Indiana University-Purdue University Indianapolis (IUPUI) / Epidemiologic and clinical studies routinely collect longitudinal measures of multiple outcomes. These longitudinal outcomes can be used to establish the temporal order of relevant biological processes and their association with the onset of clinical symptoms. In the first part of this thesis, we proposed to use bivariate change point models for two longitudinal outcomes with a focus on estimating the correlation between the two change points. We adopted a Bayesian approach for parameter estimation and inference. In the second part, we considered the situation when time-to-event outcome is also collected along with multiple longitudinal biomarkers measured until the occurrence of the event or censoring. Joint models for longitudinal and time-to-event data can be used to estimate the association between the characteristics of the longitudinal measures over time and survival time. We developed a maximum-likelihood method to joint model multiple longitudinal biomarkers and a time-to-event outcome. In addition, we focused on predicting conditional survival probabilities and evaluating the predictive accuracy of multiple longitudinal biomarkers in the joint modeling framework. We assessed the performance of the proposed methods in simulation studies and applied the new methods to data sets from two cohort studies. / National Institutes of Health (NIH) Grants R01 AG019181, R24 MH080827, P30 AG10133, R01 AG09956.

This qualitative study was aimed at exploring and describing the theoretical and practical experiences of second-year critical care nursing students. Purposive sampling was done, and unstructured interviews and narrative descriptions were used as data collection tools. An adaptation of Johns's Framework, the Guideline for the Facilitation of Reflection as Teaching Strategy, was used during interviews to guide participants in reflecting on theory-practice integration. Multiple strategies were used to ensure the trustworthiness of the study. Concerning patient data, communication, and the administration of life-saving medications, theory-practice integration did occur. Regarding treatment and the outcome of nursing interventions, it seemed that knowledge deficiencies and a lack of exposure to practical situations contributed to the inability to apply theory to practice. This apparent inability evoked negative feelings, such as guilt. Discrepancies between practice and theory taught led to confusion. Guided reflection assisted students in gaining a new perspective on nursing and theory-practice integration. / Health Studies / M.A. (Health Studies)

This qualitative study was aimed at exploring and describing the theoretical and practical experiences of second-year critical care nursing students. Purposive sampling was done, and unstructured interviews and narrative descriptions were used as data collection tools. An adaptation of Johns's Framework, the Guideline for the Facilitation of Reflection as Teaching Strategy, was used during interviews to guide participants in reflecting on theory-practice integration. Multiple strategies were used to ensure the trustworthiness of the study. Concerning patient data, communication, and the administration of life-saving medications, theory-practice integration did occur. Regarding treatment and the outcome of nursing interventions, it seemed that knowledge deficiencies and a lack of exposure to practical situations contributed to the inability to apply theory to practice. This apparent inability evoked negative feelings, such as guilt. Discrepancies between practice and theory taught led to confusion. Guided reflection assisted students in gaining a new perspective on nursing and theory-practice integration. / Health Studies / M.A. (Health Studies)