Tai Hing Lam

The University of Hong Kong, Hong Kong, Hong Kong

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Publications (298)1354.6 Total impact

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    ABSTRACT: The numbers of women smoking have risen 72.5% since 1990 with the increasing population - from 56,100 to 96,800 in 2012, reflecting an alarming situation in Hong Kong. The study aimed to describe the smoking behaviour, attitudes and associated factors among women in Hong Kong. A qualitative cross-sectional study involving semi-structured interview was conducted with Chinese women from five community centres in different districts in Hong Kong in 2010. A purposive sample of 73 female participants (24 current smokers, 20 ex-smokers and 29 never-smokers) were recruited. The 73 women were classified by their smoking status and age to form 15 focus groups. Most informants knew about the general health hazards of smoking, such as cancer and heart or respiratory diseases, but not about the female-specific health consequences of smoking. A few smokers considered smoking to be a weight control strategy, fearing a gain in weight if they gave up. Moreover, a few relied on smoking as a coping strategy to relieve negative emotions and stress. Additionally, a few smokers had misconceptions about giving up: that a loss of concentration would result, that continued smoking would not further affect their health as they had become desensitised to the chemicals in tobacco smoke or that quitting would harm their health. This study generates new knowledge about the behavior, attitudes, and experiences related to smoking of current female smokers, ex-smokers and non-smokers in Hong Kong, which is unique as a Chinese but highly westernized community but with a very low female smoking prevalence.
    BMC Public Health 12/2015; 15(1):1529. DOI:10.1186/s12889-015-1529-4 · 2.32 Impact Factor
  • Journal of the American College of Cardiology 08/2015; 66(5):592-593. DOI:10.1016/j.jacc.2015.05.048 · 15.34 Impact Factor
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    ABSTRACT: Western observational studies show that moderate alcohol use is associated with lower cardiovascular disease (CVD) risk, but these associations may be confounded by the healthier attributes of moderate users in these settings. Mendelian randomization analysis may help to ascertain the causal effect of moderate alcohol use on specific factors related to CVD and thereby clarify the role of alcohol. We used Mendelian randomization analysis with the aldehyde dehydrogenase 2 gene (ALDH2) as an instrumental variable to examine the association of alcohol units (10 g of ethanol) per day with heart rate-corrected QT interval and heart rate assessed from electrocardiogram among 4,588 older southern Chinese men in the Guangzhou Biobank Cohort Study (2003-2008). The F statistic was 77 for ALDH2 on alcohol use, suggesting little weak-instrument bias. Instrumental variable analysis showed that alcohol units were not associated with the corrected QT interval, with β = 1.04 (95% confidence interval: -0.61, 2.70) milliseconds, but they were associated with increased heart rate, with β = 0.98 (95% confidence interval: 0.04, 1.92) beat per minute. This study suggests that moderate alcohol use in men is not beneficial for heart function via QT interval or heart rate but could be detrimental. Future studies using specific cardiovascular outcomes may elucidate how alcohol affects different aspects of the cardiovascular system and, hence, the overall effects of alcohol on CVD can be estimated. © The Author 2015. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
    American journal of epidemiology 07/2015; DOI:10.1093/aje/kwv069 · 4.98 Impact Factor
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    ABSTRACT: Background Diabetes has been defined on the basis of different bio-markers, including fasting plasma glucose (FPG), 2-h plasma glucose in an oral glucose tolerance test (2hOGTT), and HbA1c. We assessed the effect of different diagnostic definitions on both the population prevalence of diabetes and the classification of previously undiagnosed individuals as having diabetes versus not having diabetes in a pooled analysis of data from population-based health examination surveys in different regions. Methods We used data from 96 population-based health examination surveys that had measured at least two of the bio-markers used for defining diabetes. Diabetes was defined using HbA1c (HbA1c ≥6·5% or history of diabetes diagnosis or using insulin or oral hypoglycemic drugs) compared with either FPG only or FPG-or-2hOGTT definitions (FPG ≥7·0 mmol/L or 2hOGTT ≥11·1 mmol/L or history of diabetes or using insulin or oral hypoglycemic drugs). We calculated diabetes prevalence, taking into account complex survey design and survey sample weights. We compared the prevalences of diabetes using different definitions graphically and by regression analyses. We calculated sensitivity and specificity of diabetes diagnosis based on HbA1c compared with diagnosis based on glucose among previously undiagnosed individuals (i.e., excluding those with history of diabetes or using insulin or oral hypoglycemic drugs). We calculated sensitivity and specificity in each survey, and then pooled results using a random-effects model. We assessed the sources of heterogeneity of sensitivity by meta-regressions for study characteristics selected a priori. Findings Population prevalence of diabetes based on FPG-or-2hOGTT was correlated with prevalence based on FPG alone (r=0·98), but was higher by 2–6 percentage points at different prevalence levels. Prevalence based on HbA1c was lower than prevalence based on FPG in 42·8% of age–sex–survey groups and higher in another 41·6%; in the other 15·6%, the two definitions provided similar prevalence estimates. The variation across studies in the relation between glucose-based and HbA1c-based prevalences was partly related to participants' age, followed by natural logarithm of per person gross domestic product, the year of survey, mean BMI, and whether the survey population was national, sub-national, or from specific communities. Diabetes defined as HbA1c 6·5% or more had a pooled sensitivity of 52·8% (95% CI 51·3–54·3%) and a pooled specificity of 99·74% (99·71–99·78%) compared with FPG 7·0 mmol/L or more for diagnosing previously undiagnosed participants; sensitivity compared with diabetes defined based on FPG-or-2hOGTT was 30·5% (28·7–32·3%). None of the preselected study-level characteristics explained the heterogeneity in the sensitivity of HbA1c versus FPG. Interpretation Different biomarkers and definitions for diabetes can provide different estimates of population prevalence of diabetes, and differentially identify people without previous diagnosis as having diabetes. Using an HbA1c-based definition alone in health surveys will not identify a substantial proportion of previously undiagnosed people who would be considered as having diabetes using a glucose-based test.
    The Lancet Diabetes & Endocrinology 06/2015; DOI:10.1016/S2213-8587(15)00129-1 · 9.19 Impact Factor
  • Man Ping Wang · Sai Yin Ho · Lok Tung Leung · Tai Hing Lam
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    ABSTRACT: Electronic cigarettes (e-cigarettes) are increasingly used in adolescents with unknown impacts on conventional cigarette smoking. We examined the associations of e-cigarette use with smoking intention, nicotine addiction and smoking cessation in Chinese adolescents. A total of 45,128 students (age 14.6±1.9; boys 51.4%) from 75 randomly selected schools in Hong Kong reported e-cigarette use (in the past 30days), conventional cigarette use and socio-demographic characteristics in an anonymous questionnaire survey. Adjusted odds ratios (AORs) of intention to smoke, morning smoking urge, intention to quit and quit attempts; and beta-coefficient (β) of cigarette consumption per day were calculated in relation to e-cigarette use. E-cigarette use was associated with intention to smoke with an AOR (95% CI) of 1.74 (1.30-2.31) in all students, 2.18 (1.12-4.23) in never and 2.79 (2.05-3.79) in ever smokers (non-significant interaction by smoking status). The associations were also significant in experimental and former smokers but not in current smokers. In current smokers, e-cigarette use was significantly associated with heavier smoking (β 2.54, 95% CI 1.28-3.81) and morning smoking urge (AOR 2.54, 95% CI 1.50-3.11), and non-significantly associated with lower quit intention (0.76, 0.52-1.09) and attempts (0.80, 0.56-1.23). E-cigarette use was associated with smoking intention in never, experimental and former smokers in Hong Kong Chinese adolescents. In current smokers, e-cigarette use was associated with nicotine addiction but not quit intention and attempts. Prospective studies with detailed measurements on e-cigarette use are warranted for further studies. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Addictive behaviors 06/2015; 50:124-127. DOI:10.1016/j.addbeh.2015.06.037 · 2.44 Impact Factor
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    ABSTRACT: There is a shortage of culturally appropriate, brief, preventive interventions designed to be sustainable and acceptable for community participants in nonwestern cultures. Parents' ability to regulate their emotions is an important factor for psychological well-being of the family. In Chinese societies, emotional regulation may be more important in light of the cultural desirability of maintaining harmonious family relationships. The objectives of our randomized controlled trial were to test the effectiveness of our Effective Parenting Programme (EPP) to increase the use of emotional management strategies (primary outcome) and enhance the parent-child relationship (secondary outcome). We utilized design characteristics that promoted recruitment, retention, and intervention sustainability. We randomized a community sample of 412 Hong Kong middle- and low-income mothers of children aged 6-8 years to the EPP or attention control group. At 3, 6 and 12- month follow up, the Effective Parent Program group reported greater increases in the use of emotion management strategies during parent-child interactions, with small to medium effect size, and lower negative affect and greater positive affect, subjective happiness, satisfaction with the parent-child relationship, and family harmony, compared to the control group, with small to medium effect size. Our results provided evidence of effectiveness for a sustainable, preventive, culturally appropriate, cognitive behaviorally-based emotion management program, in a non-clinical setting for Chinese mothers. HKCTR-1190. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Behaviour Research and Therapy 06/2015; 71. DOI:10.1016/j.brat.2015.05.011 · 3.85 Impact Factor
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    ABSTRACT: Observationally, testosterone is negatively associated with systemic inflammation, but this association is open to both residual confounding and reverse causality. Large-scale randomized controlled trials (RCTs), assessing exogenous effects, are presently unavailable. We examined the association of endogenous testosterone with well-established systemic inflammatory markers (white blood cell, granulocyte, lymphocyte and high-sensitivity C-reactive protein (hsCRP)) using a separate-sample Mendelian randomization analysis to minimize reverse causality. A genetic prediction rule for serum testosterone was developed in 289 young Chinese men with mean age of 21.0, using selected testosterone-related SNPs (rs10046, rs1008805 and rs1256031). Multivariable linear regression was used to examine the association of genetically predicted serum testosterone with inflammatory markers among 4,212 older Chinese men from the Guangzhou Biobank Cohort Study. Genetically predicted testosterone was unrelated to white blood cell count (-0.01 109/L per nmol/L testosterone, 95% confidence interval (CI) -0.05 to 0.04), granulocyte count (-0.02 109/L, 95% CI -0.06 to 0.02), lymphocyte count (0.005 109/L, 95% CI -0.01 to 0.02) and hsCRP (-0.05 mg/L, 95% CI -0.15 to 0.06). Our findings did not corroborate any anti-inflammatory effects of testosterone or corresponding potentially protective effects of testosterone on chronic diseases resulting from reduced low-grade systemic inflammation.
    PLoS ONE 05/2015; 10(5):e0126442. DOI:10.1371/journal.pone.0126442 · 3.23 Impact Factor
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    ABSTRACT: To investigate the smoking behaviours, perceptions about quitting smoking and factors associated with intention to quit in patients with type 2 diabetes mellitus. Smoking causes type 2 diabetes mellitus. There has been limited research on the needs and concerns of smokers with type 2 diabetes mellitus about quitting smoking. The study used a qualitative design. Patients diagnosed with type 2 diabetes mellitus who had a history of smoking were recruited at the outpatient diabetic clinics of two major local hospitals in Hong Kong for a semi-structured interview (n = 42), guided by the theory of planned behaviour. At data saturation, 22 current smokers and 20 ex-smokers with type 2 diabetes mellitus were recruited. The current smokers reported they had not quit smoking because of satisfaction with present health status, and misconceptions about the association between diabetes and smoking, and the perceived hazards of quitting. In contrast, ex-smokers had a positive opinion about quitting smoking, accepted advice about quitting from health professionals and received more family support than current smokers. Psychological addiction and weight gain after cessation made quitting challenging. Satisfaction with health status, inadequate knowledge about the relationship between type 2 diabetes mellitus and smoking, and misconceptions about quitting smoking resulted in negative attitudes toward quitting by type 2 diabetes mellitus smokers. Smoking peers, psychological addiction and post-cessation weight gain hindered the quitting process. Education on the causal link between smoking, type 2 diabetes mellitus and its complications is important to raise health awareness and counter misconceptions about quitting smoking. Behavioural counselling with weight control strategies should be part of a comprehensive smoking cessation intervention for type 2 diabetes mellitus smokers. © 2015 John Wiley & Sons Ltd.
    Journal of Clinical Nursing 05/2015; DOI:10.1111/jocn.12854 · 1.26 Impact Factor
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    ABSTRACT: Tobacco use is one of the most common preventable causes of death, but more than half of the Chinese men still use tobacco products. Moreover, 63.6% of Chinese smokers have stated that they would not consider quitting. Specialized and intensive smoking-cessation services are too expensive and passive to have major clinical and public health impacts in developing countries like China. Smoking cessation medications are not covered by medical insurance, and their high price prevents Chinese smokers from using them. Brief interventions are needed to provide cost-effective and timesaving tobacco dependence treatments in China mainland. We describe a two-arm randomized controlled trial for smokers who have no intention to quit. The project will be conducted in outpatient clinics at a large hospital in Beijing, China. Both arms include one face-to-face interview plus five follow-up interventions. Each intervention will last approximately one minute. Subjects allocated to the smoking-reduction intervention arm (SRI) will be advised to reduce smoking consumption to at least half of their current consumption level within the next month. All subjects in the SRI will be warned to bear in mind that an attempt to reduce smoking is an intermediate step before complete cessation. Smokers who have successfully reduced their smoking consumption will be encouraged to completely cease smoking. Controls are subjects allocated to the exercise- and diet-advice arm (EDA) and will be given advice about healthy diet and physical activity, but the advice will not include smoking cessation or reduction. Data collection will be done at baseline and at each follow-up interview using standardized questionnaires. The primary outcomes include self-reported and biochemically verified 7-day point prevalence and prolonged abstinence rates at 12-month follow-up. We expect that an intention to quit in smoking outpatients can be motivated by physicians in the clinic setting. If this very brief smoking-reduction intervention can be demonstrated to have a positive impact on long-term smoking cessation, this strategy has the potential to be a viable and acceptable approach and may be used widely in China and elsewhere. ClinicalTrials.gov: NCT02370147 (date of registration: 23th February, 2015).
    BMC Public Health 04/2015; 15(1):418. DOI:10.1186/s12889-015-1749-7 · 2.32 Impact Factor
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    ABSTRACT: The prevalence and correlates of hardcore smokers, who have high daily cigarette consumption, no quitting history and no intention to quit, have been studied in several western developed countries, but no previous trials of smoking cessation have tested intervention effectiveness for these smokers. The current study examined if hardcore smokers can benefit from smoking reduction intervention to achieve cessation, and explored the underlying reasons. A posteriori analysis was conducted on data from a randomized controlled trial of smoking reduction intervention on 1,154 smokers who did not want to quit. Odds ratios of 7-day point prevalence of abstinence, smoking reduction by at least 50% and quit attempt at the 6-month follow-up comparing subgroups of smokers were analyzed. In hardcore smokers, the odds ratio comparing the quit rate between the intervention and control group was 4.18 (95% CI: 0.51-34.65), which was greater than non-hardcore smokers (OR = 1.58, 95% CI: 0.98-2.54). The number needed to treat for hardcore and non-hardcore smokers was 8.33 (95% CI: 5.56-16.67) and 16.67 (95% CI: 8.33-233.64), respectively. In smokers who did not have quit attempt experience and those who smoked more than 15 cigarettes daily, the odds ratio comparing intervention and control group was 3.29 (95% CI: 0.72-14.98) and 1.36 (95% CI: 0.78-2.36), respectively. The a posteriori analysis provided pilot results that smoking reduction intervention may be effective to help hardcore smokers to quit and reduce smoking. Having no previous quit attempt was identified as more important than having large cigarette consumption in explaining the greater effectiveness of the intervention.
    Tobacco Induced Diseases 04/2015; 13(1):9. DOI:10.1186/s12971-015-0034-y · 1.50 Impact Factor
  • The Journal of Positive Psychology 03/2015; DOI:10.1080/17439760.2015.1025421 · 1.67 Impact Factor
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    ABSTRACT: Parental alcohol-related practices are important risk factors of adolescent drinking, but little is known about the factors associated with these parental pro-drinking practices (PPDPs). We investigated the correlates of 9 PPDPs in drinking parents of adolescents in Hong Kong. A total of 2200 students (age 14.8±2.0; boys 63.2%) participated in a school-based cross-sectional survey in 2012. Analysis was restricted to 1087 (61.8%) students with at least 1 drinking parent as PPDPs were much more common in these families. Logistic regression was used to identify correlates of each PPDP. Among 1087 students, the prevalence of PPDPs ranged from 8.2% for training drinking capacity to 65.7% for seeing parents drink. Only 14.8% of students had not experienced any of these practices. More frequent maternal drinking predicted parental training of drinking capacity. Older age predicted helping parents buy alcohol and parental encouragement of drinking. Adolescent girls were more likely to have received parental training of drinking capacity than boys. Higher perceived family affluence was associated with hearing parents saying benefits of drinking, and helping parents open bottle and pour alcohol. PPDPs were associated with parental drinking frequency and various socio-demographic factors. These results have implications on alcohol control programmes involving parents to tailor messages for reducing PPDPs based on the characteristics of adolescents and parents.
    PLoS ONE 03/2015; 10(3):e0119554. DOI:10.1371/journal.pone.0119554 · 3.23 Impact Factor
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    Lai Ming Ho · Man Ping Wang · Sai Yin Ho · Tai Hing Lam
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    ABSTRACT: Weight change predicted diseases and mortality. We investigate 3-year changes in individual body mass index (BMI) and waist circumference in Hong Kong Chinese adults. In the Population Health Survey, 7084 adults in 2003 (baseline) were followed up in 2006. Longitudinal anthropometric data were available in 2941 (41.5%) for BMI and 2956 for waist circumference. Weight status and central obesity were based on objectively measured BMI and waist circumference using Asian standards. Mean BMI (SD) increased from 22.8 (3.62) to 23.1 (3.95) (p<0.001) with 1.3 percentage point increase in prevalence of overweight and obesity (from 44.3% to 45.6%). One in 5 (22.0%) normal or underweight baseline respondents became overweight or obese and a similar proportion (24.8%) of overweight and obese respondents became normal or underweight. Prevalence of central obesity increased from 28.3% to 32.4% (p<0.001) with a non-significantly greater increase in women (30.0% to 38.1%) than men (23.0% to 26.1%) (p=0.63). A higher proportion of centrally obese respondents returned to normal (29.4%) than normal respondents developing central obesity (17.4%). This is one of the few studies in Chinese, which found dynamic longitudinal changes (increase/stable/decrease) in individual weight status and waist circumference. Future studies with better follow-up and investigating the causes of such changes are warranted.
    PLoS ONE 03/2015; 10(3):e0119827. DOI:10.1371/journal.pone.0119827 · 3.23 Impact Factor
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    ABSTRACT: In Western countries, lower socioeconomic status is associated with a higher risk of cardiovascular disease (CVD) and premature mortality. These associations may plausibly differ in Asian populations, but data are scarce and direct comparisons between the two regions are lacking. We, thus, aimed to compare such associations between Asian and Western populations in a large collaborative study, using the highest level of education attained as our measure of social status. Cohort studies in general populations conducted in Asia or Australasia. 303 036 people (71% from Asia) from 24 studies in the Asia Pacific Cohort Studies Collaboration. Studies had to have a prospective cohort study design, have accumulated at least 5000 person-years of follow-up, recorded date of birth (or age), sex and blood pressure at baseline and date of, or age at, death during follow-up. We used Cox regression models to estimate relationships between educational attainment and CVD (fatal or non-fatal), as well as all-cause, cardiovascular and cancer mortality. During more than two million person-years of follow-up, 11 065 deaths (3655 from CVD and 4313 from cancer) and 1809 CVD non-fatal events were recorded. Adjusting for classical CVD risk factors and alcohol drinking, hazard ratios (95% CIs) for primary relative to tertiary education in Asia (Australasia) were 1.81 (1.38, 2.36) (1.10 (0.99, 1.22)) for all-cause mortality, 2.47(1.47, 4.17) (1.24 (1.02, 1.51)) for CVD mortality, 1.66 (1.00, 2.78) (1.01 (0.87, 1.17)) for cancer mortality and 2.09 (1.34, 3.26) (1.23 (1.04, 1.46)) for all CVD. Lower educational attainment is associated with a higher risk of CVD or premature mortality in Asia, to a degree exceeding that in the Western populations of Australasia. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
    BMJ Open 03/2015; 5(3):e006408. DOI:10.1136/bmjopen-2014-006408 · 2.06 Impact Factor
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    ABSTRACT: The FAMILY Cohort is a longitudinal study of health, happiness and family harmony (the '3Hs') at individual, household and neighbourhood levels in Hong Kong. Using a family living in the same household as the sampling unit, the study (n = 20 279 households and 46 001 participants) consists of a composite sample from several sources, including: a population-representative random core sample (n = 8115 households and 19 533 participants); the first-degree relatives of this sample (n = 4658 households and 11 063 participants); and oversampling in three new towns (n = 2891 households and 7645 participants) and in three population subgroups with anticipated changes in family dynamics (n = 909 households and 2160 participants). Two household visits and five telephone- or web-based follow-ups were conducted over 2009-14. Data collected include socio-demographics, anthropometrics, lifestyle and behavioural factors, measures of social capital, and standardized instruments assessing the 3Hs. We also intend to collect biomaterials in future. The analytical plan includes multilevel inter-relations of the 3Hs for individuals, households, extended families and neighbourhoods. With Hong Kong's recent history of socioeconomic development, the FAMILY Cohort is therefore relevant to global urban populations currently experiencing similarly rapid economic growth. The FAMILY Cohort is currently set up as a supported access resource. © The Author 2015; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.
    International Journal of Epidemiology 01/2015; DOI:10.1093/ije/dyu257 · 9.20 Impact Factor
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    ABSTRACT: Estimates of illicit cigarette consumption are limited and the data obtained from studies funded by the tobacco industry have a tendency to inflate them. This study aimed to validate an industry-funded estimate of 35.9% for Hong Kong using a framework taken from an industry-funded report, but with more transparent data sources. Illicit cigarette consumption was estimated as the difference between total cigarette consumption and the sum of legal domestic sales and legal personal imports (duty-free consumption). Reliable data from government reports and scientifically valid routine sources were used to estimate the total cigarette consumption by Hong Kong smokers and legal domestic sales in Hong Kong. Consumption by visitors and legal duty-free consumption by Hong Kong passengers were estimated under three scenarios for the assumptions to examine the uncertainty around the estimate. A two-way sensitivity analysis was conducted using different levels of possible undeclared smoking and under-reporting of self-reported daily consumption. Illicit cigarette consumption was estimated to be about 8.2-15.4% of the total cigarette consumption in Hong Kong in 2012 with a midpoint estimate of 11.9%, as compared with the industry-funded estimate of 35.9% of cigarette consumption. The industry-funded estimate was inflated by 133-337% of the probable true value. Only with significant levels of under-reporting of daily cigarette consumption and undeclared smoking could we approximate the value reported in the industry-funded study. The industry-funded estimate inflates the likely levels of illicit cigarette consumption. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
    Tobacco Control 01/2015; 24(e2). DOI:10.1136/tobaccocontrol-2014-051937 · 5.15 Impact Factor
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    ABSTRACT: We examined how quantity and trajectory of smoking reduction influence later abstinence in smokers without intention to quit and being prescribed free nicotine replacement therapy (NRT).
    01/2015; 2:196-201. DOI:10.1016/j.pmedr.2015.02.014
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    ABSTRACT: QT interval prolongation, a predictor of cardiac arrhythmias, and elevated heart rate are associated with higher risk of cardiovascular mortality. Observationally testosterone is associated with shorter corrected QT interval and slower heart rate; however, the evidence is open to residual confounding and reverse causality. We examined the association of testosterone with electrocardiogram (ECG) parameters using a separate-sample instrumental variable (SSIV) estimator. To minimize reverse causality, a genetic score predicting testosterone was developed in 289 young Chinese men from Hong Kong, based on a parsimonious set of single nuclear polymorphisms (rs10046, rs1008805 and rs1256031). Linear regression was used to examine the association of genetically predicted testosterone with QT interval, corrected QT interval [using the Framingham formula (QTf) and Bazett formula (QTb)] and heart rate in 4212 older (50+ years) Chinese men from the Guangzhou Biobank Cohort Study. Predicted testosterone was not associated with QT interval [-0.08 ms per nmol/l testosterone, 95% confidence interval (CI) -0.81 to 0.65], QTf interval (0.40 ms per nmol/l testosterone, 95% CI -0.12 to 0.93) or heart rate (0.26 beats per minute per nmol/l testosterone, 95% CI -0.04 to 0.56), but was associated with longer QTb interval (0.66 ms per nmol/l testosterone, 95% CI 0.02 to 1.31). Our findings do not corroborate observed protective associations of testosterone with QT interval or heart rate among men, but potentially suggest effects in the other direction. Replication in a larger sample is required. © The Author 2014; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.
    International Journal of Epidemiology 12/2014; 44(2). DOI:10.1093/ije/dyu241 · 9.20 Impact Factor
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    ABSTRACT: Previous cross-sectional studies showed that short or long sleep duration was associated with memory impairment (MI), but longitudinal studies are scarce. We examined whether sleep duration was associated with memory decline or development of MI.
    Sleep 10/2014; DOI:10.5665/sleep.4162 · 5.06 Impact Factor

Publication Stats

4k Citations
1,354.60 Total Impact Points


  • 1996–2015
    • The University of Hong Kong
      • • School of Public Health
      • • Department of Community Medicine
      Hong Kong, Hong Kong
  • 2014
    • University of Queensland
      • School of Population Health
      Brisbane, Queensland, Australia
  • 2013
    • City University of Hong Kong
      Chiu-lung, Kowloon City, Hong Kong
  • 2006–2012
    • University of Birmingham
      • Department of Public Health, Epidemiology and Biostatistics
      Birmingham, ENG, United Kingdom
  • 2010
    • Queen Mary Hospital
      Hong Kong, Hong Kong
  • 2008
    • Hong Kong SAR Government
      Hong Kong, Hong Kong
  • 2007
    • The Chinese University of Hong Kong
      • Department of Medicine and Therapeutics
      Hong Kong, Hong Kong
    • Yonsei University
      Sŏul, Seoul, South Korea
    • The George Institute for Global Health
      • Renal and Metabolic Division
      Sydney, New South Wales, Australia
  • 2003
    • Isfahan University of Medical Sciences
      • Epidemiology and Biostatistics Department
      Isfahan, Ostān-e Eşfahān, Iran
  • 2000–2002
    • The University of Hong Kong - Shenzen Hospital
      Hong Kong, Hong Kong