The primarily goal of this study was to examine the patterns of cognitive and language processing of children with Specific Language Impairment (SLI) and how they related to their text comprehension, interpreted within constructivism. The study aimed to characterize the difference in language, character decoding, metacognitive processing and text comprehension between children with SLI and those under typical development; to identify the inter-relationships among their language processing, character decoding, metacognitive processing and text comprehension; and to investigate how the implementation of cognitive reading strategies instruction change their language processing, character decoding, metacognitive processing, belief towards reading and text comprehension. Two studies were carried out. In Study One, 73 participants were recruited from two Hong Kong primary schools; they were at second and third grade, 42 were diagnosed of SLI and the other were under typical development. Standardized instruments were used to tap children’s language processing and character decoding respectively. Researcher developed Metacognitive Processing Scale were adopted to rate their metacognitive and deep processing of text. A set of comprehension test, comprised of forced-choice inferential questions and two recall tasks, were used to assess their depth in understanding different types of text. Analyses indicated that SLI students did not only score poorer in language processing, but also in character decoding, metacognitive processing and text comprehension. Further analyses of both the entire sample and the SLI sample, indicated that there were significant correlations between character decoding, language processing, metacognitive processing with children’s text comprehension scores. In Study Two, there were 40 participants recruited from the SLI sample of the Study One. Cognitive reading strategy instruction program were developed. 21 participants was randomly selected to receive the experimental instruction and the another 19 were under conventional instruction as control. Besides the measures used in the Study One, interviews and teacher-reporting questionnaires were used to tap children’s belief towards reading and their classroom engagement. Analysis of pre-instruction and post-instruction tests indicated the experimental children showed significantly better progress on their oral language, text comprehension and belief about reading. Both the experimental and the control group showed similar progress on character decoding. The study offers both theoretical and educational contribution on the literacy development among the population of SLI. It identifies the role of metacognitive processing on literacy achievement. It provides the evidence of implementing cognitively-based reading strategies for literacy instruction for children with SLI within Chinese context. Upon the introduction of inclusive education, teachers now face students with much wider diversity, including a significant number of children with SLI. Possible collaboration between frontline teachers and speech therapists in designing potential classroom activities is discussed. / published_or_final_version / Education / Doctoral / Doctor of Education

Background: Although perception predicts behaviours in general, it is less clear whether perceived peer smoking prevalence is associated with smoking among children. Although the harmful effects of smoking and secondhand smoke (SHS) exposure on health are well documented, little is known about the influence of SHS exposure on smoking behaviours, and the effects of smoking on perceived health. Objectives: This thesis aims to investigate the associations of (1) overestimation of peer smoking prevalence and smoking initiation, (2) self-rated health (SRH) with smoking and SHS exposure, and (3) SHS exposure at home with smoking initiation, tobacco addiction and smoking cessation, among an under-studied population of Chinese children in Hong Kong. Methods: A prospective study among primary school students (n = 2171) was conducted in 2006 (baseline) and followed up in 2008. A cross-sectional study on youth smoking (n = 36225) was conducted in 2003/4. Self-administered, anonymous questionnaires were used to collect information on socio-demographic characteristics, smoking status of the subjects, parents, siblings and other family members and SHS exposure at home and outside home. Other detailed information on smoking perceptions and behaviours were recorded among adolescents using standard questions adapted from the Global Youth Tobacco Survey. Self-reported smoking and SHS exposure were validated using hair nicotine tests. Logistic and linear regressions were used to yield adjusted odds ratio (AOR) and β-coefficients for poor SRH, smoking initiation, tobacco addiction and smoking cessation adjusting for socio-demographic characteristics and school clustering effects. Mediation of SHS exposure at home on the associations of smoking family with smoking initiation, tobacco addiction and smoking cessation were evaluated using standard mediation procedures. Results: Experimental smoking, ex-smoking and current smoking were associated with higher AORs for poor SRH than never-smoking among adolescents. Similarly, SHS exposure among never-smoking adolescents was linked to poor SRH. Overestimation of peer smoking prevalence significantly predicted smoking initiation (AOR: 1.79, 95% CI 1.03-3.13) among primary school students after 2 years, although SHS exposure did not predict overestimation. Living in smoking families and SHS exposure at home were significantly associated with smoking initiation and tobacco addiction, and hindered smoking cessation among adolescents (All p<0.05). The association between smoking family and child smoking was mediated by SHS exposure at home. Conclusions: This study provided the first evidence that overestimation of peer smoking predicted smoking initiation among young children, and smoking was associated with poor SRH among Chinese adolescents. The significant associations of SHS exposure at home with smoking behaviours should stimulate further investigations into the underlying psychosocial and physiological mechanisms. Future prospective studies with more comprehensive measurements of smoking and SHS exposure are warranted to confirm these results. Evidence-based interventions to correct misperceptions and promote smokefree homes are needed to protect children from smoking and exposure to SHS. / published_or_final_version / Community Medicine / Doctoral / Doctor of Philosophy

Objective: Current studies examining the co-morbidity patterns of ADHD with internalizing disorders have reported inconsistent findings. Some studies have found that the inattentive subtype (ADHD-I) is more likely to be comorbid with internalizing disorders, while other studies found similar levels of comorbid internalizing disorders between the ADHD subtypes. Moreover, anxiety and depression were found to be comorbid in inattentive children high in sluggish cognitive tempo (SCT), characterized by features of sluggishness, drowsiness, and daydreaming. SCT has been postulated to be useful in discriminating a distinct inattentive subtype of ADHD-I with a different pattern of impairments. More recently, low levels of behavioral inhibition (BI)—manifested in the form of disinhibited behaviors—have also been implicated in the development of ADHD in children. The current study examines the relationships between ADHD and internalizing symptoms. The roles of SCT and BI in ADHD and internalizing symptoms are also investigated. Methods: The sample was comprised of 1,965 Hong Kong primary students between 8 and 14 years old and their parents/caregivers from 10 local schools. The children completed two self-report scales: the Revised Children Anxiety and Depression Scale (RCADS) and the Behavioral Inhibition System Scale (BISS). Their parents/caregivers completed three scales: the Attention Deficit Hyperactivity Disorder Rating Scale–IV (ADHDRS-IV), the Oppositional Defiant Disorder Scale (ODDS), and the Sluggish Cognitive Tempo Scale (SCTS). Using a psychometric approach, the relationships between the symptom clusters of ADHD (inattention and hyperactivity-impulsivity), anxiety, depression, SCT, and BI were systematically examined with correlation, regression, and factor analyses. A categorical approach was also used to classify children meeting the DSM symptom criteria to compare levels of internalizing symptoms among the three subtypes of ADHD: ADHD-I, ADHD-HI (hyperactive-impulsive), and ADHD-C (combined hyperactive and inattentive). An SCT cutoff score of 20 (the mean SCT rating among ADHD-I children) was used to further divide the ADHD-I into high- and low-SCT subgroups for planned between-group comparisons. Results: In the dimensional analyses, the inattention dimension of ADHD correlated slightly higher than the hyperactivity-impulsivity dimension with anxiety and depression as predicted. But the hyperactivity-impulsivity dimension was also significantly correlated with anxiety and depression, suggesting that hyperactive children were as likely as inattentive children to feel anxious and depressed. Regression analyses found that inattention was not predictive of anxiety and depression, while hyperactivity-impulsivity was marginally predictive of anxiety, but not depression. BI and SCT emerged as significant predictors of internalizing symptoms after controlling for age, gender, and ODD symptoms. There was evidence that SCT mediated the relationship between anxiety/depression and inattention symptoms. Using the categorical approach, between-group differences were found between the ADHD subtypes and the no-ADHD category. ADHD-I children were more anxious and depressed than children without ADHD. Differences in depressive symptoms were found between the ADHD subtypes. Children with ADHD-I had higher levels of depressive symptoms when compared to children with ADHD-HI and ADHD-C. Contrary to predictions, however, the high-SCT ADHD-I group and the low-SCT ADHD-I group did not differ in symptom levels for any anxiety disorders, major depressive disorder, or externalizing symptoms of ODD. Subtype differences in comorbid anxiety were found to be related to gender differences. The symptom levels of panic disorder were higher in females with ADHD-I, and the symptom levels of separation-anxiety disorder were higher for females with ADHD-C. Inattentive girls might present with higher levels of anxiety symptoms than boys. Conclusions: Consistent with previous studies, children with ADHD were more comorbid with anxiety and depression than children without ADHD. In addition, children with ADHD-I were more comorbid with depressive symptoms than children with ADHD-HI and ADHD-C. The higher ratings of depression in ADHD-I children appeared to be related to higher ratings of SCT found in this subtype. There was no difference in anxiety symptoms among the ADHD subtypes, but girls with clinical levels of inattention tend to experience a wider spectrum of anxiety disorders than boys. Contrary to previous research, the findings did not support the idea that SCT is useful in discriminating a distinct inattentive subtype, since this study found no comorbidity differences between the high-SCT ADHD-I and low-SCT ADHD-I groups. Despite the fact that the ADHD-I group had higher BI, there was no evidence that they had higher anxiety symptoms. Reasons for the lack of a direct relationship between BI and internalizing symptoms in ADHD are discussed. The complex roles of SCT and BI in ADHD symptoms and internalizing symptoms call for the need of further local investigation in both clinical and community samples. / published_or_final_version / Clinical Psychology / Doctoral / Doctor of Psychology

Lexical compounding refers to the process of word formation through union of lexicalized morphemes. Given that young Chinese readers learn print vocabulary as unanalyzed whole, I am uncertain whether children can effortlessly decompose bound morphemes from disyllabic words for lexical compounding to occur. With this concern, I propose a lexical blending process in parallel with lexical compounding, where words are constructed from previously learnt words that have not yet been decomposed as morphemes. This thesis investigated the mechanisms behind the lexical blending process, as well as its role in word reading among young Chinese readers, in five studies Studies One and Two examined the factors that favor lexical blending to occur. In Study One, I located a high proportion of disyllabic words and bound morphemes within a corpus of Chinese textbooks in Hong Kong. Around 40-50% of disyllabic words in Grade One to Grade Three are composed of one or more bound morphemes, which set a favorable environment for lexical blending to occur. In Study Two, I found that younger readers tended to commit more selection errors, defined as “naming the target character as a character that forms a highly frequent two-character compound word with it” (Shu, Meng, Chen, Luan and Cao, 2005), than older readers during character reading, suggesting that their representations of bound morphemes were not precise. An experiment on morpheme name judgment demonstrated that bound morphemes and low frequency morphemes embedded in high frequency words were most prone to selection errors. I further examined the lexical blending process and its contribution to reading development in Studies Three and Four. Adopting a cross-sequential design in Study Three, I found that lexical blending concurrently and longitudinally predicted Chinese word reading, after lexical compounding and other reading-related variables were partialled out. In Study Four, I located lexical class and structural relation knowledge as significant component skills of lexical blending. The process of lexical blending proceeded first with structural arrangement of words, followed by morphological decomposition and union of morphemes to eventually form a blended word. I also tested Chinese dyslexic readers’ performance on lexical blending in Study Five. Dyslexic readers exhibited difficulties in lexical blending and all the related component skills, when compared with chronological-age (CA) matched controls. Process-wise, the dyslexic readers were weaker than CA controls in both structural arrangement and morphological decomposition, while having particular difficulties in the latter process. I conclude that lexical blending is an important word formation process for young Chinese readers. To aid mastery of lexical blending, readers should be aware of the syntax in phrases and sentences, as it provides cues on structural arrangement of blended words. In addition, I suggest explicit instruction on lexical blending skills in the curriculum, with a particular focus on morphological decomposition, in order to meet the learning needs of dyslexic readers. / published_or_final_version / Psychology / Doctoral / Doctor of Philosophy

Systematic reviews were conducted to investigate the relationships between anthropometric assessments of nutritional status (adiposity) and caries experience among preschool and school-age (aged 6-12 years) children. Four relevant databases were searched for publications up to December 2011. Qualitative assessments were conducted and rated according to STROBE statement. Where feasible, quantitative syntheses were conducted. From a total of 2013 studies, 39 effective studies were identified for preschool children and 53 effective studies for school-age children. The mean ‘quality of reporting’ were 20.4 (SD 3.8) for the preschool studies and 21.4 (SD 3.9) for school-age studies. Qualitative syntheses were inconclusive about their relationships. Meta-analyses identified that preschoolers with high BMI had a greater dmfs/defs than those with normal BMI: pooled mean difference 0.93, 95% CI 0.65, 1.22, P < 0.05; and that children with low BMI had a lower dmft than those with normal BMI: pooled mean difference - 0.29, 95% CI -0.42, -0.15, P < 0.05. Among school-age children meta-analyses failed to identify any significant association. Among a random sample of 5-year-old children in Hong Kong, with a response rate of 83.1% (324/390), caries experience was associated with general adiposity (as assessed by W/H) and central adiposity (as assessed by WC). Regression analyses (adjusted for oral health behaviours and socio-demographic factors) identified that W/H z-score was associated with having caries, OR 1.41, 95% CI1.04, 1.91, P = 0.03; and ‘very high’ caries OR 1.62, 95% CI 1.05, 2.50, P = 0.03. WC z-score was associated with ‘very high’ caries experience, OR 1.72, 95% CI 1.06, 2.81, P = 0.03. Oral hygiene status was not associated with adiposity. Among a random sample of 12-year-old children in Hong Kong, with a response rate of 76.9% (514/668), oral health status was associated with adiposity. Regression analyses (adjusted for oral health behaviours and socio-demographic factors) identified that WHR z-score was associated with caries experience: ‘high’ (OR 1.33, 95% CI 1.05, 1.70, P = 0.02), and ‘very high’ (OR 1.52, 95% CI 1.10, 2.11, P = 0.01). TRSKF z-score was associated with ‘very high’ caries experience (OR 1.47, 95% CI 1.10, 1.96, P = 0.01). WC z-score was associated with ‘unhealthy’ periodontal status (OR 1.33, 95% CI 1.01, 1.76, P = 0.04). Infant growth during the first year of life was associated with oral health at 12-year-old. Accounting for birth characteristics, socio-demographics and oral health behaviours, those with slow growth trajectories (Ⅰ- smallest birth weight and slow weight gain; and Ⅱ- smallest birth weight and average weight gain) had a greater likelihood of having a ‘high’ caries experience: OR 2.68, 95% CI 1.00, 7.16, P < 0.05 and OR 3.03, 95% CI 1.22, 7.51, P < 0.05, respectively, compared to average growth trajectory subjects. In addition, those with the fastest growth trajectory (heaviest birth weight and accelerated weight gain) had a greater likelihood of having a ‘high’ caries experience, OR 2.64, 95% CI 1.01, 6.91, P <0.05. Growth trajectories were not associated with periodontal health status at 12-year-old (P > 0.05). / published_or_final_version / Dentistry / Doctoral / Doctor of Philosophy

Background: The problem of poverty in Hong Kong is worsening, particularly the disparity between the rich and poor. Although much of the public concern about this problem has concentrated on the physical development of children, the effect of disparity between the rich and poor on their psychological well-being remains relatively underexplored. A review of the literature revealed that most studies on the psychological effect of disparity between the rich and poor have been conducted in Western countries only. This study aimed to bridge this gap. Its objectives were (1) to compare the self-esteem, depressive symptoms and quality of life (QoL) of children from low- and high-income families, (2) to identify the socioeconomic and demographic characteristics affecting the psychological well-being of children, (3) to compare the livelihoods of children from low- and high-income families, and (4) to examine the effectiveness of adventure-based programme in promoting the psychological well-being of children living in poverty. Methods: This study consisted of a survey study and a pilot RCT. The survey study was conducted in 12 primary schools from the three highest and the three lowest median household income districts. A total of 1,725 children were recruited, with 898 from low-income families and 827 from high-income families. The self-esteem, depressive symptoms and QoL of them were assessed and compared. Additional 42 children were chosen to have semi-structured interviews. As for the pilot RCT, it was conducted in two primary schools in Kwai Chung Estate. A total of 120 children were recruited, of whom 56 were randomly assigned to the experimental group to receive adventure-based programme and 64 to the control group to have placebo programme. Results: For the survey study, the results showed that the children from low-income families scored significantly lower on self-esteem and QoL, and higher on depressive symptoms than the children from high-income families. Moreover, the disparity between the rich and poor was found to have the greatest impact on children's self-esteem. Regression analyses showed that housing type made the largest contribution to children's self-esteem, depressive symptoms and QoL. Additionally, the daily lives of children from low-income families were seriously affected in terms of living environment, physical health, social lives and ability to function at school. Concerning the pilot RCT, mixed between-within subjects ANOVA showed that the children in experimental group scored significantly lower on depressive symptoms and higher self-esteem than those in control group. However, such a significant effect was not found on QoL. Conclusion: The survey study provides further evidence that disparity between the rich and poor has a negative effect on children's psychological well-being. Additionally, the pilot RCT demonstrated the effectiveness of adventure-based programme in promoting the psychological well-being of children living in poverty. Implications for practice: It is vital for healthcare professionals to develop and implement appropriate interventions that promote the psychological well-being of this vulnerable group. Moreover, healthcare professionals should go beyond their normal roles to build multidisciplinary partnerships with schools and the community to promote psychological well-being among children living in poverty. / published_or_final_version / Nursing Studies / Master / Master of Philosophy

The main objective of the present thesis was to examine whether and how do different aspects of oral language skills have important contribution for the development of reading comprehension among young Chinese children. In Study 1, a three-wave longitudinal study (from K2 to P1) was conducted with 91 Chinese children, to whom measures of oral language (vocabulary, grammar and narrative discourse), word-level skills (phonological, orthographic, and morphological skills), and word reading were administered at all three time points, and reading comprehension at K3 and P1. This study found that K2 oral language skills explained considerable variance in subsequent word reading and reading comprehension two years later, and their longitudinal contribution appeared to be more important than that of K2 word-level skills. Moreover, it was found that the first-graders showed rudimentary abilities in some higher-order text comprehension skills in spoken language (e.g., sentential ambiguity detection and monitoring of textual coherence), and these language skills were highly associated with children’s reading comprehension. Results of multiple regression analyses showed that these skills had unique contribution to reading comprehension at P1 over and above that of word reading, word-level skills, and general oral language skills (i.e., vocabulary, grammatical and narrative discourse skills). The longitudinal data further demonstrated the unique prediction of sentential ambiguity detection over time. Overall, SEM analyses revealed that although the role of word reading ability was prominent to beginning reading comprehension, children’s early oral language skills at preschool were found to make an independent path to later reading comprehension through facilitating the subsequent development of higher-order comprehension skills at both sentence- and discourse-level. Since Study 1 demonstrated the importance of sentential ambiguity detection to reading comprehension, Study 2 focused on examining the emerging development of this skill in Chinese children from K2 to P1. A phase model was proposed which hypothesized that children gradually acquired the three sub-skills of sentential ambiguity detection (i.e., homophone detection, lexical ambiguity detection in sentence, and structural ambiguity detection in sentence) through successive phases. Study 2 further demonstrated the contribution of vocabulary, grammatical, and lexical compounding skills for the early acquisition of ambiguity detection in Chinese children. In Study 3, one of its aims was to determine the extent to which different kinds of preschool cognitive skills significantly predicted later word reading difficulties at the end of first grade. The results highlighted the important predicting role of meaning-related cognitive skills (i.e., vocabulary, lexical compounding, and homophone detection skills) in addition to that of phonological and orthographic skills. Apart from focusing on children’s word reading problems, Study 3 further used K-mean cluster analysis to identify a group of children at first grade, whose reading comprehension fall short of their average or good word reading ability. It was found that these unexpected poor comprehenders showed weaknesses in skills that are specifically related to text comprehension: sentential ambiguity detection, comprehension monitoring, and working memory. The practical implications for early literacy instructional approaches and early identification of children with reading difficulties were discussed. / published_or_final_version / Psychology / Doctoral / Doctor of Philosophy

Recent medical advances in cancer screening and treatments have led to dramatically decreasing mortality rates from cancer among children and adolescents. However, the cancer itself and the adverse effects of treatments remain severely devastating to their physical and psychological well-being, both during and after treatments. Numerous studies have demonstrated that regular physical activity is related to various physiological and psychological benefits for children and adolescents under cancer treatments. Nevertheless, a review of the literature reveals that children and adolescents commonly present declining levels of physical activity throughout their cancer treatments. There is so far no study has investigated the physical activity level and behaviour in particular, the influencing factors affecting the physical activity level among Hong Kong Chinese children and adolescents with cancer. Therefore, this study aimed (1) to assess and compare the physical activity levels and behaviour of healthy children and adolescents with those of children and adolescents undergoing cancer treatments and (2) to explore the various factors that influence the physical activity levels of children and adolescents with cancer in Hong Kong. A cross-sectional study, using both quantitative and qualitative approaches, was conducted. A total of 76 children and adolescents (9-to 18-year-olds) who were admitted for treatment of cancer in a paediatric oncology unit and 148 healthy counterparts who were participated in two health carnivals in Hong Kong were invited to participate in the study. Their physical activity levels, stages of change for exercise, self-efficacy for physical activity and quality of life were assessed and compared. A total of 25 participants with cancer were purposively selected for semi-structured interviews. The results of this study indicated that children and adolescents with cancer in current situation had significantly decreased levels of physical activity when compared with the premorbid situation or the healthy counterparts. The study also showed that children and adolescents with cancer presented significantly lower levels of physical activity, self-efficacy, stage of change for exercise and quality of life than the healthy participants. Furthermore, qualitative interviews revealed that the negative impacts from cancer and its treatments, the discouragement of and misunderstanding concerning physical activity, and the space limitations in Hong Kong were important factors that disengaged these young people from regular physical activity while under treatment. This study has addressed an literature gap by assessing the levels of physical activity, self-efficacy, stage of change, and quality of life among children and adolescents with cancer as compared to their healthy counterparts. The results provide further evidence that cancer and its treatments induce negative impact on the physical, psychological well-being and the quality of life in children and adolescents with cancer. It is essential for healthcare professionals to detect physical inactivity at an early stage so that appropriate interventions can be applied to correct any misunderstandings about physical activity among children and adolescents with cancer and their parents. Most importantly, interventions should be designed to promote the adoption of regular physical activity for these patients, with the aim of enhancing their physical and psychological well-being. / published_or_final_version / Nursing Studies / Master / Master of Philosophy

published_or_final_version / Education / Master / Master of Education

published_or_final_version / abstract / Speech and Hearing Sciences / Master / Master of Philosophy