Increase In Daily Mean Temperature Research Articles

Multimorbidity and emergency hospitalisations during hot weather

BackgroundPeople with chronic diseases are a commonly listed heat-vulnerable group in heat-health action plans. While prior research identifies multiple health conditions that may increase vulnerability to ambient heat, there is minimal evidence regarding the implications of multimorbidity (two or more chronic diseases). MethodsFrom the statewide hospital registry of Queensland, Australia, we identified people aged ≥15 years who had emergency hospitalisation(s) between March 2004 and April 2016 and previously had 0, 1, 2, or ≥3 of five chronic diseases: cardiovascular disease, diabetes, mental disorders, asthma/COPD, and chronic kidney disease. We conducted time-stratified case-crossover analyses to estimate the odds ratio of hospitalisations associated with ambient heat exposure in people with different numbers, types, and combinations of chronic diseases. Ambient heat exposure was defined as a 5 °C increase in daily mean temperature above the median. FindingsThere were 2,263,427 emergency hospitalisations recorded (48.7% in males and 51.3% in females). When the mean temperature increased, hospitalisation odds increased with chronic disease number, particularly in older persons (≥65 years), males, and non-indigenous people. For instance, in older persons with 0, 1, 2, or ≥3 chronic diseases, the odds ratios associated with ambient heat exposure were 1.00 (95% confidence interval: 0.96, 1.04), 1.06 (1.02, 1.09), 1.08 (1.02, 1.14), and 1.13 (1.07, 1.19), respectively. Among the chronic diseases, chronic kidney disease, and asthma/COPD, either existing alone, together, or in combination with other diseases, were associated with the highest odds of hospitalisations under ambient heat exposure. InterpretationWhile individuals with multimorbidity are considered in heat-health action plans, this study suggests the need to consider specifically examining them as a distinct and vulnerable subgroup. FundingWellcome.

Ambient Temperature Effects on Hospitalization Risk Among Farmers: A Time-Series Study on Multiple Diseases in Vietnam.

The aim of the study is to assess the effect of high temperatures on hospitalization for all causes and heat-sensitive diseases among Vietnamese farmers. The Poisson generalized linear model and distributed lag nonlinear model were used to investigate the temperature-hospitalization association for all causes and seven cause-specific disease groups. Every 1°C increase in daily mean temperature above the threshold increased the estimated relative risk (95% CI) of all-cause hospitalization by 1.022 (0.998-1.047) at the country level, 1.047 (1.007-1.089) in the south, and 0.982 (0.958-1.006) in the north. Infectious disease hospitalization was most affected by high temperatures (1.098 [1.057-1.140]). High temperatures significantly increased the risk of all-cause hospitalization for farmers 60 years and younger in three of the six provinces. The findings emphasized the need for health promotion programs to prevent heat-related health issues.

Associations between short-term ambient temperature exposure and emergency department visits for amphetamine, cocaine, and opioid use in California from 2005 to 2019

Substance use disorder is a growing public health challenge in the United States. People who use drugs may be more vulnerable to ambient heat due to the effects of drugs on thermoregulation and their risk environment. There have been limited population-based studies of ambient temperature and drug-related morbidity. We examined short-term associations between daily ambient temperature and emergency department (ED) visits for use or overdose of amphetamine, cocaine and opioids in California during the period 2005 to 2019. Daily ZIP code-level maximum, mean, and minimum temperature exposures were derived from 1-km data Daymet products. A time-stratified case-crossover design was used to estimate cumulative non-linear associations of daily temperature for lag days 0 to 3. Stratified analyses by patient sex, race, and ethnicity were also conducted. The study included over 3.4 million drug-related ED visits. We found positive associations between daily temperature and ED visits for all outcomes examined. An increase in daily mean temperature from the 50th to the 95th percentile was associated with ED visits for amphetamine use (OR = 1.072, 95% CI: 1.058, 1.086), cocaine use (OR = 1.044, 95% CI: 1.021, 1.068 and opioid use (OR = 1.041, 95% CI: 1.025, 1.057). Stronger positive associations were also observed for overdose: amphetamine overdose (OR = 1.150, 95% CI: 1.085, 1.218), cocaine overdose (OR = 1.159, 95% CI: 1.053, 1.276), and opioid overdose (OR = 1.079, 95% CI: 1.054, 1.106). In summary, people who use stimulants and opioids may be a subpopulation sensitive to short-term higher ambient temperature. Mitigating heat exposure can be considered in harm reduction strategies in response to the substance use epidemic and global climate change.

Heat exposure and hospitalizations for chronic kidney disease in China: a nationwide time series study in 261 major Chinese cities

BackgroundClimate change profoundly shapes the population health at the global scale. However, there was still insufficient and inconsistent evidence for the association between heat exposure and chronic kidney disease (CKD).MethodsIn the present study, we studied the association of heat exposure with hospitalizations for cause-specific CKD using a national inpatient database in China during the study period of hot season from 2015 to 2018. Standard time-series regression models and random-effects meta-analysis were developed to estimate the city-specific and national averaged associations at a 7 lag-day span, respectively.ResultsA total of 768,129 hospitalizations for CKD was recorded during the study period. The results showed that higher temperature was associated with elevated risk of hospitalizations for CKD, especially in sub-tropical cities. With a 1 °C increase in daily mean temperature, the cumulative relative risks (RR) over lag 0–7 d were 1.008 [95% confidence interval (CI) 1.003–1.012] for nationwide. The attributable fraction of CKD hospitalizations due to high temperatures was 5.50%. Stronger associations were observed among younger patients and those with obstructive nephropathy. Our study also found that exposure to heatwaves was associated with added risk of hospitalizations for CKD compared to non-heatwave days (RR = 1.116, 95% CI 1.069–1.166) above the effect of daily mean temperature.ConclusionsShort-term heat exposure may increase the risk of hospitalization for CKD. Our findings provide insights into the health effects of climate change and suggest the necessity of guided protection strategies against the adverse effects of high temperatures.

Ambient temperature and mental health: a systematic review and meta-analysis

Increasing evidence indicates that ambient outdoor temperature could affect mental health, which is especially concerning in the context of climate change. We aimed to comprehensively analyse the current evidence regarding the associations between ambient temperature and mental health outcomes. We did a systematic review and meta-analysis of the evidence regarding associations between ambient outdoor temperature and changes in mental health outcomes. We searched WebOfScience, Embase, PsychINFO, and PubMed for articles published from database origin up to April 7, 2022. Eligible articles were epidemiological, observational studies in humans of all ages, which evaluated real-world responses to ambient outdoor temperature, and had mental health as a documented outcome; studies of manipulated or controlled temperature or those with only physical health outcomes were excluded. All eligible studies were synthesised qualitatively. If three or more studies reported the same or equivalent effect statistics and if they had equivalent exposure, outcome, and metrics, the studies were pooled in a random-effects meta-analysis. The risk of bias for individual studies was assessed using the Newcastle-Ottawa Scale. The quality of evidence across studies was assessed using the Office of Health Assessment and Translation (OHAT) approach. 114 studies were included in the systematic review, of which 19 were suitable for meta-analysis. Three meta-analyses were conducted for suicide outcomes: a 1°C increase in mean monthly temperature was associated with an increase in incidence of 1·5% (95% CI 0·8-2·2, p<0·001; n=1 563 109, seven effects pooled from three studies); a 1°C increase in mean daily temperature was associated with an increase in incidence of 1·7% (0·3-3·0, p=0·014; n=113 523, five effects pooled from five studies); and a 1°C increase in mean monthly temperature was associated with a risk ratio of 1·01 (95% CI 1·00-1·01, p<0·001; n=111 794, six effects pooled from three studies). Three meta-analyses were conducted for hospital attendance or admission for mental illness: heatwaves versus non-heatwave periods were associated with an increase in incidence of 9·7% (95% CI 7·6-11·9, p<0·001; n=362 086, three studies); the risk ratio at the 99th percentile of daily mean temperature compared with the 50th percentile was 1·02 (95% CI 1·01-1·03, p=0·006; n=532 296, three studies); and no significant association was found between a 10°C increase in daily mean temperature and hospital attendance. In a qualitative narrative synthesis, we found that ambient outdoor temperature (including absolute temperatures, temperature variability, and heatwaves) was positively associated with attempted and completed suicides (86 studies), hospital attendance or admission for mental illness (43 studies), and worse outcomes for community mental health and wellbeing (19 studies), but much of the evidence was of low certainty with high heterogeneity. Increased temperature and temperature variability could be associated with increased cases of suicide and suicidal behaviour, hospital attendance or admission for mental illness, and poor community health and wellbeing. Climate change is likely to increase temperature anomalies, variability, and heatwaves as well as average temperatures; as such, health system leaders and policy makers must be adequately prepared and should develop adaptation strategies. More high-quality, standardised research is required to improve our understanding of these effects. None.

The impact of daily mean air temperature on the proportion of time in hypoglycemia in 2,582 children and adolescents with type 1 diabetes – Is this association clinically relevant?

ObjectivesTo study the potential association between increases in daily mean air temperature and time below range (TBR <54 mg/dl) and time above range (TAR >250 mg/dl) in children and adolescents with type 1 diabetes. Research design and methodsIndividuals with type 1 diabetes <21 years with information on daily glucose profiles from the diabetes prospective follow-up study (DPV) were included (n = 2582). Further inclusion criteria were age at least 6 months at diabetes onset, diabetes duration for at least one year and treatment years 2020–2021. Mean daily air temperature and other meteorological parameters from 78 measurement stations in Germany were linked to the individual glucose sensor profile via the five-digit postcode areas of residency. We used multivariable repeated measures fractional logistic regression models with a compound symmetry covariance structure to study the association between a 1 °C increase in daily mean temperature and time in specific glucose ranges. ResultsA 1 °C increase in daily mean temperature was associated with an acute (Odds Ratio (OR) 1.009 (95%-CI 1.007, 1.011)) and up to 7 days delayed (OR 1.003 (1.001, 1.005)) increase in TBR <54 mg/dl. Moreover, an acute decrease in TAR >250 mg/dl (OR 0.997 (0.996, 0.997)) was found. ConclusionsResults of the DPV registry showed small, but statistically significant changes in TBR and TAR in association with a short-term temperature increase. Higher blood flow and faster insulin absorption might be one possible mechanism. In times of increasing temperature fluctuations meteorological impacts on time in range could become even more relevant.

A comparison of CMIP5 and CMIP6 climate model projections for hydrological impacts in China

Abstract Global climate model (GCM) outputs from Coupled Model Inter-comparison Project Phase 5 (CMIP5) were widely used to investigate climate change impacts last 10 years. It is important to know whether Coupled Model Inter-comparison Project Phase 6 (CMIP6) is more reliable than CMIP5. Number of studies compared GCMs from two CMIPs in simulating climate variables, but they are not in the field of hydrology for large quantities of watersheds. The objective of this study is to compare CMIP5 and CMIP6 climate model projections in projecting hydrological changes between future (2071–2100) and historical (1976–2005) periods and inter-model variability of hydrological impacts for the future period over 343 catchments in China's mainland. The results show that the GCMs in CMIP6 show more increase in daily mean temperature and mean annual precipitation. However, GCMs in CMIP6 and CMIP5 show similar increases in mean and peak streamflow. Moreover, GCMs in CMIP6 show less inter-model variability for streamflow in southern and northeastern China, but more in central China, which is consistent to that for precipitation after bias correction. Overall, this comparison provides the consistency of future change and uncertainty in predicted streamflow with climate simulations, which bring confidence for hydrological impact studies using CMIP6.

Regional analysis of climate variability in Greece based on six temperature variability indicators – A cluster analysis

In this paper, a comparative analysis of climate variability between different regions of Greece based on some temperature variability indicators, is performed, in order to find out which areas have similar climate variability over time in the context of climate change. For this purpose, temperature variability, based on six temperature variability indices for 20 different stations, is calculated and, then, a K-Means clustering method is applied between the stations for each indicator. The results show that most of the regions of central and northern Greece have a high number of days where mean and minimum temperatures increase. In addition, most of these areas also have a high number of days with a continuous increase in daily mean temperature. As a result, a higher warming pace is observed in these areas than in the rest of the areas. This work is intended to serve as a reference for further scientific research on climate variability in Greece.

The Effects of Daily Temperature on Crime Events in Urban Hanoi, Vietnam Using Seven Years of Data (2013-2019).

The effects of temperature on behavior change and mental health have previously been explored, but the association between temperature and crime is less well understood, especially in developing countries. Single-city-level data were used to evaluate the association between the short-term effects of temperature on crime events in urban Hanoi, Vietnam. We used quasi-Poisson regression models to investigate the linear effects and distributed lag non-linear models to investigate the non-linear association between daily temperature and daily crime events from 2013 to 2019. There were 3884 crime events, including 1083 violent crimes and 2801 non-violent crimes during the 7-year study period. For both linear and non-linear effects, there were positive associations between an increase in daily temperature and crime, and the greatest effects were observed on the first day of exposure (lag 0). For linear effects, we estimated that each 5 °C increase in daily mean temperature was associated with a 9.9% (95%CI: 0.2; 20.5), 6.8% (95%CI: 0.6; 13.5), and 7.5% (95%CI: 2.3; 13.2) increase in the risk of violent, non-violent, and total crime, respectively. For non-linear effects, however, the crime risk plateaued at 30 °C and decreased at higher exposures, which presented an inverted U-shape response with a large statistical uncertainty.

Heat and outpatient visits of skin diseases – A multisite analysis in China, 2014–2018

BackgroundMany studies have shown that various kinds of diseases were associated with the variation of ambient temperature. However, there’s only a scrap of evidence paying attention to the link between temperature and skin diseases, and no relevant national research was performed in China. ObjectiveThis study aimed to quantify the effect of heat on skin diseases and identify the vulnerable populations and areas in China. MethodsDaily meteorological data, air pollutant data and outpatient data were collected from in 18 sites of China during 2014–2018. A time-series study with distributed lag nonlinear model and multivariate meta-analysis was applied to analyze the site-specific and pooled associations between daily mean temperature and daily outpatient visits of skin diseases by using the data of warm season (from June to September). Stratified analysis by age, sex and climate zones and subtypes of skin diseases were also conducted. ResultsWe found a positive linear relationship between the ambient temperature and risk of skin diseases, with a 1.25% (95%CI: 0.34%, 2.16%) increase of risk of outpatient visits for each 1 °C increase in daily mean temperature during the warm season. In general, groups aged 18–44 years, males and people living in temperate climate regions were more susceptible to high temperature. Immune dysfunction including dermatitis and eczema were heat-sensitive skin diseases. ConclusionsOur findings suggested that people should take notice of heat-related skin diseases and also provided some references about related health burden for strategy-makers. Targeted measures for vulnerable populations need to be taken to reduce disease burden, including monitoring and early warning systems, and sun-protection measures.

High ambient temperature and risk of hospitalization for gastrointestinal infection in Brazil: A nationwide case-crossover study during 2000–2015

BackgroundThe burden of gastrointestinal infections related to hot ambient temperature remains largely unexplored in low-to-middle income countries which have most of the cases globally and are experiencing the greatest impact from climate change. The situation is particularly true in Brazil. ObjectivesUsing medical records covering over 78 % of population, we quantify the association between high temperature and risk of hospitalization for gastrointestinal infection in Brazil between 2000 and 2015. MethodsData on hospitalization for gastrointestinal infection and weather conditions were collected from 1814 Brazilian cities during the 2000–2015 hot seasons. A time-stratified case-crossover design was used to estimate the association. Stratified analyses were performed by region, sex, age-group, type of infection and early/late study period. ResultsFor every 5 °C increase in mean daily temperature, the cumulative odds ratio (OR) of hospitalization over 0–9 days was 1.22 [95 % confidence interval (CI): 1.21, 1.23] at the national level, reaching its maximum in the south and its minimum in the north. The strength of association tended to decline across successive age-groups, with infants < 1 year most susceptible. The effect estimates were similar for men and women. Waterborne and foodborne infections were more associated with high temperature than the ‘others’ and ‘idiopathic’ groups. There was no substantial change in the association over the 16-year study period. DiscussionOur findings indicate that exposure to high temperature is associated with increased risk of hospitalization for gastrointestinal infection in the hot season, with the strength varying by region, population subgroup and infection type. There was no evidence to indicate adaptation to heat over the study duration.

Effects of Temperature and Radiation on Yield of Spring Wheat at Different Latitudes

It is of great importance to investigate spring wheat yield affected by the climate at different latitudes in the Rice-Wheat Rotation System. Two spring wheat varieties used as the study objects were planted at two locations of different latitudes in 2017–2018 and 2018–2019. Six sowing dates were selected for planting the wheat seeds. The quantity of basic seedlings for the first sowing date was 300 × 104 ha−1, which was increased by 10% on each date in the following sowing proceeding. Results showed that as the latitude increased, the mean daily temperature and effective accumulated temperature decreased, the mean solar radiation and accumulated solar radiation increased; as the effective accumulated temperature decreased, the yield decreased by 0.18 t ha−1 on average; and dry matter accumulation decreased by 0.6 t ha−1 on average. As the sowing date was delayed, the mean daily temperature and mean daily solar radiation increased, and the effective accumulated temperature and accumulated solar radiation decreased. Due to the decrease in the accumulated solar radiation and increase in mean daily temperature, the yield decreased by 0.27 t ha−1 on average and the dry matter decreased by 0.39 t ha−1 on average by postponing one sowing date. The effective accumulated temperature and accumulated solar radiation were significantly positively correlated with wheat yield and dry matter accumulation, and the mean daily temperature was significantly negatively correlated with wheat yield and dry matter accumulation. The temperature productivity at a high latitude was higher than lower latitude. The radiation productivity at a high latitude was lower than lower latitude. The productivity of the temperature and radiation first increased and then decreased when the sowing time was delayed.

Ambient temperatures associated with increased risk of motor vehicle crashes in New York and Chicago

Motor Vehicle Crashes (MVC) are a major cause of death and disability worldwide. Yet it remains unknown to what extent changes in cold and hot temperatures affect the MVC. Here we quantify the linkage between ambient temperature exposure and the MVC risk of the driver in four cities of the United States. After adjusting for confounding factors, we find both a cold effect and a hot effect on MVC in New York, and a cold effect on MVC in Chicago. A 1 °C decrease in mean daily temperature below a cold threshold of −4.8 °C is associated with an increase in the overall cumulative relative risk of MVC by 11.59% (95% CI: 5.17%–16.43%) over 0–28 lag days for New York. The respective risk increase is 1.58% (95% CI: 0.36%–2.79%) over 0–2 lag days for a 1 °C increase in mean daily temperature above the hot threshold of 26.1 °C for New York. There is no significant heat wave or cold spell effects except for the heat wave effect on the consecutive heat wave days 7–10 in New York. Our study provides evidence of the association between driver exposure to low or high temperatures and the MVC risk. Improved public- administration preventive measures and policymaking are needed to minimize the negative consequences of abnormal temperatures on road safety driving.

Relationships between short-term ambient temperature exposure and kidney disease hospitalizations in the warm season in Vietnam: A case-crossover study

BackgroundUnder a warming climate, adverse health effects of heat are an increasing concern. We evaluated associations between short-term ambient temperature exposure and hospital admission for kidney disease in Vietnam. MethodsWe linked province-level meteorologic data with admission data from 14 province-level hospitals (2003–2015). We used a case-crossover design to evaluate associations between daily ambient temperature metrics (mean, maximum, and minimum temperature and mean heat index) and risk of hospitalization for four kidney disease subtypes: glomerular diseases, renal tubulo-interstitial diseases, chronic kidney disease, and urolithiasis, including lagged (≤lag 14 days) and cumulative (≤lag 0–6 days) associations, during the warm season. We also evaluated independent associations with extreme heat days (defined as days with daily maximum temperature >95th percentile of the provincial daily maximum temperature distribution). Akaike's information criterion and patterns of risk estimates across cumulative exposure time windows and single-day lags informed our selection of final models. ResultsWe included 58,330 hospital admissions during the warm season. Daily mean temperature averaged over the same day and the previous six days (lag 0–6 days) was associated with risk of hospitalization for each kidney disease outcome with odds ratios (per 1 °C increase in daily mean temperature) of 1.07 (95% confidence interval [CI]: 0.99, 1.16) for glomerular diseases, 1.06 (95% CI: 0.96, 1.17) for renal tubulo-interstitial diseases, 1.12 (95% CI: 1.00, 1.24) for chronic kidney disease, and 1.09 (95% CI: 1.02, 1.16) for urolithiasis. We found no additional independent associations with extreme heat. Results for the four temperature metrics were similar. ConclusionsHigh ambient temperature was associated with increased risk of hospitalization for each kidney disease subtype, with the most convincing associations for chronic kidney disease and urolithiasis. Further laboratory and epidemiologic research is needed to confirm the findings and disentangle the underlying mechanisms.

Association between daily ambient temperature and drug overdose in Tokyo: a time-series study.

BackgroundPrevious studies have reported that high ambient temperature is associated with increased risk of suicide; however, the association has not been extensively investigated with drug overdose which is the most common method of unsuccessful suicidal behavior in Japan. Therefore, this study aims to examine the short-term association between daily mean temperature and the incidence of self-harm attempts by drug overdose in Tokyo, Japan.MethodsWe collected the emergency ambulance dispatch data and daily meteorological data in Tokyo from 2010 to 2014. A quasi-Poisson regression model incorporating a distributed lag non-linear function was applied to estimate the non-linear and delayed association between temperature and drug overdose, adjusting for relative humidity, seasonal and long-term trends, and days of the week. Sex, age and location-specific associations of ambient temperature with drug overdose was also estimated.Results12,937 drug overdose cases were recorded during the study period, 73.9% of which were female. We observed a non-linear association between temperature and drug overdose, with the highest risk observed at 21 °C. The highest relative risk (RR) was 1.30 (95% Confidence Interval (CI): 1.10–1.67) compared with the risk at the first percentile of daily mean temperature (2.9 °C) over 0–4 days lag period. In subgroup analyses, the RR of a drug overdose at 21 °C was 1.36 (95% CI: 1.02–1.81) for females and 1.07 (95% CI: 0.66–1.75) for males. Also, we observed that the risk was highest among those aged ≥65 years (RR = 2.54; 95% CI: 0.94–6.90), followed by those aged 15–34 years (RR = 1.25; 95% CI: 0.89–1.77) and those aged 35–64 years (RR = 1.15; 95% CI: 0.78–1.68). There was no evidence for the difference in RRs between urban (23 special wards) and sub-urban areas in Tokyo.ConclusionsAn increase in daily mean temperature was associated with increased drug overdose risk. This study indicated the positive non-linear association between temperature and incomplete attempts by drug overdose. The findings of this study may add further evidence of the association of temperature on suicidal behavior and suggests increasing more research and investigation of other modifying factors.Supplementary informationThe online version contains supplementary material available at https://doi.org/10.1265/ehpm.21-00044.

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

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. 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. 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. This nationwide study provides robust evidence that more policies should be developed to prevent heat-related hospitalizations and mitigate climate change. China Scholarship Council, and the Australian National Health and Medical Research Council.

Ambient temperature and mental health hospitalizations in Bern, Switzerland: A 45-year time-series study.

Psychiatric disorders constitute a major public health concern that are associated with substantial health and socioeconomic burden. Psychiatric patients may be more vulnerable to high temperatures, which under current climate change projections will most likely increase the burden of this public health concern. This study investigated the short-term association between ambient temperature and mental health hospitalizations in Bern, Switzerland. Daily hospitalizations for mental disorders between 1973 and 2017 were collected from the University Hospital of Psychiatry and Psychotherapy in Bern. Population-weighted daily mean ambient temperatures were derived for the catchment area of the hospital from 2.3-km gridded weather maps. Conditional quasi-Poisson regression with distributed lag linear models were applied to assess the association up to three days after the exposure. Stratified analyses were conducted by age, sex, and subdiagnosis, and by subperiods (1973-1989 and 1990-2017). Additional subanalyses were performed to assess whether larger risks were found during the warm season or were due to heatwaves. The study included a total number of 88,996 hospitalizations. Overall, the hospitalization risk increased linearly by 4.0% (95% CI 2.0%, 7.0%) for every 10°C increase in mean daily temperature. No evidence of a nonlinear association or larger risks during the warm season or heatwaves was found. Similar estimates were found across for all sex and age categories, and larger risks were found for hospitalizations related to developmental disorders (29.0%; 95% CI 9.0%, 54.0%), schizophrenia (10.0%; 95% CI 4.0%, 15.0%), and for the later rather than the earlier period (5.0%; 95% CI 2.0%, 8.0% vs. 2.0%; 95% CI -3.0%, 8.0%). Our findings suggest that increasing temperatures could negatively affect mental status in psychiatric patients. Specific public health policies are urgently needed to protect this vulnerable population from the effects of climate change.

How ambient temperature affects mood: an Ecological Momentary Assessment study in Switzerland

BACKGROUND AND AIM: Recent studies indicate that increasing temperatures could negatively affect mental health and lead to increased psychiatric hospitalizations. However, evidence on the potential mechanisms mediating this association is limited. Mood can act as a potential mediator. We aimed to investigate the short-term association between ambient temperature and daily mood in a cohort population in Lausanne, Switzerland. METHODS: Participants from CoLaus|PsyCoLaus who completed the Ecological Momentary Assessment (2015-2017) were included. Data on several mood markers were collected four times daily through a cellphone. A principal component analysis was conducted to create an aggregate index of average daily mood (transformed into a binary variable indicating the presence of positive or negative mood). The effect of daily mean temperature (DMT) on mood was assessed using a mixed-effects model, and it was controlled for sleep, day of the week, season, sunshine duration and humidity. Stratified analyses were conducted by age, sex, and presence of major depressive disorder (MDD) or generalized anxiety disorder (GAD). RESULTS:The study included a total of 946 participants. Overall, probability of having good mood increased by 2.4% (95%CI 0%, 4.5%) for each 1°C increase in DMT, instead increasing temperatures was associated with bad mood in participants with MDD (7.1%; 95%CI, -21.2%, 6.4%) and GAD (-5.7%; 95%CI -49.2%, 26.4%). Larger association estimates were found in males (4.8%; 95%CI 1.4%, 8.0%, vs 1.1%; 95%CI, -2.3%, 4.4% in females), while similar estimates were found for all age categories. CONCLUSIONS:Our preliminary findings suggest that increasing temperatures could positively affect mood in the general population. This association seems to be reversed in individuals suffering from mental disorders, thus suggesting a possible explanation for the increased morbidity in psychiatric patients during heat exposure. This finding supports the need for specific public health policies to protect this vulnerable population from the consequences of a changing climate. KEYWORDS: climate change, temperature, mood, mental health, psychiatric disorders, Ecological Momentary Assessment

Effects of ambient temperature on maternal behaviour and health-related functioning in Burkina Faso

BACKGROUND AND AIM: High ambient temperature is associated with reduced work capacity, disrupted sleep, and increased anxiety, which may impact on maternal caregiving behaviours and health-related functioning. We explored the effects of heat on normal daily activities and wellbeing in a cohort of pregnant and postpartum women in southern Burkina Faso. METHODS: We undertook secondary analysis of data collected during structured interviews with 868 pregnant and postpartum women (aged 14–47 years), on 3 occasions (between November 2013 and November 2014), in the commune of Bobo-Dioulasso. Temperature data for Bobo-Dioulasso were obtained from Tutiempo.net. Multilevel linear regression models were used to estimate the effects of daily mean temperature on women’s sleeping behaviour, mental health (Kessler Psychological Distress Scale), and time spent (minutes per typical day) on professional, household, social, and caregiving activities. Models were stratified by residential area (urban/rural), and controlled for season, pregnancy history, marital status, number of infants born, infant status (alive, absent, dead) and/or age, where appropriate. RESULTS:The population experienced year-round high temperatures (intra-annual range: 23.2℃ - 33.7℃). With every 1℃ increase in daily mean temperature, exclusive breastfeeding decreased by 2.0 minutes per day (95% CI -4.3 to 0.3), family care decreased by 1.9 minutes per day (-4.1 to 0.2), and childcare increased by 0.5 minutes per day (-0.04 to 1.0). Associations were statistically significant at the 10% level. We found no evidence of association between temperature and time spent on professional or social activities, housework, sleeping, or mental health. Temperature-outcome associations did not differ between urban and rural settings. CONCLUSIONS:This study suggests that very high temperatures may not limit work-related behaviours when individuals have little option to rest. As infants become thirstier in hot weather, it is concerning that they may be breastfed for a shorter duration when temperatures rise. KEYWORDS: Temperature, Female, Outcomes, Mental health outcomes

Socioeconomic level and associations between heat exposure and all-cause and cause-specific hospitalization in 1,814 Brazilian cities: A nationwide case-crossover study

BACKGROUND AND AIM: Little is known about socioeconomic disparities in vulnerability to heat. We aimed to evaluate whether there were socioeconomic disparities in vulnerability to heat-related all-cause and cause-specific hospitalization among Brazilian cities. METHODS: We collected daily hospitalization and weather data in the hot season (city-specific 4 adjacent hottest months each year) during 2000–2015 from 1,814 Brazilian cities covering 78.4% of the Brazilian population. A time-stratified case-crossover design modeled by quasi-Poisson regression and a distributed lag model was used to estimate city-specific heat–hospitalization association. Then meta-analysis was used to synthesize city-specific effect estimates according to different socioeconomic quartiles or levels. RESULTS:We included 49 million hospitalizations (58.5% female; median [interquartile range] age: 33.3 [19.8–55.7] years). For cities of lower middle income (LMI), upper middle income (UMI), and high income (HI) according to the World Bank’s classification, every 5°C increase in daily mean temperature during the hot season was associated with a 5.1% (95% CI 4.4%–5.7%,), 3.7% (3.3%–4.0%), and 2.6% (1.7%–3.4%) increase in all-cause hospitalization, respectively. The inter-city socioeconomic disparities in the association were strongest for children and adolescents (0–19 years) (effect estimates: 9.9% in LMI cities vs 5.2% in HI cities). The disparities were particularly evident for hospitalization due to certain diseases, including ischemic heart disease (effect estimates: 5.6% in LMI cities vs 0.5% in HI cities), asthma (3.7% vs −6.4%), pneumonia (8.0% vs 3.8%), renal diseases (9.6% vs 4.9%), mental health conditions (17.2% vs 5.5%), and neoplasms (3.1% vs −0.1%). The disparities were similar when stratifying the cities by other socioeconomic indicators (urbanization rate, literacy rate, and household income). CONCLUSIONS:Less developed cities displayed stronger associations between heat exposure and all-cause hospitalizations and certain types of cause-specific hospitalizations in Brazil. This may exacerbate the existing geographical health and socioeconomic inequalities under a changing climate. KEYWORDS: Temperature, Socio-economic factors (non-chemical stressors), Environmental disparities, Environmental justice, Big data