Urban heat island effect-related mortality under extreme heat and non-extreme heat scenarios: A 2010-2019 case study in Hong Kong

The urban heat island (UHI) effect exacerbates the adverse impact of heat on human health. However, while the UHI effect is further intensified during extreme heat events, prior studies have rarely mapped the UHI effect during extreme heat events to assess its direct temperature impact on mortality. This study examined the UHI effect during extreme heat and non-extreme heat scenarios and compared their temperature-mortality associations in Hong Kong from 2010 to 2019. Four urban heat island degree hour (UHIdh) scenarios were mapped onto Hong Kong's tertiary planning units and classified into three levels (Low, Moderate, and High). We assessed the association between temperature and non-external mortality of populations living in each UHIdh level for the extreme heat/non-extreme heat scenarios during the 2010-2019 hot seasons. Our results showed substantial differences between the temperature-mortality associations in the three levels under the UHIdh extreme heat scenario (UHIdh_EH). While there was no evidence of increased mortality in Low UHIdh_EH areas, the mortality risk in Moderate and High UHIdh_EH areas were significantly increased during periods of hot temperature, with the High UHIdh_EH areas displaying almost double the risk (RR: 1.08, 95%CI: 1.03, 1.14 vs. RR: 1.05, 95 % CI: 1.01, 1.09). However, other non-extreme heat UHI scenarios did not demonstrate as prominent of a difference. When stratified by age, the heat effects were found in Moderate and High UHIdh_EH among the elderly aged 75 and above. Our study found a difference in the temperature-mortality associations based on UHI intensity and potential heat vulnerability of populations during extreme heat events. Preventive measures should be taken to mitigate heat especially in urban areas with high UHI intensity during extreme heat events, with particular attention and support for those prone to heat vulnerability, such as the elderly and poorer populations.

Factors affecting outdoor physical activity in extreme temperatures in a sub-tropical Chinese urban population: an exploratory telephone survey

BACKGROUND

Physical activity (PA) can be affected by extreme temperatures, however fewer studies have identified factors impacting this relationship. This study sought to identify factors associated with changes of outdoor PA during extreme cold/heat events in a sub-tropical Chinese urban population, including factors of sociodemographic, health conditions, temperature-related awareness and attitude, and protective behaviours.

METHODS

Two telephone surveys were conducted a week after extreme cold/heat events in 2016 and 2017 among a cohort of Hong Kong residents over age 15. Data was collected on self-reported changes in outdoor PA level during the periods of extreme temperatures, health status, comorbidities, sociodemographic, and temperature-related awareness, and behavioural variables. We conducted multivariable logistic regression analyses to assess predictors of change in outdoor PA over the two extreme temperature events.

RESULTS AND CONCLUSION

Among 435 participants (42.8% response rate), over a third of the participants reported decreased outdoor PA level in extreme temperature events, while 10% reported an increase in extreme heat. Self-reported cardiovascular diseases were associated with decreased PA level in extreme cold, while hypertension was associated with unchanged/increased PA level in extreme heat. These results suggest physical activity to be an important consideration in the understanding of climate change-and-health pathways and meriting further research.

Projecting future temperature-related mortality using annual time series data: An example from Hong Kong

BACKGROUND

Previous studies projecting future temperature-related mortality under climate change have mostly used short-term temperature-mortality associations based on daily time series data. The present study aimed to project mortality under different Representative Concentration Pathways (RCPs) in 21st century in Hong Kong by using analysis of annual data during 1976-2018.

METHODS

We employed a degree-days approach, calculating the sum of daily degrees above or below certain temperature threshold within a relevant historical year. The yearly age-standardized mortality rates (ASMRs) were regressed on annual hot and cold degree-days in quasi-Poisson generalized additive models to assess the exposure-response function that was subsequently used to calculate future changes in ASMR. The projection was performed without and with certain human adaptation assumed.

RESULTS

ASMRs were projected to have net increases under RCPs 4.5, 6.0, and 8.5, with increased mortality attributable to excess hot days exceeding decreases attributable to excess cold days. The average net changes under RCP8.5 was estimated to be 0.12%, 12.44%, 38.99%, and 89.25% during 2030s, 2050s, 2070s, and 2090s, respectively. Higher projected ASMRs were estimated for those aged over 75 years and for cardiovascular deaths. When human adaptation was considered, slope reduction alone under RCP4.5 and 6.0 and all adaptation assumptions under RCP8.5 might still not offset its corresponding adverse impact.

CONCLUSIONS

The projected decreases in cold-related mortality do not compensate for projected increases in heat-related mortality in Hong Kong. Better public adaptations strategies are warranted for coping with the adverse health impacts of climate change on a local scale.

The effect of subjective social status on health-related quality of life decline in urban Chinese older adults: a four-year longitudinal study from Hong Kong

Background

Improving health-related quality of life (HRQOL) is becoming a major focus of old age care and social policy. Researchers have been increasingly examining subjective social status (SSS), one’s self-perceived social position, as a predictor of various health conditions. SSS encompasses not only concrete socio-economic (SES) factors but also intangible aspects of status. This study’s main objective was to examine the association between SSS and long-term change in HRQOL in older Chinese adults.

Methods

A longitudinal Hong Kong study recruited 2934 community-dwelling adults (age > 65 years). Participants completed SF-12 physical health (PCS) and mental health (MCS) HRQOL scales. This study analyzed baseline SSS-Society (self-perceived social status within Hong Kong) and SSS-Community (self-perceived status within one’s own social network) as predictors of long-term HRQOL decline. After stratifying for sex, multiple-linear-regression was performed on 4-year follow-up SF-12 PCS and MCS scores after adjusting for baseline SF-12 scores, traditional SES indicators, demographic variables, clinical conditions, and lifestyle variables.

Results

In the multivariable analyses, lower SSS-Society was associated with declines in MCS in males (β_standardized = 0.08, p = 0.001) and declines in PCS (β_standardized = 0.07, p = 0.006) and MCS (β_standardized = 0.12, p < 0.001) in females.

SSS-Community was associated with declines in PCS in males (β_standardized = 0.07, p = 0.005) and MCS in females (β_standardized = 0.14, p < 0.001).

Conclusions

SSS may be a useful supplementary tool for predicting risk of long-term HRQOL decline in older Chinese adults. Strategies to reduce perceived social inequalities may improve HRQOL in older adults.

The effect of temperature on physical activity: an aggregated timeseries analysis of smartphone users in five major Chinese cities

Background

Physical activity is an important factor in premature mortality reduction, non-communicable disease prevention, and well-being protection. Climate change will alter temperatures globally, with impacts already found on mortality and morbidity. While uncomfortable temperature is often perceived as a barrier to physical activity, the actual impact of temperature on physical activity has been less well studied, particularly in China. This study examined the associations between temperature and objectively measured physical activity among adult populations in five major Chinese cities.

Methods

Aggregated anonymized step count data was obtained between December 2017-2018 for five major Chinese cities: Beijing, Shanghai, Chongqing, Shenzhen, and Hong Kong. The associations of temperature with daily aggregated mean step count were assessed using Generalized Additive Models (GAMs), adjusted for meteorological, air pollution, and time-related variables.

Results

Significant decreases in step counts during periods of high temperatures were found for cold or temperate climate cities (Beijing, Shanghai, and Chongqing), with maximum physical activity occurring between 16 and 19.3 °C. High temperatures were associated with decreases of 800-1500 daily steps compared to optimal temperatures. For cities in subtropical climates (Shenzhen and Hong Kong), non-significant declines were found with high temperatures. Overall, females and the elderly demonstrated lower optimal temperatures for physical activity and larger decreases of step count in warmer temperatures.

Conclusions

As minor reductions in physical activity could consequentially affect health, an increased awareness of temperature’s impact on physical activity is necessary. City-wide adaptations and physical activity interventions should seek ways to sustain physical activity levels in the face of shifting temperatures from climate change.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-022-01285-1.

Selling World Health Organization's Alcohol “Best Buys” and Other Recommended Interventions in an Urban Chinese Population: Public Acceptability of Alcohol Harms Reduction Strategies in Hong Kong

Background

To counter the harms caused by alcohol use, the World Health Organization (WHO) outlined a series of evidence-based recommendations, including the highly cost-effective “Best Buys” recommendations. While many Western countries have been actively introducing alcohol harms reduction strategies, it is unclear whether these cost-effective policies would be publicly acceptable in Asian regions with traditionally low alcohol consumption. This study examines the public acceptability of WHO-recommended alcohol harms reduction strategies in an Asian city with few extant alcohol regulations.

Methods

A cross-sectional telephone survey of Hong Kong Chinese residents aged 18–74 (n = 4,000) was conducted from January to August 2018. Respondents were asked about their perceptions of various WHO-recommended strategies and consequences of their implementation. After reducing the strategies into several policy categories by principal component analysis, multivariable linear regression was performed to identify factors associated with endorsement of the various policies.

Results

Among the “Best Buys”, introduction of moderate beer/wine taxes (68.7%) and shortened alcohol retail hours (51.9%) were the most supported while bans on event sponsorships (19.5%) and public drinking events (17.7%) were the least popular. Strategies targeting young drinkers were particularly highly supported. Males, younger adults, Non-abstainers, and those who believed in drinking's social benefits were less likely to endorse stringent control measures (p < 0.05). Adults with higher household income were less supportive, partially due to concerns about infringements on local economy, lifestyles, and economic freedom. Women and older people were generally more supportive, partially because they perceived these policies would lower alcohol-related harms.

Conclusion

In order to reduce barriers to implementing WHO-recommended strategies in the region, it is imperative to increase awareness of alcohol-related harms and to strengthen beliefs in the effectiveness of these countermeasures, especially among men, young adults, and drinkers.

Does Low Subjective Social Status Predict Cognitive Decline in Chinese Older Adults? A 4-Year Longitudinal Study From Hong Kong

OBJECTIVE

Subjective social status (SSS), one's self-perceived social position, encompasses not only concrete socio-economic (SES) factors (e.g., income) but also intangible aspects of status (e.g., social capital). In recent years, there has been increasing research interest in SSS as a predictor of a vast array of health outcomes but very few studies examining effects on cognitive functioning. This study's main objective was to examine the association between SSS and long-term cognitive decline in older Chinese adults.

DESIGN

A 4-year longitudinal study.

SETTING

Hong Kong, China.

PARTICIPANTS

Chinese adults (aged ≥65) (n = 3,153).

MEASUREMENTS

This study analyzed baseline SSS-Hong Kong (self-perceived social status within Hong Kong) and SSS-Community (self-perceived status within one's own social network) as predictors of long-term cognitive decline. Multiple-linear-regression was performed on 4-year follow-up Mini-Mental-Status-Examination (MMSE) cognitive function score (score range: 0-30) after adjusting for baseline MMSE scores, traditional SES indicators (e.g., education), demographic variables (e.g., sex), clinical conditions (e.g., stroke history, depression), and lifestyle variables (e.g., physical activity levels).

RESULTS

Lower SSS-Community but not SSS-Hong Kong was associated with greater cognitive decline (unstandardized coefficient (95% CI) = 0.13 (0.07, 0.19) standardized β-coefficient = 0.08, after adjusting for objective SES measures and other background and clinical factors. The standardized β-coefficients for the SSS-Community variable were similar in magnitude to those for depression and diabetes.

CONCLUSION

Cognitive decline is influenced by self-perceived rank in proximal reference groups rather than socioeconomic comparison with society at-large. SSS-Community is a useful, single-item supplementary instrument to improve prediction of cognitive decline in elderly Chinese.

First- and second-hand alcohol-related harms among urban Chinese: A population-based study from Hong Kong

INTRODUCTION

Alcohol consumption has been steadily increasing in East Asia, however, there is comparatively little regional data of alcohol-related harms. This study examines the alcohol-related harms prevalence and risk factors in Hong Kong, a high population density city with limited alcohol regulation.

METHODS

A cross-sectional telephone survey was conducted in 2019 on Chinese adults aged 18-74 (n = 3200). Respondents were asked about various past-year first-hand drinking harms (after one's own drinking), second-hand harms (harms from other people's drinking) and views of neighbourhood alcohol outlet regulation.

RESULTS

Of drinkers, 21.1% reported first-hand alcohol harms, with physical/mental health harms (15.7%) most commonly reported. Younger-aged drinkers (adjusted odds ratios [AOR] 2.64, 95% confidence interval [CI] 1.63, 4.48) and heavy drinkers (AOR 2.34, 95% CI 1.55, 3.55) were more likely to report first-hand harms. Of the sample, 18.2% experienced past-year second-hand harms, with public harms (12.9%) most commonly reported. Young age (AOR 1.88, 95% CI 1.43, 2.49), higher education (AOR 1.44, 95% CI 1.13, 1.83), past-year binge drinking (AOR 4.29, 95% CI 3.04, 6.05) and communal living (AOR 2.04, 95% CI 1.13, 3.75) predicted greater likelihood of second-hand alcohol harms. Higher neighbourhood alcohol outlet density was not associated with any first-hand harms and only significantly predicted being inconvenienced by drinkers. Although victims of second-hand alcohol harms were more supportive of regulating outlet density, 93.3% of respondents were opposed to such policies.

DISCUSSION AND CONCLUSIONS

Although high levels of alcohol-related harms were not reported by Hong Kong adults, regulations should target young drinkers and binge drinkers who are most likely to experience drinking-related harms.

Long-term association between urban air ventilation and mortality in Hong Kong

While associations between population health outcomes and some urban design characteristics, such as green space, urban heat islands (UHI), and walkability, have been well studied, no prior studies have examined the association of urban air ventilation and health outcomes. This study used data from Hong Kong, a densely populated city, to explore the association between urban air ventilation and mortality during 2008-2014. Frontal area density (FAD), was used to measure urban ventilation, with higher FAD indicating poorer ventilation, due to structures blocking wind penetration. Negative binomial regression models were constructed to regress mortality counts for each 5-year age group, gender, and small area group, on small area level variables including green space density, population density and socioeconomic indicators. An interquartile range increase in FAD was significantly associated with a 10% (95% confidence interval (CI) 2%-19%, p = 0.019) increase in all-cause mortality and a 21% (95% CI: 2%-45%, p = 0.030) increase in asthma mortality, and non-significantly associated with a 9% (95% CI: 1%-19%, p = 0.073) in cardio-respiratory mortality. Better urban ventilation can help disperse vehicle-related pollutants and allow moderation of UHIs, and for a coastal city may allow moderation of cold temperatures. Urban planning should take ventilation into account. Further studies on urban ventilation and health outcomes from different settings are needed.

Does surrounding greenness moderate the relationship between apparent temperature and physical activity? Findings from the PHENOTYPE project

BACKGROUND

Physical activity can be affected by both meteorological conditions and surrounding greenness, but few studies have evaluated the effects of these environmental factors on physical activity simultaneously. This multi-city comparative study aimed to assess the synergetic effects of apparent temperature and surrounding greenness on physical activity in four European cities. Specifically, we aimed to identify an interaction between surrounding greenness and apparent temperature in the effects on physical activity.

METHODS

Data were collected from 352 adult residents of Barcelona (Spain), Stoke-on-Trent (United Kingdom), Doetinchem (The Netherlands), and Kaunas (Lithuania) as part of the PHENOTYPE study. Participants wore a smartphone for seven consecutive days between May-December 2013 and provided additional sociodemographic survey data. Hourly average physical activity (Metabolic Equivalent of Task (MET)) and surrounding greenness (NDVI) were derived from the Calfit mobile application collecting accelerometer and location data. Hourly apparent temperature was calculated from temperature and relative humidity, which were obtained from local meteorological stations along with other meteorological covariates (rainfall, windspeed, and sky darkness). We assessed the interaction effects of apparent temperature and surrounding greenness on hourly physical activity for each city using linear mixed models, while adjusting for meteorological, demographic, and time-related variables.

RESULTS

We found significant interactions between apparent temperature and surrounding greenness on hourly physical activity in three of four cities, aside from the coastal city of Barcelona. Significant quadratic effects of apparent temperature were found in the highest level of surrounding greenness for Stoke-on-Trent and Doetinchem, with 4% decrease in median MET observed for a 10°C departure from optimal temperature (15.2°C and 14.6°C, respectively). Significant linear effects were found for higher levels of surrounding greenness in Kaunas, whereby an increase of 10°C was associated with ∼4% increase in median MET.

CONCLUSION

Apparent temperature and surrounding greenness interacted in the effect on hourly physical activity across three of four European cities, with varying effect between cities. While quadratic effects of temperature suggest diminishing levels of physical activity in the highest greenness levels in cities of temperate climates, the variation in surrounding greenness between cities could be further explored, particularly by looking at indoor-outdoor locations. The study findings support the need for evidence-based physical activity promotion and urban design.

The impact of childhood pneumococcal conjugate vaccine immunisation on all-cause pneumonia admissions in Hong Kong: A 14-year population-based interrupted time series analysis

BACKGROUND

Nine years after the introduction of pneumococcal conjugate vaccine (PCV) in the United States, Hong Kong (HK) introduced the vaccine to its universal childhood immunisation programme in 2009. We aimed to assess the impact of childhood PCV immunisation on all-cause pneumonia (ACP) admissions among the overall population of HK.

METHODS

In this population-based interrupted time series analysis, we used territory-wide population-representative electronic health records in HK to evaluate the vaccine impact. We identified hospitalised patients with a diagnosis of pneumonia from any cause between 2004 and 2017. We applied segmented Poisson regression to assess the gradual change in the monthly incidence of ACP admissions between pre- and post-vaccination periods. Negative outcome control, subgroup and sensitivity analyses were used to test the robustness of the main analysis.

FINDINGS

Over the 14-year study period, a total of 587,607 ACP episodes were identified among 357,950 patients. The monthly age-standardised incidence of ACP fluctuated between 33.42 and 87.44 per 100,000-persons. There was a marginal decreasing trend in pneumonia admissions after PCV introduction among overall population (incidence rate ratio [IRR]: 0·9965, 95% confidence interval [CI]: 0·9932-0·9998), and older adults (≥65 years, IRR: 0·9928, 95% CI: 0·9904-0·9953) but not in younger age groups.

INTERPRETATION

There was a marginally declining trend of overall ACP admissions in HK up to eight years after childhood PCV introduction. The significance disappeared when fitting sensitivity analyses. The results indicate the complexities of using non-specific endpoints for measuring vaccine effect and the necessity of enhancing serotype surveillance systems for replacement monitoring.

FUNDING

Health and Medical Research Fund, Food and Health Bureau of the Government of Hong Kong (Reference number: 18171272).

A systematic review on lagged associations in climate-health studies

BACKGROUND

Lagged associations in climate-health studies have already been ubiquitously acknowledged in recent years. Despite extensive time-series models having proposed accounting for lags, few studies have addressed the question of maximum-lag specification, which could induce considerable deviations of effect estimates.

METHODS

We searched the PubMed and Scopus electronic databases for existing climate-health literature in the English language with a time-series or case-crossover study design published during 2000-2019 to summarize the statistical methodologies and reported lags of associations between climate variables and 14 common causes of morbidity and mortality. We also aggregated the results of the included studies by country and climate zone.

RESULTS

The associations between infectious-disease outcomes and temperatures were found to be lagged for ∼1-2 weeks for influenza, 3-6 weeks for diarrhoea, 7-12 weeks for malaria and 6-16 weeks for dengue fever. Meanwhile, the associations between both cardiovascular and respiratory diseases and hot temperatures lasted for <5 days, whereas the associations between cardiovascular diseases and cold temperatures were observed to be 10-20 days. In addition, rainfall showed a 4- to 10-week lagged association with infectious diarrheal diseases, whereas the association could be further delayed to 8-12 weeks for vector-borne diseases.

CONCLUSION

Our findings indicated some general patterns for possible lagged associations between some common health outcomes and climatic exposures, and suggested a necessity for a biologically plausible and reasonable definition of the effect lag in the modelling practices for future environmental epidemiological studies.

Association of urban built environment and socioeconomic factors with suicide mortality in high-density cities: A case study of Hong Kong

Population ageing, climate change and urbanization have been occurring rapidly globally. Evidence-based healthy city development is required to improve living quality and mitigate the adverse impact of city living on both physical and mental health. We took a high-density city as an example to explore the association of built environment and suicide mortality and preferably to offer some implications for better future city development. Poisson generalized linear models with generalized estimation equations were employed to regress suicide mortality rate on four urban built environment variables (frontal area density (FAD), sky view factor (SVF), ground coverage ratio (GCR), and street coverage ratio (SCR)), as well as socioeconomic factors, population density, and greenery. The association for different causes of death and within different subgroups was also investigated. Generally, higher FAD and GCR were associated with higher suicide mortality while higher SVF and SCR were associated with lower suicide mortality. Age was a significant effect modifier. An interquartile range increase in FAD, SVF, and GCR was associated with 0.81 (95% confidence interval (CI) 0.71-0.92), 1.41 (95% CI 1.04-1.91), and 0.70 (95% CI 0.50-0.98) times the risk of suicide among the people aged over 70, respectively. Higher population density and unmarried status were generally associated with higher suicide rate whereas higher education level was associated with a decreased risk. Unfavorable built environment could increase risks for successful suicide attempts. Better urban development with morphological control mitigating intensifying urban heat island and other micro-environment changes are warranted to promote not only physical but psychological health.

Does subjective social status predict depressive symptoms in Chinese elderly? A longitudinal study from Hong Kong

BACKGROUND

Subjective social status (SSS), one's self-perceived social status, has been gaining interest among researchers as a risk/protective factor of many health outcomes. SSS encompasses both socio-economic factors (eg, income) and intangible aspects of status (eg, esteem from peers). This study's main objective was to examine the association between SSS and future risk of depression in elderly Chinese.

METHODS

Using data from the ongoing Mr/Mrs Os study, a longitudinal study of Hong Kong Chinese elderly, this study analysed baseline SSS-Hong Kong (self-perceived social status within Hong Kong) and SSS-Community (self-perceived status within one's own social network) as predictors of Geriatric Depression Scale (GDS) score at year 4 (n=3153). The models adjusted for baseline depression scores, socio-economic status indicators, demographic variables, clinical conditions and functional status variables.

RESULTS

Higher depression scores at follow-up were independently associated with lower SSS-Hong Kong (standardised β-coefficient= -0.040, p=0.017), lower SSS-Community (standardised β-coefficient= -0.057, p=0.001), in addition to older age, female gender and stroke history. After stratifying by dementia status, higher baseline SSS was associated with less depressive symptoms only in the non-dementia group. In the multivariable models that included both SSS variables, only SSS-Community was significantly associated with year 4 GDS score. However, both SSS variables were independently associated with year 4 depression status in the logistic regression analysis.

CONCLUSION

In Chinese elderly, SSS captures aspects of social status that are not captured by traditional socio-economic indicators. SSS can be a useful supplementary tool for assessing future risk of developing mental health conditions.

Trajectory of functional outcome and health status after moderate-to-major trauma in Hong Kong: A prospective 5 year cohort study

BACKGROUND

Trauma care systems in Asia have been developing in recent years, but there has been little long-term outcome data from injured survivors. This study aims to evaluate the trajectory of functional outcome and health status up to five years after moderate to major trauma in Hong Kong.

METHODS

We report the five year follow up results of a multicentre, prospective cohort from the trauma registries of three regional trauma centres in Hong Kong. The original cohort recruited 400 adult trauma patients with ISS ≥ 9. Telephone follow up was conducted longitudinally at seven time points, and the extended Glasgow Outcome Scale (GOSE) and Short-Form 36 (SF36) were tracked.

RESULTS

119 out of 309 surviving patients (39%) completed follow up after 5 years. The trajectory of GOSE, PCS and MCS showed gradual improvements over the seven time points. 56/119 (47.1%) patients reported a GOSE = 8 (upper good recovery), and the mean PCS and MCS was 47.8 (95% CI 45.8, 49.9) and 55.8 (95% CI 54.1, 57.5) respectively at five years. Univariate logistic regression showed change in PCS - baseline to 1 year and 1 year to 2 years, and change in MCS - baseline to 1 year were associated with GOSE = 8 at 5 years. Linear mixed effects model showed differences in PCS and MCS were greatest between 1-month and 6-month follow up.

CONCLUSIONS

After injury, the most rapid improvement in PCS and MCS occurred in the first six to 12 months, but further recovery was still evident for MCS in patients aged under 65 years for up to five years.

A time-series study of the association of rainfall, relative humidity and ambient temperature with hospitalizations for rotavirus and norovirus infection among children in Hong Kong

BACKGROUND

Rotavirus and norovirus are infectious pathogens primarily affecting children under 5 years old. The impact of rainfall on diarrheal diseases remains inconclusive. This study aimed to evaluate the association between short-term variation in rainfall, temperature and humidity, and rotavirus and norovirus hospitalizations among young children in Hong Kong.

METHODS

Generalized additive negative binomial regression models with distributed lag non-linear terms, were fit with daily counts of hospital admissions due to rotavirus and norovirus infection as the outcomes and daily total rainfall and other meteorological variables as predictors, adjusting for seasonality and trend.

RESULTS

Generally, greater rainfall was associated with fewer rotavirus, but more norovirus hospitalizations. Extreme precipitation (99.5 mm, 99th percentile) was found to be associated with 0.40 (95% confidence interval (CI) 0.20-0.79) and 1.93 (95% CI 1.21-3.09) times the risk of hospitalization due to rotavirus and norovirus infection respectively, relative to trace rainfall. Stronger associations were observed in winter for rotavirus and in summer for norovirus. The duration of association with rotavirus was notably longer than norovirus. Higher temperatures were found to be associated with fewer hospitalizations for both rotavirus and norovirus infection, while higher relative humidity was generally associated with more norovirus, but fewer rotavirus, hospitalizations.

CONCLUSIONS

Both rotavirus and norovirus hospitalizations were strongly associated with recent precipitation variation but in opposite directions. With the introduction of the rotavirus vaccine norovirus is likely to become a greater threat than rotavirus and thus greater precipitation may become more clearly associated with more childhood diarrhea.

Associations of Salmonella hospitalizations with ambient temperature, humidity and rainfall in Hong Kong

BACKGROUND

Little is known about the relationship between Salmonella infection and meteorological parameters other than air temperature. This study aimed to explore associations of Salmonella hospitalizations with temperature, relative humidity (RH) and rainfall.

METHODS

With negative binomial distribution assumed, time-series regression model adjusting for season and time trend were constructed employing distributed lag non-linear models and generalized additive models. Meteorological variables including mean temperature, RH, and daily total rainfall as well as indicator variables including day of the week and public holiday were incorporated in the models.

RESULTS

Higher temperature was strongly associated with more hospitalizations over the entire range of temperatures observed. There was a net 6.13 (95%Confidence Interval (CI) 3.52-10.67) relative risk of hospitalization at a temperature of 30.5 °C, relative to 13 °C, lag 0-16 days. Positive associations were found for RH above 60% and rainfall between 0 and 0.14 mm. Extreme high humidity (96%) and trace rainfall (0.02 mm) were associated with 2.06 (95%CI 1.35-3.14), lag 0-17 day, and 1.30 (95%CI 1.01-1.67), lag 0-26 days, relative risks of hospitalizations, relative to 60% and no rain, respectively.

CONCLUSIONS

High temperatures, high RH and light rainfall are positively associated with Salmonella hospitalizations. The very strong association with temperatures implies that hotter days will lead to increases in Salmonella morbidity in the absence of other changes, and the public health implications of this could be exacerbated by global climate change.

The global epidemiology of bladder cancer: a joinpoint regression analysis of its incidence and mortality trends and projection

We tested the hypotheses that the global incidence of bladder cancer was increasing but its mortality was reducing and its incidence was positively correlated with country-specific socioeconomic development. We retrieved data on age-standardized incidence and mortality rates/100,000 from the GLOBOCAN database in 2012. Temporal patterns were examined for 39 countries from the Cancer Incidence in Five Continents volumes I-X and other national registries. We evaluated the correlation between the incidence/mortality rates and Human Development Index (HDI)/ logarithmic values of Gross Domestic Product per capita (GDP). The average annual percent change of the incidence and mortality rates in the most recent 10 years was examined by joinpoint regression analysis. The highest incidence rates were observed in Southern Europe, Western Europe and North America. The mortality rates were the highest in Western Asia and Northern Africa. The incidence was positively correlated with HDI (r = 0.66 [men]; r = 0.50 [women]) and to a lesser extent logarithmic values of GDP per capita (r = 0.60 [men]; r = 0.50 [women], all p < 0.01). Many European countries experienced incidence rise. A substantial mortality reduction was observed in most countries, yet increases in mortality rates were observed in the Philippines and Iceland. These findings identified countries where more preventive actions are required.

Seasonal modeling of hand, foot, and mouth disease as a function of meteorological variations in Chongqing, China

Hand, foot, and mouth disease (HFMD) is an enterovirus-induced infectious disease, mainly affecting children under 5 years old. Outbreaks of HFMD in recent years indicate the disease interacts with both the weather and season. This study aimed to investigate the seasonal association between HFMD and weather variation in Chongqing, China. Generalized additive models and distributed lag non-linear models based on a maximum lag of 14 days, with negative binomial distribution assumed to account for overdispersion, were constructed to model the association between reporting HFMD cases from 2009 to 2014 and daily mean temperature, relative humidity, total rainfall and sun duration, adjusting for trend, season, and day of the week. The year-round temperature and relative humidity, rainfall in summer, and sun duration in winter were all significantly associated with HFMD. An inverted-U relationship was found between mean temperature and HFMD above 19 °C in summer, with a maximum morbidity at 27 °C, while the risk increased linearly with the temperature in winter. A hockey-stick association was found for relative humidity in summer with increasing risks over 60%. Heavy rainfall, relative to no rain, was found to be associated with reduced HFMD risk in summer and 2 h of sunshine could decrease the risk by 21% in winter. The present study showed meteorological variables were differentially associated with HFMD incidence in two seasons. Short-term weather variation surveillance and forecasting could be employed as an early indicator for potential HFMD outbreaks.

International incidence and mortality trends of liver cancer: a global profile

We examined the global incidence and mortality rates of liver cancer, and evaluated the association between incidence/mortality and socioeconomic development (Human Development Index [HDI] and Gross Domestic Product [GDP]) using linear regression analysis. The average annual percent change (AAPC) of the trends was evaluated from join-point regression analysis. The global incidence of liver cancer varied widely by nine-fold, and was negatively correlated with HDI (men: r = −0.232, p = 0.003; women: r = −0.369, p < 0.001) and GDP per capita (men: r = −0.164, p = 0.036; women: r = −0.212, p = 0.007). Its mortality showed a similarly negative correlation with both indices. The greatest incidence rise in men was observed in Poland (AAPC = 17.5, 95% C.I. = 5.6, 30.9) and Brazil (AAPC = 13.2, 95% C.I. = 5.9, 21.0), whereas Germany (AAPC = 6.6, 95% C.I = 2.0, 11.5) and Norway (AAPC = 6.5, 95% C.I. = 3.2, 10.0) had the greatest increase in women. The mortality rates paralleled the incidence rates in most countries. For mortality, Malta (AAPC = 11.5, 95% C.I. = 3.9, 19.8), Australia (AAPC = 6.8, 95% C.I. = 2.2, 11.5) and Norway (APCC = 5.6, 95% C.I. = 2.8, 8.5) reported the biggest increase among men; whilst Australia (AAPC = 13.4, 95% C.I. = 7.8, 19.4) and Singapore (AAPC = 7.7, 95% C.I. = 4.1, 11.5) showed the most prominent rise among women. These epidemiological data identified countries with potentially increasing trends of liver cancer for preventive actions.

Hand, Foot and Mouth Disease in Hong Kong: A Time-Series Analysis on Its Relationship with Weather

Background

Hand, foot and mouth disease (HFMD) is an emerging enterovirus-induced infectious disease for which the environmental risk factors promoting disease circulation remain inconclusive. This study aims to quantify the association of daily weather variation with hospitalizations for HFMD in Hong Kong, a subtropical city in China.

Methods

A time series of daily counts of HFMD public hospital admissions from 2008 through 2011 in Hong Kong was regressed on daily mean temperature, relative humidity, wind speed, solar radiation and total rainfall, using a combination of negative binomial generalized additive models and distributed lag non-linear models, adjusting for trend, season, and day of week.

Results

There was a positive association between temperature and HFMD, with increasing trends from 8 to 20°C and above 25°C with a plateau in between. A hockey-stick relationship of relative humidity with HFMD was found, with markedly increasing risks over 80%. Moderate rainfall and stronger wind and solar radiation were also found to be associated with more admissions.

Conclusions

The present study provides quantitative evidence that short-term meteorological variations could be used as early indicators for potential HFMD outbreaks. Climate change is likely to lead to a substantial increase in severe HFMD cases in this subtropical city in the absence of further interventions.

The development of the Hong Kong Heat Index for enhancing the heat stress information service of the Hong Kong Observatory

This paper presents a study to develop a heat index, for use in hot and humid sub-tropical climate in Hong Kong. The study made use of hospitalization data and heat stress measurement data in Hong Kong from 2007 to 2011. The heat index, which is called Hong Kong Heat Index (HKHI), is calculated from the natural wet bulb temperature, the globe temperature, and the dry bulb temperature together with a set of coefficients applicable to the high humidity condition in the summer of Hong Kong. Analysis of the response of hospitalization rate to variation in HKHI and two other heat indices, namely Wet Bulb Globe Temperature (WBGT) and Net Effective Temperature (NET), revealed that HKHI performed generally better than WBGT and NET in reflecting the heat stress impact on excess hospitalization ratio in Hong Kong. Based on the study results, two reference criteria of HKHI were identified to establish a two-tier approach for the enhancement of the heat stress information service in Hong Kong.

Using Annual Data to Estimate the Public Health Impact of Extreme Temperatures

Short-term associations between both hot and cold ambient temperatures and higher mortality have been found worldwide. Few studies have examined these associations on longer time scales. Age-standardized mortality rates (ASMRs) were calculated for 1976-2012 for Hong Kong SAR, People's Republic of China, defining "annual" time periods in 2 ways: from May through April of the following year and from November through October. Annual frequency and severity of extreme temperatures were summarized by using a degree-days approach with extreme heat expressed as annual degree-days >29.3°C and cold as annual degree-days <27.5°C. For example, a day with a mean temperature of 25.0°C contributes 2.5 cold degree-days to the annual total. Generalized additive models were used to estimate the association between annual hot and cold degree-days and the ASMR, with adjustment for long-term trends. Increases of 10 hot or 200 cold degree-days in an annual period, the approximate interquartile ranges for these variables, were significantly (all P's ≤ 0.011) associated with 1.9% or 3.1% increases, respectively, in the annual ASMR for the May-April analyses and with 2.2% or 2.8% increases, respectively, in the November-October analyses. Associations were stronger for noncancer and elderly mortality. Mortality increases associated with extreme temperature are not simply due to short-term forward displacement of deaths that would have occurred anyway within a few weeks.

Uptake of breast screening and associated factors among Hong Kong women aged ≥50 years: a population-based survey

OBJECTIVE

To examine the uptake of breast screening and its associated factors among Hong Kong Chinese women aged ≥50 years.

STUDY DESIGN

Cross-sectional population-based survey.

METHODS

A sample of Hong Kong Chinese women was recruited through telephone random-digit dialling. The survey consisted of six sections: perceived health status, use of complementary medicine, uptake of breast screening, perceived susceptibility to cancer, family history of cancer and demographic data. The factors associated with uptake of breast screening were analysed using logistic regression analysis.

RESULTS

In total, 1002 women completed the (anonymous) telephone survey. The mean age was 63.5 (standard deviation 10.6) years. The uptake rate of breast screening among Hong Kong Chinese women aged ≥50 years was 34%. The primary reasons for undertaking breast screening were as part of a regular medical check-up (74%), prompted by local signs and symptoms (11%) and a physician's recommendation (7%). Higher educational level, married or cohabiting, family history of cancer, frequent use of complementary therapies, regular visits to a doctor or Chinese herbalist, and the recommendation of a health professional were all independently and significantly associated with increased odds of having had a mammogram.

CONCLUSIONS

This study provides community-based evidence of the need for public health policy to promote broader use of mammography services among this target population, with emphasis on the active involvement of health care professionals, through the development and implementation of appropriate evidence-based and resource-sensitive strategies.

Uptake of prostate cancer screening and associated factors among Chinese men aged 50 or more: a population-based survey

Objective

To investigate the uptake rate of prostate specific antigen (PSA) testing among Hong Kong Chinese males aged 50 or above, and identify factors associated with the likelihood of undergoing a PSA test.

Methods

A population-based telephone survey was conducted in Hong Kong in 2007. The survey covered demographic information, perceived health status, use of complementary therapy, cancer screening behavior, perceived susceptibility to cancer and family history of cancer. Descriptive statistics, percentages and logistic regression analysis were used for data analysis.

Results

A total of 1,002 men aged 50 or above took part in the study (response rate =67%), and the uptake rate of PSA testing was found to be 10%. Employment status, use of complementary therapy, perceiving regular visits to a doctor as good for health and the recommendations of health professionals were significant factors associated with PSA testing.

Conclusion

The uptake rate of PSA testing in the study population was very low. Among all the factors identified, recommendations from health professionals had the strongest association with the uptake of PSA testing, and they should therefore take an active role in educating this population about cancer prevention and detection.

Effects of 17-allylamino-17-demethoxygeldanamycin (17-AAG) in transgenic mouse models of frontotemporal lobar degeneration and Alzheimer's disease

Alzheimer's disease (AD), the most common dementia, is characterized by potentially neurotoxic aggregation of Aβ peptide and tau protein, and their deposition as amyloid plaques and neurofibrillary tangles (NFTs). Tau aggregation also occurs in other common neurodegenerative diseases. Frontotemporal dementia (FTD) can be caused by tau mutations that increase the susceptibility of tau to hyperphosphorylation and aggregation, which may cause neuronal dysfunction and deposition of NFTs. 17-allylamino-17-demethoxygeldanamycin (17-AAG) is a potent inhibitor of heat shock protein 90 (Hsp90), a cytosolic chaperone implicated in the proper folding and functions of a repertoire of client proteins. 17-AAG binds to Hsp90 and enhances degradation of Hsp90 client protein. We sought to determine whether 17-AAG can reduce Aβ and tau pathology in the brains of AD and FTD model mice expressing Aβ or P301L mutant tau, respectively. Mice were randomized to receive 25, 5, or 0 mg/kg 17-AAG thrice weekly from age eight to 11 months. Analysis was performed by rotarod test on motor function, on the area occupied by plaques in hippocampus or NFTs in medulla tissue sections, and on mortality. A high dose of 17-AAG tended to decrease NFTs in male mice (p = 0.08). Further studies are required to confirm the effect of 17-AAG in diseases of tau aggregation.

Acute adverse events from over-the-counter Chinese herbal medicines: a population-based survey of Hong Kong Chinese

Background

Although over-the-counter traditional Chinese herbal medicine (COTC) is commonly used to treat everyday illness in many parts of the world, no population-based study has been done to examine the prevalence and factors associated with COTC-related adverse events.

Methods

A cross-sectional telephone survey was conducted among Hong Kong Chinese adults in 2011 (n = 1100) with informed verbal consent. Stepwise logistic regression of demographic, attitudinal and behavioral variables was used to determine factors associated with past-year adverse events.

Results

Of study respondents, 71.7% (789/1100) reported past-year COTC use and 2.3% (25/1100) reported at least one COTC-related adverse event in the past year. Of the 27 adverse events cases reported among COTC users, the most common were allergic reactions (n = 11) dizziness (n = 5), and gastro-intestinal problems (n = 4). Pills/capsules were the dosage form that caused the highest proportion of adverse events (n = 10), followed by plasters (n = 7), creams/ointments (n = 5), and ingestible powders (n = 2).

Although COTC users reporting adverse events were more likely to report greater practices to avoid adverse events (OR = 6.47; 95% CI: 1.38-30.3); they were also more likely to possess lower education levels (OR = 9.64, 95% CI: 2.20-42.3) and to have received COTC information from non-reliable, mass-media information sources such as magazines (OR = 3.32; 95% CI: 1.01-8.50) or television (OR = 2.93; 95% CI: 1.03-10.7). Package labels were also felt to be unclear by 42.9% of COTC users. A large proportion of COTC users demonstrated low levels of COTC-related knowledge, while the main impediment to greater information-seeking was the belief that reliable COTC information is not obtainable from Western health professionals.

Conclusions

Despite global movements toward more stringent complementary medicine regulation, the limited accessibility of reliable information and widespread misperceptions among consumers present major challenges for the safe use of complementary medicine.

Effect modification of the association between meteorological variables and mortality by urban climatic conditions in the tropical city of Kaohsiung, Taiwan

A deeper understanding of extreme hot weather are needed in cities sensitive to heat effects, an investigation was done in the tropical town of Kaohsiung in Taiwan. Its 11 districts were divided into three climatic classes varying from high urban heat, low levels of green space and lack of proximity to water bodies to low urban heat, adequate green space and proximity to water bodies. Daily data on natural mortality, meteorological variables, and pollutants from May-October 1999-2008 were analysed using generalised additive models for the time-series data. Subgroup analyses were conducted, stratifying decedents according to the level of planning activity required in order to mitigate adverse heat effects in their residential areas, classifying districts as "level 1" for those requiring a high level of mitigation action; "level 2" for those requiring some action; and "level 3" for those that need only preserve existing conditions. Stratified analyses showed that mortality increases per 1 °C rise on average, either on the same day or in the previous 4 days (lags 0-4), were associated with 2.8%, 2.3% and -1.3% for level 1, 2 and 3 districts, respectively. The slope describing the association between temperature and mortality was higher above 29.0 °C resulting in corresponding increases of 4.2%, 5.0% and 0.3% per per 1 °C rise in temperature, respectively. Other meteorological variables were not significantly associated with mortality. It is concluded that hot season mortality in Kaohsiung is only sensitive to heat effects in districts classified as having unfavourably climatic conditions and requiring mitigation efforts in city planning. Urban planning measures designed to improve climatic conditions could reduce excess mortality resulting from extreme hot weather.

The mediating role of health professionals' recommendation in the uptake of colorectal cancer testing among older Chinese adults

The purpose of this study is to examine the mediating effect of health professionals' recommendations on the relationship between the characteristics of older Chinese adults and the use of colorectal cancer testing. This was a cross-sectional population-based telephone survey. A total of 2004 Chinese adults aged 50 or above were recruited between 2 and 28 May 2007 to complete an anonymous telephone survey. The survey covered demographics, perceived health status and susceptibility to cancer, utilization of complementary medicine, family history of cancer, and cancer screening behaviour. The uptake of flexible sigmoidoscopy/colonoscopy was 12%, of which only 3.4% had been recommended by health professionals. The effects of gender, a history of serious disease, perceptions related to health status and visiting doctor regularly on the flexible sigmoidoscopy/colonoscopy uptake were mediated by a health professional's recommendation. A health professional's recommendation can be a catalyst for the decision of undergoing a colorectal cancer screening test in older adult people, in particular for those who are more health-conscious. As health professionals can play a crucial role in the development of successful population-based colorectal cancer screening program, efforts should be made to facilitate them in making recommendations for colorectal cancer screening to targeted high-risk group.

Associations between mortality and meteorological and pollutant variables during the cool season in two Asian cities with sub-tropical climates: Hong Kong and Taipei

BACKGROUND

Numerous studies have found associations between extreme temperatures and human mortality but relatively few studies have been done in sub-tropical and tropical cities, especially in Asia. In this study we examine the impact of cold temperatures, cold waves and other meteorological and environmental variables on cool season mortality in 2 subtropical Asian cities.

METHODS

Separate analysis of daily mortality time-series from Hong Kong and Taipei using Generalized Additive Models with natural mortality as the outcome daily mean temperature as the main explanatory variable and relative humidity, solar radiation, wind speed, pollutants (nitrogen dioxide (NO(2)), sulfur dioxide (SO(2)), respirable suspended particulates (PM(10)), ozone (O(3)), seasonality and day of the week controlled as potential confounders. Lags up to 35 days were considered for temperature, and distributed lag models were used to determine the number of lags for final models. Subgroup analyses were also done by gender, age group, cause of death and geographical area of residence.

RESULTS

Cold temperatures were strongly associated with higher mortality with lagged effects persisting up to 3 weeks in Hong Kong and 2 weeks in Taipei. Cold effects were much stronger for deaths among older people and non-cancer deaths. Prolonged cold spells modestly but significantly raised mortality after accounting for the effects of individual cold days. Higher daily ozone levels were also strongly associated with higher short-term mortality in Taipei and Hong Kong, while relative humidity and solar radiation were weakly and inconsistently associated with mortality.

CONCLUSIONS

Cold temperatures and cold spells substantially increase short-term mortality in sub-tropical Asian cities particularly among the elderly. Greater attention needs to be paid to the adverse health effects of cold temperatures. Interventions including provisions of shelters, cold weather warnings and education about the possible health effects of cold temperature should be carried out in sub-tropical areas.

Drink driving in Hong Kong: the competing effects of random breath testing and alcohol tax reductions

AIMS

To investigate the competing effects of increased anti-drink driving legislation and the recent elimination of excise taxes on wine and beer.

DESIGN

Serial cross-sectional telephone surveys were conducted in 2006 (n = 9860) and 2011 (n = 4800).

SETTING

Hong Kong, China.

PARTICIPANTS

Chinese adults (≥18 years of age).

MEASUREMENTS

Respondents were asked about their drinking patterns, past-year experience of driving within 2 hours of drinking, drinking-related attitudes and reported deterrents to drink driving.

FINDINGS

Following the legislative changes, the age-standardized past-year prevalence of drink driving decreased significantly from 5.2 to 2.8% (P < 0.001) among all males, from 9.0 to 4.4% (P < 0.001) among male past-year drinkers and from 13.7 to 8.5% (P < 0.01) among male weekly drinkers. The past-year prevalence of drink driving in 2011 among all females (0.08%), female past-year drinkers (1.6%), male binge drinkers (12.5%), female weekly drinkers (4.7%) and female binge drinkers (7.9%) were not significantly different from 2006. Drink driving was associated independently with business sector employment [odds ratio (OR) = 2.47], past-month binge drinking (OR = 6.08) and beliefs in the benefits to one's wellbeing of drinking (OR = 2.62) among males and past-month binge drinking (OR = 5.57), belief in the social benefits of drinking (OR = 5.66) and being unmarried (OR = 3.00) in females (P < 0.05). The most commonly reported drink driving deterrents were concerns about random breath tests (93.8%) and the potential legal consequences of conviction (93.6-96.5%).

CONCLUSIONS

Despite greater alcohol consumption in Hong Kong, the current anti-drink driving strategy appears to reduce drink driving in males and prevent increased levels among females. Binge drinkers, however, remain a high-risk group that should be monitored continually.

Hospital admissions as a function of temperature, other weather phenomena and pollution levels in an urban setting in China

OBJECTIVE

To explore the relationship between weather phenomena and pollution levels and daily hospital admissions (as an approximation to morbidity patterns) in Hong Kong Special Administrative Region (SAR), China, in 1998-2009.

METHODS

Generalized additive models and lag models were constructed with data from official sources on hospital admissions and on mean daily temperature, mean daily wind speed, mean relative humidity, daily total global solar radiation, total daily rainfall and daily pollution levels.

FINDINGS

During the hot season, admissions increased by 4.5% for every increase of 1 °C above 29 °C; during the cold season, admissions increased by 1.4% for every decrease of 1 °C within the 8.2-26.9 °C range. In subgroup analyses, admissions for respiratory and infectious diseases increased during extreme heat and cold, but cardiovascular disease admissions increased only during cold temperatures. For every increase of 1 °C above 29 °C, admissions for unintentional injuries increased by 1.9%. During the cold season, for every decrease of 1 °C within the 8.2-26.9 °C range, admissions for cardiovascular diseases and intentional injuries rose by 2.1% and 2.4%, respectively. Admission patterns were not sensitive to sex. Admissions for respiratory diseases rose during hot and cold temperatures among children but only during cold temperatures among the elderly. In people aged 75 years or older, admissions for infectious diseases rose during both temperature extremes.

CONCLUSION

In Hong Kong SAR, hospitalizations rise during extreme temperatures. Public health interventions should be developed to protect children, the elderly and other vulnerable groups from excessive heat and cold.

Gender differences in the use of colorectal cancer tests among older Chinese adults

PURPOSE

The study aimed to explore the gender difference in using colorectal cancer (CRC) tests among Chinese aged 50 years or over.

METHODS

A cross-sectional study was conducted in 2004 Chinese older adults through anonymous telephone survey which covered socio-demographic variables, health status, use of complementary therapy, health-related perceptions and use of CRC tests.

RESULTS

The uptake rate of flexible sigmoidoscopy (FS)/colonoscopy was 14% for males and 10% for females, with males significantly more likely to have had the test after adjusting for their differences in socio-demographics, health status, use of complementary therapies, health-related perceptions and recommendation received from health professionals (adjusted OR = 1.5, 95% CI: 1.1-2.0, p = 0.005). The uptake of fecal occult blood test was nearly the same (19%) for both genders. Further interaction analyses indicates that the effect of a family history of cancer on the uptake of a FS/colonoscopy is significantly weaker in males than in females (the interaction odds ratio = 0.4, 95% CI: 0.2-0.8, p = 0.011), whereas a male perceived that visiting a doctor is good for health will be more likely to have an uptake of a FS/colonoscopy than a female with such perception (the interaction odds ratio = 2.1, 95% CI: 1.1-3.8, p = 0.018).

CONCLUSIONS

The uptake of CRC tests was low in this average-risk population. More effort is needed to educate the public about the importance and benefits of CRC tests. In view of the gender differences in some determinants of FS/colonoscopy uptake, particular attention should be given to develop gender-specific strategies to improve the rate.

Weather, pollution, and acute myocardial infarction in Hong Kong and Taiwan

BACKGROUND

Several previous studies examined the association between acute myocardial infarction (AMI) incidence and temperature and/or air pollution. Results of these studies have been inconsistent and few studies have been done in cities with sub-tropical or tropical climates.

METHODS

Daily data on AMI hospitalizations, mean temperature and humidity, and pollutants, were collected for 2000-2009 for three warm-climate Asian cities. Poisson Generalized Additive Models were used to regress daily AMI counts on temperature, humidity, and pollutants while controlling for day of the week, long-term trends and seasonal effects. Smoothing splines allowing non-linear associations were used for temperature and humidity while pollutants were modeled as linear terms.

RESULTS

A 1°C drop below a threshold temperature of 24°C was significantly (p<.0001) associated with AMI hospitalization increases of 3.7% (average lag 0-13 temperature) in Hong Kong, 2.6% (average lag 0-15) in Taipei, and 4.0% (average lag 0-11) in Kaohsiung. No significant heat effects were observed. Among pollutants same day nitrogen dioxide (NO2) levels were the strongest predictors in all three cities, with a 10mg/m(3) increase in NO2 being associated with a 1.1% rise in AMI hospitalization in Hong Kong, and a 10 ppb rise being associated with 4.4% and 2.6% rises in Taipei and Kaohsiung, respectively.

CONCLUSIONS

Cool temperatures and higher NO2 levels substantially raised AMI risk in these warm-climate cities and the effect sizes we observed were stronger than those found in previous studies. More attention should be paid to the health dangers of cold weather in warm-climate cities.

Weather, season, and daily stroke admissions in Hong Kong

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.

Effect modification of the association between short-term meteorological factors and mortality by urban heat islands in Hong Kong

BACKGROUND

Prior studies from around the world have indicated that very high temperatures tend to increase summertime mortality. However possible effect modification by urban micro heat islands has only been examined by a few studies in North America and Europe. This study examined whether daily mortality in micro heat island areas of Hong Kong was more sensitive to short term changes in meteorological conditions than in other areas.

METHOD

An urban heat island index (UHII) was calculated for each of Hong Kong's 248 geographical tertiary planning units (TPU). Daily counts of all natural deaths among Hong Kong residents were stratified according to whether the place of residence of the decedent was in a TPU with high (above the median) or low UHII. Poisson Generalized Additive Models (GAMs) were used to estimate the association between meteorological variables and mortality while adjusting for trend, seasonality, pollutants and flu epidemics. Analyses were restricted to the hot season (June-September).

RESULTS

Mean temperatures (lags 0-4) above 29 °C and low mean wind speeds (lags 0-4) were significantly associated with higher daily mortality and these associations were stronger in areas with high UHII. A 1 °C rise above 29 °C was associated with a 4.1% (95% confidence interval (CI): 0.7%, 7.6%) increase in natural mortality in areas with high UHII but only a 0.7% (95% CI: -2.4%, 3.9%) increase in low UHII areas. Lower mean wind speeds (5(th) percentile vs. 95(th) percentile) were associated with a 5.7% (95% CI: 2.7, 8.9) mortality increase in high UHII areas vs. a -0.3% (95% CI: -3.2%, 2.6%) change in low UHII areas.

CONCLUSION

The results suggest that urban micro heat islands exacerbate the negative health consequences of high temperatures and low wind speeds. Urban planning measures designed to mitigate heat island effects may lessen the health effects of unfavorable summertime meteorological conditions.

Differences in the compliance with hospital infection control practices during the 2009 influenza H1N1 pandemic in three countries

BACKGROUND

In December 2009, the World Health Organization (WHO) issued updated guidelines on the prevention of H1N1 influenza virus in healthcare settings. In 2010, the WHO pandemic influenza alert level was still at phase 6.

AIM

To study the practice of infection control measures during the 2009 influenza H1N1 pandemic among healthcare workers (HCWs) in three countries.

METHODS

A standardized, self-administered anonymous questionnaire survey was conducted in 2010 among doctors, nurses and allied HCWs in 120 hospital-based clinical departments in Hong Kong, Singapore and the UK. Questions were asked on demographics; previous experience and perceived severity of influenza; infection control practices; uptake of seasonal influenza vaccination and H1N1 vaccination. Multiple logistic regression was used to test the independent association with different factors.

FINDINGS

A total of 2100 HCWs in the three countries participated. They reported high compliance (>80%) with infection control procedures regarded as standard for droplet-transmitted infections including wearing and changing gloves, and washing hands before and after patient contact. However, the reported use of masks with indirect or direct patient contact (surgical or N95 as required by their hospital) varied considerably (96.4% and 70.4% for Hong Kong; 82.3% and 87.7% for Singapore; 25.3% and 62.0% for the UK). Reported compliance was associated with job title, number of patient contacts and perceived severity of pandemics. There was no association between the uptake for seasonal or 2009 H1N1 vaccines and compliance.

CONCLUSIONS

Compliance with infection control measures for pandemic influenza appears to vary widely depending on the setting.

Knowledge of avian influenza (H5N1) among poultry workers, Hong Kong, China

In 2009, a cross-sectional survey of 360 poultry workers in Hong Kong, China, showed that workers had inadequate levels of avian influenza (H5N1) risk knowledge, preventive behavior, and outbreak preparedness. The main barriers to preventive practices were low perceived benefits and interference with work. Poultry workers require occupation-specific health promotion.

Significant associations of prostate-specific antigen nadir and time to prostate-specific antigen nadir with survival in prostate cancer patients treated with androgen-deprivation therapy

OBJECTIVE

The influence of prostate-specific antigen (PSA) kinetics on the outcome of metastatic prostate cancer (PCa) after androgen-deprivation therapy (ADT) remains poorly characterised. We evaluated the prognostic significance of PSA nadir and time to PSA nadir as well as their interactive effect on prostate cancer-specific mortality (PCSM) and all-cause mortality (ACM) after ADT.

METHODS

A total of 650 men with advanced or metastatic PCa treated with ADT were studied. The prognostic significance of PSA nadir and time to PSA nadir on PCSM and ACM were analysed using Kaplan-Meier analysis and the Cox regression model.

RESULTS

On multivariate analysis, clinical M1 stage, Gleason Score 8-10, PSA nadir ≥ 0.2 ng/ml and time to PSA nadir < 10 months were independent predictors of PCSM and ACM. The combined analysis showed that patient with higher PSA nadir and shorter time to PSA nadir had significantly higher risk of PCSM and ACM compared to those with lower PSA nadir and longer time to PSA nadir (hazard ratios = 6.30 and 4.79, respectively, all P < 0.001).

CONCLUSIONS

Our results suggest that higher PSA nadir level and faster time to reach PSA nadir after ADT were associated with shorter survival for PCa.

Analysis of spatio-temporal variations in stroke incidence and case-fatality in Hong Kong

Geographical variations in stroke incidence and case-fatality have been documented worldwide. This study examines whether there are spatio-temporal variations in stroke incidence and case-fatality in Hong Kong and attempts to determine to what extent socioeconomic status (SES) and healthcare provision account for these variations. Residence-based hospital discharge data from the Hospital Authority (HA) in Hong Kong were geo-referenced and used to examine incidence rates and case-fatality rates by stroke subtype among the population aged 35 years and above in 1999-2007. Multilevel models were used to examine the spatio-temporal variations. Ischemic stroke incidence was found to decrease among those aged above 55 years, while hemorrhagic stroke incidence increased. Ischemic stroke case-fatality was found to decrease but hemorrhagic stroke case-fatality remained stable. For both subtypes, there were significant variations in stroke incidence and case-fatality across the districts of residence, but insignificant variations across HA service clusters. Only variations in ischemic stroke incidence and hemorrhagic stroke case-fatality at the district level could be partly explained by district-level SES. Identification of districts with higher risk for stroke incidence and case-fatality would help to formulate enhanced preventive measures. Future studies are needed to identify factors that contribute to the geographical variations.

Risk factors of hospitalization and readmission of patients with COPD in Hong Kong population: analysis of hospital admission records

BACKGROUND

Chronic Obstructive Pulmonary Disease (COPD) accounts for around 4% of all public hospital annual admissions in Hong Kong. By year 2020, COPD will be ranked fifth among the conditions with the highest burden to the society. This study identifies admission and unplanned readmission of COPD patients, factors affecting unplanned readmission, and estimates its cost burden on the public healthcare system in Hong Kong.

METHODS

This is a retrospective study analyzing COPD admissions to all public hospitals in Hong Kong. All admission episodes to acute medical wards with the principal diagnosis of COPD (ICD-9:490-492, 494-496) from January 2006 to December 2007 were captured. Unplanned readmission was defined as an admission which followed a previous admission within 30 days.

RESULTS

In 2006 and 2007, 65497 (8.0%) of episodes from medical wards were identified as COPD admissions, and among these, 15882 (24.2%) were unplanned readmissions. The mean age of COPD patients was 76.81 ± 9.59 years and 77% were male. Unplanned readmission was significantly associated with male gender, receiving public assistance and living in nursing homes while no association was found with the Charlson comorbidity index. Patients who were readmitted unplanned had a significant longer acute length of stay (β = 0.3894, P < 0.001) after adjustment for other covariates.

CONCLUSIONS

Unplanned readmission of COPD patients has a huge impact on the public healthcare system. A systematic approach in programme provision and a good discharge planning process targeting on COPD patients who are at high risk of unplanned readmission are essential.

Impact of prostate-specific antigen (PSA) nadir and time to PSA nadir on disease progression in prostate cancer treated with androgen-deprivation therapy

BACKGROUND

The influence of PSA kinetics on the outcome of metastatic prostate cancer after androgen deprivation therapy (ADT) is not well understood. We evaluated the prognostic significance of PSA nadir and time to PSA nadir as well as their potential interactive effect on the progression of disease after ADT.

METHODS

A total of 650 men with advanced or metastatic prostate cancer treated with ADT were studied. The prognostic significance of PSA nadir and time to PSA nadir on disease progression were analyzed using Kaplan-Meier analysis and the Cox regression model.

RESULTS

We found that both PSA nadir and time to PSA nadir were independent and significant predictors of disease progression. Patients with higher PSA nadir (≥0.2 ng/ml) and shorter time to PSA nadir (<10 months) had significant shorter time to disease progression after adjusting for other covariates. The combined analyses showed a potential synergistic effect of these two variables on disease progression. Patient with higher PSA nadir and shorter time to PSA nadir had significantly higher risk for disease progression compared to those with lower PSA nadir and longer time to PSA nadir (Hazard Ratios (HR) = 3.11, P < 0.001).

CONCLUSIONS

We concluded that both PSA nadir and time to PSA nadir are significant predictors of disease progression for prostate cancer patients receiving ADT.