time periods. Therefore covariates that were not time-dependent were automatically adjusted in this study.<br>Methods:Subjects were patients who had falling at one hospital between April 1, 2008 and November 30, 2009. Data were collected from incident report forms and medical records. Odds ratio for changes in the dose of benzodiazepines were calculated using conditional logistic regression analyses.<br>Results:A total of 422 falling by elderly people were eligible for this study. The odds ratio for increased amounts of benzodiazepines was 2.02(95% Confidence Interval(CI):1.15, 3.56). On the other hand, the odds ratio for decreased amounts of benzodiazepines was 1.11(95%CI:0.63,1.97).<br>Conclusion:There was an association between increased amounts of benzodiazepines and falling. Hence, it is considered meaningful to pay attention to falling when amounts of benzodiazepines are increased to prevent falling in hospitals.
ABSTRACT
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.
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Case-Control Studies , Cross-Over Studies , BiasABSTRACT
Objective Using case-crossover design to explore the association between ambient air pollution and the hospital emergency room visits for respiratory diseases (International Classification of Diseases, tenth vision ICD-10: J00-J99) in Beijing, China. Methods Data regarding the daily hospital emergency room visits' of the respiratory diseases (ICD-10: J00-J99)were obtained in 2004.01.01-2005.12.31, from the Peking University Third Hospital and data on relevant air pollution and meteorological factors from the local municipal environmental monitoring center and meteorology bureau of Beijing, respectively. Time-stratified case-crossover technique was used to evaluate their relationships. Results from the bi-directional control sampling approach were compared with unidirectional approach. Results Using a unidirectional control sampling approach,the results obtained from a conditional logistic regression model (multi-pollutant model) after adjusting for meteorological variables, showed that the ORs of the hospital emergency room visits for the respiratory diseases associated with each 10 μg/m3 increment of PM10, SO2, NO2 were 1.010(95%CI: 1.005-1.014), 1.010(95%CI: 1.001-1.018) ,0.996(95%CI:0.983-1.009) respectively.In the bi-directional control sampling approach, the ORs were 1.002(95%CI:0.998-1.005)、 1.011 (95%CI:1.003-1.018)、 1.012(95%CI: 1.001-1.022). Conclusion Results from this study provided evidence that higher levels of ambient air pollutants increased the risk of hospital emergency room visits for respiratory diseases.