Kwok-Kei Mak

The association between internet addiction and psychiatric co-morbidity: a meta-analysis

BackgroundThis study evaluates the association between Internal Addiction (IA) and psychiatric co-morbidity in the literature.MethodsMeta-analyses were conducted on cross-sectional, case–control and cohort studies which examined the relationship between IA and psychiatric co-morbidity. Selected studies were extracted from major online databases. The inclusion criteria are as follows: 1) studies conducted on human subjects; 2) IA and psychiatric co-morbidity were assessed by standardised questionnaires; and 3) availability of adequate information to calculate the effect size. Random-effects models were used to calculate the aggregate prevalence and the pooled odds ratios (OR).ResultsEight studies comprising 1641 patients suffering from IA and 11210 controls were included. Our analyses demonstrated a significant and positive association between IA and alcohol abuse (OR = 3.05, 95% CI = 2.14-4.37, z = 6.12, P < 0.001), attention deficit and hyperactivity (OR = 2.85, 95% CI = 2.15-3.77, z = 7.27, P < 0.001), depression (OR = 2.77, 95% CI = 2.04-3.75, z = 6.55, P < 0.001) and anxiety (OR = 2.70, 95% CI = 1.46-4.97, z = 3.18, P = 0.001).ConclusionsIA is significantly associated with alcohol abuse, attention deficit and hyperactivity, depression and anxiety.

Epidemiology of Internet Behaviors and Addiction Among Adolescents in Six Asian Countries

Internet addiction has become a serious behavioral health problem in Asia. However, there are no up-to-date country comparisons. The Asian Adolescent Risk Behavior Survey (AARBS) screens and compares the prevalence of Internet behaviors and addiction in adolescents in six Asian countries. A total of 5,366 adolescents aged 12-18 years were recruited from six Asian countries: China, Hong Kong, Japan, South Korea, Malaysia, and the Philippines. Participants completed a structured questionnaire on their Internet use in the 2012-2013 school year. Internet addiction was assessed using the Internet Addiction Test (IAT) and the Revised Chen Internet Addiction Scale (CIAS-R). The variations in Internet behaviors and addiction across countries were examined. The overall prevalence of smartphone ownership is 62%, ranging from 41% in China to 84% in South Korea. Moreover, participation in online gaming ranges from 11% in China to 39% in Japan. Hong Kong has the highest number of adolescents reporting daily or above Internet use (68%). Internet addiction is highest in the Philippines, according to both the IAT (5%) and the CIAS-R (21%). Internet addictive behavior is common among adolescents in Asian countries. Problematic Internet use is prevalent and characterized by risky cyberbehaviors.

Health-related physical fitness and weight status in Hong Kong adolescents

BackgroundThis study was designed to investigate the relation between health-related physical fitness and weight status in Hong Kong adolescents.Methods3,204 students aged 12-18 years participated in the Hong Kong Student Obesity Surveillance (HKSOS) project in 2006-2007. Anthropometric measures (height, weight) and health-related fitness (push-up, sit-up, sit-and-reach, 9-minute run) were assessed. Body mass index (BMI) was computed to classify participants into normal weight, underweight (Grade I, II/III), overweight, and obese groups. The associations of health-related physical fitness with BMI and weight status were examined by partial correlation coefficients and analysis of covariance, respectively.ResultsMore boys than girls were overweight or obese (18.0% vs 8.7%), but more girls than boys were underweight (22.3% vs 16.7%). Boys performed significantly (P < 0.001) better in sit-up (38.8 vs 31.6 times/min) and 9-minute run (1632.1 vs 1353.2 m), but poorer in sit-and-reach (27.4 vs 32.2 cm) than girls. All four physical fitness tests were significantly positively correlated with each other in both sexes, and BMI was only weakly correlated with sit up and sit-and-reach tests in boys. Decreasing performance (P for trend < 0.05) was observed from normal weight to overweight and obese for push-up, sit-up, and 9-minute run in both sexes. From normal weight to Grade I and Grade II/III underweight, decreasing performance (P for trend < 0.05) for sit-up and sit-and-reach in both sexes and for push-up in boys was observed.ConclusionsThe relations between BMI and health-related physical fitness in adolescents were non-linear. Overweight/obese and underweight adolescents had poorer performance in push-up and sit-up tests than normal weight adolescents. Different aspects of health-related physical fitness may serve as immediate indicators of potential health risks for underweight and overweight adolescents.

Comprehensive smoke-free legislation and displacement of smoking into the homes of young children in Hong Kong.

Objective To investigate the effect of comprehensive smoke-free legislation in 2007 on the exposure of children to secondhand smoke (SHS) in Hong Kong. Methods Two cross-sectional questionnaire surveys were conducted, before (2006) and after (2008) the implementation of smoke-free legislation, among primary 2–4 students (equivalent to US grades 2–4) from 19 and 24 randomly selected schools, respectively. Adjusted ORs for SHS exposure at home and outside home post-legislation compared with pre-legislation were calculated. The strength of the association between SHS exposure and respiratory symptoms in each survey was used as an indirect indicator of the intensity of exposure. Results Among 3243 and 4965 never smoking students in the 2006 and 2008 surveys, the prevalence of SHS exposure in the past 7 days increased both at home (from 10.2% to 14.1%) and outside home (from 19.8% to 27.2%). Post-legislation, students were 56% more likely (p<0.01) to report SHS exposure at home coupled with an insignificantly stronger association between SHS exposure and respiratory symptoms. Similarly, students were 60% more likely (p<0.001) to report SHS exposure outside home in 2008, but the association between SHS exposure and respiratory symptoms became insignificantly weaker. Parental smoking rates were similar before and after legislation. Conclusions The prevalence of exposure to SHS at home and outside home have both increased among primary school students in Hong Kong post-legislation. Comprehensive smoke-free legislation without strong support for smoking cessation might have displaced smoking into the homes of young children.

Prevalence of anxiety and depressive symptoms in adolescents with asthma: A meta-analysis and meta-regression

To cite this article: Lu Y, Mak K‐K, van Bever HPS, Ng TP, Mak A, Ho RC‐M. Prevalence of anxiety and depressive symptoms in adolescents with asthma: A meta‐analysis and meta‐regression. Pediatr Allergy Immunol 2012: 23: 707–715.

Smoking and sleep disorders in Chinese adolescents

OBJECTIVE To investigate the association between adolescent smoking and sleep disorders. METHODS In the Hong Kong student obesity surveillance project, 29,397 Chinese students, aged 12-18 years, completed a health survey. Insomnia was defined as having any of the following three symptoms: difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS) and early morning awakening (EMA). The presence of snoring and difficulty breathing during sleep (DBS) was also reported. Logistic regression yielded adjusted odds ratios (ORs) for each sleep disorder by smoking status. RESULTS Compared with never smokers, the ORs (95% CI) of insomnia were 1.39 (1.25-1.54) for experimenters (smoked once or a few times) and 0.91 (0.83-1.00) for current smokers. The corresponding ORs were 1.42 (1.16-1.74) and 3.58 (3.15-4.06) for snoring (P for trend<0.001) and 1.40 (1.10-1.79) and 3.39 (2.97-4.03) for DBS (P for trend<0.001). Current smokers compared with never smokers were less likely to report DIS (OR=0.43, 95% CI=0.38-0.50, P<0.001) and EMA (OR=0.83, 95% CI=0.73-0.94, P=0.003), but more likely to report DMS (OR=1.45, 95% CI=1.28-1.63, P<0.001). CONCLUSIONS In terms of dosage, adolescent smoking was associated with snoring and DBS, with increasing ORs from never smokers to experimental and current smokers. Current smoking was associated positively with DMS, but negatively with DIS and EMA.

Polymorphisms of the serotonin transporter gene and post-stroke depression: a meta-analysis

Background Polymorphisms of the gene encoding the serotonin transporter—specifically, length variation in the serotonin-transporter-linked polymorphic region (5-HTTLPR), a single-nucleotide polymorphism in the 5-HTTLPR (rs25531), and variable number of tandem repeats (VNTR) in the second intron 2 (STin2)—have been implicated in the development of post-stroke depression (PSD). Objective To evaluate the association between polymorphisms of the serotonin transporter gene and PSD in the medical literature. Methods Random-effects meta-analyses were conducted on cross-sectional, case–control and cohort studies examining relations between polymorphisms of the gene encoding the serotonin transporter and the risk of developing PSD. Results Four studies comprising 260 stroke patients with PSD and 381 without were included. Our analyses showed a significant and positive association between the homozygous short variation (S) allele genotype of the 5-HTTLPR (SS) and PSD (random-effects pooled OR 2.05, 95% CI 1.41 to 2.98, z=3.79, p<0.001). Our analyses also showed a significant and negative association between the homozygous long variation (L) allele genotype of the 5-HTTLPR (LL) and PSD (random-effects OR 0.52, 95% CI 0.27 to 0.97, z=−2.07, p=0.039). No statistically significant association of PSD with heterozygous S and L allele genotype for 5-HTTLPR or other polymorphisms with rs25531 and STin2 VNTR was found. Heterogeneity and publication bias were not statistically significant. The major limitation of this meta-analysis is that we could not assess the interaction between stroke, environmental stress and PSD. Conclusions The 5-HTTLPR SS genotype may be a risk factor for PSD. The 5-HTTLPR LL genotype showed a significant negative association with PSD. Further research to assess the sensitivity and specificity of predicting the risk of developing PSD by screening for the 5-HTTLPR genotype in stroke patients is required.

Views on the peer review system of biomedical journals: an online survey of academics from high-ranking universities

BackgroundPeer review is the major method used by biomedical journals for making the decision of publishing an article. This cross-sectional survey assesses views concerning the review system of biomedical journals among academics globally.MethodsA total of 28,009 biomedical academics from high-ranking universities listed by the 2009 Times Higher Education Quacquarelli Symonds (THE-QS) World University Rankings were contacted by email between March 2010 and August 2010. 1,340 completed an online survey which focused on their academic background, negative experiences and views on biomedical journal peer review and the results were compared among basic scientists, clinicians and clinician scientists.ResultsFewer than half of the respondents agreed that the peer review systems of biomedical journals were fair (48.4%), scientific (47.5%), or transparent (25.1%). Nevertheless, 58.2% of the respondents agreed that authors should remain anonymous and 64.4% agreed that reviewers should not be disclosed. Most, (67.7%) agreed to the establishment of an appeal system. The proportion of native English-speaking respondents who agreed that the “peer review system is fair” was significantly higher than for non-native respondents (p = 0.02). Similarly, the proportion of clinicians stating that the “peer review system is fair” was significantly higher than that for basic scientists and clinician-scientists (p = 0.004). For females, (β = −0.1, p = 0.03), the frequency of encountering personal attacks in reviewers’ comments (β = −0.1, p = 0.002) and the frequency of imposition of unnecessary references by reviewers (β = −0.06, p = 0.04) were independently and inversely associated with agreement that “the peer review system is fair”.ConclusionAcademics are divided on the issue of whether the biomedical journal peer review system is fair, scientific and transparent. A majority of academics agreed with the double-blind peer review and to the establishment of an appeal system. Female academics, experience of personal attacks and imposition of unnecessary references by reviewers were related to disagreement about fairness of the peer review system of biomedical journals.

Smoking of Parents and Best Friend—Independent and Combined Effects on Adolescent Smoking and Intention to Initiate and Quit Smoking

INTRODUCTION This study investigates the independent and combined effects of smoking of parents and best friend on smoking and the intention to initiate or quit smoking in adolescents. METHODS In this school-based survey, 6,553 Hong Kong students aged 13-18 reported their demographic characteristics, smoking status of themselves, parents, and best friend; and intention to smoke (initiation among never-smokers and reinitiation among ex-smokers) or quit smoking among current smokers. Logistic regression yielded adjusted odds ratios (AORs) of student smoking (current/ever) and intention to smoke or quit smoking for parental (paternal/maternal/both parents vs. none) and best friend (yes vs. no) smoking. RESULTS Parental smoking and having a smoking best friend were associated with adolescent current smoking, ever smoking, and intention to initiate smoking. Having a smoking best friend was also associated with reinitiating and quitting smoking. The AORs (95% CI) of current smoking for having a smoking best friend, in addition to smoking father, mother, or both were 19.14 (14.36-25.51), 20.38 (12.42-33.43), and 24.18 (15.89-36.77). The respective AORs of ever smoking were 8.30 (6.74-10.22), 8.92 (5.63-14.12), and 11.99 (8.05-17.87). CONCLUSIONS Parental smoking and best friend smoking have independent effects on adolescent smoking behaviors. Their combined effects on current and ever smoking were particularly large. Smoking prevention programs should pay special attention to adolescents with both best friend and parents who smoke.

The associations of sociocultural attitudes towards appearance with body dissatisfaction and eating behaviors in Hong Kong adolescents

OBJECTIVES Western culture has great influences on body dissatisfaction and related eating behaviors in adolescents. This study aimed to assess the sociocultural influences on eating attitudes and motivations among Hong Kong Chinese adolescents. METHODS In 2007, 909 adolescents (mean age = 14.7 years, 55.3% boys) completed a survey with Stunkards Figure Rating Scale (FRS), Motivation for Eating Scale (MFES), Eating Attitudes Test (EAT), Revised Restraint Scale (RRS), and Sociocultural Attitudes Towards Appearance Scale (SATAQ). In addition, their body mass index (BMI) was objectively measured. RESULTS Our results indicated that Hong Kong adolescents, particularly girls exhibited a remarked level of body dissatisfaction, external, emotional, restrained and disordered eating behaviors. Hierarchical regression analyses indicated that age, sex and BMI were the most common contributing factors to individual eating styles. SATAQ significantly accounted for an additional variance of body dissatisfaction (2%), physical eating (2%), external eating (1%), emotional eating (3%), restrained eating (5%), and disordered eating (5%). CONCLUSIONS In Hong Kong, the sociocultural influences on body image and eating disturbance were supported.