Data obtained from longitudinal surveys using complex multi-stage sampling designs contain cross-sectional dependencies among units caused by inherent hierarchies in the data, and within subject correlation arising due to repeated measurements. The statistical methods used for analyzing such data should account for stratification, clustering and unequal probability of selection as well as within-subject correlations due to repeated measurements. <p>The complex multi-stage design approach has been used in the longitudinal National Population Health Survey (NPHS). This on-going survey collects information on health determinants and outcomes in a sample of the general Canadian population. <p>This dissertation compares the model-based and design-based approaches used to determine the risk factors of asthma prevalence in the Canadian female population of the NPHS (marginal model). Weighted, unweighted and robust statistical methods were used to examine the risk factors of the incidence of asthma (event history analysis) and of recurrent asthma episodes (recurrent survival analysis). Missing data analysis was used to study the bias associated with incomplete data. To determine the risk factors of asthma prevalence, the Generalized Estimating Equations (GEE) approach was used for marginal modeling (model-based approach) followed by Taylor Linearization and bootstrap estimation of standard errors (design-based approach). The incidence of asthma (event history analysis) was estimated using weighted, unweighted and robust methods. Recurrent event history analysis was conducted using Anderson and Gill, Wei, Lin and Weissfeld (WLW) and Prentice, Williams and Peterson (PWP) approaches. To assess the presence of bias associated with missing data, the weighted GEE and pattern-mixture models were used.<p>The prevalence of asthma in the Canadian female population was 6.9% (6.1-7.7) at the end of Cycle 5. When comparing model-based and design- based approaches for asthma prevalence, design-based method provided unbiased estimates of standard errors. The overall incidence of asthma in this population, excluding those with asthma at baseline, was 10.5/1000/year (9.2-12.1). For the event history analysis, the robust method provided the most stable estimates and standard errors. <p>For recurrent event history, the WLW method provided stable standard error estimates. Finally, for the missing data approach, the pattern-mixture model produced the most stable standard errors <p>To conclude, design-based approaches should be preferred over model-based approaches for analyzing complex survey data, as the former provides the most unbiased parameter estimates and standard errors.

By using Michigan and SPF surveys, this thesis compares the group-level inflation-forecast performance as well as information transmission between two main market participation groups, consumers and professional forecasters. Group-level performance are in terms of forecasting different U.S. inflation indexes and evaluated using forecast accuracy measured by RMSE as well as predictive power tested by a linear model. In addition, consumers are decomposed into three sub-groups based on educational attainment and income distribution to explore within-group heterogeneity. The results indicate that both consumer groups and professionals show poor forecast performance for all the inflation measures, except professionals’ performance for CPI-Core. Further, gathering downward-biased inflation forecasts from professionals is a possible reason that contributes to highly educated consumers’ inflation-forecast performance for price changes of expenditure categories they care.

The Coles Hill uranium deposit in Pittsylvania County, Virginia represents the largest unmined uranium resource in the United States, with an estimated resource of 110 million pounds of U3O8 in place with a cutoff grade of 0.025 wt% U3O8. The deposit is localized along a geologic unit that parallels the Chatham Fault, which separates the Triassic Danville Basin to the east from the older crystalline rocks to the west. The location of the Chatham Fault is important to understanding distribution of ore and for developing an effective mine plan. In this study the Chatham Fault location has been inferred from ground conductivity and ground penetrating radar (GPR) surveys. Anomalies in the data are consistent with previously mapped fault locations based on drillhole and geophysical data, such as gravity and magnetic surveys, collected in the 1980s. These results confirm that the strike of the Chatham Fault is approximately N40ºE and dips to the southeast with dip values ranging from 70º, in the northeast, to 50º, in the southwest. / Master of Science

BACKGROUND: Diabetic foot complications are the leading cause of lower extremity amputation and diabetes-related hospitalisation in Australia. Studies demonstrate significant reductions in amputations and hospitalisation when health professionals implement best practice management. Whilst other nations have surveyed health professionals on specific diabetic foot management, to the best of the authors' knowledge this appears not to have occurred in Australia. The primary aim of this study was to examine Australian podiatrists' diabetic foot management compared with best practice recommendations by the Australian National Health Medical Research Council. METHODS: A 36-item Australian Diabetic Foot Management survey, employing seven-point Likert scales (0 = Never; 7 = Always) to measure multiple aspects of best practice diabetic foot management was developed. The survey was briefly tested for face and content validity. The survey was electronically distributed to Australian podiatrists via professional associations. Demographics including sex, years treating patients with diabetes, employment-sector and patient numbers were also collected. Chi-squared and Mann Whitney U tests were used to test differences between sub-groups. RESULTS: Three hundred and eleven podiatrists responded; 222 (71%) were female, 158 (51%) from the public sector and 11-15 years median experience. Participants reported treating a median of 21-30 diabetes patients each week, including 1-5 with foot ulcers. Overall, participants registered median scores of at least "very often" (>6) in their use of most items covering best practice diabetic foot management. Notable exceptions were: "never" (1 (1 - 3)) using total contact casting, "sometimes" (4 (2 - 5)) performing an ankle brachial index, "sometimes" (4 (1 - 6)) using University of Texas Wound Classification System, and "sometimes" (4 (3 - 6) referring to specialist multi-disciplinary foot teams. Public sector podiatrists reported higher use or access on all those items compared to private sector podiatrists (p < 0.01). CONCLUSIONS: This study provides the first baseline information on Australian podiatrists' adherence to best practice diabetic foot guidelines. It appears podiatrists manage large caseloads of people with diabetes and are generally implementing best practice guidelines recommendations with some notable exceptions. Further studies are required to identify barriers to implementing these recommendations to ensure all Australians with diabetes have access to best practice care to prevent amputations.

Risk perception for rare, low-probability hazards, such as tsunamis, tends to be low due to individual's unfamiliarity with them and the tendency to see them as synonymous with non-occurrence events. Visitors to an area tend to have even lower risk perception and knowledge of hazards, warning systems and appropriate actions to take during an event. Risk perception, however, can increase, if only temporarily, after a catastrophic event, such as the 2004 Boxing Day tsunami. To determine the changes in resident's knowledge and perception and the differences between those of residents and visitors two surveys were conducted. In the first survey interview style surveying was conducted at eleven locations in the coastal Christchurch and Banks Peninsula area of the Canterbury Region The questionnaire was composed of scaled, open, and closed ended questions and the main themes included knowledge of risk, preparation and warnings, what to do during a tsunami, and changes since the 2004 Boxing Day tsunami. The second survey of five coastal communities was conducted via a postal questionnaire and was aimed at obtaining residential views. Survey data was then analysed with Statistical Package for the Social Sciences (SPSS) statistical software. The residential data was compared with that of the non-residents to determine the differences in perception of residents and visitors. The residential information was then compared with survey data from the 2003 National Coastal Survey. Visitors knew less about general tsunami information such as when the last tsunami occurred and were less likely to believe that a tsunami could occur imminently. Non-residents reported less receipt of information and did considerably less information seeking. Differences in knowledge of warning systems were difficult to ascertain. The Boxing Day event certainly made an impact, increasing people's knowledge and awareness, though most likely only temporarily.

No description available.

No description available.

No description available.

This thesis presents a novel approach to evaluating intercity travel demand given the introduction of a new travel mode. A joint RP-SP survey is designed to collect both experienced and hypothetical travel decisions. The stated preference aspect of the survey evaluates the level-of-service attributes that influence intercity mode choice. Emphasis is placed on the effects of local accessibility by adapting a geographical disaggregation at the Forward Sortation Area (FSA). Survey distribution collected data primarily through the use of online social networks such as Facebook and Reddit in addition to an online marketing research survey panel. Intercity mode choice was modeled with Random Utility Maximizing (RUM) discrete choice models and is represented by Multinomial Logit (MNL) and Nested Logit (NL) choice structures. Key finding is that access to transit stations significantly influences intercity mode choices.

This thesis presents a novel approach to evaluating intercity travel demand given the introduction of a new travel mode. A joint RP-SP survey is designed to collect both experienced and hypothetical travel decisions. The stated preference aspect of the survey evaluates the level-of-service attributes that influence intercity mode choice. Emphasis is placed on the effects of local accessibility by adapting a geographical disaggregation at the Forward Sortation Area (FSA). Survey distribution collected data primarily through the use of online social networks such as Facebook and Reddit in addition to an online marketing research survey panel. Intercity mode choice was modeled with Random Utility Maximizing (RUM) discrete choice models and is represented by Multinomial Logit (MNL) and Nested Logit (NL) choice structures. Key finding is that access to transit stations significantly influences intercity mode choices.