Cluster randomized controlled trials are increasingly used to assess the effectiveness of life-style interventions in improvement of health services or prevention of disease. However, statistical methods in the analysis of cluster randomized controlled trials are not well established especially for analyzing binary outcomes. This project is motivated by the Community Hypertension Assessment Trial (CHAT) to assess the effectiveness of a 12-month community-based blood pressure management program in improving the management and monitoring of high blood pressure (BP) among older people. The study is a paired cluster randomized controlled trial, where the family physicians' practices are the clusters randomly allocated to CHAT intervention or usual practice, and a random sample of 55 patients 65 years and older were selected from the 14 practices in each study arm for health record review. The primary outcome was controlled BP over 12 months defined as systolic BP c:; 140 and diastolic BP c:; 90 for patients without diabetes or target organ damage or systolic BP c:; 130 and diastolic BP c:; 80 for patients with diabetes or target organ damage. Secondary outcomes include frequency of BP monitoring and average BP over a 12 month period. The clinical objective of this project is to evaluate the effectiveness of the CHAT intervention. The statistical objective is to compare Bayesian and classical methods of analyzing cluster-randomized trials using CHAT study as an example. We compared the results of different cluster-level analysis methods: i) un-weighted regression, ii) weighted regression, iii) random-effects meta-analytic approach, and different individual-level analyses: i) standard logistic regression, ii) robust standard errors approach, iii) generalized estimating equations, iv) random-effect logistic regression, v) Bayesian random-effect regression. We find that there is no sufficient evidence in support of the effectiveness of the CHAT intervention on all outcomes. For BP control, odds ratio (95% confidence interval) is 1.14 (0.72, 1.80) from generalized estimating equations. This result remains robust under different methods. We also find that the results from different statistical methods are different. The results from cluster-level analysis methods are quite different, while the results from the individual-level analysis methods are similar. We conclude that using various methods to analyze the trial provide good sensitivity analyses to help in interpreting the results of cluster randomized trials. Extensive simulation studies comparing the statistical powers of the different methods in different situations are required. / Thesis / Master of Science (MS)

Hybridity, as it is currently understood in the Peace and Conflict Studies (PCS) and International Relations (IR) literature, is defined by the complex interactions between ‘the liberal peace' and ‘the local'. However, under this theoretical liberal-local rubric, the ways in which power is practiced has already been determined; how resistance is expressed and the forms it assumes have already been established. While it has yielded numerous important insights into how power circulates and resistance manifests in peacebuilding operations, the theoretical approach conceals other significant dynamics which escape detection by ‘the liberal peace' and ‘the local'. However, these undetected dimensions of hybridity comprise the very processes that emerge in ways which destabilise the boundaries between ‘the liberal peace' and ‘the local' and reshape the contours of the emerging post-liberal peace. Instead of accepting the liberal-local distinction which defines this theoretical hybridity, this thesis advances an alternative methodological approach to exploring the tensions at play in peacebuilding projects. Rather than deploying theoretical distinctions in order to explain or understand complex hybrid processes, this thesis develops a methodological strategy for exploring the tensions between how actors design a peacebuilding project and how that project changes as actors work to translate that project into complex, everyday living sites (Callon, 1986; Law, 1997; Akrich, 1992). This tension is expressed as practical hybridity. The process of practical hybridity unfolds as the concrete material changes, modifications, and adaptations that emerge as actors appropriate and contingently translate organised practices in new ways and for different purposes. Through an ongoing process of practical hybridity, the boundaries and distinction which define the distinction between ‘the liberal peace' and ‘the local' become increasingly unstable. Amidst this instability, the practices which characterised ‘the liberal peace' are becoming stretched into a post-liberal peace. Drawing on the work of Richmond (2011a; Richmond & Mitchell, 2012), Latour (1987b; 1988; 2004), and Schatzki (2002), and based on over five months of field research, this this thesis traces the process of practical hybridity at play during the implementation and evaluation of a peacebuilding project in Liberia. I participated as a research assistant on a Randomised Control Trial (RCT), implemented by a small research team under the auspices of the Oxford University's Centre for the Study of African Economies (CSAE). The team was assessing the impact of a legal empowerment programme managed by The Carter Center: the Community Justice Advisor (CJA) programme. As the CSAE's evaluation of the CJA programme unfolded, many dynamics associated with theoretical liberal-local hybridity surfaced; however, it also became apparent that this theoretical formulation obscured important dimensions which were reshaping what peacebuilding practice is in the process of becoming in the emerging post-liberal world.

No description available.