PubMed Health⌕ Search

Biomedical subjects

Tai-Hing Lam

Publications and source records attributed to Tai-Hing Lam.

At least 37 records · Page 2Linked to original sources
PubMed2004

Smoking, drinking and colorectal cancer in Hong Kong Chinese: a case-control study.

Expert opinions differ on the causal role of cigarettes and alcohol in colorectal cancer. This study investigates such associations in Hong Kong Chinese. A hospital-based case-control study was conducted from April 1998 to March 2000. Newly diagnosed colorectal adenocarcinoma and sex- and age-matched inpatient controls without gastrointestinal and malignant conditions were included. Structured interviews were conducted using a validated questionnaire to study any association of smoking, drinking and the lifelong extent of such exposures with colorectal cancer risk. We successfully interviewed 822 cases and 926 controls. Current regular cigarette smokers had an increased rectal cancer risk (adjusted OR = 1.44; 95% CI = 1.001-2.06). Increasing tertiles of smoking duration in ever smokers was also associated with increased rectal cancer risk (p trend = 0.038). An increased risk of colorectal cancer was found in current drinkers (adjusted OR = 1.42; 95% CI = 1.09-1.85) and in those who drank > or = 4 days (current and ex-drinkers) or > 4 units (ever and ex-drinkers) weekly. Moreover, colorectal cancer risk was found to decrease with increasing duration of drinking abstention (p trend = 0.006). This is the first report of a positive association between cigarette smoking and rectal cancer risk in a Chinese population. Current drinkers and those who drank regularly and heavily had increased colorectal cancer risk. Moreover, this study is the first to show that drinking cessation could be effective in reversing such increased risk in a duration-dependent manner. These new findings are important for cancer prevention and healthcare promotion.

Adenocarcinoma↗
PubMed2004

Secondhand smoke exposure, smoking hygiene, and hospitalization in the first 18 months of life.

BACKGROUND: Recognizing the suboptimal public health effects of a complete cessation strategy for parents and child caregivers who smoke, some researchers have called for a harm reduction approach; however, the evidence remains scanty and controversial. OBJECTIVE: To examine the effects of secondhand smoke and smoking hygiene on infant health and related health care costs during the first 18 months of life. METHODS: We conducted prospective follow-up on 8327 newborns during April and May of 1997 for 18 months in a population-based birth cohort of infants from Hong Kong, China. MAIN OUTCOME MEASURES: Number of hospital admissions, adjusted odds ratios for ever hospitalization for each secondhand smoke exposure variable, and corresponding population attributable risks. RESULTS: Most secondhand smoke exposure came from fathers and other household contacts, whereas only 2.8% of mothers smoked postpartum. The odds ratio of ever hospitalization due to all illnesses combined for infants living in a household with any (maternal, paternal, or other) smoker who was smoking at least 3 m away from the infant, as reported by a parent, was 1.00 (95% confidence interval, 0.88-1.13) compared with those in a smoke-free household. The corresponding odds ratio for infants living with any smoker at home with poor smoking hygiene (<3 m away) was 1.28 (95% confidence interval, 1.07-1.52), which translated into 2.8% of all inpatient episodes in the first year of life, representing an additional 616 admissions. CONCLUSIONS: Hospital admission was significantly more likely among infants exposed to secondhand smoke if it was accompanied by poor smoking hygiene. Harm reduction strategies should be rigorously adhered to when complete cessation is not possible.

Adult↗
PubMed2004

Leisure time physical activity and mortality in Hong Kong: case-control study of all adult deaths in 1998.

PURPOSE: Physical activity is associated with longevity; however, whether these beneficial effects extend to Chinese populations is unclear. We examined the relationship between leisure time physical activity (LTPA) and mortality in Hong Kong. METHODS: Using a case-control study, past (10 years prior) levels of LTPA were ascertained via proxy informants for 24,079 dead cases (81% of all registered deaths) and 13,054 live controls aged #10878;35 years and were analyzed by unmatched logistic regression to determine their association with all-cause and cause-specific mortality. RESULTS: Compared with an exercise frequency of <1 episode per month, > or = 1 episode of LTPA per month was inversely associated with all-cause mortality [multivariable odds ratio (OR)=0.63, 95% confidence interval (CI), 0.59, 0.68 for males; OR=0.75, 95% CI, 0.70, 0.80 for females; adjusted for age, education, smoking status, alcohol consumption, and physical demand at work]. Each activity level above the reference level of <1 episode per month (i.e., 1 episode per month to 1-3 episodes per week, > or = 4 episodes per week) had approximately the same level of risk reduction and no dose-response gradient was observed. The inverse association was stronger for cardiovascular than cancer deaths, particularly in males and was strongest for respiratory mortality. One-fifth of all 31,349 registered deaths in those aged 35 years and over in Hong Kong in 1998 were attributable to physical inactivity. CONCLUSION: The present data confirm and extend previous findings in Caucasian populations on the association between leisure time physical activity and longevity. The population attributable risk from physical inactivity exceeds that due to tobacco smoking in this Hong Kong Chinese population. We predict mainland China will witness a similarly large mortality burden as it undergoes further socioeconomic development in the next few decades.

Adult↗
PubMed2004

Stage of change for general health promotion action and health-related lifestyle practices in Chinese adults.

BACKGROUND: We propose general health promotion action (GHPA) to represent the general intention and actual practices aimed to promote health. The transtheoretical model (TTM) has not been applied to GHPA. The objectives of this study were to determine whether TTM can be applied to Chinese adults by measuring the subjects' stage of change for GHPA, and to study whether stage for GHPA is associated with health-related lifestyle practices. METHODS: Randomly selected Hong Kong Chinese subjects (3233) aged 18-64 were interviewed in telephone survey. RESULTS: Thirty-nine percent had not taken any health promotion actions and had no intention to do so (precontemplation). Twelve percent had taken action but had no intention to continue (at-risk for relapse). Three percent had not taken any actions and intended to do so in the next 6 months, but not in the next 1 month (contemplation). Eleven percent had not taken any actions but intended to do so in the next 1 month (preparation). Fifteen percent had been taking action for less than 6 months and intended to continue (action). Twenty-one percent had been taking action for at least 6 months and intended to continue (maintenance). Precontemplators were less likely than maintainers to be never smokers (OR = 0.62; 95% CI = 0.49-0.80), exercisers (0.097; 0.077-0.12), to eat fruit twice a day (0.53; 0.41-0.69) and remove fat when eating (0.72; 0.54-0.95), with increasing trends in the odds of reporting these practices from precontemplation to maintenance. CONCLUSIONS: Our findings have provided preliminary findings on the applicability of TTM on GHPA in Chinese adults with evidences of concurrent criterion validity.

Adult↗
PubMed2004

A tale of two cities: community psychobehavioral surveillance and related impact on outbreak control in Hong Kong and Singapore during the severe acute respiratory syndrome epidemic.

OBJECTIVES: To compare the public's knowledge and perception of SARS and the extent to which various precautionary measures were adopted in Hong Kong and Singapore. DESIGN: Cross-sectional telephone survey of 705 Hong Kong and 1,201 Singapore adults selected by random-digit dialing. RESULTS: Hong Kong respondents had significantly higher anxiety than Singapore respondents (State Trait Anxiety Inventory [STAI] score, 2.06 vs 1.77; P < .001). The former group also reported more frequent headaches, difficulty breathing, dizziness, rhinorrhea, and sore throat. More than 90% in both cities were willing to be quarantined if they had close contact with a SARS case, and 70% or more would be compliant for social contacts. Most respondents (86.7% in Hong Kong vs 71.4% in Singapore; P < .001) knew that SARS could be transmitted via respiratory droplets, although fewer (75.8% in Hong Kong vs 62.1% in Singapore; P < .001) knew that fomites were also a possible transmission source. Twenty-three percent of Hong Kong and 11.9% of Singapore respondents believed that they were "very likely" or "somewhat likely" to contract SARS during the current outbreak (P < .001). There were large differences between Hong Kong and Singapore in the adoption of personal precautionary measures. Respondents with higher levels of anxiety, better knowledge about SARS, and greater risk perceptions were more likely to take comprehensive precautionary measures against the infection, as were older, female, and more educated individuals. CONCLUSION: Comparative psychobehavioral surveillance and analysis could yield important insights into generic versus population-specific issues that could be used to inform, design, and evaluate public health infection control policy measures.

Adolescent↗
PubMed2004

Establishment and evaluation of a smoking cessation clinic in Hong Kong: a model for the future service provider.

BACKGROUND: In the West, the effectiveness of smoking cessation programmes is well established. Smoking cessation programmes in the East are rare. We evaluated a pilot smoking cessation health centre (SCHC) of the Hong Kong Council on Smoking and Health (COSH). METHODS: The clinic operated 3 days a week from 6 to 9 pm. Smokers were recruited mainly by low cost publicity. Trained counsellors provided individual counselling and a 1 week free supply of nicotine replacement therapy (NRT). The programme was evaluated in terms of process, outcome and cost. RESULTS: During August 2000 to January 2002, 2212 calls were received through the clinic hotline and 1203 smokers attended the clinic. Eight hundred and forty-one were successfully followed up at 12 months. Based on intention-to-treat analysis, the 7 day point prevalence quit rate at 12 months (not smoking any cigarette during the past 7 days at the 12 month follow-up) was 27 per cent (95 per cent confidence interval, CI 25-30 per cent). The average cost per quitter was USD 339 (USD 440 including NRT cost for a 1 week free supply). Other benefits included training of healthcare workers and medical students, organization of seminars, health talks and self-help groups, and promotion of research and training. CONCLUSION: This first evaluation of a clinic-based smoking cessation service in Asia showed that the service was acceptable to Chinese smokers. The quit rate in this pilot part-time clinic is comparable to those of full-time and better funded clinics in the West. A part-time smoking cessation clinic is a promising model for piloting smoking cessation services in the East.

Adult↗
PubMed2004

SARS-CoV antibody prevalence in all Hong Kong patient contacts.

A total of 1,068 asymptomatic close contacts of patients with severe acute respiratory (SARS) from the 2003 epidemic in Hong Kong were serologically tested, and 2 (0.19%) were positive for SARS coronavirus immunoglobulin G antibody. SARS rarely manifests as a subclinical infection, and at present, wild animal species are the only important natural reservoirs of the virus.

Adolescent↗
PubMed2003

Randomised controlled trial of clinical decision support tools to improve learning of evidence based medicine in medical students.

OBJECTIVE: To assess the educational effectiveness on learning evidence based medicine of a handheld computer clinical decision support tool compared with a pocket card containing guidelines and a control. DESIGN: Randomised controlled trial. SETTING: University of Hong Kong, 2001. PARTICIPANTS: 169 fourth year medical students. MAIN OUTCOME MEASURES: Factor and individual item scores from a validated questionnaire on five key self reported measures: personal application and current use of evidence based medicine; future use of evidence based medicine; use of evidence during and after clerking patients; frequency of discussing the role of evidence during teaching rounds; and self perceived confidence in clinical decision making. RESULTS: The handheld computer improved participants' educational experience with evidence based medicine the most, with significant improvements in all outcome scores. More modest improvements were found with the pocket card, whereas the control group showed no appreciable changes in any of the key outcomes. No significant deterioration was observed in the improvements even after withdrawal of the handheld computer during an eight week washout period, suggesting at least short term sustainability of effects. CONCLUSIONS: Rapid and convenient access to valid and relevant evidence on a portable computing device can improve learning in evidence based medicine, increase current and future use of evidence, and boost students' confidence in clinical decision making.

Adult↗
PubMed2003

Epidemiological determinants of spread of causal agent of severe acute respiratory syndrome in Hong Kong.

BACKGROUND: Health authorities worldwide, especially in the Asia Pacific region, are seeking effective public-health interventions in the continuing epidemic of severe acute respiratory syndrome (SARS). We assessed the epidemiology of SARS in Hong Kong. METHODS: We included 1425 cases reported up to April 28, 2003. An integrated database was constructed from several sources containing information on epidemiological, demographic, and clinical variables. We estimated the key epidemiological distributions: infection to onset, onset to admission, admission to death, and admission to discharge. We measured associations between the estimated case fatality rate and patients' age and the time from onset to admission. FINDINGS: After the initial phase of exponential growth, the rate of confirmed cases fell to less than 20 per day by April 28. Public-health interventions included encouragement to report to hospital rapidly after the onset of clinical symptoms, contact tracing for confirmed and suspected cases, and quarantining, monitoring, and restricting the travel of contacts. The mean incubation period of the disease is estimated to be 6.4 days (95% CI 5.2-7.7). The mean time from onset of clinical symptoms to admission to hospital varied between 3 and 5 days, with longer times earlier in the epidemic. The estimated case fatality rate was 13.2% (9.8-16.8) for patients younger than 60 years and 43.3% (35.2-52.4) for patients aged 60 years or older assuming a parametric gamma distribution. A non-parametric method yielded estimates of 6.8% (4.0-9.6) and 55.0% (45.3-64.7), respectively. Case clusters have played an important part in the course of the epidemic. INTERPRETATION: Patients' age was strongly associated with outcome. The time between onset of symptoms and admission to hospital did not alter outcome, but shorter intervals will be important to the wider population by restricting the infectious period before patients are placed in quarantine.

Adolescent↗
PubMed2003

Transmission dynamics of the etiological agent of SARS in Hong Kong: impact of public health interventions.

We present an analysis of the first 10 weeks of the severe acute respiratory syndrome (SARS) epidemic in Hong Kong. The epidemic to date has been characterized by two large clusters-initiated by two separate "super-spread" events (SSEs)-and by ongoing community transmission. By fitting a stochastic model to data on 1512 cases, including these clusters, we show that the etiological agent of SARS is moderately transmissible. Excluding SSEs, we estimate that 2.7 secondary infections were generated per case on average at the start of the epidemic, with a substantial contribution from hospital transmission. Transmission rates fell during the epidemic, primarily as a result of reductions in population contact rates and improved hospital infection control, but also because of more rapid hospital attendance by symptomatic individuals. As a result, the epidemic is now in decline, although continued vigilance is necessary for this to be maintained. Restrictions on longer range population movement are shown to be a potentially useful additional control measure in some contexts. We estimate that most currently infected persons are now hospitalized, which highlights the importance of control of nosocomial transmission.

Cluster Analysis↗
PubMed2003

Waist to stature ratio is more strongly associated with cardiovascular risk factors than other simple anthropometric indices.

PURPOSE: To determine which is the best anthropometric index among body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR) and waist to stature ratio (WSR) in relation to cardiovascular risk factors. METHODS: A representative sample of 2895 Hong Kong Chinese aged 25 to 74 years received medical examinations in 1995 and 1996. Anthropometric indices and cardiovascular risk factors in blood were measured, and partial correlation and Receiver Operator Characteristic (ROC) curves were used in analysis. RESULTS: Among 11 cardiovascular risk factors in partial correlation analysis, including ties WSR had the highest r in 6 in men, and 5 in women; followed by WC with 4 in men and 6 in women. In ROC analyses of 21 risk factors and health conditions, the area under curve (AUC) of WSR was the largest for most (13 of 21) factors in men and 10 in women; followed by WHR with 14 in women but only 5 in men. The optimal WSR cutoff value was 0.48 for both men and women. CONCLUSIONS: WSR is the best simple anthropometric index in predicting a wide range of cardiovascular risk factors and related health conditions. A simple message that one's waist circumference should not exceed half the stature is recommended for the public.

Adult↗
PubMed2002

Cardiorespiratory and all-cause mortality after restrictions on sulphur content of fuel in Hong Kong: an intervention study.

BACKGROUND: In July, 1990, a restriction was introduced over one weekend that required all power plants and road vehicles in Hong Kong to use fuel oil with a sulphur content of not more than 0.5% by weight. This intervention led to an immediate fall in ambient sulphur dioxide (SO2). We assessed the effect of this intervention on mortality over the next 5 years. METHODS: Changes in trends in deaths were estimated by a Poisson regression model of deaths each month between 1985 and 1995. Changes in seasonal deaths immediately after the intervention were measured by the increase in deaths from warm to cool season. We also estimated the annual proportional change in number of deaths before and after the intervention. We used age-specific death rates to estimate person-years of life gained. FINDINGS: In the first 12 months after introduction of the restriction, a substantial reduction in seasonal deaths was noted, followed by a peak in the cool-season death rate between 13 and 24 months, returning to the expected pattern during years 3-5. Compared with predictions, the intervention led to a significant decline in the average annual trend in deaths from all causes (2.1%; p=0.001), respiratory (3.9%; p=0.0014) and cardiovascular (2.0%; p=0.0214) diseases, but not from other causes. The average gain in life expectancy per year of exposure to the lower pollutant concentration was 20 days (females) to 41 days (males). INTERPRETATION: Pollution resulting from sulphur-rich fuels has an effect on death rates, especially respiratory and cardiovascular deaths. The outcome of the Hong Kong intervention provides direct evidence that control of this pollution has immediate and long-term health benefits.

Adolescent↗
PubMed2002

Cesarean trends.

Explore the source record for details and available documents.

Cesarean Section↗
PubMed2002

The development and evaluation of an integrated community-based, patient-centred learning activity at the University of Hong Kong.

OBJECTIVE: To develop and evaluate the Patient Care Project (PCP), an integrated patient-centred, community-based learning activity, implemented at the University of Hong Kong since 1992. DESIGN: The PCP, a required course in the first 2 preclinical years, is structured into four learning cycles over 9 months. Each cycle consists of a patient interview followed by a debriefing group tutorial. In-depth interviews with the same patient allow students to explore the impact of disease and patients' illness experience, as well as the contribution of the wider determinants of health to their condition. The debriefing tutorial frames empirical observations into theoretical models and its format reinforces habits of problem-based learning. The programme was evaluated using survey questionnaires completed by students, patients and tutors. PARTICIPANTS: 324 first- and second-year medical students. RESULTS: Students, participating patients and tutors all rated the PCP positively in end-of-course evaluations. Specifically, 68% of students commented that the PCP had met all or most of its stated objectives, while there was nearly unanimous agreement among patients that students demonstrated understanding and empathy in the visits and interviews. Tutor appraisal of student performance also indicated the attainment of all stated aims and objectives overall. CONCLUSIONS: The PCP is a valuable contribution to community-based learning and the promotion of the patient-centred clinical method.

Curriculum↗
PubMed2002

Maternal, paternal and environmental tobacco smoking and breast feeding.

The effects of environmental tobacco smoke (ETS) on breast-feeding patterns are poorly understood, while those of parental smoking on breast-feeding initiation vs. duration have not been clearly delineated. We conducted a prospective, population-based birth cohort study to examine the independent effects of maternal, paternal and ETS on breast-feeding initiation and duration. A total of 6747 Hong Kong Chinese infants were recruited and followed up in 1997-8. We obtained detailed household smoking history and recorded breast-feeding patterns in three follow-up interviews over 9 months. We found that both maternal and paternal smoking were associated with not initiating breast feeding (odds ratio [OR] for ever maternal smoking = 2.51, 95% confidence interval [CI] = 1.63, 3.86; OR for ever paternal smoking = 1.22, 95% CI = 1.08, 1.39). Exposure to ETS in utero and post partum were also related to not starting breast feeding (OR(ETS in utero) = 1.10, 95% CI = 0.99,1.24; OR(ETS post partum) = 1.21, 95% CI = 1.08, 1.36). These effects, however, did not persist for breast-feeding duration of < or = 4 months. Cox proportional hazards modelling confirmed the lack of association between any form of smoking and breast-feeding duration. Our findings suggest that smoking of any kind, during or after pregnancy, is a strong risk indicator for not initiating breast feeding. Smoking as a risk indicator for underlying socio-economic, demographic and psychosocial factors is probably responsible for most of the observed adverse effects, although we cannot rule out direct contributions from pathophysiological mechanisms. Public health strategies directed at these underlying factors should be vigorously pursued to reduce the adverse effects of tobacco on breast feeding and infant health in general.

Adult↗
PubMed2002

Breastfeeding rates in Hong Kong: a comparison of the 1987 and 1997 birth cohorts.

BACKGROUND: Low breastfeeding rates are an issue of international public health concern. Anecdotal reports suggest very low breastfeeding rates in Asia, but no population-based studies have been conducted in the region. To determine the secular trend in breastfeeding practice in an Asian postindustrialized metropolitan community, we examined data from two population-based birth cohorts of Hong Kong infants in 1987 and 1997. METHODS: Annual population rates of breastfeeding initiation and duration were estimated from the birth cohorts, considering the change in breastfeeding rates over 10 years with correction for sociodemographic and birth characteristics. Factors associated with breastfeeding practice were identified using multivariate logistic regression modeling in a pooled analysis of individual data of both cohorts. RESULTS: Overall, 26.8 percent of mothers initiated breastfeeding in 1987, and the rate increased to 33.5 percent in 1997. The rate would have been 27.4 percent in 1987 if the distributions of method of delivery, birthweight, birth order, maternal age, education, and employment status had been the same as in 1997. Only 7.6 percent of infants remained on the breast for more than 1 month in 1987 compared with 20.4 percent a decade later. Similarly, the rate for breastfeeding more than 3 months increased from 3.9 to 10.3 percent. Total breastfeeding duration was significantly longer in 1997 than 10 years earlier. CONCLUSIONS: This is the first systematic report of secular variations of breastfeeding rates in Asia. Hong Kong should set higher but realistic goals for breastfeeding that emphasize both initiation and maintenance. Given the wide latitude for improvement in terms of readily modifiable risk factors, such as smoking and cesarean section, these new goals should focus on improving rates in these targeted groups where breastfeeding rates are lowest.

Adult↗
PubMed2002

Maximal isometric muscle strength of the cervical spine in healthy volunteers.

OBJECTIVE: To describe the maximal isometric neck muscle strength in healthy Chinese volunteers, in six different directions, as measured by a Multi Cervical Rehabilitation Unit. DESIGN: A standardized cross-sectional observational study. SETTING: A university rehabilitation unit. SUBJECTS: Ninety-one healthy volunteers aged 20-84. METHODS: During the measurement the subject was instructed to do three consecutive steady contractions as hard as possible, with a 10-second rest in between each contraction and a 2-minute rest between different directions. The peak isometric strength for each of the six directions (flexion, extension, lateral flexions, protraction and retraction) was calculated. RESULTS: No significant difference was found in muscle strength between different age groups. Isometric muscle strength in the direction of right lateral flexion was significantly greater than that to the left in men (p = 0.030), but no difference was found in women (p = 0.297). Isometric strength in all directions in men was 1.2-1.7 times that in women (all p < 0.028). Correlations between physical measurements (height and weight) and strength values were all insignificant in both genders. CONCLUSION: Men have approximately 20-70% greater isometric neck muscle strength than women. Both men and women can maintain high levels of cervical muscle strength in six different directions up to their seventh decade. There is no significant correlation between physical measurements and isometric neck muscle strength.

Adult↗