While a stable diagnosis of Autism Spectrum Disorders can be made as early as 2 years of age, the diagnosis of mild ASD cases are usually not made until primary school age or much later; and yet it is these milder cases that can benefit the most from early intervention. The present study aimed at pushing the identification of mild ASD children earlier to preschool age. A review of current screening tools revealed that they were not effective in identifying milder ASD variants. One reason perhaps is that the existing tools rely primarily on parental reports. Note that young children with mild ASD often function adequately interacting with an adult who knows them well; they typically face more difficulty in free play with other children. Parents as a result may not be in a good position to detect milder ASD. The present study therefore took a very different approach from existing screening tools by developing a more objective scale based on observation by of peer interaction in preschools. Considering peer interaction deficits are central for ASD, and deficits of these milder individuals might be more obvious in a setting that tax their social skills. A screening tool based on peer interaction observation in preschool, namely the Structured Classroom Observation Scale (SCOS), was thus developed. Drawing on existing screening tools and experts input, 84 items were compiled and pilot tested. An initial psychometric study of the scale was conducted using a community sample, with 304 preschoolers aged 3 and 4, from four English-language international schools in Hong Kong. The initial 84-item version was trimmed substantially to result in a user-friendly 13-item observation scale with good psychometric properties. The final SCOS includes 3 items depicting self-regulation challenges and 10 items describing difficulties in peer interaction. The initial psychometric study using a community sample indicated substantial interrater reliability (u= .76) and acceptable test-retest reliability (ICC = .72). The average agreement for individual items was less satisfactory (T = .40). Using Latent Class Analysis, the present scale delineated the children into 4 groups: Typical, Shy, Behavioral and High Risk of ASD. A subsequent validity study (n = 186) comparing the SCOS with ADOS scores showed that the class membership of the children based on SCOS predicted their ADOS results, after controlling for age and gender. Children from the High Risk group were found to have significantly higher Calibrated ADOS Severity scores than the other 3 groups; and their mean ADOS scores (i.e., 8.18) were above the cutoff for ASD on the ADOS. A 9-month follow found more reports of parental concerns in the High Risk group with ADOS scores above the cutoff. Discriminant validity of the SCOS was demonstrated between the scale and Head Start Competence Scale (parent version). In contrast to the usual portrayal of active but odd stereotypical children with Asperger Syndrome, the High Risk group identified by the SCOS consisted of children with infrequent interfering behaviors. They were relatively passive but not necessarily odd during social interactions, which might perhaps explain why early identification was difficult. The current scale also identified another two groups of children (Shy group and Behavioral group), which will require longitudinal follow up to ascertain educational or intervention implications. / published_or_final_version / Clinical Psychology / Doctoral / Doctor of Psychology

Background: Human papillomavirus (HPV) DNA test is more sensitive and can detect more high-grade cervical intraepithelial lesions than cytology test in cervical cancer screening. There are studies confirming HPV test being more effective in cervical cancer screening by detecting the persistence of HPV infection that could lead to cancer. However, the costs associated with a HPV test is higher than a cytology test. Moreover, HPV test is less specific which could subject more women to further triage tests or unnecessary invasive diagnostic procedures. Therefore healthcare costs could possibly increase if primary HPV screening is to be adopted. Study objective: The aim of the study is to systematically review the cost-effectiveness of primary HPV testing in cervical cancer screening Method: Electronic search was performed in three biomedical databases (PubMed, Medline, Cochrane Library) and one economic evaluation database to identify relevant studies. Studies were selected according to the explicit inclusion and exclusion criteria defined. Only those studies carried out in high-income countries were included so that result could be better applied to Hong Kong. Results: A total of 19 studies were included in this systematic review. Cytology-only method is generally not cost-effective. To be cost-effective, it has to be performed in a longer screening interval which would reduce not only the screening costs but also a reduction in the health outcomes. Among the different options in HPV-based primary screening, HPV testing with cytology triage is the most cost-effective strategy in many of the studies. Combined HPV/cytology co-screening could achieve the biggest health benefit but is also most costly. HPV-based screening is more cost-effective for those >30 years of age and is usually less cost-effective if applied to young women. From the result in sensitivity analysis, HPV-based screening is sensitive to an increase in the costs of the HPV test, a low HPV test sensitivity and a low screening compliance rate. Conclusion: Primary HPV screening is cost-effective and generally performs better than cytology screening. The result of this systematic review guides the future direction of developing an optimal cervical screening strategy in Hong Kong. Local context has to be considered when examining the cost-effectiveness of primary HPV testing for cervical screening. Good quality local epidemiological data on HPV infection and cervical cancer and screening would be required to aid future research on the application of HPV test for cervical cancer screening in Hong Kong. / published_or_final_version / Public Health / Master / Master of Public Health

In cervical screening programmes, Papanicolaou test (Pap test) is the key screening tool. However Pap test is difficult to implement in low-resource region. Introduction of an economic, cost-effective and less skill demanding equipment is hence a potential direction of advance in cervical screening methodology. 　　Cervical carcinogenesis involves genetic instability which leads to chromosomal aneuploidy. Evaluation of aneuploidy may hence provide information for identifying cancer and precursor cells. An automated DNA-image-cytometry system (DNA-imager) capable of quantitating the DNA content of cells has recently been developed. 　　To evaluate the efficacy of DNA-imager in cervical cancer screening, a total of 483 residual ThinPrep liquid-based cytology (LBC) samples after diagnosis were retrieved and evaluated by the DNA-imager. The high risk human papillomavirus (HPV) status of the atypical squamous cells of undetermined significance (ASC-US) samples has been tested as a parallel study. According to established criteria, 423 out of the 483 samples were satisfactory for downstream analysis. The samples were designated “Normal”, “Suspicious” or “Abnormal” according to their DNA aneuploidy and proliferation activity. 　　Significantly more high grade lesion samples (HSIL and SCC) were designated as “Abnormal” by DNA-imager than were lower grade lesion samples (Negative, ASC-US, AGC, ASC-H, and LSIL) (94.19% vs 51.04%, p<0.0001). For detecting ≥HSIL, DNA-imager achieved high sensitivity and specificity (94.19% and 48.96%) using “Abnormal” as cut off. Adopting a more stringent definition of “Suspicious” or “Abnormal” would increase the sensitivity to 100% but decreased the specificity to 24.33%. 　　 　　Regarding ASC-US triage, DNA-imager achieved a sensitivity and specificity of 80.00% and 71.29% respectively when “Abnormal” was used as test positive to predict cases with ≥HSIL follow-up in the next two year. The sensitivity increased but the specificity decreased to 90.00% and 34.65% respectively if “Suspicious or above” was used as indicator of undesirable follow-up. HR-HPV test, on the other hand, was able to identify all cases with ≥HSIL upon follow-up (sensitivity = 100%) but the specificity was only 15.84%. Among these ASC-US sample, test positivity of the two tests showed poor concordance with each other (Cohen’s κ = 0.062 and 0.074 respectively for “Suspicious or above” or “Abnormal”, respectively). 　　Our findings suggested that DNA-imager may be a useful tool for automated primary screening of cervical cancer 3 / published_or_final_version / Pathology / Master / Master of Medical Sciences

No description available.

No description available.

Screening is generally considered a useful strategy in the prevention of chronic diseases. The notion is that early detection through the use of certain screening tests can facilitate effective preventive measures to be undertaken which can then lead to improved prognosis from or ultimate avoidance of serious clinical diseases. The enthusiasm for screening in the United States is high and can be seen by the size of public demand for it. Rapid technological advances and knowledge expansion in the past decade have further facilitated the introduction of new tests and screening opportunities. In the mean time, the concept of screening has undergone subtle changes. Previous emphasis on clear and demonstrable population health benefits has been slowly replaced by an emphasis on individual responsibility for the surveillance of personal health risks. Disease screening is frequently advocated as part of a health promotion programme. As a clinician who has worked in breast cancer screening and who is wary of the complexities and problems associated with disease screening, my contention is that the enthusiasm for screening may not ultimately be conducive to health and well-being. This thesis represents an effort to understand the popularity and enthusiasm for disease screening, how it has come about and, why it may not be conducive to health and well-being. The thesis begins with a description of the phenomenon to be followed by a detailed examination of the scientific principles behind disease screening. It then moves on to discover how the phenomenon might have come about by first considering the evolution of biomedicine over the centuries and then its present endeavour in the form of surveillance medicine as well as the latter�s relationship with today�s market economy. Using relevant case studies that involve, for example, cancer and prenatal genetic screening, this thesis explores different concerns relating to health and well-being, including such topics as the creation of health roles, the reconfiguration of human values and interpersonal relationships as well as medicalisation. A final chapter offers an account of health and well-being and sums up why the enthusiasm for screening may not be conducive to health and well-being. The enthusiasm for screening compels people to assume health as a moral virtue. Screening is turned into a ritual that people consume to attain salvation. Since diseases may lead to death, diseases must be avoided though screening. Yet health is not just about the absence of disease. Health and well-being can only be realised by the individual within the context of the individual�s life as a whole. The institution of biomedicine has undeniable responsibility to ensure that screening will not be used to the detriment of individuals� health and well-being. Without condemning disease screening as a potentially useful tool in the prevention of disease, this thesis advocates prudence in its utilisation. People must not be compelled to attend screening through programmes of promotion (commercially related or not). Rather, autonomous decisions must be facilitated as far as possible through the provision of clear, accurate and factual information.

Screening is generally considered a useful strategy in the prevention of chronic diseases. The notion is that early detection through the use of certain screening tests can facilitate effective preventive measures to be undertaken which can then lead to improved prognosis from or ultimate avoidance of serious clinical diseases. The enthusiasm for screening in the United States is high and can be seen by the size of public demand for it. Rapid technological advances and knowledge expansion in the past decade have further facilitated the introduction of new tests and screening opportunities. In the mean time, the concept of screening has undergone subtle changes. Previous emphasis on clear and demonstrable population health benefits has been slowly replaced by an emphasis on individual responsibility for the surveillance of personal health risks. Disease screening is frequently advocated as part of a health promotion programme. As a clinician who has worked in breast cancer screening and who is wary of the complexities and problems associated with disease screening, my contention is that the enthusiasm for screening may not ultimately be conducive to health and well-being. This thesis represents an effort to understand the popularity and enthusiasm for disease screening, how it has come about and, why it may not be conducive to health and well-being. The thesis begins with a description of the phenomenon to be followed by a detailed examination of the scientific principles behind disease screening. It then moves on to discover how the phenomenon might have come about by first considering the evolution of biomedicine over the centuries and then its present endeavour in the form of surveillance medicine as well as the latter�s relationship with today�s market economy. Using relevant case studies that involve, for example, cancer and prenatal genetic screening, this thesis explores different concerns relating to health and well-being, including such topics as the creation of health roles, the reconfiguration of human values and interpersonal relationships as well as medicalisation. A final chapter offers an account of health and well-being and sums up why the enthusiasm for screening may not be conducive to health and well-being. The enthusiasm for screening compels people to assume health as a moral virtue. Screening is turned into a ritual that people consume to attain salvation. Since diseases may lead to death, diseases must be avoided though screening. Yet health is not just about the absence of disease. Health and well-being can only be realised by the individual within the context of the individual�s life as a whole. The institution of biomedicine has undeniable responsibility to ensure that screening will not be used to the detriment of individuals� health and well-being. Without condemning disease screening as a potentially useful tool in the prevention of disease, this thesis advocates prudence in its utilisation. People must not be compelled to attend screening through programmes of promotion (commercially related or not). Rather, autonomous decisions must be facilitated as far as possible through the provision of clear, accurate and factual information.

Thesis (Ph.D.)--University of Adelaide, Dept. of Statistics, 1998? / Bibliography: leaves 223-229.

Thesis (Ph. D.)--University of Canterbury, 2008. / Typescript (photocopy). "October 2008." Includes bibliographical references (p. 230-243). Also available via the World Wide Web.

Thesis (M.P.H.)--University of Michigan, 1946.