rang: Reconstructing reproducible R computational environments.

A complete declarative description of the computational environment is usually missing when researchers share their materials. Without such description, software obsolescence and missing system components can jeopardize computational reproducibility in the future, even when data and computer code are available. The R package rang is a complete solution for generating the declarative description for other researchers to automatically reconstruct the computational environment at a specific time point. The reconstruction process, based on Docker, has been tested for R code as old as 2001. The declarative description generated by rang satisfies the definition of a reproducible research compendium and can be shared as such. In this contribution, we show how rang can be used to make otherwise unexecutable code, spanning fields such as computational social science and bioinformatics, executable again. We also provide instructions on how to use rang to construct reproducible and shareable research compendia of current research. The package is currently available from CRAN (https://cran.r-project.org/web/packages/rang/index.html) and GitHub (https://github.com/chainsawriot/rang).

Whose research benefits more from Twitter? On Twitter-worthiness of communication research and its role in reinforcing disparities of the field.

Twitter has become an important promotional tool for scholarly work, but individual academic publications have varied degrees of visibility on the platform. We explain this variation through the concept of Twitter-worthiness: factors making certain academic publications more likely to be visible on Twitter. Using publications from communication studies as our analytical case, we conduct statistical analyses of 32187 articles spanning 82 journals. Findings show that publications from G12 countries, covering social media topics and published open access tend to be mentioned more on Twitter. Similar to prior studies, this study demonstrates that Twitter mentions are associated with peer citations. Nevertheless, Twitter also has the potential to reinforce pre-existing disparities between communication research communities, especially between researchers from developed and less-developed regions. Open access, however, does not reinforce such disparities.

Adopting YouTube to Promote Health: Analysis of State Health Departments.

INTRODUCTION: We describe videos posted to the YouTube video-sharing Web site by US state health departments (SHDs) and associated institutional factors. METHODS: YouTube channels from SHDs were identified, their data retrieved, and their videos saved to a playlist on January 10, 2016. Ten randomly sampled videos from each channel were manually coded for topics. The 2012 Association of State and Territorial Health Officials profile survey was used to obtain information on staff, expenditure, and top 5 priorities for each SHD. Descriptive statistics and univariable regression were conducted. RESULTS: Forty-three SHDs had YouTube channels. Together, all SHDs posted 3957 videos, accumulated 12,151,720 views, and gained 6302 subscribers. In total, 415 videos were manually coded. Information about the agency (17.6%), communicable diseases (12.5%), and mother/infant health (8.9%) comprised the largest share of topics. No statistically significant association was observed between the log-transformed number of videos posted on an SHD's YouTube channel and any of the explanatory variables of SHD staffing and expenditure in 2011. The number of full-time employees (r = 0.34, p = 0.03), number of epidemiologists and biostatisticians (r = 0.41, p = 0.01), and 2011 total year expenditure (r = 0.38, p = 0.02) were positively correlated with the log-transformed number of views per YouTube video posted by SHDs. No meaningful patterns of statistical association were observed between the percentage of expenditure on a specific program area and the topics of videos. CONCLUSION: Most SHDs are using YouTube, which provides a unique opportunity for SHDs to disseminate health messages.

How did Ebola information spread on twitter: broadcasting or viral spreading?

BACKGROUND: Information and emotions towards public health issues could spread widely through online social networks. Although aggregate metrics on the volume of information diffusion are available, we know little about how information spreads on online social networks. Health information could be transmitted from one to many (i.e. broadcasting) or from a chain of individual to individual (i.e. viral spreading). The aim of this study is to examine the spreading pattern of Ebola information on Twitter and identify influential users regarding Ebola messages. METHODS: Our data was purchased from GNIP. We obtained all Ebola-related tweets posted globally from March 23, 2014 to May 31, 2015. We reconstructed Ebola-related retweeting paths based on Twitter content and the follower-followee relationships. Social network analysis was performed to investigate retweeting patterns. In addition to describing the diffusion structures, we classify users in the network into four categories (i.e., influential user, hidden influential user, disseminator, common user) based on following and retweeting patterns. RESULTS: On average, 91% of the retweets were directly retweeted from the initial message. Moreover, 47.5% of the retweeting paths of the original tweets had a depth of 1 (i.e., from the seed user to its immediate followers). These observations suggested that the broadcasting was more pervasive than viral spreading. We found that influential users and hidden influential users triggered more retweets than disseminators and common users. Disseminators and common users relied more on the viral model for spreading information beyond their immediate followers via influential and hidden influential users. CONCLUSIONS: Broadcasting was the dominant mechanism of information diffusion of a major health event on Twitter. It suggests that public health communicators can work beneficially with influential and hidden influential users to get the message across, because influential and hidden influential users can reach more people that are not following the public health Twitter accounts. Although both influential users and hidden influential users can trigger many retweets, recognizing and using the hidden influential users as the source of information could potentially be a cost-effective communication strategy for public health promotion. However, challenges remain due to uncertain credibility of these hidden influential users.

Twitter and Middle East respiratory syndrome, South Korea, 2015: A multi-lingual study.

BACKGROUND: Different linguo-cultural communities might react to an outbreak differently. The 2015 South Korean MERS outbreak presented an opportunity for us to compare tweets responding to the same outbreak in different languages. METHODS: We obtained a 1% sample through Twitter streaming application programming interface from June 1 to 30, 2015. We identified MERS-related tweets with keywords such as 'MERS' and its translation in five different languages. We translated non-English tweets into English for statistical comparison. RESULTS: We retrieved MERS-related Twitter data in five languages: Korean (N = 21,823), English (N = 4024), Thai (N = 2084), Japanese (N = 1334) and Indonesian (N = 1256). Categories of randomly selected user profiles (p < 0.001) and the top 30 sources of retweets (p < 0.001) differed between the five language corpora. Among the randomly selected user profiles, K-pop fans ranged from 4% in the Korean corpus to 70% in the Thai corpus; media ranged from 0% (Thai) to 14% (Indonesian); political advocates ranged from 0% (Thai) to 19% (Japanese); medical professionals ranged from 0% (Thai) to 7% (English). Among the top 30 sources of retweets for each corpus (150 in total), 70 (46.7%) were media; 29 (19.3%) were K-pop fans; 7 (4.7%) were political; 9 (6%) were medical; and 35 (23.3%) were categorized as 'Others'. We performed chi-square feature selection and identified the top 20 keywords that were most unique to each corpus. CONCLUSION: Different linguo-cultural communities exist on Twitter and they might react to the same outbreak differently. Understanding audiences' unique Twitter cultures will allow public health agencies to develop appropriate Twitter health communication strategies.

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 ß2-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.

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 c(2) 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.

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

BACKGROUND: Internet 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. METHODS: Multiple 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. RESULTS: This 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. CONCLUSIONS: Explanations are given for the findings. We conclude that intervention programs designed to serve as precautionary measures for risk minimisation should be considered.

Natural history of snoring in Hong Kong adolescents.

AIM: To determine the natural history of snoring in children when they reached adolescence and the underlying risk factors for persistence of habitual snoring. METHODS: A follow-up telephone survey was conducted to determine the natural history of snoring in children who reached adolescence. The targeted interviewees of the follow-up survey were parents of 3047 children. Adolescents who were snoring ≥6 nights a week were defined as habitual snorers. Potential risk factors for persistent and incident habitual snoring were studied, including age, gender, allergic rhinitis, asthma, body mass index (BMI), sleep duration and daytime sleepiness. RESULTS: Of the 3047 subjects, 2005 (65.8%) were successfully interviewed by phone. The prevalence of habitual snorers was 12.7%. Ninety-one adolescents were persistent habitual snorers. Allergic rhinitis, male gender and higher BMI at follow-up were identified as significant risk factors for persistent habitual snoring. A further 163 children were identified as incident habitual snorers. The risk factors for incident habitual snoring included male gender, asthma, higher BMI at follow-up and younger age at the first survey. In the current study, the mean sleep duration was 7.6 ± 1.0 h. Overall, 90% of the current cohort slept less than the lower limit of international recommendations for sleep duration. CONCLUSIONS: Around 40.6% of habitually snoring children continued to snore habitually as adolescents in the current study, while 9.2% of the initial non-habitual snorers became habitual snorers. Male gender and higher BMI were significant risk factors for both persistent and incident habitual snoring.

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

BACKGROUND: As 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. METHODS: Keyword 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. RESULTS: The 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. CONCLUSIONS: These results demonstrate that social media could be a useful measure of public awareness and reaction to disease outbreak information released by health authorities.

A review of normal values of infant sleep polysomnography.

BACKGROUND: The objective of this study was to summarize current information about the normal values on infant sleep polysomnography for clinical use. METHODS: MEDLINE (Ovid), EMBASE (Ovid), and CINAHL (Ovid) from January 1976 to May 2007 were searched. Two reviewers independently reviewed all relevant articles, using preset inclusion criteria. The population of interest included children aged less than 1 year. Studies in infants with known major anomalies were excluded. The results on apneas were extracted and analyzed. RESULTS: For obstructive apnea, the upper limit of normal values was less than 1.0 per hour, and for mixed apnea, the current data suggested the upper limit of normal values was less than 1.0 per hour. For central apnea defined as cessation of respiratory efforts for more than 3 seconds, the current data suggested that the upper limit of the normal central apnea index was 45 per hour for 1-month-old infants, 30 per hour for 2-month-old infants, 22 per hour for 3-month-old infants, and between 10 and 20 for the older age groups. For the desaturation episode defined as SpO2 less than 80% for any length of time, the current data suggested the upper limit of normal values to be 14.7 episodes per hour for day 1, 41 episodes for day 4, and 15.1 episodes for day 39. CONCLUSION: The normal values of obstructive apnea, mixed apnea, and central apnea are well established for neonates and infants. With these normal values, sleep polysomnography study should be routinely used to quantify the severity of breathing disorders during sleep in those neonates at risk for these disorders.

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.

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

PURPOSE: The aim of this study was to study the interactions among age, gender, and snoring across all age groups METHODS: All 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. RESULTS: From 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, τ (2) 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. CONCLUSION: This 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.

Risk factors for post-operative complications in Chinese children with tonsillectomy and adenoidectomy for obstructive sleep apnea syndrome.

PURPOSE: Tonsillectomy and adenoidectomy (T&A) is commonly performed in children with obstructive apnea syndrome (OSAS). It was our hospital practice to observe all patients post T&A in the pediatric intensive care unit. We aim to describe the post-operative complications after tonsillectomy and adenoidectomy in children with OSAS and to identify risk factors for these complications. METHOD: Medical records of patients from 1 to 16 years old with OSAS and T&A done in this department were retrieved for analysis from April 1999 to July 2006. Information of the individual patients including the demographic data, polysomnography data, and presence of post-operative complications were recorded and analyzed. RESULTS: A total of 86 patient records were analyzed (M/F = 69:17). The mean BMI z score was 1.13 ± 1.53, and 36% of patients were classified as obese with z > 1.96. The median apnea-hypopnea index (AHI) before T&A was 9.8 episodes/h. Only six patients had post-operative desaturation. No bleeding complications were reported in our cohort. It was found that patients with desaturation after T&A had significantly higher mean BMI z score than children without desaturation (p = 0.014). There was otherwise no significant difference between the age, sex, AHI score, and the history of allergic rhinitis or asthma between the two groups. CONCLUSION: Our results showed that most children with OSAS underwent T&A without complications. The respiratory complication rate was 7%, and desaturation was the most common post-operative complication. Children with higher BMI z score were more likely to have desaturation after T&A (p = 0.014). Hence, careful monitoring with pulse oximeter after T&A should be offered to those who are obese.

Validation of Pediatric Index of Mortality 2 in three pediatric intensive care units in Hong Kong.

OBJECTIVE: To compare the probabilities of death predicted by Pediatric Index of Mortality 2 (PIM2) and Pediatric Index of Mortality 1 (PIM1) models against actual mortalities in 3 pediatric intensive care units in Hong Kong. METHODS: All consecutive patients admitted to pediatric intensive care units in 3 regional non-teaching hospitals between Jan 2006 and December 2006 were included. The data required for PIM1 and PIM2 were collected. The probabilities of death predicted by PIM1 and PIM2 were validated against the actual probability of mortality. RESULTS: Of the 540 patients were included in this study, only seven deaths were observed (1.3%). PIM 1 and PIM 2 overestimated the mortality rate by giving a greater mortality rate. (PIM1: 13.4, Standardized mortality ratio = 0.52, 95% CI = 0.14 to 0.91; PIM2: 14.2, Standardized mortality ratio =0.49, 95% CI = 0.13 to 0.86) The discrimination of PIM1 and PIM2 were satisfactory as reflected by area under receiver-operator characteristic curve of 0.889 (95% CI: 0.703 to 1.000) and 0.904 (95% CI: 0.738 to 1.000) respectively. Calibration was not possible due to insufficient death cases. CONCLUSIONS: The current study showed that PIM2 and PIM1 had similar accuracy in mortality prediction in Hong Kong. The current study also demonstrated the difficulty to calibrate the mortality model when actual mortality rate is low.

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.

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.