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Previous studies examining daily temperature and stroke incidence have given conflicting results. We undertook this retrospective study of all stroke admissions in those aged 35 years old and above to Hong Kong public hospitals from 1999 through 2006 in order to better understand the effects of meteorological conditions on stroke risk in a subtropical setting. We used Poisson Generalized Additive Models with daily hemorrhagic (HS) and ischemic stroke (IS) counts separately as outcomes, and daily mean temperature, humidity, solar radiation, rainfall, air pressure, pollutants, flu consultation rates, day of week, holidays, time trend and seasonality as predictors. Lagged effects of temperature, humidity and pollutants were also considered. A total of 23,457 HS and 107,505 IS admissions were analyzed. Mean daily temperature had a strong, consistent, negative linear association with HS admissions over the range (8.2-31.8°C) observed. A 1°C lower average temperature over the same day and previous 4 days (lags 0-4) being associated with a 2.7% (95% CI: 2.0-3.4%, P < .0.0001) higher admission rate after controlling for other variables. This association was stronger among older subjects and females. Higher lag 0-4 average change in air pressure from previous day was modestly associated with higher HS risk. The association between IS and temperature was weaker and apparent only below 22°C, with a 1°C lower average temperature (lags 0-13) below this threshold being associated with a 1.6% (95% CI:1.0-2.2%, P < 0.0001) higher IS admission rate. Pollutant levels were not associated with HS or IS. Future studies should examine HS and IS risk separately. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: This study aims at determining whether there is a seasonal pattern of falls among older people in Hong Kong and exploring the possible mechanisms underlying the seasonal pattern. Methods: The falls data were obtained from a 1-year prospective study conducted in 200–2007 which includes all the older people aged 60 years or more with a fall presenting to Accident and Emergency Department of a regional hospital in Hong Kong. The occurrence of falls among the 12 months was recorded and was used to correlate with weather data, including air temperature, relative humidity, and rainfall, in each month during the study period. Analyses were also carried out to examine if there was any signification association between occurrence of falls in four seasons and various factors, including age, gender and living arrangement of the fallers, location of falls, and predisposing factors for their falls. Results: There was a peak in occurrence of falls among the older people during winter. A significant correlation was found between a higher number of falls and lower air temperature and lower relative humidity. Age, gender, and location of falls for the fallers were not associated with the peak seasons (winter and autumn) and nonpeak seasons (spring and summer). Significantly larger proportion of falls occurred among people living in old age home during the peak season compared with the nonpeak season. Higher proportion of fallers during the peak season had lower limbs weakness as compared with that in nonpeak season. Multivariate logistic regression showed that only living arrangement and risky behavior were significantly associated with fall occurrence in peak season. Conclusion: A higher incidence of falls in winter among older people in Hong Kong was observed and possible mechanisms contributing to this seasonal pattern were explored. Further studies on intervention to minimize its impact on risk of falling among older people are indicated. [Copyright &y& Elsevier]

In summer May–September, deaths associated with heat stroke are found to occur when the daily maximum net effective temperature NET exceeds 26. Using Poisson regression, it is estimated that the mean mortality associated with heat stroke would double perunit rise in NET beyond 26. In contrast to those in most temperate regions, the daily mortality for circulatory and respiratory related causes of death is not statistically correlated to the daily maximum NET or temperature in summer. In winter November–March, there are statistically significant negativelagged correlations between the daily minimum NET and the daily mortality attributed to circulatory and respiratory diseases. The increase in mortality perunit decrease in NET is found to be the highest for hypothermia, and slightly higher for circulatory causes than respiratory causes. Deaths associated with hypothermia start to occur when the daily minimum NET is less than 14 and the mean mortality is estimated to increase by about 1.3fold perunit fall in NET below 14. The elderly age group age 65 years is found to be more vulnerable to NET changes when compared to other age groups. Copyright © 2008 Royal Meteorological Society [ABSTRACT FROM AUTHOR]