Chung-hong Chan

Ambulatory blood pressure before and after adenotonsillectomy in children with obstructive sleep apnea.

INTRODUCTION Hypertension is found to be associated with obstructive sleep apnea (OSA) in both children and adults. But data on the effect of blood pressure after adenotonsillectomy (AT) for children with OSA are limited and controversial. OBJECTIVE To assess the impact of AT on different parameters of 24-h ambulatory blood pressure monitoring in children with OSA. METHODS We retrospectively reviewed records of OSA children who had undergone AT and a repeated sleep polysomnography after AT from 2001 to 2008. RESULTS Forty-four children were identified and included in the analysis. The mean apnea-hypopnea index (AHI) dropped from 14.14+/-15.9 to 3.3+/-7.1. (p<0.001). Twenty (45%) were cured of OSA. After AT, the diastolic BP load decreased significantly. Six out of eight (75%) hypertensive children became normotensive after surgery. For the pre-AT hypertensive group, both systolic and diastolic blood pressure decreased significantly during sleep after AT. However, eight children who were normotensive before AT became hypertensive after AT. These 10 post-AT hypertensive patients were more likely to have post-AT AHI>1 than the post-AT normotensive group, although the difference did not reach statistical significance. CONCLUSION In the current cohort of OSA children, 44% were cured of OSA and a significant decrease in overall diastolic blood pressure load in 24-h ambulatory blood pressure was achieved after adenotonsillectomy for children with OSA. But hypertension may persist or even occur in those previously normotensive children despite the improvement in AHI. Persistence of OSA may be a risk factor and further study is required. Cure of OSA should not be assumed after AT and follow-up PSG should be performed together with 24-h ambulatory blood pressure monitoring. In light of the current findings, long term study of the blood pressure is warranted for children with OSA.

Chinese social media reaction to the MERS-CoV and avian influenza A(H7N9) outbreaks

BackgroundAs internet and social media use have skyrocketed, epidemiologists have begun to use online data such as Google query data and Twitter trends to track the activity levels of influenza and other infectious diseases. In China, Weibo is an extremely popular microblogging site that is equivalent to Twitter. Capitalizing on the wealth of public opinion data contained in posts on Weibo, this study used Weibo as a measure of the Chinese people’s reactions to two different outbreaks: the 2012 Middle East Respiratory Syndrome Coronavirus (MERS-CoV) outbreak, and the 2013 outbreak of human infection of avian influenza A(H7N9) in China.MethodsKeyword searches were performed in Weibo data collected by The University of Hong Kong’s Weiboscope project. Baseline values were determined for each keyword and reaction values per million posts in the days after outbreak information was released to the public.ResultsThe results show that the Chinese people reacted significantly to both outbreaks online, where their social media reaction was two orders of magnitude stronger to the H7N9 influenza outbreak that happened in China than the MERS-CoV outbreak that was far away from China.ConclusionsThese results demonstrate that social media could be a useful measure of public awareness and reaction to disease outbreak information released by health authorities.

An update on childhood snoring

Habitual snoring or daily snoring is a symptom of sleep‐disordered breathing (SDB) in children and it is reported in about 10% of children. SDB includes primary snoring, upper airway resistance syndrome (UARS), obstructive hypoventilation syndrome and obstructive sleep apnea syndrome (OSAS). Classification of SDB in a particular snoring child requires an overnight polysomnography (PSG). Manual scoring of PSG is mandatory in children. Risk factors for SDB include allergic rhinitis, passive smoking, obesity, dysmorphic syndromes and neuromuscular disorders. Conclusion: Treatment includes general measures like treatment of allergic rhinitis, weight reduction in obese children, and avoidance of sleep deprivation. Specific measures include removal of adenoid and tonsils. Complications of SDB include neurocognitive impairment, hypertension and failure to thrive.

Non-contact infrared thermometry temperature measurement for screening fever in children

Abstract Background: During the SARS epidemic, mass fever screening at border control points and public hospitals was done by measuring forehead temperature by non-contact infrared thermometry. However, its accuracy is not well documented. Methods: We evaluated the agreement of non-contact infrared forehead temperature (NIFT) measurement by comparing NIFT readings with tympanic temperatures taken in children (1 mth to 18 yrs) admitted to the general paediatric wards of Kwong Wah Hospital, Hong Kong. Results: A total of 567 patients were recruited and 1000 pairs of readings were obtained. The incidence of fever, defined as tympanic temperature (in rectal model) >38°C (100.4°F), was 12.3%. The mean difference between NIFT and tympanic temperature was 2.34°C (4.21°F) and the 95% limit of agreement between NIFT and tympanic temperature was 0.26–4.42°C (0.47–7.96°F). NIFT was significantly lower than tympanic temperature readings. The optimal cut-off point of NIFT derived from the receiver-operator characteristics curve for fever definition was 35.1°C (95.2°F). The sensitivity, specificity, positive predictive value and negative predictive value of this cut-off point for fever screening were 89.4%, 75.4%, 33.7% and 98.1%, respectively. Conclusions: NIFT measurement has a reasonable accuracy in detecting tympanic fever in children. However, one should be aware of the high false-positive rate of fever screening using NIFT.

Heart rate variability in childhood obstructive sleep apnea.

The identification of patients with obstructive sleep apnea (OSA) is important because of morbidities associated with OSA. A previous adult study demonstrated the use of heart rate variability (HRV) as a tool to identify patients with moderate to severe OSA. Either a reduction in time parameters or an increase in LF/HF ratio was seen at overnight or 24‐hr studies suggestive of increased sympathetic modulation. To study the feasibility of daytime HRV as a screening tool, a short‐term recording of HRV is studied. Since it was shown in adult study that increased normalized LF, decreased normalized HF and increased LF/HF ratio could be detectable during supine rest at daytime awake period, the authors hypothesize that the differences are also detectable in children. Children who underwent sleep polysomnography for suspected OSA were recruited. Subjects were classified OSA if apnea‐hypopnea index (AHI) > 1.5/hr and non‐OSA if AHI ≤ 1.5/hr. Continuous 1‐hr electrocardiographic monitoring was recorded in awake children during the day. Parameters from time domain and frequency domain were analyzed. Seventy‐four male and 17 female snoring subjects were included in this study. Fifty‐one (56%) and 40 (44%) of them were classified as “non‐OSA” and “OSA,” respectively. pNN50, a parameter for parasympathetic modulation, was significantly reduced in the OSA group when compared with the non‐OSA group. Using multiple regression, all time domain variables were shown to be decreased in OSA group. Our results suggest that 1‐hr study of HRV may be a feasible tool in identifying children with OSA. Pediatr Pulmonol. 2011; 46:205–210.

Social Media's Initial Reaction to Information and Misinformation on Ebola, August 2014: Facts and Rumors.

Objective. We analyzed misinformation about Ebola circulating on Twitter and Sina Weibo, the leading Chinese microblog platform, at the outset of the global response to the 2014–2015 Ebola epidemic to help public health agencies develop their social media communication strategies. Methods. We retrieved Twitter and Sina Weibo data created within 24 hours of the World Health Organization announcement of a Public Health Emergency of International Concern (Batch 1 from August 8, 2014, 06:50:00 Greenwich Mean Time [GMT] to August 9, 2014, 06:49:59 GMT) and seven days later (Batch 2 from August 15, 2014, 06:50:00 GMT to August 16, 2014, 06:49:59 GMT). We obtained and analyzed a 1% random sample of tweets containing the keyword Ebola. We retrieved all Sina Weibo posts with Chinese keywords for Ebola for analysis. We analyzed changes in frequencies of keywords, hashtags, and Web links using relative risk (RR) and c2 feature selection algorithm. We identified misinformation by manual coding and categorizing randomly selected sub-datasets. Results. We identified two speculative treatments (i.e., bathing in or drinking saltwater and ingestion of Nano Silver, an experimental drug) in our analysis of changes in frequencies of keywords and hashtags. Saltwater was speculated to be protective against Ebola in Batch 1 tweets but their mentions decreased in Batch 2 (RR=0.11 for “salt” and RR=0.14 for “water”). Nano Silver mentions were higher in Batch 2 than in Batch 1 (RR=10.5). In our manually coded samples, Ebola-related misinformation constituted about 2% of Twitter and Sina Weibo content. A range of 36%–58% of the posts were news about the Ebola outbreak and 19%–24% of the posts were health information and responses to misinformation in both batches. In Batch 2, 43% of Chinese microblogs focused on the Chinese government sending medical assistance to Guinea. Conclusion. Misinformation about Ebola was circulated at a very low level globally in social media in either batch. Qualitative and quantitative analyses of social media posts can provide relevant information to public health agencies during emergency responses.

Gender difference in snoring and how it changes with age: systematic review and meta-regression.

PurposeThe aim of this study was to study the interactions among age, gender, and snoring across all age groupsMethodsAll cross-sectional study reporting gender-specific prevalence of snoring in general population published from 1966 through July 2008 were included and were meta-analyzed. The sources of heterogeneity among primary studies were studied by meta-regression.ResultsFrom a total of 1,593 citations reviewed, 63 were included in the analysis of snoring. These 63 studies were comprised 104,337 and 110,474, respectively. A combined odds ratio of 1.89 with a 95% confidence interval of 1.75–2.03 for male versus female was found. The heterogeneity was significant with an estimated between-study variance, τ2 being 0.065 and 95% confidence interval of 0.0397–0.0941. Multiple meta-regression showed that age were the significant effect modifier of the relationship between snoring and gender.ConclusionThis study found a consistent male predominance in snoring among the general population, and the heterogeneity in the risk of snoring between two genders can be partly explained by age.

Exploring the relationship between cyberbullying and unnatural child death: an ecological study of twenty-four European countries

BackgroundInternet risk has been recognised as a child safety problem, but evidence is insufficient to conclude that a child’s online risk exposure can lead to physical harm. This study aims to explore the ecological relationship between Internet risk exposure and unnatural child death.MethodsMultiple secondary data sources were used: online exposure to content about self-harm, cyberbullying, and Internet addiction data (EU Kids Online survey, 2010); and mortality data (European Detailed Mortality Database, 2010 or the latest year if not available) of 24 European countries. Correlations were found using quasi-Poisson regression. Countries’ prevalence rates of psychiatric problems (European Social Survey Round 3 and 6, 2006 and 2012) were used to test for possible spuriousness.ResultsThis study finds that countries with higher rates of cyberbullying were more likely to have a higher incidence of unnatural child death. A 1 percent rise in the prevalence of cyberbullying translated into a 28% increase in risk of unnatural child death (95% CI: 2%-57%). No evidence was found to substantiate confounding effect of the national prevalence of depressive symptoms or traditional bullying.ConclusionsExplanations are given for the findings. We conclude that intervention programs designed to serve as precautionary measures for risk minimisation should be considered.

Validation of sleep‐related breathing disorder scale in Hong Kong Chinese snoring children

The purpose of this study is to validate the previously‐validated Taiwan Chinese version of Sleep‐Related Breathing Disorder scale (SRBD scale) in Hong Kong Chinese snoring children. SRBD scale is an instrument used for prediction of obstructive sleep apnea syndrome. (OSA) The Chinese version of SRBD scale were previously translated and validated in Taiwan. The same questionnaire were administered in a group of 102 snoring children (mean age: 10.7 and 65 boys) from a sleep laboratory in Hong Kong before their sleep studies. The SRBD scores were then validated against the results from sleep studies. By using the definition of apnea‐hypopnea index larger than 1.5 as OSA, 28 children (27.5%) had polysomnography‐confirmed OSA. The sensitivity, specificity, positive likelihood ratio and negative likelihood ratio of the previously validated cut‐off of SRBD score > 0.33 for OSA were 0.5, 0.55, 1.12, and 0.90, respectively. The area under ROC curve was only 0.58, indicates suboptimal performance of SRBD score in predicting OSA. In summary, our study concluded that the previously reported Chinese SRBD scale is not accurate in identifying presence of OSA in Hong Kong Chinese snoring children. Pediatr Pulmonol. 2012. 47:795–800.

A randomized placebo-controlled trial of traditional Chinese medicine as an add-on therapy to oral montelukast in the treatment of mild persistent asthma in children

OBJECTIVES Traditional Chinese medicine are commonly used for treatment of asthma. However, there are only very limited data about its efficacy in children. Therefore, we aimed to determine the efficacy of augmented Yu Ping Feng San (aYPFS) as an add-on to oral montelukast compared with montelukast alone for treatment of mild persistent asthma in children. DESIGN A single centre, placebo-controlled, double-blinded, randomized control trial was carried out. Participants with age 6-18 years who had mild persistent asthma were randomized according to random number list to receive either aYPFS plus montelukast for 24 weeks or placebo plus montelukast for 24 weeks. Primary outcome measure was lung function parameters. Secondary outcome measures were Asthma Control Test™ (ACT™) and Paediatric Allergic Disease Quality of Life Questionnaire (PADQLQ) scores, symptom-free days, short-acting β2-agonist use, use of rescue oral corticosteroids, days of hospitalization for asthma and number of emergency consultation with GPs or AED department. RESULTS Twenty-eight participants were randomized to aYPFS group and twenty-nine to placebo group. There was no significant difference in baseline characteristics. There was significant improvement in ACT™ score in aYPFS group (up to 6.9% change from baseline) (p=0.016) but not in the control group. There were no significant differences between groups in other primary and secondary outcome parameters. Dropout because of adverse effects is comparable in both groups. CONCLUSION Traditional Chinese medicine aYPFS as an add-on to montelukast improved symptoms of asthma control. Further studies with larger sample size are needed to evaluate its efficacy and safety in childhood asthma.