Weather variability, tides, and Barmah Forest virus disease in the Gladstone region, Australia

In this study we examined the impact of weather variability and tides on the transmission of Barmah Forest virus (BFV) disease and developed a weather-based forecasting model for BFV disease in the Gladstone region, Australia. We used seasonal autoregressive integrated moving-average (SARIMA) models to determine the contribution of weather variables to BFV transmission after the time-series data of response and explanatory variables were made stationary through seasonal differencing. We obtained data on the monthly counts of BFV cases, weather variables (e.g., mean minimum and maximum temperature, total rainfall, and mean relative humidity), high and low tides, and the population size in the Gladstone region between January 1992 and December 2001 from the Queensland Department of Health, Australian Bureau of Meteorology, Queensland Department of Transport, and Australian Bureau of Statistics, respectively. The SARIMA model shows that the 5-month moving average of minimum temperature (b=0.15, p-value<0.001) was statistically significantly and positively associated with BFV disease, whereas high tide in the current month (b=-1.03, p-value=0.04) was statistically significantly and inversely associated with it. However, no significant association was found for other variables. These results may be applied to forecast the occurrence of BFV disease and to use public health resources in BFV control and prevention.     

The effect of season and weather on suicide rates in the elderly in British Columbia

OBJECTIVES: The authors examined the relationship of suicide in the elderly (65 years and older) to season and weather and compared it to that in the younger population (10-64 years). METHODS: Information on suicides and on weather was obtained for British Columbia for the period 1981 to 1991. The association of suicide with season and weather was assessed using Poisson regression. RESULTS: Whereas younger suicides were associated with season, showing a spring-summer peak, elderly suicides were associated with actual weather. They increased with higher mean daily temperature for the current month (RR = 1.16, 95% CI 1.05-1.28 for each 2.5 degrees C change in mean temperature), and with lower mean daily temperature for the preceding three months (RR = 1.12, 95% CI 1.01-1.23). CONCLUSIONS: Elderly suicide rates appear to be affected by deviations of monthly mean temperature from values expected for that time of year. Increased support by service agencies at times of predicted high risk is suggested.     

Sudden infant death syndrome and weather temperature

The relationship between the days on which sudden infant death syndrome (SIDS) occurred and the daily minimum temperature was examined in Auckland (1979-1984) and Christchurch (1979-1987). There was a marked winter excess of deaths in both regions. There was a significant negative correlation between the monthly mean minimum temperature and SIDS rate for both regions (r = -0.43, n = 347, P less than 0.0001). The monthly mean minimum temperature describes SIDS mortality equally as well as the three variables of daily minimum temperature, season and geographical location. There was a significant association of SIDS with minimum temperature 4 and 5 days prior to the death after adjusting for the effect of monthly mean minimum temperature. The days preceding death were on average colder than the other days, but the effect was small, especially when compared with the magnitude of the temperature differences between consecutive months.     

Seasonal variation in the incidence of hip fracture among white persons aged 65 years and older in the United States, 1984-1987

This study uses 44 consecutive months of data from the Health Care Financing Administration to assess seasonal trends in hip fracture incidence among the United States white population aged 65 years and older. The authors studied a total of 621,387 cases of hip fracture which occurred from January 1984 to September 1987. During the study period, hip fracture incidence rates display a distinctive pattern of seasonal periodicity; high rates are found in the winter and low rates in the summer among both males and females. This pattern of seasonal periodicity is consistent at ages 65-74 years, 75-84 years, and greater than or equal to 85 years. When the time series of rates are stratified into five geographic levels, each level covering 5 degrees of latitude, the distinctive pattern of seasonal periodicity is the same for all levels.     

Seasonal variation in mortality from ischemic heart disease and cerebrovascular disease in Okinawa and Osaka: the possible role of air temperature

Okinawa is located in a subtropical area and is well-known for low mortality due to ischemic heart disease (IH-D) and cerebrovascular disease (CVD). However, the factors that contribute to these low mortality rates remain unclear. We examined the seasonal variation in the mortality due to IHD and CVD among Okinawa and Osaka residents, aged 45 to 84 years, between 1992 and 1996. In addition, we studied if there was a relationship between the monthly mortality rate from IHD or CVD and the monthly mean daily air temperature in Naha City and Osaka City. Data on the monthly mean daily air temperature was obtained from the meteorological stations in Naha City and Osaka City. Our results showed that there were inverse correlations between the monthly mean daily temperature in a city and each of the monthly mortality from IHD in Okinawa (r=-0.794, p<0.01), the monthly mortality from CVD in Okinawa (r=-0.837, p<0.001), and the monthly mortality from CVD in Osaka (r=-0.954, p<0.001). In Osaka, the monthly mortality rate from IHD was at or near its minimum value when the mean daily temperature was approximately 25 degrees C (in September), and it increased in a linear fashion as the mean monthly temperature fell (r=-0.975, p<0.001). The difference between the monthly mortality from IHD or CVD among the Okinawa and the Osaka residents increased in the winter season in comparison with that in the other seasons, with the exception for IHD in July and in August. These findings indicate that the lower mortality from IHD and CVD in Okinawa is affected, at least in part, by Okinawa's warm winter.     

Correlation between risk factors and mortality in elderly patients with femoral neck fracture with 5-year follow-up

Hip fractures are associated with increased mortality in the elderly. There are only a few studies based on large patient number covering a nationwide health care system. AIM: The aim of this study was to investigate the mortality following primary treatment in patients over 60 with acute, monotraumatic femoral neck fracture on monthly and annual base during a 5-year follow-up period; and to evaluate the effect of different risk factors on mortality during the follow-up. METHODS: Data were derived from the nationwide database of the National Health Insurance Fund Administration. The evaluation includes patients with femoral neck fracture discharged from inpatient care institutions in 2000 following a primary surgical treatment. Weekly, monthly and annual mortality rates, and its monthly and annual trends according to risk factors were calculated. Logistic and Cox regression analysis was performed to evaluate the correlation between risk factors and mortality. RESULTS: 3783 patients were involved in the study with a mean age of 77,97 years (SD 8,52). The mortality rates were 1,71% (during the first week), 8,99% (30 days), 30,74% (first year) and 61,88% (in 5 years). Mortality showed a declining trend up to the 5th month, and is stagnant after the first year. Risk factor analysis showed that higher risk of mortality is associated with male sex and higher age group up to 5 years, co-morbidities up to 4 years, lateral type femoral neck fracture and 12 hours delay of primary treatment up to 2 years, early local complications up to 1 year and surgical treatment during week-end up to 1 month. Surgical treatment delivered in national health institutes and university clinics resulted in a lower mortality risk up to 1 year. CONCLUSIONS: In order to reduce mortality during the management of hip fractures, the authors emphasize the importance of delay of treatment within 12 hours, appropriate selection of methods corresponding to fracture type, providing the same conditions for primary treatment during all days of the week, to organize the treatment to special centres, appropriate acute care and follow-up corresponding to the general health status and co-morbidities of patients.     

蚊媒传染病气象影响因素分析

目的探索气象因素与蚊类种群动态变化和蚊媒传染病[流行性乙型脑炎（乙脑）、疟疾和登革热]发病的关系，为实施蚊媒传染病预防和控制策略提供科学依据。方法收集温州市20042006年疟疾、乙脑和登革热发病资料、2004—2006年蚊类种群密度季节消长监测资料及同期的平均气温、平均最高气温、平均最低气温、相对湿度、日照时间、降雨天数、降雨量等气象资料，用相关分析和多元逐步回归分析方法进行分析。结果2004—2006年蚊类密度与同期平均气温、最高气温、最低气温、降雨量、相对湿度、日照时间有较高的正相关关系，与降雨天数无关。回归方程为Y=23．671＋0．190x3＋0．299x4，x3、x4分别代表最低平均气温和相对湿度。结论气象因素影响着蚊类密度的变化，尤其是平均最低气温和相对湿度，从而成为影响蚊媒传染病发病的主要气象因素。     

Spatio-temporal patterns of diarrhoeal mortality in Mexico

Diarrhoeal mortality rates in Mexican children dramatically declined during the 1980s and 1990s, concomitant with a temporal shift in peak deaths from summer to autumn-winter. The spatial dynamics of these patterns have not previously been studied. We first describe the seasonal features of paediatric diarrhoeal mortality in Mexico as a whole, then across individual states. While no geographical gradients in the magnitude of diarrhoeal mortality rates have been detected in recent years, we identified a distinct spatial pattern in the timing of peak mortality rate. In the 1980s the summer peak mortality was earliest around Mexico's capital and later in states to the southeast and northwest. Our results suggest that the direction and timing of those annual waves are related to the mean monthly precipitation and mean daily temperature. This pattern has disintegrated in recent years as the summer peak has diminished.     

High summer temperatures and mortality in the Czech Republic 1982-2000

The heat-stress-related mortality, which is among main impacts of periods of high summer temperature on society, was reported in many European countries, but analyses focusing on central European population have been rare. Results of the analysis for the period of 1982-2000 in the Czech Republic indicate that heat stress leads to a considerably increased all-causes mortality and mortality due to cardiovascular diseases. Periods with the highest deviations of the daily number of deaths from a baseline (in all-year data) are influenza epidemics and heat waves; the distribution of days with the highest excess mortality in a year is clearly bimodal, showing a main peak in winter and a secondary one in summer. Summer days with a considerably increased mortality are almost entirely days with a positive temperature deviation from the seasonal course. Deviations of mortality from the baseline exceed 100 deaths daily (more than 30% relative increase) in heat wave peaks, and the excess total mortality during the severe 1994 heat waves was +456 deaths (+10.3%) for June 17 to 30, and 8 deaths (+12.3%) for July 24 to August 8. The relative increase in mortality due to cardiovascular diseases was even more pronounced. The mortality displacement effect played an important role, since it was estimated to account for as much as 52% of the total number of victims for the June 1994 heat wave and 48% for the July-August heat wave. People who would die soon without oppressive weather conditions make about half of the total number of deaths, which is a larger value compared to what other studies reported. The increased mortality is observed at maximum (average, minimum) daily temperatures higher than 25 degrees C (18 degrees C, 14 degrees C) and their anomalies from mean seasonal courses larger than 3 degrees C. The same values hold for both the total and cardiovascular mortality. The mortality response at high temperatures is more pronounced in females than males. Correlations between mortality and temperature variables (including heat index) are positive and statistically significant (P = 0.01), stronger for deviations of meteorological variables from seasonal courses than for raw values, in females than males, and for heat index than for any temperature variable and summer simmer index. The unlagged correlations are stronger than correlations with lags 1-3 days; positive values of correlation coefficients hold for lags 0 to 3 days only while at lags of 4 to 25 days, the link is negative (mostly statistically significant) which demonstrates the mortality displacement effect and its time extent.     

Lower ambient temperature was associated with an increased risk of hospitalization for stroke and acute myocardial infarction in young women

OBJECTIVE: Results of investigations into the impact of seasonal variation on the incidence of cardiovascular diseases (CVD) have been inconsistent. Using the WHO Collaborative Study of CVD and Steroid Hormone Contraception database, we attempted to examine the relationship between variation in three climatic variables and risk of hospitalization for venous thromboembolism (VTE), arterial stroke, and acute myocardial infarction (AMI). STUDY DESIGN AND SETTING: We compared the monthly mean temperature, rainfall, and humidity with rates of hospitalized VTE, stroke, and AMI among young women aged 15-49 from 17 different countries in Africa, Asia, Europe, Latin America, and the Caribbean by using a negative binomial regression model. RESULTS: The study included 1146, 2,269, and 369 cases of VTE, stroke, and AMI, respectively. Significant associations between temperature and hospital admission rates of stroke and AMI, but not VTE, were apparent. Lagging the effects of temperature suggested that these effects were relatively acute, within a period of a month. CONCLUSION: These data may help in understanding the mechanisms whereby stroke and AMI events are triggered.     

Treatment and temperature series study for use in public health. The case of Castilla-La Mancha, Spain

BACKGROUND: Numerous articles relate atmospheric variables to health indicators. In large regions, such as Castilla-La Mancha, it may be necessary to divide the region into areas in terms of the atmospheric variables available by selecting a representative weather station for each zone. This article focuses on analyzing the daily temperature data from numerous Castilla La Mancha observatories and reducing the number thereof to a few representative stations for being used in studies relating atmospheric variables to health indicators in this region. METHODS: Castilla-La Mancha weather stations were selected in terms of the number of years available and missing data. After filling in the gaps in the selected series, to detect any possible discontinuities and to homogenize the series, the daily temperature data is used in hierarchical cluster and factorial analyses by principal components. RESULTS: Factorial analyses extract one single factor by using the maximum, mean or minimum temperature series. For the maximum temperatures, this factor explains 93.45% of the variance, with an eigenvalue of 39.249. The "Compuesta" station in Toledo shows correlation coefficients in the principal components matrix of 0.987, 0.991 and 0.981 respectively for the maximum, mean and minimum temperature series. CONCLUSIONS: Castilla-La Mancha is an isoclimatic region in terms of the temperature, the "Compuesta" station in Toledo being selected as the representative station for the region for public health studies. The results afford the possibility of conducting studies broken down into small units such as the provinces, with the stations in the government capitals as a reference.     

Effects of long-term fluoride in drinking water on risks of hip fracture of the elderly: an ecologic study based on database of hospitalization episodes]

OBJECTIVES: Fluoridation of drinking water is known to decrease dental caries, particularly in children. However, the effects of fluoridated water on bone over several decades are still in controversy. To assess the risk of hip fracture related to water fluoridation, we evaluated the hip fracture-related hospitalizations of the elderly between a fluoridated city and non-fluoridated cities in Korea. METHODS: Cheongju as a fluoridated area and Chungju, Chuncheon, Suwon, Wonju as non-fluoridated areas were chosen for the study. We established a database of hip fracture hospitalization episode based on the claims data submitted to the Health Insurance Review Agency from January 1995 to December 2002. The hip fracture hospitalization episodes that satisfied the conditions were those that occurred in patients over 65 years old, the injuries had a hip fracture code (ICD-9 820, ICD-10 S72) and the patients were hospitalized for at least 7days. A total of 80,558 cases of hip fracture hospitalization episodes were analyzed. RESULTS: The admission rates for hip fracture increased with the age of the men and women in both a fluoridated city and the non-fluoridated cities (p<0.01). The relative risk of hip fracture increased significantly both for men and women as their age increased. However, any difference in the hip fracture admission rates was not consistently observed between the fluoridated city and the nonfluoridated cities. CONCLUSIONS: We cannot conclude that fluoridation of drinking water increases the risk of hip fracture in the elderly.     

Sudden infant deaths and seasonality in Tasmania, 1970-1976

Analyses of monthly minimum temperatures and daily minimum temperatures show that significantly more Sudden Infant Deaths and 'pneumonitis' deaths occur in colder conditions in southern Tasmania. Low minimum monthly and low minimum daily temperatures 'explain' part of the observed winter seasonal peak of deaths. However, a sharp change of temperature over 24 hours, either upwards or downwards, is associated with fewer deaths than occurred when little or no change of temperature had been experienced. Utilising the additional data of the Tasmania-wide series it is shown that the winter seasonal effect is especially evident in infants over 3 months of age compared with those aged only 0-3 months, in whom seasonal variation did not occur.     

Daily mortality in Madrid community 1986–1992: Relationship with meteorological variables

Daily mortality displays a seasonal pattern linked to weather, air pollution, photoperiod length, influenza incidence and diet, among which temperature ranks as a leading cause. This study thus sought to assess the relationship between temperature, relative humidity, wind speed and mortality in the Madrid Autonomous Region (Spain) for the period January 1986–December 1992, controlling for the effects of air pollution and influenza incidence. Daily data on maximum, minimum and 24-hour mean temperature, relative humidity and wind speed were matched against daily mortality. Transfer function was identified using the Box–Jenkins pre-whitening method. Multivariate time series regression models were used to control for the confounding effects of air pollution and influenza incidence. Separate seasonal analyses were carried out for winter and summer periods. A J-shaped relationship between outdoor temperature, relative humidity and daily mortality was found. Mortality proved to be inversely related to cold temperature (4- to 11-day lag) and directly related to warm temperature (1-day lag). High relative humidity during summer periods was negatively related to mortality. Thermal variation ascribable to Madrid's mesothermal Mediterranean climate was strongly related to daily mortality, even where air pollution and influenza incidence were controlled for.     

Air pollution and daily hospital admissions for cardiovascular diseases in Windsor, Ontario

OBJECTIVE: To examine the role that ambient air pollution plays in exacerbating cardiovascular disease hospitalization in Windsor, Ontario. METHODS: The number of daily cardiac hospital admissions was obtained from all Windsor hospitals from April 1, 1995 to December 31, 2000 and linked to concentrations of ambient air pollutants and weather variables. The logarithm of daily counts of hospitalization was regressed on the levels of pollutants, after adjusting for seasonal, weekly cycles, and weather variables using time series analysis with natural splines as smoothing functions. RESULTS: Of all the pollutants considered, sulphur dioxide (SO2) had the strongest effect on cardiac hospitalization among the > or = 65 age group. The percentage increase in daily admission was 2.6% for current day sulphur dioxide level (95% CI: 0.5-6.4), 4.0% for 2-day mean level (95% CI: 0.1-6.9), and 5.6% (95% CI: 1.5-9.9) for 3-day mean level for an increase in interquartile range of 19.3 ppb. When particulate PM10 was included in the model, the contributing effect of sulphur dioxide remained significant for the > or = 65 age group for all three levels. CONCLUSIONS: Short-term effects of sulphur dioxide are associated significantly to daily cardiac hospital admissions for people > or = 65 years of age living in Windsor. Since Windsor is a border city, additional monitoring and assessment is recommended to determine if air quality and resultant health effects have deteriorated since traffic congestion at the border has increased following the events of September 11, 2001.     

Seasonal variation of mean birth weight and births in Nagano Prefecture]

Seasonal variation of mean birth weight in Nagano Prefecture was examined by a traditional time series analysis, which decomposes the variation in a series into trend, seasonal variation, other cyclic changes, and remaining irregular fluctuations, based on the data in Vital Statistics from January 1974 to December 1983. The seasonal index of mean birth weight showed a unimodal pattern with a peak in June for males, and a bimodal pattern with peaks in spring and autumn in females with statistical significance. Previous reports have revealed that gestational period is the most important factor associated with birth weight. Therefore, we carried out time series analysis for the mean gestational period and observed an apparent seasonal periodicity, which showed a unimodal pattern with a bottom in winter for both sexes and parities. According to the results of statistical testing of the degree of coincidence between two time series, the time series of mean birth weight and that of mean gestational periods showed statistically significant coincidences in their monthly variations for multiparae. On the other hand, mean birth weight at 40 gestational weeks, which reflects the intrauterine growth, did not show seasonality. These results suggest that seasonality in gestational periods might play an important role in creating seasonal variations of mean birth weight in Nagano Prefecture. The average daily number of births by month also showed apparent seasonalities both for primiparae and multiparae. Primiparae showed a bimodal pattern with peaks in February and August, while multiparae showed a unimodal pattern with a peak in May and a bottom in November. It has been said that the seasonality in marriage is one of important factors associated with seasonal variation in births.(ABSTRACT TRUNCATED AT 250 WORDS)     

Seasonal variation in admissions of psychiatric patients and its relation to seasonal variation in their births.

Inpatient admissions to all psychiatric hospital beds in England and Wales in 1970-73 were studied by month of admission for eight diagnostic groups. The admission rates for schizophrenia showed a pronounced seasonal variation, with a maximum in summer. The seasonal pattern for schizophrenia was very similar to the one shown for mania, although somewhat less marked. The admission rates for neurosis and for the large group of 'all other non-psychotic mental illness' showed little evidence of seasonal variation as there was could largely be explained by social factors. In schizophrenic and manic patients, the pattern of seasonal admissions (peak months July and August) is similar to the pattern reported for their births (peak months February and March). This is consistent with the hypothesis of an abnormal seasonal pattern of parental conception as the cause of the abnormal birth pattern.     

循环系统疾病的发病规律及其预测模型

目的讨论循环系统疾病(高血压、心肌梗死和脑卒中)发病的月和年际变化规律及与气象因素的关系,并建立月发病气象预测模型。方法利用2000—2008年乌鲁木齐市循环系统疾病逐月发病人数资料分析其变化规律,结合同期地面气象A文件资料中气温、气压、日照时数、总云量、相对湿度、平均风速等因子进行相关分析和逐步回归分析。结果循环系统疾病发病人数逐年呈现上升态势,2000—2004年变化相对平稳,高值年出现在2008年;春季病多发,秋冬季最少;高发期为单峰双月型,低发期为双峰单月型;利用旬预测模型F检验,趋势拟合准确率高血压SS=59%,脑卒中SS=63%、心肌梗死SS=83%。结论可结合未来旬天气预报进行循环系统疾病发生趋势预测,为采取针对性的预防循环系统疾病发生的措施提供依据。     

Time trends in incidence rates of first hip fracture in the Uppsala Health Care Region, Sweden, 1965-1983

Time trends from 1965 through 1983 for age-specific and age-standardized rates of first hospital admission for a proximal femur fracture were studied in the Uppsala Health Care Region, Sweden, using a centralized register for inpatient care. During the 19-year study period, 29,277 hospital admissions for a first hip fracture were recorded in this population of about 1.5 million persons. The total number of first hip fracture admissions per year increased for both sexes. Age-standardized admission rates for both cervical and trochanteric fractures increased in men (average change per year of 1.8% and 2.6%, respectively) in contrast to the decreased admission rate for cervical fractures (-1.6% per year) and a stable rate for trochanteric fractures (0.4% per year) in women. The cumulative rate of cervical or trochanteric fracture at ages 30-79 years increased 46% in men (from 42/1,000 population in 1965 to 61.5/1,000 population in 1983) in contrast to a 24% decrease in women (from 134/1,000 population in 1965 to 101.5/1,000 population in 1983). The female:male ratio of age-standardized incidence rates decreased for both types of fracture during the study period. This finding of stable or decreasing rates of hip fracture in women contrasts with the findings of most previous studies.     

2000-2004年广州市某城区气温变化与居民死亡的关系分析

[目的]探讨气温对城区居民死亡的影响。[方法]收集2000-2004年广州市某城区居民死亡资料和相应时段的气象资料,分析热日、冷日、平日3类天气情况下居民死亡及死因的变化。[结果]广州市某区2000-2004年合计死亡15802例。月死亡率为40．79／10万～89．46／10万（62．25／10万±9．22／10万）;同期月平均气温为（13．6～30．5）℃（22．9±5．3）℃。观察期间,逐月死亡率与月平均气温呈负相关（r=-0．59,P〈O．01）。死亡率在冬季最冷月（1月）前后达最高峰．其他季节波动不大,在夏季最热月（8月）前后形成1个相对高峰。夏季最高气温在34℃以上时。随气温的升高死亡率显著增加;冬季最低气温在10℃以下时,死亡率显著增加。不同日均气温条件下,居民前5位死因中恶性肿瘤死亡数占全死因死亡数比例的差异有统计学意义（P〈0．05）。2004年6月27日至7月3日持续高温,6月25日至7月9日的半月内居民3日平均死亡30．6例,是当年夏季3日平均死亡数（24．1例）的1．27倍。[结论]广州市城区气温变化对某区居民死亡有显著影响,居民死亡率在气温高或气温低时均呈升高趋势。