Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 15 of 15 for “"sample size calculation"”.
-
Methods of sample size calculation for clinical trials
Sample size calculations should be an important part of the design of a trial, but are researchers choosing sensible trial sizes? This thesis looks at ways of determining appropriate sample sizes for Normal, binary and ordinal data. The inadequacies of existing sample size and power calculation …
-
Extending Sample Size Calculation for the Cox Proportional Hazards Model
… lymphoma disease. The popularly used sample size formula derived under the Cox proportional hazards (PH) model may not be proper to design a survival trial with a cure fraction, since the PH model assumption may be violated. To account for a cure fraction, the PH cure model is widely …
-
Sample Size Calculation Based on the Semiparametric Analysis of Short-term and Long-term Hazard Ratios
We derive sample size formulae for survival data with non-proportional hazard functions under both fixed and contiguous alternatives. Sample size determination has been widely discussed in literature for studies with failure-time endpoints. Many researchers have developed methods with the …
-
Design and Monitoring of Clinical Trials with Clustered Time-to-Event Endpoint
… there are only few methods proposed for sample size calculation, especially when the cluster sizes are variable. In this dissertation, we aim to derive sample size formula for clustered survival endpoint based on nonparametric weighted rank tests. First, we propose closed form sample size …
-
Topics in Bayesian sample size determination and Bayesian model selection.
… The first topic is related to Bayesian sample size determination with a misclassified prevalence variable when two possibly dependent diagnostic tests are used for estimation. After accounting for the dependence structure, the required sample size will be larger than that assuming …
-
Bayesian Methods for the Design and Analysis of Cluster Randomised Controlled Trials
… implications, both in terms of study design and sample size calculation, and in analysis. The methodology underpinning the cluster randomised design is now well-established in the statistical literature. However, the overwhelming majority of methodological developments to date have been within …
-
Inferential Methods For Quantile Regression With Applications to Infant Birth Weight
… tools of interest to researchers, power/sample size calculation, and tests for lack of fit. As more studies in the health sciences use quantile regression the method will achieve greater exposure and researchers will become more comfortable with its use and more familiar with its …
-
Statistical Methods for Variability Management in High-Performance Computing
… parameter estimation and derives a formula for sample size calculation. The developed method is then applied to HPC variability data. Chapter 4 focuses on the prediction of functional outcomes with both qualitative and quantitative factors. Instead of a scalar description of I/O variability, the …
-
Public health nutrition intervention to delay the progression of HIV to AIDS among people living with HIV (PLWHIV) in Abuja, Nigeria
… centres in Abuja, Nigeria. Based on the sample size calculation, inclusion and exclusion criteria, 400 participants (adult, male and female from different religious background) were selected through simple randomisation. Out of these 400 participants, 100 were randomly selected for the …
-
Examining the role of organisational learning in customer relations management : a case study of microfinance institutions in the Central business district of Lusaka, Zambia.
… as well as an estimated 200 Customers of MFIs. A sample of 70 participants was used to participate in the study using the Taro Yamane method for sample size calculation. Quota sampling was used to select the elements in the sample. The gathered data was analysed using thematic analysis. The study …
-
Examining the role of organisational learning in customer relations management : a case study of microfinance institutions in the Central business district of Lusaka, Zambia.
… as well as an estimated 200 Customers of MFIs. A sample of 70 participants was used to participate in the study using the Taro Yamane method for sample size calculation. Quota sampling was used to select the elements in the sample. The gathered data was analysed using thematic analysis. The study …
-
Measuring Nutritional Status, Hydration and Body Composition Changes in Acute Stroke
… pureed diet, nilby- mouth feeding regimen). Sample size was small to generalize a conclusion on the association between body composition changes in acute stay and outcomes. MF-BIA BioScan 920-2 did not show diagnostic accuracy in diagnosing dehydration in stroke patients. MF-BIA BioScan 920-2 …
-
Integrating patients with intermittent claudication into an established cardiac rehabilitation programme: a feasibility study with embedded pilot
… of IC participants, was used for an a priori sample size calculation to inform a future RCT study. Both the quantitative and qualitative data was used to evaluate the study’s methodology to guide a future large-scale RCT. Results: Eligibility rates were 85% for the IC control group, 92% for …
-
Innovative Methods for the Design and Analysis of Phase II Clinical Trials
… this project proposes novel methods for sample size planning and adaptive cost-optimized sample size re-estimation for DCTs. Simulations demonstrate that these methods ensure that DCTs maintain their efficiency, scalability, and statistical power while accounting for the heterogeneity …
-
Minimally invasive treatment of venous insufficiency using endovenous laser ablation
… pain scores and analgesia requirements. The sample size calculation established that 115 patients would be required to detect any significant relationship. Results Study 1: EVLTAP took longer, but significantly decreased the requirement for subsequent interventions. There was no impairment in …