Association between tobacco industry denormalisation beliefs and support for tobacco endgame policies: a population-based study in Hong Kong.

OBJECTIVES: To examine the associations between tobacco industry denormalisation (TID) beliefs and support for tobacco endgame policies. METHODS: A total of 2810 randomly selected adult respondents of population-based tobacco policy-related surveys (2018-2019) were included. TID beliefs (agree vs disagree/unsure) were measured by seven items: tobacco manufacturers ignore health, induce addiction, hide harm, spread false information, lure smoking, interfere with tobacco control policies and should be responsible for health problems. Score of each item was summed up and dichotomised (median=5, >5 strong beliefs; ≤5 weak beliefs). Support for tobacco endgame policies on total bans of tobacco sales (yes/no) and use (yes/no) was reported. Associations between TID beliefs and tobacco endgame policies support across various smoking status were analysed, adjusting for sociodemographics. RESULTS: Fewer smokers (23.3%) had strong beliefs of TID than ex-smokers (48.4%) and never smokers (48.5%) (p<0.001). Support for total bans on tobacco sales (74.6%) and use (76.9%) was lower in smokers (33.3% and 35.3%) than ex-smokers (74.3% and 77.9%) and never smokers (76.0% and 78.3%) (all p values<0.001). An increase in the number of TID beliefs supported was positively associated with support for a total ban on sales (adjusted risk ratio 1.06, 95% CI 1.05 to 1.08, p<0.001) and use (1.06, 95% CI 1.05 to 1.07, p<0.001). The corresponding associations were stronger in smokers than non-smokers (sales: 1.87 vs 1.25, p value for interaction=0.03; use: 1.78 vs 1.21, p value for interaction=0.03). CONCLUSION: Stronger TID belief was associated with greater support for total bans on tobacco sales and use. TID intervention may increase support for tobacco endgame, especially in current smokers.

Effect of Adding Personalized Instant Messaging Apps to a Brief Smoking Cessation Model in Community Smokers in Hong Kong: Pragmatic Randomized Clinical Trial.

BACKGROUND: While text messaging has proven effective for smoking cessation (SC), engagement in the intervention remains suboptimal. OBJECTIVE: This study aims to evaluate whether using more interactive and adaptive instant messaging (IM) apps on smartphones, which enable personalization and chatting with SC advisors, can enhance SC outcomes beyond the provision of brief SC advice and active referral (AR) to SC services. METHODS: From December 2018 to November 2019, we proactively recruited 700 adult Chinese daily cigarette users in Hong Kong. Participants were randomized in a 1:1 ratio. At baseline, all participants received face-to-face brief advice on SC. Additionally, they were introduced to local SC services and assisted in selecting one. The intervention group received an additional 26 personalized regular messages and access to interactive chatting through IM apps for 3 months. The regular messages aimed to enhance self-efficacy, social support, and behavioral capacity for quitting, as well as to clarify outcome expectations related to cessation. We developed 3 sets of messages tailored to the planned quit date (within 30 days, 60 days, and undecided). Participants in the intervention group could initiate chatting with SC advisors on IM themselves or through prompts from regular messages or proactive inquiries from SC advisors. The control group received 26 SMS text messages focusing on general health. The primary outcomes were smoking abstinence validated by carbon monoxide levels of <4 parts per million at 6 and 12 months after the start of the intervention. RESULTS: Of the participants, 505/700 (72.1%) were male, and 450/648 (69.4%) were aged 40 or above. Planning to quit within 30 days was reported by 500/648 (77.2%) participants, with fewer intervention group members (124/332, 37.3%) reporting previous quit attempts compared with the control group (152/335, 45.4%; P=.04). At the 6- and 12-month follow-ups (with retention rates of 456/700, 65.1%, and 446/700, 63.7%, respectively), validated abstinence rates were comparable between the intervention (14/350, 4.0%, and 19/350, 5.4%) and control (11/350, 3.1% and 21/350, 6.0%) groups. Compared with the control group, the intervention group reported greater utilization of SC services at 12 months (RR 1.26, 95% CI 1.01-1.56). Within the intervention group, engaging in chat sessions with SC advisors predicted better validated abstinence at 6 months (RR 3.29, 95% CI 1.13-9.63) and any use of SC services (RR 1.66, 95% CI 1.14-2.43 at 6 months; RR 1.67, 95% CI 1.26-2.23 at 12 months). CONCLUSIONS: An IM-based intervention, providing support and assistance alongside brief SC advice and AR, did not yield further increases in quitting rates but did encourage the utilization of SC services. Future research could explore whether enhanced SC service utilization leads to improved long-term SC outcomes. TRIAL REGISTRATION: ClinicalTrials.gov NCT03800719; https://clinicaltrials.gov/ct2/show/NCT03800719.

Changes in Tobacco Use in the Early Phase of Coronavirus Disease 2019 Pandemic in Hong Kong: A Qualitative Study.

INTRODUCTION: Changes in tobacco use and related personal and environmental factors amid the coronavirus disease 2019 (COVID-19) pandemic can be captured by qualitative studies, but they are few in non-Western populations. AIMS AND METHODS: We assessed the perceived links between tobacco use and COVID-19, and changes in the use of cigarettes, electronic cigarettes (ECs), and heated tobacco products (HTPs) in the early phase of the pandemic in Hong Kong, where lockdown was not implemented. Semi-structured telephone interviews were conducted from January to June 2021 in 95 participants (36 EC users, 28 HTP users, and 32 exclusive cigarette users). Transcriptions were coded using deductive and inductive approaches, and factors for changes were nested in the social-ecological model. RESULTS: Two-thirds of participants perceived their infection susceptibility was the same as never tobacco users, and 44.2% perceived more severe COVID-19 disease if infected. Amid the pandemic, tobacco use decreased overall but increased indoors for all three products. Increased tobacco use was mostly attributed to increased emotional distress, while decreases were attributed to various personal (health concerns) and environmental factors (e.g., COVID-19 regulations). Perceived convenience and lower costs were reasons for increased EC use. Limited access to HTPs was compensated by cigarette use. CONCLUSIONS: Many participants were unaware of the potential harm of tobacco use on COVID-19. Overall tobacco use decreased due to COVID-19 regulations, which may not be sustainable post-pandemic. Indoor consumption increased, supporting a comprehensive smoke-free policy that covers private indoor areas. Better cessation services targeting EC, HTP, and cigarette use are needed. IMPLICATIONS: Smokers need better awareness of the risk of tobacco use on COVID-19. Smoking cessation services can be improved by offering brief advice, strengthening advocacy against secondhand smoke, and covering EC and HTP use, highlighting their potential harms to users and others, and their risk of addiction and relapse to cigarette use.

Cigarettes, heated tobacco products and dual use: exhaled carbon monoxide, saliva cotinine and total tobacco consumed by Hong Kong tobacco users.

BACKGROUND: Independent studies on exhaled carbon monoxide (CO) and saliva cotinine levels in regular heated tobacco product (HTP) users, and how they compare with conventional cigarette (CC) smokers, are lacking. METHODS: A total of 3294 current users of CCs, HTPs or electronic cigarettes (ECs) from a household survey and a smoking hotspot survey were classified into seven groups: exclusive users of CCs, HTPs, ECs; dual users of CCs and HTPs, CCs and ECs, HTPs and ECs; and triple users. We measured exhaled CO level using the piCo Smokerlyzer (n=780) and saliva cotinine using NicAlert cotinine test strips (n=620). Among the seven groups, the differences in (1) CO and cotinine levels were examined using Kruskal-Wallis test, and (2) the average daily tobacco consumption in the past 30 days was examined using multivariable linear regression. RESULTS: Both exclusive and dual users of CCs had a higher CO level than exclusive HTP or EC users (p<0.05). Exhaled CO levels were similar between HTP and EC users, as were saliva cotinine levels among the seven groups. Compared with exclusive CC users, those who also used HTPs or ECs smoked fewer CCs (CCs+HTPs: adjusted coefficient -2.79, 95% CI -3.90 to -1.69; CCs+ECs: -1.34, 95% CI -2.34 to -0.34), but consumed more tobacco sticks equivalent in total (2.79 (95% CI 1.61 to 3.96); 1.95 (95% CI 0.79 to 3.12)). CONCLUSIONS: HTP or EC use showed lower exhaled CO but similar saliva cotinine levels compared with CC use. Dual users of CCs and HTPs/ECs smoked fewer CCs than exclusive CC users, but consumed more tobacco in total.

Cognitive Activities, Lifestyle Factors, and Risk of Cognitive Impairment, with an Analysis of the Apolipoprotein Epsilon 4 Genotype.

INTRODUCTION: Cognitive stimulating activities and a healthy lifestyle are associated with less cognitive impairment. However, whether the association is varied by Apolipoprotein epsilon 4 (APOE ε4) allele carrier status remains inconclusive. We aimed to investigate whether the association of cognitively stimulating activities and a healthy lifestyle with the risk of cognitive impairment varied by APOE ε4 allele carrier status. METHODS: A case-control study was conducted for adults aged 60 years and above. Six province administrative units (Beijing, Shanghai, Hubei, Sichuan, Guangxi, and Yunnan) were included using stratified multistage cluster sampling. A total of 1,300 individuals were identified with cognitive impairment (cases) at enrollment and were matched 1:2 on sex, age (±2 years), and residential district with controls who were cognitively normal at the time of the evaluation. We used a standardized questionnaire to collect information on cognitive stimulating activities, lifestyle factors, demographics, and comorbidity. Cognitive stimulating activities included reading books or newspapers, playing cards or mahjong, using the Internet, socializing with neighbors, and community activities. Lifestyle factors included smoking, alcohol drinking, daily tea drinking, and regular exercise. We used logistic regression to assess the interaction between cognitive stimulating activities, lifestyle factors, and APOE ε4 allele carrier status (yes/no) on the risk of cognitive impairment. We tested for additive interaction by estimating relative excess risk (RERI) due to interaction and multiplicative interaction employing the p value of the interaction term of each lifestyle factor and APOE ε4 into the model. RESULTS: Four cognitive stimulating activities were associated with less cognitive impairment regardless of APOE ε4 status. Using the Internet (odds ratio [OR]: 0.53, 95% confidence interval [CI]: 0.30-0.95), daily tea drinking (OR: 0.79; 95% CI: 0.63-0.98), and regular exercise (OR: 0.78; 95% CI: 0.65-0.94) were associated with less cognitive impairment only in noncarriers. Multiplicative and additive interactions were found between community activities and APOE ε4 carrier status (multiplicative p value = 0.03; RERI 0.738, 95% CI: 0.201-1.275). CONCLUSION: The associations between cognitive activities and cognitive impairment were robust regardless of the APOE ε4 carrier status, while the associations between lifestyle factors and cognitive impairment varied by APOE ε4 carrier status.

Skipping Breakfast and Eating Breakfast Away From Home Were Prospectively Associated With Emotional and Behavioral Problems in 115,217 Chinese Adolescents.

BACKGROUND: Breakfast is deemed the most important meal of the day. We examined the prospective associations of breakfast habits with emotional/behavioral problems in adolescents and potential effect modification. METHODS: 115,217 Primary 6 students (United States Grade 6; mean age, 11.9; standard deviation [SD], 0.59 years) who attended the Student Health Service of Department of Health in Hong Kong in 2004/05, 2006/07, 2008/09 were followed till Secondary 6 (United States Grade 12). Emotional/behavioral problems were biennially examined using Youth Self-Report since Secondary 2 (United States Grade 8). Lifestyles were biennially examined using standardized questionnaires since Primary 6. Prospective associations of breakfast habit with emotional/behavioral problems and potential effect modification were examined using generalized estimating equations. RESULTS: Compared with eating breakfast at home, eating breakfast away from home was significantly associated with total emotional/behavioral problems and seven syndromes, including withdrawal, somatic complaints, anxiety/depression, thought problems, attention problems, delinquent behaviors, and aggressive behaviors (adjusted odds ratios [AORs] 1.22-2.04), while skipping breakfast showed stronger associations with the above problems and social problems (AORs 1.34-2.29). Stronger associations were observed in younger students for total and attention problems (P < 0.03) and in those with lower weight status for delinquent behaviors (P = 0.005). CONCLUSION: Eating breakfast away from home and especially skipping breakfast were prospectively associated with adolescent emotional/behavioral problems. The associations weakened with increasing age for total emotional/behavioral and attention problems, and weakened with higher weight status for delinquent behaviors, highlighting the vulnerability of younger and underweight children. If the associations are causal, increasing home breakfast may reduce adolescent emotional/behavioral problems and benefit psychosocial health.

Perception of heated tobacco products and support for regulations: a cross-sectional study in Hong Kong.

BACKGROUND: Hong Kong has proposed banning the sale of heated tobacco products (HTPs). Perceptions of reduced harms and effectiveness for quitting combustible cigarettes (CCs) of HTPs due to their promotions may erode public support for regulations. We assessed the associations between perceptions of HTPs and support for regulations in Hong Kong. METHODS: In two population-based landline surveys conducted in 2018-2019, 1985 respondents (51.4% male; 22.7% aged 60+ years) reported perceived relative harm of HTPs to CCs and effectiveness for quitting CCs, and support for five HTP regulations (ban on promotion and advertisements, use in smoke-free areas, sales to minors, registration before sale, sale licence) and a total ban on sale. Current and former smokers were oversampled due to low prevalence. Descriptive statistics were weighted to the general population. Associations were analysed, adjusting for sociodemographic characteristics, smoking status and ever HTP use. RESULTS: 27.4% (N=515) of respondents perceived HTPs as less harmful, and 18.8% (N=1299) perceived them as effective for quitting CCs. Support was generally high (at least one regulation, 99.1%, N=1959; all five regulations, 66.8%, N=1114; total ban, 63.5%, N=946). Perceptions of reduced harm were associated with lower support for all five regulations (adjusted risk ratio 0.85, 0.75 to 0.96) and a total ban on sale (0.58, 0.51 to 0.66). Results were similar for perceptions of effectiveness for quitting. CONCLUSIONS: Lower support for HTP regulations and a total ban on sale were associated with perceptions of reduced harm and effectiveness for quitting CCs of HTPs in Hong Kong.

Adversity coping capability and its associations with mental health and family wellbeing amid the COVID-19 pandemic in Hong Kong.

BACKGROUND: Adversity coping capability (ACC) is important amid the COVID-19 pandemic. We examined the associations of ACC as measured by our one-item ACC scale (ACC-1) with mental health, family well-being and validity of ACC-1 in Hong Kong. METHODS: A cross-sectional survey was conducted on Hong Kong Chinese adults aged ≥ 18 years by landline, mobile phone, and online survey from February to March 2021, when the fourth wave of COVID-19 was under control. ACC-1 consisted of the question: "How do you rate your capability to cope with adversities?" with higher scores (0-10) indicating stronger ACC. The associations of ACC with socioeconomic characteristics, resilience, mental health, and family wellbeing were examined by linear regression coefficients (ßs). Data were weighted by sex, age, and education of the general population. RESULTS: Of 7441 respondents, after weighing, 52.2% were female and 79.1% were aged 18 to 64 years. ACC-1 showed good construct validity, with higher ACC being associated with higher levels of resilience (adjusted ß = 0.29), personal happiness (0.55), family happiness (0.42), family wellbeing (0.41), and family communication quality (0.41), and lower levels of depressive symptoms (-0.30), anxiety (-0.30), loneliness (-0.15); incremental validity with additional contributions of ACC to mental health and family wellbeing; and known-group validity with older age and favorable socioeconomic characteristics showing higher ACC (all P < 0.02). Females (mean ± standard deviation: 6.04 ± 1.82 vs 6.15 ± 1.96 [male]) and unemployed respondents (5.30 ± 1.99 vs 6.11 ± 2.03 [in paid employment]) had lower ACC (all P ≤ 0.02). CONCLUSIONS: We have first shown that stronger ACC was associated with better mental health and family wellbeing, and the results support ACC-1 as a simple and valid measure of ACC.

Late-onset or chronic overweight/obesity predicts low self-esteem in early adolescence: a longitudinal cohort study.

BACKGROUND: How weight status changes with time may affect self-esteem was seldom studied. We identified the distinct trajectories of overweight/obesity over age and assessed their associations with different domains of self-esteem in Hong Kong Chinese children. METHODS: Territory-wide longitudinal data of 48,558 children (girls: 50.0%; 6.3 ± 0.51 years) studying Primary 1 in the academic cohorts of 1995/96 and 1996/97 followed till Primary 6 were obtained from the Student Health Service of Hong Kong. Weight was annually measured and categorized as underweight/normal and overweight/obese and self-esteem was measured in Primary 6. Distinct trajectories of weight status were first identified using growth mixture modeling and their associations with low self-esteem were assessed by logistic regression. RESULTS: Four distinct overweight/obesity trajectories were identified: never (76.8%), late-onset (8.1%), early-onset (4.2%) and chronic (10.9%) overweight/obesity. Compared with children who were never overweight/obese, more of those in the late-onset or chronic overweight/obesity group showed low self-esteem and specific domains including general, social and academic/school-related (adjusted odds ratios: 1.20 - 1.43, all P < 0.001) except parent/home-related self-esteem (P = 0.36), whereas children being in the early-onset overweight/obesity group showed no significant difference (P ≥ 0.53) except a lower risk of low social self-esteem (adjusted odds ratio = 0.82, P = 0.03). CONCLUSIONS: Late-onset or chronic overweight/obesity predicted low general, social and academic/school-related self-esteem. Children who successfully reduced weight may have equal levels of self-esteem or even better social self-esteem than those being always underweight/normal weight. Overweight/obese children had a vulnerability to self-esteem in non-domestic environments.

Exposure to health misinformation about COVID-19 and increased tobacco and alcohol use: a population-based survey in Hong Kong.

INTRODUCTION: Health information about COVID-19 has been circulating in social networking sites, including unproven claims that smoking and alcohol drinking could protect against COVID-19. We examined if exposure to such claims was associated with changes in tobacco and alcohol consumption. METHODS: We conducted a population-based, landline and mobile phone survey of 1501 randomly sampled adults aged 18 years or older (47.5% male) in Hong Kong in April 2020. Respondents reported if they had ever seen claims that 'smoking/alcohol drinking can protect against COVID-19' from popular social networking platforms. Current tobacco and alcohol users reported if they had increased or reduced their consumption since the outbreak. Prevalence data were weighted by sex, age and education of the general adult population. RESULTS: 19.0% (95% CI 16.8% to 21.4%) of all respondents reported having seen claims that 'smoking/alcohol drinking can protect against COVID-19' from social networking sites. Multinomial logistic regression showed that exposure to the claims was significantly associated with increased tobacco use (OR 2.37, 95% CI 1.08 to 5.20) in current tobacco users (N=280) and increased alcohol use (OR 4.16, 95% CI 2.00 to 8.67) in current drinkers (N=722), adjusting for sex, age, education level, alcohol/tobacco use status, home isolation, anxiety and depressive symptoms, and survey method. CONCLUSION: Our results first showed that exposure to health misinformation that smoking/alcohol drinking can protect against COVID-19 was associated with self-reported increases in tobacco and alcohol consumption in Chinese during the pandemic.

Dietary fiber intake from fresh and preserved food and risk of nasopharyngeal carcinoma: observational evidence from a Chinese population.

BACKGROUND: The role of dietary fiber intake on risk of nasopharyngeal carcinoma (NPC) remains unclear. We examined the associations of dietary fiber intake on the risk of NPC adjusting for a comprehensive list of potential confounders. METHODS: Using data from a multicenter case-control study, we included 815 histologically confirmed NPC incident cases and 1502 controls in Hong Kong, China recruited in 2014-2017. Odds ratios (ORs) of NPC (cases vs controls) for dietary fiber intake from different sources at different life periods (age 13-18, age 19-30, and 10 years before recruitment) were evaluated using unconditional logistic regression, adjusting for sex, age, socioeconomic status, smoking and drinking status, occupational hazards, family history of cancer, salted fish, and total energy intake in Model 1, Epstein-Barr virus viral capsid antigen serological status in Model 2, and duration of sun exposure and circulating 25-hydroxyvitamin D in Model 3. RESULTS: Higher intake of total dietary fiber 10 years before recruitment was significantly associated with decreased NPC risk, with demonstrable dose-response relationship (P-values for trend = 0.001, 0.020 and 0.024 in Models 1-3, respectively). The adjusted ORs (95% CI) in the highest versus the lowest quartile were 0.51 (0.38-0.69) in Model 1, 0.48 (0.33-0.69) in Model 2, and 0.48 (0.33-0.70) in Model 3. However, the association was less clear after adjustment of other potential confounders (e.g. EBV) in the two younger periods (age of 13-18 and 19-30 years). Risks of NPC were significantly lower for dietary fiber intake from fresh vegetables and fruits and soybean products over all three periods, with dose-response relationships observed in all Models (P-values for trend for age 13-18, age 19-30 and 10 years before recruitment were, respectively, 0.002, 0.009 and 0.001 for Model1; 0.020, 0.031 and 0.003 for Model 2; and 0.022, 0.037 and 0.004 for Model 3). No clear association of NPC risk with dietary fiber intake from preserved vegetables, fruits and condiments was observed. CONCLUSION: Our study has shown the protective role of dietary fiber from fresh food items in NPC risk, but no association for total dietary fiber intake was observed, probably because total intake also included intake of preserved food. Further studies with detailed dietary information and in prospective settings are needed to confirm this finding, and to explore the possible underlying biological mechanisms.

Heated tobacco products use in Chinese adults in Hong Kong: a population-based cross-sectional study.

INTRODUCTION: We investigated heated tobacco products (HTPs) use and associated factors in Chinese adults in Hong Kong where HTPs are not formally marketed yet, and cigarette smoking prevalence was the lowest in the developed world. METHODS: A population-based landline telephone survey in 2017 interviewed 5131 (45.2% male; 26.7% aged ≥60) adults to collect information on awareness, intention to use, ever use of HTPs, cigarette smoking status and sociodemographic characteristics. Descriptive statistics were weighted by the age, sex and smoking status of the Hong Kong adult population. Sociodemographics were mutually adjusted in logistic regression to yield adjusted ORs (AORs) for awareness of HTPs, controlling for smoking status. RESULTS: Overall, 11.3% (95% CI 10.0% to 12.7%) were aware of HTPs and 1.0 % (0.8%-1.2%) had ever used it. Awareness was associated with aged 40-49 years (AOR 1.37, 95% CI 1.01 to 1.87) or 30-39 years (2.03, 1.41-2.91) (vs ≥60 years), born in Hong Kong (1.37, 1.11-1.68) and higher monthly household income (p for trend 0.001). Ever HTP users had higher educational attainment and monthly household income, and more were aged 30-39 and economically active (all p<0.003). In never HTP users, intention to use HTPs (7.3%, 4.9%-10.8%) were more prevalent in respondents with similar characteristics (all p<0.008). More current (vs never) smokers were aware of HTPs, intent to use HTPs and had ever used HTPs (all p<0.001). CONCLUSION: Higher socioeconomic status was associated with HTP use and intention to use. Public health education on HTPs is needed especially for this high-risk group.

Exposure to e-cigarette advertising, attitudes, and use susceptibility in adolescents who had never used e-cigarettes or cigarettes.

BACKGROUND: Tobacco advertisements have been banned in Hong Kong, but low intensity e-cigarette (EC) advertising can still be found in various media outlets. We investigated the associations between exposure to EC advertising and susceptibility to EC use in adolescents who had never used cigarettes or ECs, with potential mediation by attitudes towards ECs and the tobacco industry. METHODS: The School-based Smoking Survey 2016/17 assessed exposure to EC advertising in the past 30 days, attitudes towards ECs and the tobacco industry, susceptibility to EC use, and other covariates. Generalised linear mixed models and multiple mediation analysis methods were used in data analyses. RESULTS: Among 7082 students (mean age 14.9 years), 28.8% reported exposure to EC advertising. Exposure was associated with being uncertain about the harm of EC use, being tolerant towards ECs, believing the tobacco industry is respectable, and being susceptible to EC use; the magnitudes of these associations increased with the number of types of advertising exposed (0, 1, and ≥ 2) (all p-values < 0.01). These attitudinal factors were in turn associated with EC use susceptibility (all p-values < 0.001). The perception that tobacco companies make youth smoke was not associated with the advertising exposure or EC use susceptibility. Of the total effects of EC advertising on use susceptibility, only 16.6% were mediated by attitudinal factors: perceived harm (3.1%), attitudes towards ECs (8.2%), and attitudes towards the tobacco industry (4.9%). CONCLUSIONS: Even exposure to low intensity EC advertising was associated with susceptibility to EC use in adolescents who had never used cigarettes or ECs. The association was weakly mediated by tolerant attitudes towards ECs and the tobacco industry. The government should reinforce the regulations on EC advertising to protect adolescent health.

Effect of prepaid and promised financial incentive on follow-up survey response in cigarette smokers: a randomized controlled trial.

BACKGROUND: Monetary incentive is often used to increase response rate in smokers' survey, but such effect of prepaid and promised incentives in a follow-up survey is unknown. We compared the effect of different incentive schemes on the consent and retention rates in a follow-up survey of adult cigarette smokers. METHODS: This was a randomized controlled trial (RCT) in Hong Kong, China. Smokers who completed a non-incentivized baseline telephone smoking survey were invited to a 3-month follow-up, with randomization into (1) the control group (no incentive), (2) a promised HK$100 (US$12.8) incentive upon completion, (3) a promised HK$200 (US$25.6) incentive upon completion, or (4) a prepaid HK$100 incentive plus another promised HK$100 incentive ("mixed incentive"). Crude risk ratios from log-binomial regression models were used to assess if the 3 incentive schemes predicted higher rates of consent at baseline or retention at 3-month than no incentive. RESULTS: In total, 1246 smokers were enrolled. The overall consent and retention rates were 37.1 and 23.0%, respectively. Both rates generally increased with the incentive amount and offer of prepaid incentive. The mixed incentive scheme marginally increased the retention rate versus no incentive (26.8% vs 20.3%; risk ratio (RR) = 1.32; 95% CI: 1.00-1.76; P = 0.053), but not the consent rate (RR = 1.13; 95% CI: 0.93-1.38; P = 0.22). Among the consented participants, approximately 50% in the mixed incentive group received the mailed prepaid incentive, who achieved a higher retention rate than the group without incentives (82.8% vs 56.1%; RR = 1.48; 95% CI: 1.21-1.80; P < 0.01). CONCLUSION: The mixed incentive scheme combining the prepaid and promised incentive was effective to increase the follow-up retention rate by 48%. We recommend this mixed incentive scheme to increase the follow-up retention rate. More efficient methods of delivering the incentive are needed to maximize its effects. TRIAL REGISTRATION: U.S. Clinical Trials registry (clinicaltrials.gov, retrospectively registered, reference number: NCT03297866 ).

Tobacco Industry Denormalization Beliefs in Hong Kong Adolescents.

BACKGROUND: Tobacco industry denormalization (TID) seeks to expose the industry's misconducts. Research on TID beliefs, meaning negative attitudes toward the tobacco industry (TI), may inform TID programs, but was limited to western populations. We investigated TID beliefs and their association with smoking and sociodemographic characteristics in Hong Kong adolescents. METHODS: In a school-based cross-sectional survey of 14214 students (mean age 15.0 years, 51.5% boys), TID beliefs were assessed by two questions: (1) whether the TI was respectable and (2) whether the TI tried to get youth to smoke, each with four options from "definitely no" to "definitely yes." Smoking susceptibility and behaviors were also assessed. Sociodemographic characteristics included age, sex, perceived family affluence, highest parental education, numbers of co-residing smokers, and school-level smoking prevalence. RESULTS: Of all students, 77.6% considered the TI not respectable and 56.6% believed that the TI tried to get youth to smoke. Stronger TID beliefs were inversely associated with smoking susceptibility and behaviors. For example, students considering the TI definitely not respectable (vs. definitely yes) were 56% (95% confidence intervals [CI] = 45% to 66%), 49% (95% CI = 41% to 56%), and 53% (95% CI = 36% to 65%) less likely to be susceptible to smoking (among never-smokers) and be ever- and current smokers, respectively. Of all correlates examined, only younger age and having no co-residing smoker were associated with TID beliefs. CONCLUSIONS: Substantial proportions of Hong Kong adolescents did not hold TID beliefs, but those who did were less likely to smoke. Our results suggest that TID programs may help reduce adolescent smoking. IMPLICATIONS: The TI's misconducts and responsibility for the tobacco epidemic were not well known by Hong Kong adolescents. TID beliefs in this population were inversely associated with smoking. These findings suggest that TID programs in local adolescents may be of value. The investigation into the correlates of TID beliefs found that socioeconomic status and school-level smoking prevalence were not associated with TID beliefs. This suggests that local TID programs targeting adolescents in general, for example, mass-media campaigns, may be more appropriate than those targeting particular schools or selected groups of adolescents.

The reliability and validity of the Chinese Short Warwick-Edinburgh Mental Well-being Scale in the general population of Hong Kong.

PURPOSE: To evaluate the reliability and validity of the 7-item Chinese Short Warwick-Edinburgh Mental Well-being Scale (SWEMWBS) in Hong Kong Chinese. METHODS: Under "A Jockey Club Initiative for a Harmonious Society" project, a random telephone survey was conducted in 2017 on 1331 Hong Kong Chinese residents aged ≥ 18. A confirmatory factor analysis (CFA) was conducted to test the factorial validity. The Spearman correlations of the SWEMWBS with other scales including the 12-item short form health survey (SF-12), family well-being, self-rated health, the global happiness item (GHI), subjective happiness scale (SHS), and patient health questionnaire-4 (PHQ-4), were used to evaluate the convergent and divergent validity. Known-group validity was also assessed. We calculated congeneric reliability based on standardized factor loadings and error variances. Two-week test-retest reliability was assessed in 100 randomly selected respondents using intraclass correlation coefficient (ICC). RESULTS: Among the weighted sample, 55.9% were female and 72.9% were 25 to 64 years old. The CFA indicated good validity of the SWEMWBS. The SWEMWBS had moderate correlations with SHS, SF-12 mental component, PHQ-4 and GHI, but a weak correlation with SF-12 physical component. Older respondents, those with higher education level, married, working, with higher household income reported higher level of well-being. The congeneric reliability of the SWEMWBS was 0.85. Moderate to good test-retest reliability was observed (ICC 0.70, 95% CI 0.55 to 0.80). CONCLUSION: The Chinese SWEMWBS showed good validity and reliability for measuring well-being in the general population of Hong Kong.

Increasing socioeconomic disparities in sedentary behaviors in Chinese children.

BACKGROUND: Sedentary behaviors are prevalent in Chinese children, however, the studies on their trends and socioeconomic disparities are scarce. We examined the time trends of daily television (TV) viewing and video game playing and the associated socioeconomic factors in Chinese children in Hong Kong, the most developed and westernized city in China. METHODS: In a panel data study involving 538,300 primary four and 510,294 primary six students from 1999/2000 to 2008/09, data on socioeconomic status, sedentary behaviors (TV viewing and video game playing) and other lifestyle habits were collected using a self-administered questionnaire. Trends in sedentary behaviors over time were assessed. Their socioeconomic disparities were examined by interactions in generalized estimating equations with the adjustment for weight status and extracurricular physical activities. RESULTS: The age and sex-standardized prevalence of ≥2 h daily TV viewing decreased from 51.4% (95% confidence interval [CI] 51.1-51.8%) in 1999/2000 to 43.8% (95% CI 43.4-44.2%) in 2008/09 (P for trend < 0.001), whereas that of ≥1 h daily video game playing increased from 8.2% (95% CI 7.9-8.4%) to 22.4% (95% CI 22.0-22.7%). Both sedentary behaviors were more prevalent in boys than girls, but the disparities decreased over time (Ratio of odds ratio [ROR] = 0.996 and 0.924 for TV viewing and video game playing, respectively). In contrast, both sedentary behaviors were increasingly more prevalent in children whose parents had lower education levels or non-managerial/professional occupations (ROR 1.006-1.082). CONCLUSIONS: Children in lower socioeconomic families in Hong Kong were increasingly at risk of having sedentary behaviors over years and thus deserve more attention. Effective strategies targeting children and/or their parents of lower socioeconomic status are needed to reduce sedentary behaviors.

Secondhand Smoke From Multiple Sources, Thirdhand Smoke and Respiratory Symptoms in Hong Kong Adolescents.

Introduction: Reports on involuntary tobacco smoke exposure in children have focused mostly on secondhand smoke (SHS) from smoking inside the home. We studied the separate and combined prevalence of SHS exposure from multiple sources and thirdhand smoke (THS) and the associations with respiratory symptoms in Hong Kong adolescents. Methods: In 2010-2011, 61 810 Secondary 1 (US Grade 7) to seven students reported their smoking status, respiratory symptoms, and exposure to four sources of tobacco smoke in the past 7 days. Weighted prevalence of exposure was calculated. Associations with respiratory symptoms were analyzed in 50 762 never smokers using logistic regression. Results: Tobacco smoke exposure at home was 23.2% considering SHS exposure from inside the home, but increased to 33.2% including SHS from neighbors and 36.2% further including THS. Including SHS outside home (55.3%), 63.3% of adolescents were exposed to SHS anywhere or THS at home. In never smokers, SHS from each source and THS at home were linearly associated with respiratory symptoms. Exposure to more sources yielded stronger associations with respiratory symptoms (p for trend<.001). The adjusted odds ratios (95% CI) were 1.04 (0.97-1.11), 1.12 (1.03-1.22), 1.40 (1.26-1.56) and 1.99 (1.74-2.28) for 1, 2, 3, and 4 sources, respectively. Conclusions: Although Hong Kong's smoking prevalence is among the lowest in the developed world, over 60% of its adolescents were involuntarily exposed to tobacco smoke from one or more sources with a linear association with respiratory symptoms in never smokers. More stringent policies are needed to protect adolescents from tobacco smoke. Implications: In a high-density urban setting, involuntary exposure to tobacco smoke in adolescents can be much higher than the smoking prevalence of the general population, especially if SHS exposure from multiple sources and THS are also considered. Such exposures have important health implications as demonstrated by their linear associations with respiratory symptoms. Tobacco control measures effective in reducing smoking prevalence may have little effect in reducing adolescent exposure to tobacco smoke, especially in the private home, in which other public health strategies are urgently needed.

Associations of unhappiness with sociodemographic factors and unhealthy behaviours in Chinese adolescents.

Background: Evidence on the effects of lack of physical exercise, alcohol drinking and smoking on happiness is limited and inconsistent. We examined the associations of unhappiness with sociodemographic factors and these unhealthy behaviours in Chinese adolescents. In a school-based survey in 2012-13 in Hong Kong, 45 857 secondary school students (mean age 14.8 years, 54.0% boys) reported their happiness level (not happy at all/not very happy/happy/very happy), frequency of physical exercise, alcohol drinking status, smoking status and sociodemographic factors. A main and a sensitivity analysis examined the associations of unhappiness with the study factors, treating unhappiness as a binary (combining 'not happy at all' and 'not very happy') and a four-level ordered variable, respectively. The main and the sensitivity analysis both showed that unhappiness was associated with older age, very poor families, non-intact families, more co-residing smokers, lack of physical exercise and alcohol drinking; current smokers were unhappier than never and ex-smokers; unhappiness also increased significantly with the number of unhealthy behaviours ( P for trend < 0.001). In Chinese adolescents, unhappiness levels were higher in those who had a very poor family, a non-intact family and more co-residing smokers, and in those who were physically inactive, drank alcohol and smoked.

Mediating effects of body composition between physical activity and body esteem in Hong Kong adolescents: a structural equation modeling approach.

This study investigated the mediating role of body mass index (BMI) in the relationship between physical activity and body esteem in adolescents. Nine hundred and five Hong Kong Chinese students aged 12-18 years participated in a cross-sectional study in 2007. Students' BMI was computed as an indicator of their body composition. Their physical activity level and body esteem were examined using the Physical Activity Rating for Children and Youth (PARCY) and Body Esteem Scale (BES), respectively. Structural equation modelling was used to investigate the mediating effects of BMI and physical activity in predicting body esteem, with stratification by sex. The overall fit of the hypothesized models was satisfactory in boys (NFI = 0.94; NNFI = 0.88; CFI = 0.95; RMSEA = 0.07) and girls (NFI = 0.89; NNFI = 0.77; CFI = 0.91; RMSEA = 0.11). When BMI was considered as a mediator, higher physical activity had a significant negative total effect on body esteem in boys, but not in girls. The indirect effect of higher physical activity on body esteem via BMI was positive in boys, but negative in girls. CONCLUSIONS: Regular physical activity may help overweight adolescents, especially boys, improve their body esteem. Kinesiologists and health professionals could explore the use of physical activity prescriptions for weight management, aiming at body esteem improvement in community health programs for adolescents. WHAT IS KNOWN: Among Western adolescents, negative body esteem is more pervasive in girls than in boys. There are consistent findings of the association between higher body mass index and lower body esteem in adolescents, but the association between physical activity and body esteem are equivocal. WHAT IS NEW: A negative association between body mass index and body esteem was found in both Hong Kong adolescent boys and girls. The indirect effect of physical activity on body esteem via body mass index was positive in Hong Kong adolescent boys, but negative in girls.