Lee Nga Lan. / Thesis submitted in: June 1997. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references. / Abstract also in Chinese. / Abstract --- p.i / Acknowledgment --- p.iii / Table of contents --- p.iv / List of tables --- p.viii / List of figures --- p.x / Glossary of abbreviations --- p.xi / Chapter CHAPTER 1. --- INTRODUCTION --- p.1 / Chapter CHAPTER 2. --- BACKGROUND --- p.3 / Chapter 2.1 --- OUTBREAKS OF SOLVENT INDUCED NEUROPATHY IN MAN --- p.3 / Chapter 2.2 --- WORLD-WIDE INVESTIGATIONS ON ORGANIC SOLVENTS HAZARDS --- p.5 / Chapter 2.3 --- HEALTH EEFECTS OF ORGANIC SOLVENTS --- p.8 / Chapter 2.3.1 --- Effects on the Nervous System --- p.9 / Chapter (a) --- Peripheral Nervous System / Chapter (b) --- Central Nervous System / Chapter 2.3.2 --- Other Effects --- p.13 / Chapter 2.4 --- METHODOLOGICAL ISSUES IN THE INVESTIGATION OF SOLVENT NEUROTOXICITY --- p.14 / Chapter 2.4.1 --- Study Design --- p.15 / Chapter 2.4.2 --- Exposure Measurements --- p.17 / Chapter 2.4.3 --- Outcome Effects Measurements --- p.18 / Chapter 2.5 --- UNSOLVED PROBLEMS IN THE STUDY OF SOLVENT NEUROTOXICITY --- p.20 / Chapter 2.6 --- ORGANIC SOLVENTS IN THE PRINTING INDUSTRY --- p.21 / Chapter 2.7 --- PRINTING METHODS --- p.25 / Chapter 2.8 --- OFFSET LITHOGRAPHY --- p.27 / Chapter 2.8.1 --- Principles of Offset Lithography --- p.28 / Chapter 2.8.2 --- Image Carriers for Offset Lithography --- p.29 / Chapter 2.8.3 --- Lithographic Presses --- p.32 / Chapter 2.8.4 --- Printing Process --- p.34 / Chapter CHAPTER 3. --- STUDY OBJECTIVES AND METHODS --- p.37 / Chapter 3.1 --- OBJECTIVES --- p.37 / Chapter 3.2 --- METHODS --- p.38 / Chapter 3.2.1 --- Study Population --- p.38 / Chapter 3.2.2 --- Visits --- p.41 / Chapter 3.2.3 --- Workers' Health Assessment --- p.42 / Chapter 3.2.4 --- Air Sampling --- p.44 / Chapter 3.2.5 --- Definition of Exposures --- p.48 / Chapter 3.3 --- DATA ANALYSIS --- p.49 / Chapter CHAPTER 4. --- RESULTS --- p.51 / Chapter 4.1 --- RESPONSE RATE --- p.51 / Chapter 4.2 --- CHARACTERISTICS OF THE STUDY POPULATION --- p.53 / Chapter 4.2.1 --- Printing Companies --- p.53 / Chapter 4.2.2 --- Study Subjects --- p.56 / Chapter 4.3 --- HEALTH PROBLEMS OF STUDY SUBJECTS --- p.60 / Chapter 4.3.1 --- Sick Leave --- p.60 / Chapter 4.3.2 --- Prevalence of Subjective Symptoms --- p.61 / Chapter 4.3.3 --- Mean Number of Symptoms --- p.64 / Chapter 4.4 --- AIR SAMPLING RESULTS --- p.66 / Chapter 4.4.1 --- Mean Concentration Levels of Solvents --- p.71 / Chapter 4.4.2 --- Mean Concentration Levels of Solvents by Printing Plants --- p.73 / Chapter 4.4.3 --- Mean Concentration Levels of Solvents by Locations --- p.75 / Chapter 4.5 --- EXPOSURE-RESPONSE RELATIONSHIPS BETWEEN ORGANIC SOLVENTS AND SYMPTOMS --- p.77 / Chapter 4.6 --- RISK FACTORS FOR SUBJECTIVE SYMPTOMS --- p.85 / Chapter CHAPTER 5. --- DISCUSSIONS --- p.90 / Chapter 5.1 --- RESPONSE RATE --- p.90 / Chapter 5.2 --- SOURCES OF BIAS --- p.91 / Chapter 5.3 --- STUDY SUBJECTS --- p.92 / Chapter 5.4 --- SOLVENT EXPOSURES --- p.93 / Chapter 5.4.1 --- Occupational Hygiene --- p.93 / Chapter 5.4.2 --- Exposure Classification --- p.95 / Chapter 5.4.3 --- Chemical Interaction --- p.98 / Chapter 5.5 --- HEALTH PROBLEMS --- p.99 / Chapter CHAPTER 6. --- CONCLUSION --- p.103 / REFERENCES --- p.105 / APPENDICES --- p.120 / Appendices A1 to A9: Newspaper reports on polyneuropathy induced by organic solvents in a Hong Kong printing factory --- p.120 / Appendix B: Telephone follow up form --- p.129 / Appendix C: Letter to the printing factory employer --- p.130 / Appendix D: Subjective symptom questionnaire for solvent workers --- p.131 / Appendix E: Questionnaire for exposed group workers --- p.132 / Appendix F: Questionnaire for non-exposed group workers --- p.140 / Appendix G: NIOSH Sampling and Analytical Method 1400 --- p.145 / Appendix H: NIOSH Sampling and Analytical Method 1500 --- p.150 / "Appendix I: Chemical Analytical Method from Department of Hygiene, School of Public Health, Sun Yat Sen University of Medical Sciences" --- p.157 / Appendix J: Air Sampling Worksheet --- p.159 / BIBLIOGRAPHY --- p.162

Song Hong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves ). / Abstracts in English and Chinese; questionnaire in Chinese. / Abstract (English) --- p.i / Abstract (Chinese) --- p.iv / Acknowledgments --- p.vi / Table of Contents --- p.vii / List of tables --- p.x / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Printing industry and organic solvents exposure --- p.1 / Chapter 1.2 --- Risk of low level exposures to organic solvents --- p.2 / Chapter 1.3 --- Using neurobehavioral methods to study the subclinical effects --- p.3 / Chapter Chapter 2 --- Literature review --- p.4 / Chapter 2.1 --- Organic solvents and neurobehavioral impairment --- p.4 / Chapter 2.2 --- Methodology of Neurobehavioral Test --- p.6 / Chapter 2.2.1 --- Criteria for selecting test battery --- p.7 / Chapter 2.2.2 --- Standardization of neurobehavioral test battery --- p.8 / Chapter 2.2.3 --- Reliability and validity --- p.9 / Chapter 2.2.4 --- Confounding factors of neurobehavioral test --- p.10 / Chapter 2.3 --- Neurobehavioral effects of different levels of solvent exposures --- p.12 / Chapter 2.3.1 --- Positive results in field studies --- p.12 / Chapter 2.3.2 --- Negative results in field studies --- p.17 / Chapter 2.3.3 --- Dose-response relationship in the field studies --- p.18 / Chapter 2.3.4 --- To separate acute and chronic effects --- p.20 / Chapter 2.3.5 --- The long-term effects of solvent exposure --- p.21 / Chapter 2.4 --- Limitations of these studies --- p.23 / Chapter 2.5 --- Summary --- p.26 / Chapter Chapter 3 --- Aims and Objectives --- p.31 / Chapter 3.1 --- Aims of the present research --- p.31 / Chapter 3.2 --- Position of this study cm this research domain --- p.32 / Chapter Chapter 4 --- Subjects and Method --- p.33 / Chapter 4.1 --- Study design --- p.33 / Chapter 4.2 --- Study population and sampling --- p.33 / Chapter 4.2.1 --- Participation --- p.33 / Chapter 4.2.2 --- Exposed group --- p.34 / Chapter 4.2.3 --- Reference group --- p.34 / Chapter 4.2.4 --- Sample size estimation --- p.34 / Chapter 4.3 --- Data collection --- p.36 / Chapter 4.3.1 --- Exposure assessment --- p.36 / Chapter 4.3.1.1 --- Air sample measurements --- p.36 / Chapter 4.3.1.2 --- Biological monitoring --- p.38 / Chapter 4.3.2. --- Medical assessment --- p.38 / Chapter 4.3.2.1 --- Pre-test questionnaire --- p.39 / Chapter 4.3.2.2 --- Neurobehavioral assessment --- p.39 / Chapter 4.4 --- Data Analysis --- p.43 / Chapter 4.4.1 --- Data Processing --- p.43 / Chapter 4.4.2 --- Statistical analysis --- p.44 / Chapter 4.4.2.1 --- Descriptive analysis --- p.44 / Chapter 4.4.2.2 --- Identifying the main confounding factories --- p.44 / Chapter 4.4.2.3 --- Comparing the tests score adjusted for confounding --- p.45 / Chapter 4.4.2.4 --- Dose-response analysis --- p.45 / Chapter Chapter 5 --- Results --- p.47 / Chapter 5.1 --- Demographic characteristics of the subjects --- p.47 / Chapter 5.2 --- Comparison of the basic characteristics between the exposed group and the reference group --- p.48 / Chapter 5.3 --- Comparison of the symptoms between the exposed group and the reference group --- p.49 / Chapter 5.4 --- Comparison of the scores of neurobehavioral tests between the exposed group and the reference group --- p.51 / Chapter 5.5 --- Identifying potential confounding of neurobehavioral test --- p.51 / Chapter 5.5.1 --- Main confounding factors of NCTB test on performance tests --- p.51 / Chapter 5.5.2 --- Main confounding factors of Profile of Mood States --- p.54 / Chapter 5.6 --- Groups comparison of the neurobehavioral effects --- p.57 / Chapter 5.6.1 --- Comparison of the adjusted mean scores between the exposed group and the reference group --- p.57 / Chapter 5.6.2 --- Groups comparison of the adjusted tests score in Factories C and G respectively --- p.58 / Chapter 5.7 --- Exposure assessment --- p.61 / Chapter 5.7.1 --- Air sampling results of the printing factories --- p.62 / Chapter 5.7.2 --- Relationship between results of active and passive sampling systems --- p.63 / Chapter 5.7.3 --- Biological monitoring --- p.63 / Chapter 5.8 --- Dose-response relationship --- p.65 / Chapter Chapter 6 --- Discussion --- p.69 / Chapter 6.1 --- Findings of this study --- p.69 / Chapter 6.1.1 --- Subjective symptoms --- p.69 / Chapter 6.1.2 --- Neurobehavioral effects --- p.70 / Chapter 6.1.3 --- Exposure intensity --- p.72 / Chapter 6.1.4. --- Dose-response relationship --- p.75 / Chapter 6.2 --- Applications of the study results --- p.76 / Chapter 6.2.1 --- The need for prevention measures --- p.77 / Chapter 6.2.2 --- Contributing to re-setting of OELs --- p.77 / Chapter 6.2.3. --- The evidence on neurotoxicology --- p.78 / Chapter 6.3 --- Limitations of the study --- p.79 / Chapter 6.3.1. --- Possibility of bias --- p.79 / Chapter 6.3.2. --- Lack of historical hygiene measurement data --- p.80 / Chapter 6.3.3. --- Influence of workshift --- p.81 / Chapter 6.3.4. --- Combined exposures to noise and organic solvents --- p.82 / Chapter 6.4 --- Conclusion --- p.83 / Appendices --- p.84 / Appendix 1 --- p.84 / Appendix 2 --- p.97 / Appendix 3 --- p.102 / Appendix 4 --- p.103 / Appendix 5 The Administration of The WHO-NCTB Tests --- p.114 / Test 1 Profile of Mood States Test --- p.115 / Test 2. Simple Reaction Time Test --- p.116 / Test 3. Digit Span Test Test --- p.119 / Test 4. Santa Ana Test --- p.120 / Test 5. Digit Symbol Test --- p.122 / Test 6. Benton Visual Retention Test --- p.123 / Test 7. Pursuit Aiming Test --- p.125 / Appendix 6 --- p.126 / Reference List --- p.127

Yeung Sai Mo, Simon. / "June 2002." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (p. 255-278). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.

Doctorat en sciences sociales, politiques et économiques / info:eu-repo/semantics/nonPublished

目的：本研究主要目的是建立預測模型來判定矽肺發生的累積風險從而推薦適宜的胸片照射年限並從而評估常規監測和推薦監測策略的成本效益。此外，本研究還評價了常規診斷和驗證性診斷的符合度以及在驗證性診斷中邀請的三位專家之間的符合度。 / 方法：總計有3492男性接塵工人在1964年1月1日到1974年12月31日期間進入本隊列並隨訪至2008年12月31日。不同閱片專家根據中國最新塵肺病診斷標準 （GBZ70-2009））分別閱片總計9084張。對專家之間閱片結果的兩兩比較和兩種診斷結果的比較均采用Cohen’s Kappa檢驗。應用三種篩選方法（強制所有變量同時進入模型，後退逐步篩選，以及Least Absolute Shrinkage and Selection Operator (LASSO)篩選。LASSO模型作為最優模型，以分數量表的方式來表達。根據分數，把工人分成高、中、低危險組，並估計這三組不同危險水平工人的累積危險度。運用0.1% 累積危險度來判定不同危险的工人及不同期別的矽肺病人的射線照射年限。多狀態Markov模型用於計算矽塵暴露工人不同狀態的年轉移概率，並應用Markov成本效益分析方法來估計每獲得一個生命年的成本效益。 / 結果：截至2008年底，本矽塵暴露隊列共計發現298例矽肺病人（累計發病率為8.53%），死亡1347例（死亡比例為38.57%）。本研究發現常規診斷和驗證性診斷有很好的符合度 （Kappa值為0.89， 95%可信區間為0.88-0.91）。基於LASSO模型的分數量表具有很好的診斷識別能力 （ROC曲線下面積為0.83， 95%可信區間為0.81-0.86）。根據0.1%累積危險度標準，我們判定低危險組工人第一次射線照射的時間為第11年，推薦每兩年隨訪一次；中等危險組工人和高危險組工人的第一次射線照射時間分別為第11年和第5年，推薦每年隨訪一次。矽肺病人未晉級到三期以前均一年隨訪一次。矽塵暴露工人的年轉移概率為：從健康狀態向疑似病例轉移的概率為0.0198，從疑似病例向一期矽肺轉移的概率為0.038，從一期矽肺向二期矽肺轉移的概率為0.0516，從二期矽肺向三期矽肺轉移的概率為0.059，從三期矽肺向死亡轉移的概率為0.18。在1964到2008年間，診斷一例矽肺病例平均花費醫療成本為21853.11美元，非醫療成本為5993.30美元。模擬10,000矽塵暴露工人在未來40年按照當前的狀態轉移概率，應用常規的職業健康檢查為手段獲得一個生命年的成本效益為43.60美元，應用推薦的職業健康檢查為手段獲得一個生命年的成本效益為46.99美元。 / 結論：本研究在最優預測模型的基礎上為不同矽肺危險度的矽塵暴露工人首次提供了科學的證據來判定射線照射的適宜年限，亦為未來矽塵暴露工人的職業健康監測提供了科學理論依據，雖然本研究推薦的監測策略獲得同常規策略相類似的成本和效益。 / Objectives: The primary objective was to develop prediction models for determining the optimal intervals of chest radiographic surveillance for workers exposed to silica dust; the second primary objective is to assess the cost per case identification and compare the cost per life year gained under routine medical surveillance program with that under the recommended program for workers exposed to silica dust in China. In addition, the inter-rater agreement amongst three invited radiologists on rereading the chest radiographs and the agreement between the original diagnoses of silicosis (from routine reports) and the verified diagnoses reassessed by the three experts were also evaluated. / Methods: A total of 3492 male workers exposed to silica dust in an iron ore during the period 1964 - 1974 were recruited into this retrospective cohort study. All cohort members were followed up through the end of 2008 to observe the occurrence of silicosis and overall profile of mortality. All 9084 chest X-ray films were reread by three radiologists who had been qualified as experts at the national level according to the Chinese National Diagnostic Criteria of Pneumoconiosis (GBZ70-2009). The diagnosis of silicosis made by the panel of these three invited experts was referred to the “verified diagnosis“. Cohen’s Kappa test was used to test inter-rater agreements of three invited readers on chest radiographs and the agreement on the diagnosis of silicosis obtained from routine medical surveillance (i.e., the original routine diagnosis) was compared with those verified by the 3 qualified readers (i.e., the verified diagnosis). The multivariate Cox’s proportional hazard regression models were developed to predict the silicosis occurrence based on three selection approaches entry of all predictors at the same time, backward stepwise selection, and Least Absolute Shrinkage and Selection Operator (LASSO) selection. The LASSO model showed the best model fit which was thus regarded as the final model for predicting a score chart. / Based on this practically used score chart, we then classified workers into three groups of different risk levels of silicosis (low, moderate, and high). We estimated the cumulative risk of silicosis over years of follow-up for these three groups of workers at different risk levels. We used 1 per thousand of cumulative risk for developing silicosis as a “benchmark“ to determine the intervals of radiologic surveillance for workers with different risks of silicosis. Multi-state Markov model was used to calculate the transition probabilities of different states of silicosis and the analysis on cost and effectiveness was performed. / Results: By the end of 2008, the cumulative incidence rate of silicosis was 8.53% (298 silicosis cases) and a total of 1347 deaths (38.57%) were observed. / Good inter-rater agreements were observed amongst three invited radiologists for rereading all the chest films. Kappa value for the agreement between the original diagnoses and the verified diagnoses was 0.89 (95% confidence interval [95%CI], 0.88-0.91). / The model with the best fit was LASSO Cox model which showed a good discrimination with an area of 0.83 (95%CI, 0.81-0.86) under the receiver operating characteristic (ROC) curve. We classified workers into 3 risk groups according to the score chart obtained from the LASSO Cox model, and found the observed probabilities matched well to the predictions. According to 1 per thousand “benchmark“, we can determine that the initial interval of radiographic surveillance for workers in the low risk group was 11 years and a subsequent biyearly examination was recommended. The initial examination interval was 11 years and 5 years respectively for workers in the middle and high risk group, and then a yearly examination was recommended. For patients with silicosis, an annual radiological surveillance program was recommended regardless of the stage of pneumoconiosis. / According to results from multi-state model, we estimated that the yearly transition probability was 0.0198 for silica dust exposed workers from healthy state to the suspected silicosis cases (sojourn time = 47 years), 0.0338 from suspected silicosis cases to silicosis stage one (sojourn time = 23 years), 0.0516 from silicosis stage one to stage two (sojourn time = 9 years), 0.059 from silicosis stage two to stage three (sojourn time = 6 years), and 0.18 from silicosis stage three to death (sojourn time = 5 years). / During the period 1964 to 2008, the average direct medical cost spent on identifying one silicosis case was US$ 21853.11 and the non-medical cost for identifying one case was US$ 5993.30 per case. The estimated medical cost regarding per life year gained was US$ 43.60 under the routine medical surveillance program and it would be US$ 46.99 if the newly recommended surveillance program is adopted. / Conclusion: This study is the first to provide scientific evidence on determining the optimal intervals of radiographic surveillance for workers at different risk levels of silicosis based on the ‘best’ prediction model. Although our study revealed similar cost and effectiveness for using the recommended occupational health examination strategy compared with the routine program, this study is the first to provide scientific theory for guiding evidence-based occupational medical surveillance on workers exposed to silica dust in the world. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Chen, Minghui. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 195-210). / Abstract also in Chinese. / Abstract (English) --- p.i / Abstract (Chinese) --- p.v / Acknowledgements --- p.vii / List of contents --- p.ix / List of tables --- p.xv / List of figures --- p.xviii / List of main abbreviations --- p.xx / Chapter Section I --- Introduction and Literature Review --- p.1 / Chapter Chapter 1 --- Introduction --- p.2 / Chapter Chapter 2 --- Literature Review of Medical Examination, Prediction model and Economic Evaluation in Silicosis --- p.7 / Chapter 2.1 --- The aims of this literature review --- p.7 / Chapter 2.2 --- Search strategies and selection criteria --- p.7 / Chapter 2.3 --- Searching results --- p.8 / Chapter 2.4 --- Critical appraisal criteria and quality of selected studies --- p.9 / Chapter 2.4.1 --- Critical appraisal criteria --- p.9 / Chapter 2.4.2 --- Quality of selected studies --- p.10 / Chapter 2.5 --- Overview of effectiveness of chest radiography in medical surveillance of silicosis for workers exposed to silica dust --- p.15 / Chapter 2.5.1 --- Occupational medical surveillance for workers exposed to silica dust --- p.15 / Chapter 2.5.2 --- Comparison of CT or HRCT and chest radiography --- p.16 / Chapter 2.5.3 --- Comparison of digital radiography (DR) and chest radiography --- p.17 / Chapter 2.5.4 --- Other tests to be relevant to silicosis diagnosis --- p.23 / Chapter 2.5.5 --- The effectiveness of chest radiography in medical surveillance and diagnosis of silicosis --- p.24 / Chapter 2.5.6 --- Comparison between the ILO Classification and the Chinese Diagnostic criteria of pneumoconiosis --- p.25 / Chapter 2.6 --- Overview of application of prediction model in silicosis and a review on methodology in prediction model --- p.32 / Chapter 2.6.1 --- Application of prediction model in occupational diseases --- p.32 / Chapter 2.6.2 --- Overview of application of predicting model in pneumoconiosis including silicosis in China in recent 10 years --- p.34 / Chapter 2.6.3 --- Development of prediction model and the applications from practical perspectives --- p.35 / Chapter 2.7 --- A review on economic evaluation in occupational diseases and the screening interval analyses --- p.42 / Chapter 2.7.1 --- An overview on economic evaluation in pneumoconiosis --- p.42 / Chapter 2.7.2 --- Overview of economic evaluation in occupational health and safety and screening interval analyses --- p.44 / Chapter 2.7.3 --- Overview for methodology of performing CEA --- p.45 / Chapter 2.8 --- Research gaps were found from this literature review --- p.52 / Chapter Section II --- Objectives and Methods --- p.53 / Chapter Chapter 3 --- General aims and objectives --- p.54 / Chapter 3.1 --- General aims --- p.54 / Chapter 3.2 --- Primary objectives --- p.54 / Chapter 3.3 --- Secondary objective --- p.54 / Chapter Chapter 4 --- Methodology and Research Plans --- p.55 / Chapter 4.1 --- Study Design --- p.55 / Chapter 4.2 --- The cohort --- p.55 / Chapter 4.3 --- Follow-up --- p.58 / Chapter 4.4 --- Data Collection --- p.58 / Chapter 4.4.1 --- Baseline information --- p.58 / Chapter 4.4.2 --- Diagnosis of silicosis and the verification --- p.59 / Chapter 4.4.3 --- Occupational hygiene monitoring data --- p.60 / Chapter 4.4.4 --- Cost data of medical examination --- p.61 / Chapter 4.5 --- Data Entry and Data Analyses --- p.62 / Chapter Section III --- Results and Discussions --- p.65 / Chapter Chapter 5 --- Description of the cohort --- p.66 / Chapter 5.1 --- Cohort recruitment --- p.66 / Chapter 5.2 --- Baseline characteristics --- p.69 / Chapter 5.3 --- Change of respirable silica dust concentration over time --- p.71 / Chapter 5.5 --- Occurrence of silicosis --- p.73 / Chapter 5.5.1 --- Basic characteristics of silicosis patients --- p.73 / Chapter 5.5.2 --- Trend of silicosis occurrence with calendar year --- p.78 / Chapter 5.5.3 --- Trend of silicosis occurrence with age of entering the cohort --- p.78 / Chapter 5.5.4 --- Trend of silicosis occurrence with cumulative exposure to respirable silica dust --- p.78 / Chapter 5.6 --- Survival distribution at different respirable silica dust exposure levels --- p.79 / Chapter 5.7 --- A summary of the results in Chapter 5 --- p.82 / Chapter Chapter 6 --- Agreement between the routine diagnosis of silicosis and the verified ‘new panel’ diagnosis --- p.83 / Chapter [Summary] --- p.83 / Chapter 6.1 --- Background --- p.85 / Chapter 6.2 --- Methodology --- p.86 / Chapter 6.2.1 --- The routine and the verified diagnosis of silicosis --- p.86 / Chapter 6.2.2 --- Inter-rater agreement --- p.87 / Chapter 6.3 --- Results --- p.89 / Chapter 6.3.1 --- Technical quality of chest X-ray films --- p.89 / Chapter 6.3.2 --- Inter-rater agreement amongst readers --- p.89 / Chapter 6.3.3 --- Agreement between the routine and the verified diagnosis of silicosis --- p.93 / Chapter 6.3.4 --- Agreement of the progression of silicosis between the routine and verified diagnosis --- p.95 / Chapter 6.4 --- Discussion --- p.97 / Chapter Chapter 7 --- Developing prediction model for determining the optimal intervals of chest radiographic examinations for workers at different risks of silicosis --- p.100 / Chapter [Summary] --- p.100 / Chapter 7.1 --- Background --- p.102 / Chapter 7.2 --- Methods --- p.104 / Chapter 7.2.1 --- The cohort and outcome determination --- p.104 / Chapter 7.2.2 --- Developing prediction models for silicosis --- p.107 / Chapter 7.2.3 --- Coding of Predictors --- p.113 / Chapter 7.3 --- Results --- p.118 / Chapter 7.3.1 --- Model Specifications --- p.118 / Chapter 7.3.2 --- Stepwise Selection and LASSO selection --- p.119 / Chapter 7.3.3 --- Model Validations: Stability and Optimism --- p.119 / Chapter 7.3.4 --- Model Presentations --- p.126 / Chapter 7.3.5 --- Cut-off point of follow up year for determining examination intervals --- p.130 / Chapter 7.4 --- Discussions --- p.136 / Chapter Chapter 8 --- Transition probabilities of multi-states for workers with silica dust exposure --- p.141 / Chapter [Summary] --- p.141 / Chapter 8.1 --- Background --- p.143 / Chapter 8.2 --- Methodology of multi-state model --- p.145 / Chapter 8.2.1 --- Survival data and multi-state model --- p.145 / Chapter 8.2.2 --- Markov model and transition states --- p.151 / Chapter 8.2.3 --- Model assessment --- p.153 / Chapter 8.3 --- Results --- p.154 / Chapter 8.3.1 --- Initial values specification and estimates of intensity matrix --- p.154 / Chapter 8.3.2 --- Transition probability matrix, mean sojourn times, and survival situation --- p.159 / Chapter 8.3.3 --- Observed and expected prevalence of each state for Model assessment --- p.163 / Chapter 8.4 --- Discussion --- p.165 / Chapter Chapter 9 --- Cost effectiveness analysis of occupational medical surveillance for workers exposed to silica dust --- p.168 / Chapter [Summary] --- p.168 / Chapter 9.1 --- Background --- p.170 / Chapter 9.2 --- Methodologies --- p.171 / Chapter 9.2.1 --- Costs and effectiveness --- p.171 / Chapter 9.2.2 --- Cost per silicosis identification estimation in the iron ore during 1964 to 2008 --- p.172 / Chapter 9.2.3 --- Cost effectiveness analysis in the Markov model --- p.173 / Chapter 9.3 --- Results --- p.176 / Chapter 9.3.1 --- Cost estimation and cost per silicosis identification in the iron ore cohort --- p.176 / Chapter 9.3.2 --- Cost effectiveness analysis in the Markov model --- p.181 / Chapter 9.4 --- Discussion --- p.187 / Chapter Section IV --- Conclusions and Implications --- p.191 / Chapter Chapter 10 --- Conclusions, implications, and recommendations --- p.192 / Chapter 10.1 --- Conclusions --- p.192 / Chapter 10.2 --- Implications and recommendations --- p.193 / Reference list --- p.195 / Chapter Appendix I --- Chest Radiographic Imaging of Different Diagnostic Criteria for Pneumoconiosis in China --- p.211 / Chapter Appendix II --- Diagnosis Stages among Different Diagnostic Criteria for Pneumoconiosis in China --- p.212 / Chapter Appendix III --- Publications in journals and international conferences during the PhD study --- p.213 / Chapter Supplement I --- Syntax for test proportionality of Cox model in R survival package and LASSO model in R penalized package --- p.215 / Chapter Supplement II --- Guideline of applying the prediction model in practice --- p.216 / Chapter Supplement III --- Syntax for multi-state model in R msm package --- p.221 / Chapter Supplement IV --- An example for cost estimation of adjusting inflation and exchanging --- p.222 / Chapter Supplement V --- Cost estimation of workers, suspected silicosis cases and silicosis patients in the iron ore during 1964 - 2008 --- p.223 / Chapter Supplement V (Continued) --- Cost estimation of workers, suspected silicosis cases and silicosis patients in the iron ore during 1964 - 2008 --- p.224 / Chapter Supplement VI --- Number of deaths for all cause of death in the iron ore cohort until 2008 --- p.225 / Chapter Supplement VII --- Decision tree of Markov model in the study --- p.226 / Chapter Supplement VII (Continued) --- Decision tree of Markov model in the study --- p.227

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.

Thesis (M.Tech.: Chiropractic) -Dept. of Chiropractic, Durban Institute of Technology, 2006. xiii, 44 leaves, Annexures A-F / The purpose of this study is to determine whether the cumulative effect of studying, and practising manual therapeutic techniques (including receiving manipulation), is associated with chiropractic students experiencing low back pain (LBP). According to Smith (2005), students currently registered in the Durban Institute of Technology Health faculty were found to have the highest proportion of LBP when compared to students in other faculties. Thirty seven percent of the students with LBP were chiropractic students. In a study performed by Macanuel et al. (2005) on undergraduate chiropractic training, it was concluded that chiropractic students experience side effects during chiropractic technique class. There is epidemiological evidence that chiropractors are a high-risk group of health professionals who experience low back disorders (Tim 1996, Lorme and Naqv 2003, Rupert and Ebete 2004). Rupert and Ebete (2004) suggest that the majority of chiropractors have suffered an occupational injury primarily related to administering manual procedures.

Thesis (PhD)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: Healthcare workers (HCWs) wear latex gloves to protect themselves and their patients against the transmission of microbial, viral and bloodborne diseases. These individuals are primarily exposed to latex via cutaneous (direct contact) and mucocutaneous (inhalation of airborne allergens on glove powder) routes. Repeated exposure leads to the formation of circulating latex-specific IgE and subsequent sensitisation with varying clinical expression. The airconditioning system of the Tygerberg Hospital (TBH) complex was investigated for the presence of aerosolised cornstarch glove powder and proteins. Dust samples were collected from 14 areas with different levels of latex glove usage. Dust samples were spectrophotometrically compared to a calibration graph of pure glove powder. The detection of starch and proteins in all the dust samples confirmed the presence of glove powder and possibly airborne latex allergens in the airconditioning ducts. As expected, the high exposure areas showed the highest concentrations of both starch and proteins. It is possible that other proteins than latex were involved, but the confirmed high level of protein contamination should be a cause for concern. Correlation between starch and protein levels was highly significant (p<0.01) in all instances. A total of 500 questionnaires were circulated for completion by HCWs from TBH. The response rate was 69.8%. After considering specific inclusion criteria, a study group of 152 individuals was compiled (28 males, 124 females). All subjects had current latex exposure and suffered from at least three pre-defined symptoms. Serum was collected from all subjects and dermal fluid from 31 subjects. Total IgE and latex specific IgE analysis were done on all serum and dermal fluid samples. Latex-specific IgE was positive (>0.35 IU/ℓ) in 23 serum and six dermal fluid samples. Skin prick tests (SPTs)for latex were done on 59 subjects with negative serum latex-specific IgE and 34 had positive results. Twelve subjects with negative latex-specific IgE and latex SPTs underwent patch tests with the European Standard Series, a piece of latex glove and glove powder in petrolatum. Three subjects had positive results to one or more of these allergens. Western blot analysis for latex was done on all positive sera and dermal fluid collected from these subjects. Western blot analysis for latex proved to be more sensitive than the capRAST, because it was able to identify specific bands in samples with negative capRAST results. All subjects showed a band for Hev b 1, which has been confirmed as a powder-bound airborne allergen. Hev b 6.01 is associated with HCWs with cutaneous symptoms and this band was recognised by 81% of the subjects. These findings confirmed that airborne and cutaneous routes are the major routes of exposure in HCWs. According to their laboratory results, subjects were divided into the following subgroups and compared statistically: Group A (serum positive, n=23), Group B (SPT positive, n=34) and Group C (negative, n=25). Group D (withdrawn, n=70) could not be used for statistical comparisons, due to incomplete results. An overall latex allergy prevalence of 38% was found. Group A differed significantly from Group B and Group C for most clinical and special investigations. Group A and B were also combined to represent all subjects with positive results (Cohort AB). The Allergy Score and Class were highly significant when Cohort AB was compared to Group C. The selection of clinical symptoms was confirmed to be relevant and work-related deterioration on any of the symptoms should bear a high index of suspicion in the evaluation of latex allergy. Numerical indices and specific symptoms showed high positive predictive values and the Allergy Score produced statistical significance in the positive subgroups when compared to the negative subgroup. Paired statistical significance was confirmed between the Allergy Score and occupational exposure (number of years, hours and pairs per week). The areas with the highest occupational latex exposure in HCWs are the face and hands. Different occupations also have different levels of exposure and two subgroups of HCWs (16 laboratory technologists and 13 theatre staff) were investigated for sebum content on different facial areas and the palms and dorsal areas of both hands. Baseline measurements were done before putting on gloves. In 21 subjects follow up measurements were done following three to four hours of occupational exposure, but before washing their hands. Baseline and follow up values were compared for all the different anatomical regions. Levels on the forehead and cheeks increased over time, while the level on the nose decreased. All hand regions decreased significantly during occupational exposure, suggesting that glove powder contributes to dryness of the skin. In conclusion, the problem posed by latex allergy will not be solved overnight and will probably remain a major occupational hazard for years to come. It is currently not possible to avoid exposure to latex, but it is imperative to institute safety measures to prevent further sensitisation in predisposed individuals and manage those already affected. / AFRIKAANSE OPSOMMING: Gesondheidswerkers dra lateks handskoene om hulleself en hulle pasiënte te beskerm teen die oordrag van mikrobiale, virale en bloed-gedraagde siektes. Die lateks blootstelling vind hier hoofsaaklik plaas via kutane (direkte velkontak) en mukokutane (inaseming van lug-gedraagde allergene op hanskoen poeier) roetes. Herhaalde blootstelling veroorsaak sirkulerende lateksspesifieke IgE en sensitisasie met variërende kliniese beelde. Die lugreëlingstelsel van die Tygerberg hospitaalkompleks is ondersoek vir die teenwoordigheid van handskoenpoeier (stysel) en lateks proteïene. Stofmonsters is versamel in 14 areas wat verskillende blootstellingsvlakke verteenwoordig het. Die stofmonsters is spektrofotometries vergelyk met "n kalibrasiekurwe van suiwer hanskoenpoeier. Stysel en proteïene kon in al die stofmonsters aangetoon word en het die teenwoordigheid van handskoenpoeier en moontlike luggedraagde lateks proteïene in die lugreëlingstelsel bevestig. Soos verwag kon word, het die hoogste stysel en proteïen waardes in hoë blootstellingsareas voorgekom. Hoogs beduidende statistiese korrelasies (p<0.01) tussen die stysel en proteïenvlakke kon aangedui word in alle monsters. "n Totaal van 500 vraelyste is gesirkuleer vir voltooiing deur TBH gesondheidswerkers, waarvan 69.8% voltooide vraelyste terugontvang is. Na evaluering van insluitingskriteria, is "n studiegroep van 152 individue saamgestel (28 mans, 124 vrouens). Almal het huidige lateks blootstelling en ten minste drie het vooraf gedefinieerde simptome gerapporteer. Serum is van die hele groep versamel en dermale vog van 31 proefpersone. Totale IgE en lateks-spesifieke IgE vlakke is op alle serum en dermale vog bepaal. Positiewe resultate (>0.35 IU/ℓ) is verkry in 23 serum en ses dermaIe vog monsters. Velpriktoets vir lateks is op 59 proefpersone uitgevoer en 34 daarvan het positiewe resultate opgelewer. Twaalf proefpersone met negatiewe lateks-spesifieke IgE en velpriktoets resultate het kutane plaktoetse ondergaan met die Europese Standaard Reeks, "n stukkie lateks handskoen en handskoenpoeier in petrolatum. Drie proefpersone het positiewe resultate teen een of meer van die allergene gehad. Westerse kladanalise vir lateks is op alle positiewe serum gedoen, asook die dermale vogte van hierdie proefpersone. Westerse kladanalise vir lateks blyk baie meer sensitief te wees as die capRAST, aangesien dit spesifieke bande kon identifiseer in monsters capRAST resultate. Alle monsters het "n band getoon vir Hev b 1, "n poeier-gebinde, luggedraade allergeen. Hev b 6.01 is geassosieer met gesondheidswerkers met velsimptome en hierdie band is gevind in 81% van die monsters. Hierdie resultate bevestig dat die belangrikste blootstelling aan lateks in gesondheidswerkers deur die vel en inaseming plaasvind. Proefpersone is in die volgende drie groepe verdeel volgens laboratorium resultate en statisties vergelyk: Groep A (positiewe serum, n=23), Groep B (positiewe velpriktoetse, n=34) en Groep C (negatief, n=25). Groep D (onttrek, n=70) kon nie vir betekenisvolle statistiese vergelykings aangewend word nie, as gevolg van onvolledige resultate. 'n Finale lateks allergie prevalensie van 38% is gevind. Groep A het hoogs beduidend verskil van Groep B en C vir die meeste van die kliniese en spesiale laboratoriumondersoeke. Groep A en B is gekombineer om alle proefpersone in te sluit met positiewe resultate (Kohort AB). Die Allergie Telling en Klas van Kohort AB was hoogs beduidend in vergelyking met Groep C. Die gekose simptome is bevestig as relevant en enige werksverwante verergering van simptome moet met 'n hoë mate van agterdog bejeën word in lateks allergie. Numeriese indekse en spesifieke simptome het hoë positiewe voorspellingswaardes gelewer en die Allergie Telling was hoogs beduidend in die positiewe subgroep in vergelyking met die negatiewe subgroep. Gepaarde statistiese beduidenheid is ook gevind tussen die Allergie Telling en beroepsblootstelling (jare van blootstelling, uur en paar handskoene per week). Die meeste beroepsblootstelling aan lateks in gesondheidswerkers vind plaas op die hande en gesig. Verskillende beroepe het ook verskillende blootstellingsvlakke en two subgroepe gesondheidswerkers (16 laboratorium tegnoloë en 13 teater personeel) is ondersoek vir die sebumgehalte op veskillende areas van die gesig en hande. Basislynvlakke is gemeet voordat handskoene aangetrek is en in 21 gevalle is opvolgvlakke gemeet na drie tot vier uur beroepsblootstelling, maar voor die hande gewas is. Basislyn en opvolgvlakke is met mekaar vergelyk vir al die anatomiese areas. Die voorkop en wange het 'n toename in sebumgehalte getoon, terwyl dié van die neus afgeneem het. AI die areas op die hande toon 'n hoogs beduidende afname tydens beroepsblootstelling, wat impliseer dat hanskoenpoeier moontlik bydra tot droogheid van die vel. In samevatting, die lateks allergie probleem sal nie oornag opgelos word nie en sal waarskynlik 'n belangrike beroepsrisiko bly vir die aansienlike toekoms. Totale vermyding van lateks is tans onmoontlik en daarom is dit van uiterste belang om voorsorgmaatreëls in plek te stel om verdere sensitisasie in blootgestelde individue te verhoed en die wat reeds geaffekteer is, effektief te hanteer.