Heng Zhang

Impact of weather factors on hand, foot and mouth disease, and its role in short-term incidence trend forecast in Huainan City, Anhui Province.

Hand, foot, and mouth disease (HFMD) is one of the most common communicable diseases in China, and current climate change had been recognized as a significant contributor. Nevertheless, no reliable models have been put forward to predict the dynamics of HFMD cases based on short-term weather variations. The present study aimed to examine the association between weather factors and HFMD, and to explore the accuracy of seasonal auto-regressive integrated moving average (SARIMA) model with local weather conditions in forecasting HFMD. Weather and HFMD data from 2009 to 2014 in Huainan, China, were used. Poisson regression model combined with a distributed lag non-linear model (DLNM) was applied to examine the relationship between weather factors and HFMD. The forecasting model for HFMD was performed by using the SARIMA model. The results showed that temperature rise was significantly associated with an elevated risk of HFMD. Yet, no correlations between relative humidity, barometric pressure and rainfall, and HFMD were observed. SARIMA models with temperature variable fitted HFMD data better than the model without it (sR2 increased, while the BIC decreased), and the SARIMA (0, 1, 1)(0, 1, 0)52 offered the best fit for HFMD data. In addition, compared with females and nursery children, males and scattered children may be more suitable for using SARIMA model to predict the number of HFMD cases and it has high precision. In conclusion, high temperature could increase the risk of contracting HFMD. SARIMA model with temperature variable can effectively improve its forecast accuracy, which can provide valuable information for the policy makers and public health to construct a best-fitting model and optimize HFMD prevention.

Exposure to bisphenol A and the development of asthma: A systematic review of cohort studies

BACKGROUNDnThere is conflicting evidence about the association between bisphenol A (BPA) exposure and childhood asthma risk. We aimed to review the epidemiological literature on the relationship between prenatal or postnatal exposure to BPA and the risk of childhood asthma/wheeze.nnnMETHODSnThe PubMed database was systematically searched, and additional studies were found by searching reference lists of relevant articles.nnnRESULTSnSix studies fulfilled the eligibility criteria. Three studies found that prenatal BPA exposure is associated with an increased risk of childhood wheeze, while another study reported a reduced risk of wheeze. Regarding the postnatal BPA exposure, three studies demonstrated an increased risk of childhood asthma/wheeze.nnnCONCLUSIONSnThe mean prenatal BPA was associated with the risk of childhood wheeze/asthma. Besides, the influence of BPA exposure during the second trimester of pregnancy on the prevalence of childhood wheeze was marked. Further studies are urgently needed to explore the underlying mechanism about adverse effect of BPA exposure on childhood wheeze/asthma.

Is greater temperature change within a day associated with increased emergency admissions for schizophrenia

BACKGROUNDnDiurnal temperature range (DTR), as an important index of climate change, has been increasingly used to evaluate the impacts of temperature variability on human health. However, little is known about the effects of DTR on schizophrenia.nnnOBJECTIVEnThe present study aims to examine the relationship between DTR and schizophrenia admissions, and further, to explore whether the association varied by individual characteristics and study periods.nnnMETHODSnA Poisson generalized linear regression combined with distributed lag non-linear model (DLNM) was applied to analyze daily DTR and schizophrenia data from Hefei, China during 2005 to 2014, after adjusting for long-term and seasonal trends, mean temperature, relative humidity and other confounding factors.nnnRESULTSnAn acute adverse effect of extremely high DTR on schizophrenia was observed, with a 2.7% (95% CI: 1.007-1.047) increase of daily schizophrenia admissions after exposure to extremely high DTR (95th percentile vs. 50th percentile). The risk for schizophrenia onset due to large DTR exposure increased from the first five years (2005-2009) to the second five years (2010-2014). Additionally, the patient aged 15-29 and 50-64years, male patients, patients born in spring/autumn, and married patients appeared to be more vulnerable to DTR effect. However, there was no significant association between moderately high DTR (75th percentile) and schizophrenia.nnnCONCLUSIONSnThis study suggests that extremely high DTR is a potential trigger for schizophrenia admissions in Hefei, China. Our findings may provide valuable information to decisions-makers and guidance to health practitioners.

Ambient temperature, humidity and hand, foot, and mouth disease: A systematic review and meta-analysis

BACKGROUNDnThe relationship between ambient temperature, humidity and hand, foot, and mouth disease (HFMD) has been highlighted in East and Southeast Asia, which showed multiple different results. Therefore, our goal is to conduct a meta-analysis to further clarify this relationship and to quantify the size of these effects as well as the susceptible populations.nnnMETHODSnPubMed, Web of science, and Cochrane library were searched up to November 22, 2017 for articles analyzing the relationships between ambient temperature, humidity and incidence of HFMD. We assessed sources of heterogeneity by study design (temperature measure and exposed time resolution), population vulnerability (national income level and regional climate) and evaluated pooled effect estimates for the subgroups identified in the heterogeneity analysis.nnnRESULTSnWe identified 11 studies with 19 estimates of the relationship between ambient temperature, humidity and incidence of HFMD. It was found that per 1°C increase in the temperature and per 1% increase in the relative humidity were both significantly associated with increased incidence of HFMD (temperature: IRR, 1.05; 95% CI, 1.02-1.08; relative humidity: IRR, 1.01; 95% CI, 1.00-1.02). Subgroup analysis showed that people living in subtropical and middle income areas had a higher risk of incidence of HFMD.nnnCONCLUSIONSnAmbient temperature and humidity may increase the incidence of HFMD in Asia-Pacific regions. Further studies are needed to clarify the relationship between ambient temperature, humidity and incidence of HFMD in various settings with distinct climate, socioeconomic, and demographic features.

The burden of extreme heat and heatwave on emergency ambulance dispatches: A time-series study in Huainan, China.

BACKGROUNDnAlthough studies have well documented increased mortality risk during extreme heat and heatwaves, few have examined their impacts on emergency ambulance dispatches under different temperature metrics. Additionally, evidence on the attributable risk of emergency ambulance dispatches due to extreme heat and heatwaves is scarce around the world.nnnMETHODSnA distributed lag nonlinear model (DLNM) was applied to quantify the impact of extreme heat and heatwaves on emergency ambulance dispatches in Huainan, China, during 2011-2013. Several local extreme heat and heatwave definitions were tested by using percentile of daily mean temperature (i.e., 95th, 97.5th and 99th) and duration (i.e.,≥2 consecutive days and ≥3 consecutive days). The fraction of emergency ambulance dispatches attributable to extreme heat and heatwaves was also quantitatively estimated.nnnRESULTSnBoth extreme heat and heatwaves were significantly associated with increases in emergency ambulance dispatches, and their effects appeared to be acute. For extreme heat effects, the relative risks (RRs) of emergency ambulance dispatches at lag0 steadily increased from 95th percentile of daily mean temperature (1.03, 95% confidence interval (CI): 1.01-1.05) to 99th percentile (1.07, 95% CI: 1.05-1.10). For heatwave effects, we observed that RRs of emergency ambulance dispatches at lag0 fluctuated between 1.03 and 1.05 across different heatwave definitions. Notably, the fraction of emergency ambulance dispatches attributable to extreme heat decreased with higher percentile of daily mean temperature, dropping from 2.24% (95% CI: 1.41%-2.99%) at 95th percentile to 0.69% (95% CI: 0.45%-0.92%) at 99th percentile. Likewise, we found that heatwaves with higher intensity and (or) longer duration accounted for lower fraction of emergency ambulance dispatches, varying between 0.51%-1.52%.nnnCONCLUSIONSnOur findings may have important implications for the development of local heat warming systems and public health interventions to lessen the impact of extreme heat events on population health.

Is the serious ambient air pollution associated with increased admissions for schizophrenia

BACKGROUNDnMuch of the research has shown an increased risk of psychiatric disorders in association with elevated exposure to air pollution, such as NO2, PM10 and SO2. However, few studies investigate the effect of these air pollution on the risk of schizophrenia admissions and the lagged effect among different subgroups.nnnMETHODSnA distributed lag non-linear model (DLNM) combined with a Poisson generalized linear regression model was applied to analyzing the relationship between schizophrenia and air pollution. At first, according to the minimum AIC criterion, we discussed the lagged effect of NO2, PM10 and SO2 for 5u202fdays, 4u202fdays and 10u202fdays, respectively. Then, we chose benchmarks as references (25th) to conduct comparisons with different levels of pollutant concentrations (90th and 95th). All patients were retrieved from the Psychiatric Hospital of TongLing (nu202f=u202f3469) from January 2014 to December 2016. Daily air pollutants and meteorological data were collected from the Chinese national air quality monitoring (NAQM) and Meteorological Bureau. Subgroup analysis was conducted by gender (male and female), age (0-19 ages, 20-39 ages, 40-59 ages andu202f≥u202f60 ages) and occupation (farmer, worker and unemployed).nnnRESULTSnThe effects of the three air pollutants were statistically significant to schizophrenia admissions. We found that NO2 and PM10 have short-term effects of 4u202fdays and 3u202fdays (NO2: lag 0-4 RR, 1.84(95% CI: 1.49-2.27), PM10: lag 0-3 RR, 1.97(95%CI: 1.57-2.36)), respectively. SO2 had longer effects for 10u202fdays (SO2: lag 0-10 RR, 2.93(95%CI: 2.10-4.10)). Additionally, it significantly increased the risk of schizophrenia episode in subjects with male, 20-59 ages, farmer and worker.nnnCONCLUSIONnWe find adverse effects of ambient air pollutants on schizophrenia admissions in TongLing, China, which may provide valuable information for the policy makers and local health authorities to conduct effective intervention of air pollution on schizophrenia.

Effect of increasing temperature on daily hospital admissions for schizophrenia in Hefei, China: a time-series analysis

OBJECTIVEnTo investigate the relationship between ambient temperature and hospital admissions for schizophrenia in Hefei, China.nnnSTUDY DESIGNnAn ecological design was used to explore the effect of ambient temperature on hospital admissions for schizophrenia.nnnMETHODSnDaily data on hospital admissions for schizophrenia and meteorological data for the warm season (May-October) in 2005-2014 were obtained from Anhui Mental Health Centre and Hefei Bureau of Meteorology, respectively. Poisson generalised linear regression model combined with a distributed lag non-linear model was used to analyse the effects of temperature on admissions for schizophrenia. Stratified analyses according to individual characteristics, such as age and sex, were also conducted.nnnRESULTSnA significant relationship was found between ambient temperature and admissions for schizophrenia. High temperature appeared to have a delayed effect on admissions for schizophrenia, and a temperature of 28°C (75th percentile) at lag 0-4 days was associated with a 7% (95% confidence interval: 4-11%) increase in admissions for schizophrenia. Stratified analyses showed that male patients, patients aged 21-60 years and married patients were more vulnerable to high temperature, and the temperature effects for those groups occurred at a lag of 1 day.nnnCONCLUSIONnHigh temperature poses significant risks for schizophrenia in subtropical regions. Future preventive measures for reducing the occurrence of schizophrenia should be considered for susceptible populations.

Effect of diurnal temperature range on the outpatient visits for acute bronchitis in children: a time-series study in Hefei, China

OBJECTIVESnTo determine the relationship between diurnal temperature range (DTR) and outpatient visits for childhood acute bronchitis (AB) in Hefei, China, to analyze whether DTR effect was delayed, and to explore the susceptible populations.nnnSTUDY DESIGNnAn ecological study.nnnMETHODSnA Poisson generalized linear regression model combined with a distributed lag non-linear model was used to analyze the relationship between DTR and childhood AB from Hefei, China during 2010-2013, after adjusting for long-term trend and seasonality, mean temperature and relative humidity.nnnRESULTSnAn adverse effect of DTR on childhood AB was observed, and the impact of DTR was greatest at three days lag, with a 1.0% (95% confidence intervalxa0=xa00.5-1.6%) increase of AB cases per 1xa0°C increment of DTR. Female children and children aged 0-4 years appeared to be more vulnerable to DTR effect than other children.nnnCONCLUSIONSnOur study suggests that large DTR may increase the incidence of childhood AB in Hefei, particularly for those who are female and young. Caregivers and health practitioners should be made aware of the potential threat posed by large DTR.

Impact of short-term temperature variability on emergency hospital admissions for schizophrenia stratified by season of birth

Diurnal temperature range (DTR) and temperature change between neighboring days (TCN) are important meteorological indicators closely associated with global climate change. However, up to date, there have been no studies addressing the impacts of both DTR and TCN on emergency hospital admissions for schizophrenia. We conducted a time-series analysis to assess the relationship between temperature variability and daily schizophrenia onset in Hefei, an inland city in southeast China. Daily meteorological data and emergency hospital admissions for schizophrenia from 2005 to 2014 in Hefei were collected. After stratifying by season of birth, Poisson generalized linear regression combined with distributed lag nonlinear model (DLNM) was used to examine the relationship between temperature variability and schizophrenia, adjusting for long-term trend and seasonality, mean temperature, and relative humidity. Our analysis revealed that extreme temperature variability may increase the risk for schizophrenia onset among patients born in spring, while no such association was found in patients born in summer and autumn. In patients born in spring, the relative risks of extremely high DTR comparing the 95th and 99th percentiles with the reference (50th, 10xa0°C) at 3-day lag were 1.078 (95xa0% confidence interval (CI) 1.025–1.135) and 1.159 (95xa0% CI 1.050–1.279), respectively. For TCN effects, only comparing 99th percentile with reference (50th, 0.7xa0°C) was significantly associated with emergency hospital admissions for schizophrenia (relative risk (RR) 1.111, 95xa0% CI 1.002–1.231). This study suggested that exposure to extreme temperature variability in short-term may trigger later days of schizophrenia onset for patients born in spring, which may have important implications for developing intervention strategies to prevent large temperature variability exposure.

Ambient temperature, sunlight duration, and suicide: A systematic review and meta-analysis

BACKGROUNDnThe relationship between sunlight hours, temperature, and suicide has been investigated in many previous studies, but with inconsistent findings. We conducted this meta-analysis aiming at providing clear evidence about whether sunlight hours and temperature can affect the risk of suicide.nnnMETHODSnRelevant literature published before 7 Jul 2018 was searched in three electronic database of PubMed, Web of science and Cochrane. Between-study heterogeneity in the effect estimates were examined by study design (i.e., exposure time resolution, temperature measure and suicide classification) and population vulnerability (i.e., sex, national income level, climate zone and study location).nnnRESULTSnRegarding temperature-suicide association, we identified 14 studies that provided 23 effect estimates for meta-analysis. Our random-effects model showed that each 1u202f°C increase in temperature was significantly associated with a 1% increase in the incidence of suicide (Incidence Rate Radio (IRR)u202f=u202f1.01; 95%CIu202f=u202f1.00-1.02; pu202f<u202f0.05). As for sunlight duration and suicide, 11 effect estimates from 4 studies were pooled using a fixed-effects model. Significant association between sunlight duration (per 1u202fh increase) and the risk of suicide was not observed, and the pooled IRR was 1.00 (95%CIu202f=u202f0.99-1.01; pu202f>u202f0.05). There was significant heterogeneity between previous studies effect estimates, and significantly lower heterogeneity was noted for the female group, for studies that did analyses at daily scale, and for studies using mean temperature as the exposure indicator.nnnCONCLUSIONnOur findings suggest a significant and positive association between temperature rises and incidence of suicide, and a non-significant association between sunlight duration and incidence of suicide. Populations living in tropical and temperate zones or at middle-income level may be particularly vulnerable to temperature increase.