Search

Abstract Background We hypothesized that socio-economic development could, via nutritionally driven levels of pubertal sex-steroids, promote a pro-inflammatory state among men but not women in developing countries. We tested this hypothesis, using recalled childhood meat eating as a proxy for childhood nutrition, in southern China. Methods We used multivariable linear regression in the Guangzhou Biobank Cohort Study phase 3 (2006-8) to examine the adjusted associations of recalled childhood meat eating, Results Adjusted for age, childhood socio-economic position, education and smoking, childhood meat eating had sex-specific associations with white blood cell count and lymphocyte count, but not granulocyte count. Men with childhood meat eating almost daily compared to 9/L, 95% confidence interval (CI) 0.10 to 0.56) and higher lymphocyte count (0.16 109/L, 95% CI 0.07 to 0.25). Adjustment for obesity slightly attenuated these associations. Conclusion If confirmed, this hypothesis implies that economic development and the associated improvements in nutrition at puberty may be less beneficial among men than women; consistent with the widening sex differentials in life expectancy with economic development.

Abstract Background Birth weight is negatively associated with cardiovascular diseases and diabetes, but the associations are less well-established in developing populations where birth weight is often unavailable. We studied the association of birth weight and cardiovascular risk, using birth rank as an instrumental variable, in Southern China. Methods We used published data on birth weight by birth rank from an appropriate population and baseline data from the Guangzhou Biobank Cohort Study phases 2 & 3 (2005-8) to examine the adjusted associations, using instrumental variable analysis, of birth weight with clinically measured cardiovascular risk factors and the metabolic syndrome in older (≥ 50 years) men (n = 5,051) and women (n = 13,907). Results Estimated birth weight was associated with lower blood pressure (systolic -0.25 mm Hg 95% confidence interval (CI), -0.53 to 0.03 and diastolic -0.33 mm Hg 95% CI -0.48 to -0.18 per standard deviation higher birth weight), but had little association with glucose, lipids, waist-hip ratio, body mass index or the metabolic syndrome, adjusted for age, sex, early environment and number of offspring. Conclusion Birth weight may impact blood pressure; however associations of birth weight with other cardiovascular risk factors may not be related to foetal exposures, but speculatively could be an historical co-incidence, with corresponding implications for prevention.

Abstract Background No country is fully prepared for a 1918-like pandemic influenza. Averting a pandemic of H5N1 influenza virus depends on the successful control of its endemicity, outbreaks in poultry and occasional spillage into human which carries a case-fatality rate of over 50%. The use of perimetric depopulation and vaccination has failed to halt the spread of the epidemic. Blanket vaccination for all poultry over a large geographical area is difficult. A combination of moratorium, segregation of water fowls from chickens and vaccination have been proved to be effective in the Hong Kong Special Administrative Region (HKSAR) since 2002 despite endemicity and outbreaks in neighbouring regions. Systematic surveillance in southern China showed that ducks and geese are the primary reservoirs which transmit the virus to chickens, minor poultry and even migratory birds. Presentation of the hypothesis We hypothesize that this combination of moratorium, poultry segregation and targeted vaccination if successfully adapted to an affected district or province in any geographical region with high endemicity would set an example for the control in other regions. Testing the hypothesis A planned one-off moratorium of 3 weeks at the hottest month of the year should decrease the environmental burden as a source of re-infection. Backyard farms will then be re-populated by hatchlings from virus-free chickens and minor poultry only. Targeted immunization of the ducks and geese present only in the industrial farms and also the chickens would be strictly implemented as blanket immunization of all backyard poultry is almost impossible. Freely grazing ducks and geese would not be allowed until neutralizing antibodies of H5 subtype virus is achieved. As a proof of concept, a simple mathematical model with susceptible-infected-recovered (SIR) structure of coupled epidemics between aquatic birds (mainly ducks and geese) and chickens was used to estimate transmissibility within and between these two poultry populations. In the field the hypothesis is tested by prospective surveillance of poultry and immunocompetent patients hospitalized for severe pneumonia for the virus before and after the institution of these measures. Implications of the Hypothesis A combination of targeted immunization with the correct vaccine, segregation of poultry species and moratorium of poultry in addition to the present surveillance, biosecurity and hygienic measures at the farm, market and personal levels could be important in the successful control of the H5N1 virus in poultry and human for an extensive geographical region with continuing outbreaks. Alternatively a lesser scale of intervention at the district level can be considered if there is virus detection without evidence of excess poultry deaths since asymptomatic shedding is common in waterfowls.

Aims: To examine the population impact and economic costs associated with environmental tobacco smoke (ETS) in Chinese infants with non-smoking mothers. Methods: Prospective, population based birth cohort study in Hong [...]

Background: During the 2009 influenza A (H1N1) pandemic, household transmission studies were implemented to better understand the characteristics of the transmission of the novel virus in a confined setting.Methods: We conducted a systematic review and meta-analysis to assess and summarize the findings of these studies. We identified 27 articles, around half of which reported studies conducted in May and June 2009.Results: In 13 of the 27 studies (48%) that collected respiratory specimens from household contacts, point estimates of the risk of secondary infection ranged from 3% to 38%, with substantial heterogeneity. Meta-regression analyses revealed that a part of the heterogeneity reflected varying case ascertainment and study designs. The estimates of symptomatic secondary infection risk, based on 20 studies identifying febrile acute respiratory illness among household contacts, also showed substantial variability, with point estimates ranging from 4% to 37%.Conclusions: Transmission of the 2009 pandemic virus in households appeared to vary among countries and settings, with differences in estimates of the secondary infection risk also partly due to differences in study designs. [ABSTRACT FROM AUTHOR]

Background Early puberty often occurs in migrants from less to more economically developed locations, particularly among girls, perhaps because of mismatched inter-generational conditions. However, migrants may differ from their host population in many ways.Objective In an ethnically homogenous Chinese population in a developed environment, we examined the association of mother's growth environment (proxied by migration status) with age at onset of puberty. We assessed differences by sex and whether associations were independent of intra-uterine growth.Methods We used interval-censored survival analyses in 3832 boys and 3279 girls (follow-up rate of 92%) from the ‘Children of 1997’ birth cohort, comprising 88% of births in Hong Kong in April and May 1997, to examine the adjusted association of mother's migration status (born and raised in mainland China or in comparatively more developed Hong Kong), with clinically assessed age at onset of puberty (Tanner stage II for breast/genital and pubic hair development).Results Children with mothers from a less developed environment had earlier onset of breast/genital [time ratio (TR) 0.987, 95% confidence intervals (CIs) 0.980–0.993] and pubic hair (TR 0.993, 95% CI 0.986–1.000) development, independent of birth size for gestational age and socio-economic position, possibly with a more marked association in girls.Conclusion Mismatch of growth conditions between mothers and children was associated with younger age at onset of puberty. Given the association of early puberty with chronic diseases, inter-generational influences may be relevant to the emerging epidemics of these diseases in rapidly developing populations where age of puberty is declining sharply. [ABSTRACT FROM AUTHOR]

Background: Previous studies identifying associations between influenza and acute cardiac events may have been confounded by climatic factors. Differing seasonal patterns of influenza activity in Hong Kong and England and Wales provide a natural experiment to examine associations with myocardial infarction (MI) independent of cold weather effects.Methods: Weekly clinical and laboratory influenza surveillance data, environmental temperature and humidity data, and counts of MI-associated hospitalizations and deaths were obtained for England and Wales and for Hong Kong for the period 1998-2008. We used Poisson regression models that included environmental and seasonal variables to investigate the relationship between influenza and MI.Results: There were ≥1.2 million MI-associated hospitalizations and 410,204 MI-associated deaths in England and Wales, with a marked peak in the winter season. In Hong Kong, the incidence of MI, on the basis of 65,108 hospitalizations and 18,780 deaths, had a large winter and smaller summer peak, mirroring patterns of influenza activity. There was strong evidence for a link between influenza and MI both in England and Wales, where 3.1%-3.4% of MI-associated deaths (P < .001) and 0.7%-1.2% of MI-associated hospitalizations (P < .001) were attributable to influenza, and in Hong Kong, where the corresponding figures were 3.9%-5.6% (P = .018) and 3.0%-3.3% (P = .002).Conclusions: Influenza was associated with an increase in MI-associated deaths and hospitalizations in 2 contrasting settings. [ABSTRACT FROM AUTHOR]

PURPOSE: A high rate of infant growth may be associated with adult cardiovascular disease. We investigated factors associated with infant weight growth in a large sample from the recently transitioned population of Hong Kong. METHODS: We used a nonlinear shape invariant model with random effects among 5949 term, singletons (77% follow-up) from a population-representative Hong Kong Chinese birth cohort 'Children of 1997' to investigate factors associated with weight growth in the first year of life. RESULTS: Overall birth weight was lower but infant growth was more rapid than the 2006 WHO standards. Shorter gestation and lower birth order were associated with lower birth weight and faster infant growth. Female sex, maternal smoking in pregnancy, and a mother born in Hong Kong were associated with lower birth weight, but not with faster growth. Higher maternal education was associated with faster infant growth, grades 10-11 (1.03, 95% confidence interval [CI] = 1.03-1.05), greater than or equal to grade12 (1.07, CI = 1.04-1.09) compared with less than or equal to grade 9. CONCLUSIONS: Infant growth may respond more rapidly to socio-economic development than birth weight. Whether mother's education is associated with rapid infant growth via current conditions or her own 'constitution' is unclear, nevertheless we believe this study illustrates the importance of contextually specific research for understanding the determinants of population health. [ABSTRACT FROM AUTHOR]

Objective: Physical activity may modify the association of adiposity with type 2 diabetes. We investigated the independent and joint association of adiposity and physical activity with fasting plasma glucose, impaired fasting glucose, and type 2 diabetes in a Chinese population.Research Design and Methods: Middle-aged and older Chinese (n=28,946, ≥50 years, 72.4%women) from the Guangzhou Biobank Cohort Study were examined in 2003-2008. Multivariable regression was used in a cross-sectional analysis.Results: BMI, waist circumference, and waist-to-hip ratio (WHR) were positively associated with type 2 diabetes after multiple adjustment, most strongly for WHR with odds ratio (OR) of 3.99 (95% CI 3.60-4.42) for highest compared with lowest tertile. Lack of moderate-to-vigorous physical activity, but not walking, was associated with diabetes with an OR of 1.29 (1.17-1.41). The association of moderate-to-vigorous activity with fasting glucose varied with WHR tertiles (P=0.01 for interaction). Within the high WHR tertile, participants who had a lack of moderate-to-vigorous activity had an OR of 3.87 (3.22-4.65) for diabetes, whereas those who were active had an OR of 2.94 (2.41-3.59).Conclusions: In this population, WHR was a better measure of adiposity-related diabetes risk than BMI or waist circumference. Higher moderate-to-vigorous activity was associated with lower diabetes risk, especially in abdominally obese individuals. [ABSTRACT FROM AUTHOR]

BACKGROUND: Research on trends in cancer incidence has usually examined single sites in populations that long ago completed the economic transition. The trends in 11 cancers in three groups in the recently transitioned Hong Kong Chinese population were examined to delineate the effects of economic transition and provide generalised aetiological insights. METHODS: Sex-specific Poisson models were fitted to cancer incidence in Hong Kong (1974-2003) to examine age, period and birth cohort effects. Cancers were grouped as: hormonally modulated (including breast, endometrium, ovary and prostate), infection-related (cervix, liver, nasopharynx, lymphoma and stomach) and lifestyle-related (colorectum and lung). RESULTS: Age-standardised incidence of hormonally modulated female cancers increased for the first generation (women born approximately 1940) to experience puberty in the transitioning environment of Hong Kong. Prostate cancer incidence increased, despite a downturn for the first generation growing up in Hong Kong. Incidence of infection-related cancers decreased, mainly due to birth cohort effects; coinciding with birth for liver cancer and lymphoma, with reaching adulthood for cervical and male nasopharyngeal cancers, and with a generation for stomach cancer. Lifestyle-related cancers had sex-specific declines by birth cohort. CONCLUSION: With economic transition and the associated lifestyle changes, environmentally determined levels of pubertal female hormones may drive intergenerational increases in hormonally related female cancers. Economic development, via improved living conditions, may also reduce infection-related cancers, possibly including prostate cancer; however, the effects depend on transmission dynamics and perhaps specific public health initiatives. In traditional societies, males may benefit from economic development sooner than females. [ABSTRACT FROM AUTHOR]

Myxovirus resistance A (MxA) is an antiviral protein induced by interferon alpha and beta (IFN-alpha, IFN-beta) that can inhibit viral replication. The minor alleles of the -88G>T and -123C>A MxA promoter single-nucleotide polymorphisms (SNPs) are associated with increased promoter activity and altered response to IFN-alpha and IFN-beta treatment. Here, we demonstrate that the -123A minor allele provided stronger binding affinity to nuclear proteins extracted from IFN-beta-untreated cells than did the wild-type allele, whereas the -88T allele showed preferential binding after IFN-beta stimulation. Endogenous IFN-alpha and IFN-beta induction can be suppressed in severe acute respiratory syndrome (SARS) coronavirus infection. In support of our in vitro findings, a large case-control genetic-association study for SARS coronavirus infection confirmed that the -123A minor-allele carriers were significantly associated with lower risk of SARS coronavirus infection, whereas the -88T minor-allele carriers were insignificant after adjustment for confounding effects. This suggests that -123C>A plays a more important role in modulating basal MxA expression, thus contributing more significantly to innate immune response against viral infections that suppress endogenous IFN-alpha and IFN-beta induction such as SARS coronavirus. [ABSTRACT FROM AUTHOR]

BACKGROUND: Childhood adiposity in developed countries is often associated with lower socio-economic position (SEP) of the family and neighbourhood. However, the association of adiposity with SEP varies with national income. The authors examined whether childhood BMI was associated with family or neighbourhood socio-economic characteristics in a recently and rapidly developed Chinese population. METHODS: The authors used multilevel modelling in Hong Kong's population-representative 'Children of 1997' birth cohort (n=8327) to examine the association of BMI z-score and overweight (including obesity) at ages 6-11 years with parental education, mother's birthplace, sex and neighbourhood median income. RESULTS: In 7108 (85% successful follow-up) children, boys were more adipose than girls. The association of parental education with BMI z-score varied with mother's birthplace (p value for interaction 0.001). In children of Hong Kong-born mothers, parental education was negatively associated with BMI z-score (mean difference -0.15, 95% CI -0.25 to -0.05 for highest compared with lowest). However, in children of mainland China-born mothers, parental education was positively associated with BMI z-score (0.18, 95% CI 0.02 to 0.34 in the same comparison). Neighbourhood had no association with BMI z-score. CONCLUSIONS: In this recently developed Chinese population, there was no consistent association between socio-economic characteristics and childhood BMI. Other factors, such as experience of economic transition, as proxied by mother's place of birth, exerted a modifying impact. The cultural and biological mechanisms underlying these socio-historical intergenerational influences need to be determined, so that effective interventions can be implemented in China and elsewhere. [ABSTRACT FROM AUTHOR]

In June 2006, the Centers for Disease Control and Prevention released a request for applications to identify, improve, and evaluate the effectiveness of nonpharmaceutical interventions (NPIs)-strategies other than vaccines and antiviral medications-to mitigate the spread of pandemic influenza within communities and across international borders (RFA-CI06-010). These studies have provided major contributions to seasonal and pandemic influenza knowledge. Nonetheless, key concerns were identified related to the acceptability and protective efficacy of NPIs. Large-scale intervention studies conducted over multiple influenza epidemics, as well as smaller studies in controlled laboratory settings, are needed to address the gaps in the research on transmission and mitigation of influenza in the community setting. The current novel influenza A (H1N1) pandemic underscores the importance of influenza research. [ABSTRACT FROM AUTHOR]

SUMMARYInfluenza viruses circulate around the world every year. From time to time new strains emerge and cause global pandemics. Many national and international health agencies recommended the use of face masks during the 2009 influenza A (H1N1) pandemic. We reviewed the English-language literature on this subject to inform public health preparedness. There is some evidence to support the wearing of masks or respirators during illness to protect others, and public health emphasis on mask wearing during illness may help to reduce influenza virus transmission. There are fewer data to support the use of masks or respirators to prevent becoming infected. Further studies in controlled settings and studies of natural infections in healthcare and community settings are required to better define the effectiveness of face masks and respirators in preventing influenza virus transmission. [ABSTRACT FROM AUTHOR]

Background: Few data are available about the effectiveness of nonpharmaceutical interventions for preventing influenza virus transmission.Objective: To investigate whether hand hygiene and use of facemasks prevents household transmission of influenza.Design: Cluster randomized, controlled trial. Randomization was computer generated; allocation was concealed from treating physicians and clinics and implemented by study nurses at the time of the initial household visit. Participants and personnel administering the interventions were not blinded to group assignment. (ClinicalTrials.gov registration number: NCT00425893)Setting: Households in Hong Kong.Patients: 407 people presenting to outpatient clinics with influenza-like illness who were positive for influenza A or B virus by rapid testing (index patients) and 794 household members (contacts) in 259 households.Intervention: Lifestyle education (control) (134 households), hand hygiene (136 households), or surgical facemasks plus hand hygiene (137 households) for all household members.Measurements: Influenza virus infection in contacts, as confirmed by reverse-transcription polymerase chain reaction (RT-PCR) or diagnosed clinically after 7 days.Results: Sixty (8%) contacts in the 259 households had RT-PCR-confirmed influenza virus infection in the 7 days after intervention. Hand hygiene with or without facemasks seemed to reduce influenza transmission, but the differences compared with the control group were not significant. In 154 households in which interventions were implemented within 36 hours of symptom onset in the index patient, transmission of RT-PCR-confirmed infection seemed reduced, an effect attributable to fewer infections among participants using facemasks plus hand hygiene (adjusted odds ratio, 0.33 [95% CI, 0.13 to 0.87]). Adherence to interventions varied.Limitation: The delay from index patient symptom onset to intervention and variable adherence may have mitigated intervention effectiveness.Conclusion: Hand hygiene and facemasks seemed to prevent household transmission of influenza virus when implemented within 36 hours of index patient symptom onset. These findings suggest that nonpharmaceutical interventions are important for mitigation of pandemic and interpandemic influenza.Primary Funding Source: Centers for Disease Control and Prevention. [ABSTRACT FROM AUTHOR]

BACKGROUND: In observational studies, mainly from Western Caucasian populations, moderate alcohol use has been shown to be associated with a lower risk of diabetes. However, whether the protection is due to the attributes of alcohol or to those of moderate alcohol users is difficult to disentangle. A population with a different distribution of alcohol consumption and diabetes prevalence from Western populations was studied as a counterfactual comparison. METHODS: Baseline data from the Guangzhou Biobank Cohort Study phases 1 and 2 (2003-6) were used to examine the adjusted associations, using multivariable censored linear regression, of alcohol use with fasting blood glucose in older (> or =50 years) men (n = 5740) and women (n = 14 274) from southern China. Moderate alcohol use was defined as weekly drinking of < or =210 g alcohol in men and < or =140 g in women. The expected associations of alcohol with high-density lipoprotein (HDL) cholesterol and blood pressure were also checked. RESULTS: Moderate alcohol users had very similar fasting glucose levels to never users, adjusted for age, sex, socioeconomic status, smoking and physical activity. In contrast, moderate alcohol users had higher HDL-cholesterol by 0.05 mmol/litre (95% CI 0.02 to 0.07). Excessive (more than moderate) alcohol users had higher fasting glucose. CONCLUSIONS: In an understudied population with a different pattern of alcohol use from the populations usually studied, the biologically expected effects of moderate alcohol use were seen, but there was little effect on fasting glucose. Although cross-sectional studies cannot be conclusive, this pattern of findings, if confirmed, suggests that moderate alcohol use may not affect fasting glucose, although excessive use may be a risk factor. [ABSTRACT FROM AUTHOR]

BACKGROUND: Inappropriate use of antibiotics is one of the important factors attributing to emergence of drug-resistant pathogens. Infection with multidrug-resistant pathogens adversely affects quality of medical care. CONTEXT: Queen Elizabeth Hospital, an 1800-bed acute service hospital in Hong Kong. Antibiotics are commonly prescribed for treating acute infections. KEY MEASURES FOR IMPROVEMENT: Reduce inappropriate prescription of broad-spectrum antibiotics and overall antibiotic prescription through implementation of a multidisciplinary antibiotics stewardship programme (ASP). STRATEGIES FOR CHANGE: A multidisciplinary programme involving policy and guideline formulation, education and feedback, monthly antibiotic consumption and cost monitoring, antimicrobial susceptibility pattern reporting and concurrent feedbacks for commonly prescribed broad-spectrum antibiotics was implemented in 2004. Predefined logistics to prescribe 'restricted' antibiotics were formulated and implemented with collaborative efforts from clinical and non-clinical departments. The programme was supported by management at department and hospital levels. EFFECTS OF CHANGE: Broad-spectrum antibiotics were prescribed inappropriately in 28.9% (n = 192) clinical scenarios. The ASP reduced the restricted and total antibiotic consumption as well as the antibiotics-related costs. Predefined clinical outcomes were not adversely affected. Economic analysis suggested that the extra human cost in running ASP could be offset by savings from antibiotic expenditure. LESSONS LEARNED: It is cost-effective to implement a multidisciplinary ASP in acute service hospitals as the programme reduces antibiotic consumption and results in overall cost savings. The quality of medical care is not jeopardized as the important clinical outcomes are not adversely affected. The generalisability and sustainability of ASPs in other clinical contexts warrant further studies to ensure the continuous success of this programme. [ABSTRACT FROM AUTHOR]

BACKGROUND: Second-hand smoke (SHS) exposure is a modifiable cause of ill health. Despite the smoking ban in public places introduced in Hong Kong in 2007, infants and children continue to be exposed within the home. AIMS: To determine the critical windows of SHS exposure and the duration of its impact on serious infectious morbidity in the first 8 years of life. METHODS: The Hong Kong 'Children of 1997' birth cohort is a prospective, population-based study of 8327 children comprising 88% of all births in April and May 1997, of whom 7402 (89%) were followed up until their eighth birthday in 2005. We used multivariable Cox regression to assess the relation between postnatal SHS exposure and risk of first admission to public hospitals (together accounting for >95% total bed-days overall) for respiratory, other and all infections from birth to 8 years of age, for all individuals and for vulnerable subgroups. RESULTS: Overall, household SHS exposure within 3 metres in early life was associated with a higher risk of admission for infectious illness up until 8 years of age (hazard ratio 1.14, 95% CI 1.00 to 1.31), after adjustment for sex, birthweight, gestational age, feeding method, maternal age, highest parental education and proxies of preferred service sector. The association was strongest in the first 6 months of life (HR 1.45, 95% CI 1.15 to 1.83). In vulnerable subgroups such as premature babies, the association held through to 8 years of age (HR 2.00, 95% CI 1.08 to 3.72). Infants exposed to SHS in the first 3 months of life were most vulnerable to infectious causes of hospitalisation. CONCLUSION: Household SHS exposure in early infancy increases severe infectious morbidity requiring hospital admission. Reducing SHS exposure in infants and particularly in more vulnerable infants will lower the bed-days burden due to infectious causes. [ABSTRACT FROM AUTHOR]

The extensive data collection and contact tracing that occurred during the 2003 outbreak of severe acute respiratory syndrome (SARS) in Hong Kong, China, allowed the authors to examine how the probability of transmission varied from the date of symptom onset to the date of hospitalization for household contacts of SARS patients. Using a discrete-time likelihood model, the authors estimated the transmission probability per contact for each day following the onset of symptoms. The results suggested that there may be two peaks in the probability of SARS transmission, the first occurring around day 2 after symptom onset and the second occurring approximately 10 days after symptom onset. Index patients who were aged 60 years or older or whose lactate dehydrogenase level was elevated upon admission to the hospital (indicating higher viral loads) were more likely to transmit SARS to their contacts. There was little variation in the daily transmission probabilities before versus after the introduction of public health interventions on or around March 26, 2003. This study suggests that the probability of transmission of SARS is dependent upon characteristics of the index patients and does not simply reflect temporal variability in the viral load of SARS cases. [ABSTRACT FROM AUTHOR]

BACKGROUND: Although the harms of smoking are well established, it is unclear how they extend into old age in the Chinese. AIM: To examine the relationship of smoking with all-cause and major cause-specific mortality in elderly Chinese men and women, respectively, in Hong Kong. METHODS: Mortality by smoking status was examined in a prospective cohort study of 56,167 (18,749 men, 37,416 women) Chinese aged > or = 65 years enrolled from 1998 to 2000 at all the 18 elderly health centres of the Hong Kong Government Department of Health. RESULTS: After a mean follow-up of 4.1 years, 1848 male and 2035 female deaths occurred among 54,214 subjects (96.5% successful follow-up). At baseline, more men than women were current smokers (20.3% vs 4.0%) and former smokers (40.8% vs 7.9%). The adjusted RRs (95% CI) for all-cause mortality in former and current smokers, compared with never smokers, were 1.39 (1.23 to 1.56) and 1.75 (1.53 to 2.00) in men and 1.43 (1.25 to 1.64) and 1.38 (1.14 to 1.68) in women, respectively. For current smokers, the RRs (95% CI) for all-cause mortality were 1.59 (1.39 to 1.82), 1.72 (1.48 to 2.00) and 1.84 (1.43 to 2.35) for daily consumption of 1-9, 10-20 and > 21 cigarettes, respectively (p for trend <0.001). RRs (95% CI) were 1.49 (1.30 to 1.72) and 2.20 (1.88 to 2.57) in former and current smokers for all deaths from cancer, and 1.24 (1.04 to 1.47) and 1.57 (1.28 to 1.94) for all cardiovascular deaths, respectively. Quitters had significantly lower risks of death than current smokers from all causes, lung cancer, all cancers, stroke and all cardiovascular diseases. CONCLUSIONS: In old age, smoking continues to be a major cause of death, and quitting is beneficial. Smoking cessation is urgently needed in rapidly ageing populations in the East. [ABSTRACT FROM AUTHOR]