| 341. |
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| 342. |
- Rocklöv, Joacim, 1979-, et al.
(author)
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Mortality related to temperature and persistentextreme temperatures : a study of cause-specificand age-stratified mortality
- 2011
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In: Occupational and Environmental Medicine. - : BMJ Publishing Group Ltd. - 1351-0711 .- 1470-7926. ; 68:7, s. 531-536
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Journal article (peer-reviewed)abstract
- Objectives: High and low ambient temperatures are associated with large numbers of deaths annually. Many studies show higher mortalities during heatwaves. However, such effects are rarely explicitly incorporated in models of temperature and mortality, although dehydration followed by cardiovascular stress is more likely to occur. The authors aim to establish time-series models in which the effects of persistent extreme temperature and temperature in general can be disentangled.Methods: The authors established time-series Poisson regression models based on cause-specific mortality and age-stratified mortality in Stockholm County (Sweden), 1990–2002, adjusting for time trends and potential confounders, and studied the effects of temperature and persistence of extreme temperature.Results: Persistent extremely high temperature was associated with additional deaths, and the risk of death increased significantly per day of extended heat exposure. Extreme exposure to heat was associated with higher death rates in adults and for cardiovascular causes of death, compared with a rise in temperature. Warmer temperatures increase daily mortality from natural causes, while decreasing colder temperatures increase the risk of cardiovascular deaths. Furthermore, the impact of warm and cold temperatures decreases within the season, while the impact of persistent extremely high temperatures remains similar throughout the summer.Conclusions: The authors found the mortality impact of persistence of extreme high temperatures to increase proportionally to the length of the heat episode in addition to the effects of temperature based on the temperature–mortality relationship. Thus, the additional effect of persistent extreme heat was found to be important to incorporate for models of mortality related to ambient temperatures to avoid negatively biased attributed risks, especially for cardiovascular mortality. Moreover, the effects associated with non-extreme temperatures may decline as the pool of fragile individuals shrink as well as due to acclimatisation/adaptation. However, a similar decline was not observed for the effects associated with extreme heat episodes.
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| 343. |
- Rocklöv, Joacim, 1979-
(author)
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Short-term effects of ambient temperature on daily deaths and hospital admissions
- 2010
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Doctoral thesis (other academic/artistic)abstract
- Background: Incidence of death and hospitalizations have been observed to depend on short-term changes in weather and to increase with extreme temperatures. This thesis aims to strengthen the scientific knowledge on the relationship between temperature and daily deaths, but also the relationship between temperature and daily hospital admissions. Methods: We constructed time series regression models using daily counts of death and daily weather from the Stockholm area incorporating adjustment for potential confounding factors, season, and long-term time trends. From these models, we established the short-term relationship with daily temperatures and the associated relative risks on daily deaths allowing for a delay between exposure and subsequent deaths. Daily hospital admissions and daily temperatures were analyzed correspondingly using data from Skåne. Results: Hot and cold temperatures significantly impact on mortality rates as well as rates of hospitalization in Sweden. We found an immediate heat effect on daily deaths, while the impacts of cold temperatures were delayed up to a week after exposure. Cold-related deaths are generally cardiovascular in nature, while deaths resulting from warm temperatures are cardiovascular, respiratory as well as non-cardiorespiratory in nature. The impacts following a heat wave appear to increase proportionally with the length of the extreme hot conditions. The results suggest that the population aged 45 years and older is the main group at elevated risk of death when exposed to high and low temperatures. Moreover, the results suggest that there are several factors of susceptibility on an individual basis that correspond to larger relative risk with high and/or low temperatures. Daily hospitalisations increased in particular among individuals with respiratory illnesses during extreme persistent heat, whereas high temperatures in general have little impact. In contrast, hospitalizations increased for up to two weeks following exposure to cold temperatures. Conclusions: The health impacts related to temperature are a serious concern and the attributed impacts are likely to increase to some extent in the future due to an ageing population. Public health preventive strategies should be developed to prevent health consequences related to heat waves and cold temperatures. Future studies should aim at identifying susceptible individuals with elevated death risk at hot and cold ambient temperature conditions.
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| 344. |
- Rocklöv, Joacim, et al.
(author)
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Susceptibility to mortality related to temperature and heat and cold wave duration in the population of Stockholm County, Sweden
- 2014
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In: Global Health Action. - : CoAction Publishing. - 1654-9716 .- 1654-9880. ; 7, s. 22737-
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Journal article (peer-reviewed)abstract
- BACKGROUND: Ambient temperatures can cause an increase in mortality. A better understanding is needed of how health status and other factors modify the risk associated with high and low temperatures, to improve the basis of preventive measures. Differences in susceptibility to temperature and to heat and cold wave duration are relatively unexplored.OBJECTIVES: We studied the associations between mortality and temperature and heat and cold wave duration, stratified by age and individual and medical factors.METHODS: Deaths among all residents of Stockholm County between 1990 and 2002 were linked to discharge diagnosis data from hospital admissions, and associations were examined using the time stratified case-crossover design. Analyses were stratified by gender, age, pre-existing disease, country of origin, and municipality level wealth, and adjusted for potential confounding factors. Results : The effect on mortality by heat wave duration was higher for lower ages, in areas with lower wealth, for hospitalized patients younger than age 65. Odds were elevated among females younger than age 65, in groups with a previous hospital admission for mental disorders, and in persons with previous cardiovascular disease. Gradual increases in summer temperatures were associated with mortality in people older than 80 years, and with mortality in groups with a previous myocardial infarction and with chronic obstructive pulmonary disease (COPD) in the population younger than 65 years. During winter, mortality was associated with a decrease in temperature particularly in men and with the duration of cold spells for the population older than 80. A history of hospitalization for myocardial infarction increased the odds associated with cold temperatures among the population older than 65. Previous mental disease or substance abuse increased the odds of death among the population younger than 65.CONCLUSION: To increase effectiveness, we suggest preventive efforts should not assume susceptible groups are the same for warm and cold days and heat and cold waves, respectively.
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| 345. |
- Rocklöv, Joacim, et al.
(author)
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The effect of high ambient temperature on the elderly population in three regions of Sweden
- 2010
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In: International journal of environmental research and public health. - : MDPI AG. - 1661-7827 .- 1660-4601. ; 7:6, s. 2607-2619
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Journal article (peer-reviewed)abstract
- The short-term effects of high temperatures are a serious concern in the context of climate change. In areas that today have mild climates the research activity has been rather limited, despite the fact that differences in temperature susceptibility will play a fundamental role in understanding the exposure, acclimatization, adaptation and health risks of a changing climate. In addition, many studies employ biometeorological indexes without careful investigation of the regional heterogeneity in the impact of relative humidity. We aimed to investigate the effects of summer temperature and relative humidity and regional differences in three regions of Sweden allowing for heterogeneity of the effect over the scale of summer temperature. To do so, we collected mortality data for ages 65+ from Stockholm, Göteborg and Skåne from the Swedish National Board of Health and Welfare and the Swedish Meteorological and Hydrological Institute for the years 1998 through 2005. In Stockholm and Skåne on average 22 deaths per day occurred, while in Göteborg the mean frequency of daily deaths was 10. We fitted time-series regression models to estimate relative risks of high ambient temperatures on daily mortality using smooth functions to control for confounders, and estimated non-linear effects of exposure while allowing for auto-regressive correlation of observations within summers. The effect of temperature on mortality was found distributed over the same or following day, with statistically significant cumulative combined relative risk of about 5.1% (CI = 0.3, 10.1) per °C above the 90th percentile of summer temperature. The effect of high relative humidity was statistically significant in only one of the regions, as was the effect of relative humidity (above 80th percentile) and temperature (above 90th percentile). In the southernmost region studied there appeared to be a significant increase in mortality with decreasing low summer temperatures that was not apparent in the two more northerly situated regions. The effects of warm temperatures on the elderly population in Sweden are rather strong and consistent across different regions after adjustment for mortality displacement. The impact of relative humidity appears to be different in regions, and may be a more important predictor of mortality in some areas.
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| 346. |
- Rocklöv, Joacim, 1979-, et al.
(author)
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The effect of temperature on mortality in Stockholm 1998-2003 : a study of lag structures and heatwave effects
- 2008
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In: Scandinavian Journal of Public Health. - : SAGE Publications. - 1403-4948 .- 1651-1905. ; 36:5, s. 516-523
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Journal article (peer-reviewed)abstract
- AIMS: To describe seasonal patterns of natural mortality in Stockholm as well as the temperature-mortality relationship and the lag structure for effects of high and low temperatures; to describe the impact of high temperatures on cardiovascular and respiratory mortality, and the general effect of high temperatures in different age groups; and to investigate whether there is any indication of an additional heatwave or cold spell effect. METHODS: Generalized additive Poisson regression models were fitted to mortality and temperature data from Stockholm from the period 1998-2003, controlling for influenza, season, time trends, week day, and holidays. RESULTS: The mortality in Stockholm followed a seasonal pattern, with a peak in the winter season. The ;;optimal temperature'' was around 11-12 degrees C. Above this temperature, the cumulative general relative risk (RR) corresponded to a 1.4% (95% confidence interval (CI)=0.8-2.0) increase per degrees C, and below this temperature the cumulative RR corresponded to a 0.7% (95% CI=0.5-0.9) decrease per degrees C. Age-specific RRS were estimated above the threshold for age <65 years, age 65-74 years, and age >74 years, with estimated increases of 0.5% (not significant), 1.5% (not significant) and 1.6% (95% CI=0.9-2.3) per degrees C, respectively. The RRs for cardiovascular and respiratory causes were studied above the breakpoint, and estimated to be 1.1% (95% CI=0.3-2.0) and 4.3% (95% CI=2.2-6.5) per degrees C, respectively. The lag structures from moving averages and polynomial distributed lag models coincided with a rather direct effect during summer (lag 0 and 1) and a more prolonged effect during winter, covering about a week. The inclusion of an indicator of heatwaves added an increase in daily mortality of 3.1-7.7%, depending on the threshold. CONCLUSIONS: These results show that the predicted increase in heat events must also be taken seriously in Scandinavia, whatever the extent of the decreasing cold related mortality. The relative risks associated with heat and heatwaves seem stronger than the cold effects and thus a larger public health threat, since northern populations have not yet adapted to heat as have been done over a long time for the cold periods. The pressure on the healthcare sector will probably increase in the warm season, periodically it may become even greater than the pressure due to cold weather, which will be a new phenomenon for the healthcare sector to cope with. We need to be prepared for these kind of events by developing adaptation and education strategies to handle the consequences that a warmer climate will have for public health and the healthcare sector.
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| 347. |
- Rocklöv, Joacim, 1979-, et al.
(author)
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Winter mortality modifies the heat-mortality association the following summer
- 2009
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In: European Respiratory Journal. - : European Respiratory Society (ERS). - 0903-1936 .- 1399-3003. ; 33:2, s. 245-251
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Journal article (peer-reviewed)abstract
- The present study aimed to investigate how the heat-related increase in deaths in summer and the extent of mortality displacement depend on influenza and other categories of mortality in the previous winter, which when low leaves a greater pool of susceptible individuals. Mortality data from Stockholm, Sweden, from 1990-2002 were stratified into a summer period and a winter period. A Poisson regression model was established for the daily mortality in the summer, with temperature and confounders as explanatory variables. In addition, indicators of total, respiratory, cardiovascular and influenza mortality of the winter period were incorporated as effect modifiers in the summer model, and lagged effects in strata defined by indicators were studied. A high rate of respiratory as well as cardiovascular mortality in winter reduced the heat effect the following summer, and influenza mortality tended to do so as well. The cumulative effect per degrees C increase was 0.95% below and 0.89% above a threshold (21.3 degrees C) after a winter with low cardiovascular and respiratory mortality, but -0.23% below and 0.21% above the threshold after a winter with high cardiovascular and respiratory mortality. The current study shows that high respiratory, cardiovascular and influenza mortality in winter leads to lower temperature effects in the following summer. It also suggests that persons for whom influenza may be fatal are often also susceptible to heat and this subgroup might, therefore, not benefit as much as expected from influenza vaccinations.
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| 348. |
- Saers, Johannes, et al.
(author)
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Respiratory symptoms among Swedish soldiers after military service abroad: association with time spent in a desert environment
- 2017
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In: European Clinical Respiratory Journal. - : Informa UK Limited. - 2001-8525. ; 4:1
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Journal article (peer-reviewed)abstract
- Introduction: The aim of this paper was to study whether Swedish soldiers who have served abroad had a higher prevalence of respiratory symptoms than the general population and, if this was the case, also to study whether this was associated with time spent in a desert environment. Methods: The prevalence of respiratory symptoms among 1,080 veterans from Kosovo and Afghanistan was compared with that in almost 27,000 subjects from a general population sample, using propensity score matching and logistic regression. Results: The prevalence of wheeze (16.3 vs. 12.3%), wheeze without a cold (11.1 vs. 8.0%), nocturnal coughing (26.6 vs. 20.1%) and chronic bronchitis (12.3 vs. 6.8%) was significantly higher among soldiers than controls (p < 0.05). A dose-response-related association was found between time spent in a desert environment and wheeze, wheeze with breathlessness and wheeze when not having a cold. Having been exposed to desert storms was related to nocturnal cough and chronic bronchitis. Conclusion: Swedish soldiers who had served abroad had a higher prevalence of wheeze and cough than a control group from the general population. The association between being exposed to a desert environment and respiratory symptoms indicates that further protective measures should be introduced for military personnel serving in a desert environment.
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| 349. |
- Samoli, Evangelia, et al.
(author)
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Short-term effects of carbon monoxide on mortality : an analysis within the APHEA project.
- 2007
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In: Journal of Environmental Health Perspectives. - Research Triangle Park, N.C. : U.S. Dept. of Health, Education, and Welfare, Public Health Service. - 0091-6765 .- 1552-9924. ; 115:11, s. 1578-1583
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Journal article (peer-reviewed)abstract
- Objectives: We investigated the short-term effects of carbon monoxide on total and cardiovascular mortality in 19 European cities participating in the APHEA-2 (Air Pollution and Health: A European Approach) project. Methods: We examined the association using hierarchical models implemented in two stages. In the first stage, data from each city were analyzed separately, whereas in the second stage the city-specific air pollution estimates were regressed on city-specific covariates to obtain overall estimates and to explore sources of possible heterogeneity. We evaluated the sensitivity of our results by applying different degrees of smoothing for seasonality control in the city-specific analysis. Results: We found significant associations of CO with total and cardiovascular mortality. A 1-mg/m3 increase in the 2-day mean of CO levels was associated with a 1.20% [95% confidence interval (CI), 0.63–1.77%] increase in total deaths and a 1.25% (95% CI, 0.30–2.21%) increase in cardiovascular deaths. There was indication of confounding with black smoke and nitrogen dioxide, but the pollutant-adjusted effect of CO on mortality remained at least marginally statistically significant. The effect of CO on total and cardiovascular mortality was observed mainly in western and southern European cities and was larger when the standardized mortality rate was lower. Conclusions: The results of this large study are consistent with an independent effect of CO on mortality. The heterogeneity found in the effect estimates among cities may be explained partly by specific city characteristics.
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| 350. |
- Samoli, E, et al.
(author)
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Short-term effects of nitrogen dioxide on mortality : an analysis within the APHEA project
- 2006
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In: European Respiratory Journal. - Copenhagen : Munksgaard. - 0903-1936 .- 1399-3003. ; 27:6, s. 1129-1138
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Journal article (peer-reviewed)abstract
- The short-term effects of nitrogen dioxide (NO2) on total, cardiovascular and respiratory mortality in 30 European cities participating in the Air Pollution on Health: a European Approach (APHEA)-2 project were investigated. The association was examined using hierarchical models implemented in two stages. In the first stage, data from each city were analysed separately, whereas in the second stage, the city-specific air pollution estimates were regressed on city-specific covariates to obtain overall estimates and to explore sources of possible heterogeneity. A significant association of NO2 with total, cardiovascular and respiratory mortality was found, with stronger effects on cause-specific mortality. There was evidence of confounding in respiratory mortality with black smoke and sulphur dioxide. The effect of NO2 on total and cardiovascular mortality was observed mainly in western and southern European cities, and was larger when smoking prevalence was lower and household gas consumption was higher. The effect of NO2 on respiratory mortality was higher in cities with a larger proportion of elderly persons in the population and higher levels of particulate matter with a 50% cut-off aerodynamic diameter of 10 μm. The results of this large study are consistent with an independent effect of nitrogen dioxide on mortality, but the role of nitrogen dioxide as a surrogate of other unmeasured pollutants cannot be completely ruled out.
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