A Bayesian approach to estimating the intraclass correlation coefficient

A Bayesian approach to estimating the intraclass correlation coefficient was used for this research project. The background of the intraclass correlation coefficient, a summary of its standard estimators, and a review of basic Bayesian terminology and methodology were presented. The conditional posterior density of the intraclass correlation coefficient was then derived and estimation procedures related to this derivation were shown in detail. Three examples of applications of the conditional posterior density to specific data sets were also included. Two sets of simulation experiments were performed to compare the mean and mode of the conditional posterior density of the intraclass correlation coefficient to more traditional estimators. Non-Bayesian methods of estimation used were: the methods of analysis of variance and maximum likelihood for balanced data; and the methods of MIVQUE (Minimum Variance Quadratic Unbiased Estimation) and maximum likelihood for unbalanced data. The overall conclusion of this research project was that Bayesian estimates of the intraclass correlation coefficient can be appropriate, useful and practical alternatives to traditional methods of estimation. ^

Collaborative Conversations for Change: A SolutionFocused Approach to Family Centered Practice

The renewed interest in Family Centered Practice, prompted by the funding of Family Preservation and Support Programs, has created a need for training practitioners at a number of different levels and for a variety of roles. This paper will describe a training program for Family Centered Practice. Building on an empowerment model, the author presents an approach for working with families and children that views the tragedies of the past as resources, rather than the major cause of present problems. Collaborative Conversations for Change adapts the solution-focused therapy model to nontherapy roles that are required for a program to be family centered. Although these roles are not therapy, they are nevertheless therapeutic and reinforce clients' strengths. These collaborative conversations, however brief they may be, recognize that the client is the expert on his/her pain and struggles and the practitioner is the expert on assisting her/him plan change. Additionally, illustrations from a cross-cultural perspective demonstrate the utility of collaborative conversation in enhancing cultural competence.

AIDS talk

The observations of Michel Foucault, noted Twentieth Century French philosopher, regarding modern power relations and orders of discourse, form the framework utilized to analyze and interpret the power struggles of AIDS activists and their opponents--the religious and radical right, and the administrative agencies of the 'Liberal' welfare State. Supported by the tools of sociolinguistic inquiry, the analysis highlights the success of a safer sex campaign in Houston, Texas to illustrate the dynamics of cultural and political change by means of discursive transformations initiated by the gay micro-culture. The KS/AIDS Foundation, allied with both the biomedical community and gay entertainment spheres, was successful in conveying biomedical cautions that resulted in altered personal behavior and modified public attitudes by using linguistic conventions consonant with the discourse of the Houston gay micro-culture. The transformation of discursive practices transgressed not only the Houston gay micro-culture's boundaries, but the city boundaries of Houston as well. In addition to cultural and political change, moderate and confrontational gay activists also sought to change the cognitive boundaries surrounding 'the gold standard' for clinical research trials.^ From a Foucauldian perspective, the same-sex community evolved from the subordinated Other to a position of power in a period of five years. Transformations in discursive practices and power relations are exemplified by the changing definitions employed by AIDS policy-makers, the public validation of community-based research and the establishment of parallel track drug studies. Finally, transformations in discursive practices surrounding the issues of HIV antibody testing are interpreted using Foucault's six points of power relations. The Montrose Clinic provides the case study for this investigation. The clinic turned the technical rationalities of the State against itself to achieve its own ends and those of the gay micro-culture--anonymous testing with pre and post test counseling. AIDS Talk portrays a dramatic transformation in discursive practices and power relations that transcends the historical moment to provide a model for future activists. Volume 2 contains copies of fugitive primary source materials largely unavailable elsewhere. Original documents are archived in the Harris County Medical Archives in the Houston Academy of Medicine located in the Texas Medical Center Library, Houston, Texas. ^

Effect of nonnormal random components on level and power in group-randomized trials

The use of group-randomized trials is particularly widespread in the evaluation of health care, educational, and screening strategies. Group-randomized trials represent a subset of a larger class of designs often labeled nested, hierarchical, or multilevel and are characterized by the randomization of intact social units or groups, rather than individuals. The application of random effects models to group-randomized trials requires the specification of fixed and random components of the model. The underlying assumption is usually that these random components are normally distributed. This research is intended to determine if the Type I error rate and power are affected when the assumption of normality for the random component representing the group effect is violated. ^ In this study, simulated data are used to examine the Type I error rate, power, bias and mean squared error of the estimates of the fixed effect and the observed intraclass correlation coefficient (ICC) when the random component representing the group effect possess distributions with non-normal characteristics, such as heavy tails or severe skewness. The simulated data are generated with various characteristics (e.g. number of schools per condition, number of students per school, and several within school ICCs) observed in most small, school-based, group-randomized trials. The analysis is carried out using SAS PROC MIXED, Version 6.12, with random effects specified in a random statement and restricted maximum likelihood (REML) estimation specified. The results from the non-normally distributed data are compared to the results obtained from the analysis of data with similar design characteristics but normally distributed random effects. ^ The results suggest that the violation of the normality assumption for the group component by a skewed or heavy-tailed distribution does not appear to influence the estimation of the fixed effect, Type I error, and power. Negative biases were detected when estimating the sample ICC and dramatically increased in magnitude as the true ICC increased. These biases were not as pronounced when the true ICC was within the range observed in most group-randomized trials (i.e. 0.00 to 0.05). The normally distributed group effect also resulted in bias ICC estimates when the true ICC was greater than 0.05. However, this may be a result of higher correlation within the data. ^

Ligand-directed targeting of malignant gliomas

The dramatic poor survival of patients diagnosed with glioblastoma multiforme (GBM) is a reflection of the struggles that accompany traditional treatments. Thus, the development of molecular-based targeted therapies represents new windows for intervention. In this study, we hypothesized that we could select peptide-ligands that selectively target GBM based on the idea that the glioma microenvironment may induce or modify the expression of cell surface receptors that could be accessed by circulating peptides. To select the peptides we employed two distinct in vivo screenings. First, a random phage-displayed peptide library was injected into mice bearing intracranial tumors. Phage that bound to tumor were recovered and sequenced. We found that the tumor-derived phage CLSYKGRC, CNKVSTKC and CQSSREKC were recovered with the highest frequencies and used for subsequent targeting experiments. Second, the phage peptide library was injected into mice without tumors and phage were recovered from brain and sequenced. A phage-displayed peptide (CRTIGPSVC) with homology to transferrin (Tf) was selected and injected into brain tumor-bearing mice. Results showed that after 6 hours of circulation, the CLSYKGRC, CNKVSTKC and CQSSREKC-phage selectively targeted GBM vasculature. In contrast, Tf-like phage accumulated outside the tumor blood vessels in the cytoplasm of cells located within GBM, suggesting it was internalized in vivo. However, after short periods of circulation this phage was restricted to the tumor vasculature. Importantly, none of the selected phage targeted normal brain cells in animals bearing intracranial tumors. An affinity column coupled to the CNKVSTKC zpeptide was used to identify receptors from GBM. Using mass-spectrometry Vimentin, a marker of glial malignancy, was identified as a potential receptor. Other studies showed that the Tf-like phage bound selectively to Apo-Tf (iron free), with no binding to Holo-Tf (iron loaded) or to Tf receptor (TfR). However, the binding of Tf-like phage to glioma cells that express TfR increased in the presence of Apo-Tf. Thus, the Tf-like phage could indirectly target TfR using the endogenous Tf pathway. We propose that the novel peptides identified in this study could be conjugated to therapeutic or imaging agents for use GBM. ^

Evidence of reliability and validity of IPAQ for Mexican-American adults

Physical activity is a key component of life-style modification process which helps to reduce the risk of developing chronic diseases. It is important to have accurate estimates of physical activity to identify sedentary populations where interventions might be helpful. The International Physical Activity Questionnaire (IPAQ) short version has been used to estimate physical activity in diverse populations. However, there is little literature depicting the use of the IPAQ short version in Mexican America population. This study addressed the predictive validity and test-retest reliability of the IPAQ short version in Mexican American adults. The analysis was performed on 97 participants enrolled in the Cameron County Hispanic Cohort. Individuals selected in this study were 18 years of age or older. The predictive validity was evaluated by studying the relationship between physical activity and biomarkers known to be correlated with physical activity, namely, TNF-α, Adiponectin, and HDL. Multiple linear regression analysis was performed to delineate predictive validity. To assess test-retest reliability, two IPAQ-short last seven days questionnaires were interviewer administered to the participants on the same day, approximately two hours apart. Test-Retest reliability of IPAQ was estimated by performing intraclass correlations between the readings at two different time periods. The study showed that the IPAQ – short version used in the above study had acceptable test-retest reliability in the Mexican American population. This study showed that the IPAQ – short version did not have acceptable predictive validity when looking at physical activity and TNF-α, Adiponectin, and HDL in this sample.^

Affect and cognition measures in preference-based decisions: Validity testing of the Ottawa Decisional Conflict Scale and a decision-specific anxiety measure with men eligible for prostate cancer screening

Background. At present, prostate cancer screening (PCS) guidelines require a discussion of risks, benefits, alternatives, and personal values, making decision aids an important tool to help convey information and to help clarify values. Objective: The overall goal of this study is to provide evidence of the reliability and validity of a PCS anxiety measure and the Decisional Conflict Scale (DCS). Methods. Using data from a randomized, controlled PCS decision aid trial that measured PCS anxiety at baseline and DCS at baseline (T0) and at two-weeks (T2), four psychometric properties were assessed: (1) internal consistency reliability, indicated by factor analysis intraclass correlations and Cronbach's α; (2) construct validity, indicated by patterns of Pearson correlations among subscales; (3) discriminant validity, indicated by the measure's ability to discriminate between undecided men and those with a definite screening intention; and (4) factor validity and invariance using confirmatory factor analyses (CFA). Results. The PCS anxiety measure had adequate internal consistency reliability and good construct and discriminant validity. CFAs indicated that the 3-factor model did not have adequate fit. CFAs for a general PCS anxiety measure and a PSA anxiety measure indicated adequate fit. The general PCS anxiety measure was invariant across clinics. The DCS had adequate internal consistency reliability except for the support subscale and had adequate discriminate validity. Good construct validity was found at the private clinic, but was only found for the feeling informed subscale at the public clinic. The traditional DCS did not have adequate fit at T0 or at T2. The alternative DCS had adequate fit at T0 but was not identified at T2. Factor loadings indicated that two subscales, feeling informed and feeling clear about values, were not distinct factors. Conclusions. Our general PCS anxiety measure can be used in PCS decision aid studies. The alternative DCS may be appropriate for men eligible for PCS. Implications: More emphasis needs to be placed on the development of PCS anxiety items relating to testing procedures. We recommend that the two DCS versions be validated in other samples of men eligible for PCS and in other health care decisions that involve uncertainty. ^

MS#73 William C. Moloney, M.D., papers; 1952-1954

Dr. Moloney kept a personal journal, with photographs, for much of his two years with the Atomic Bomb Casualty Commission in Japan. Along with other scientists, he studied the biological and medical effects of ionized radiation on the survivors of the Hiroshima and Nagasaki atomic bombings. In January of 1986, Dr. Moloney donated his journal, correspondence and diary pages to the Harris County Medical Archive, whose collections were later incorporated into the Texas Medical Center Library. Dr. Moloney's journal is in relatively good shape containing a mix of handwritten notes and comments, news-clippings, photos, and ephemera. The journal is an important record of personal impressions, thoughts and details of events during a pivotal time in Japan. This 192-pagee journal gives new insights into the work of the ABCC and into the people who participated in that work. The journal covers the period from April 1952 to February 1954. In these documents, Moloney records his struggles with understanding the Japanese culture, his frustration at not being allowed to treat the survivors he studied, and his concerns, fears, hopes and revelations as he dealt with the bombing survivors and their children. The original papers are open for research at the John P. McGovern Historical Collections and Research Center in the TMC Library in Houston.

A study of nutrition promotion in and consumer nutrition environments of hospitals

Dietary intake is a complex, health-related behavior, and although individual-level theoretical models explain some variation in dietary intake, comprehensive theoretical models such as the ecological framework describe the multiple levels which influence diet-related behaviors. Thus, the ecological framework is a preferred model for designing comprehensive nutrition interventions. While ecological-based nutrition interventions have been described, little work has focused on interventions in the hospital setting. Because hospitals are considered the hallmarks of health, it might seem that hospitals would regularly engage in worksite nutrition promotion; however, recent publications and other anecdotal evidence have indicated otherwise. The first paper of this dissertation systematically reviewed the scientific literature between 1996 and 2012 and identified 13 outcome evaluation trials for hospital-based worksite nutrition interventions. Of these 13 interventions, only one intervention targeted three of the four levels of the ecological framework and no intervention targeted all four levels. Only half of the interventions targeted the physical environment of hospitals, thus warranting more investigation into this specific level of the ecological framework in this setting. ^ A critical type of nutrition-related physical environments is the consumer nutrition environment. Although other tools measure the consumer nutrition environments of stores and restaurants, no tool specifically measured the consumer nutrition environments of hospitals until the CDC developed the Healthy Hospital Environment Scan for Cafeterias, Vending Machines, and Gift Shops (HHES-CVG). The HHES-CVG, a tool which measures the consumer nutrition environments of hospital cafeterias, vending machines, and gifts shops, was released in November 2011, and in the second paper of this dissertation, the reliability of this tool was investigated. Two trained raters visited 39 hospitals across Southern California between February and May 2012, and based on analyses of the raters' findings, the HHES-CVG exhibited strong reliability metrics (inter-observer agreement between 74 and 100%, and an intraclass correlation coefficient of 0.961 for the overall nutrition composite score). Because the HHES-CVG was found to be a reliable tool, the third paper of this dissertation presented HHES-CVG results from the 39 hospitals. Overall, hospitals only scored about one-fourth of the total possible points for the nutrition composite score, indicating that most facilities do not have acceptable consumer nutrition environments. Some of the best practices observed in cafeterias were significantly associated with having a large facility and with having a contracted foodservice operation, but overall nutrition composite score was not associated with any specific facility or operation type. ^ The dissertation concluded that much work is needed in order to improve the consumer nutrition environments of hospitals. Practitioners and healthcare administrators should consider starting with ecological-based interventions addressing all levels including the physical environment.^