My study investigated internal consistency estimates of psychometric surveys as an operationalization of the state of measurement precision of constructs in industrial and organizational (I/O) psychology. Analyses were conducted of samples used in research articles published in the Journal of Applied Psychology between 1975 and 2010 in five year intervals (K = 934) from 480 articles yielding 1427 coefficients. Articles and their respective samples were coded for test-taker characteristics (e.g., age, gender, and ethnicity), research settings (e.g., lab and field studies), and actual tests (e.g., number of items and scale anchor points). A reliability and inter-item correlations depository was developed for I/O variables and construct groups. Personality measures had significantly lower inter-item correlations than other construct groups. Also, internal consistency estimates and reporting practices were evaluated over time, demonstrating an improvement in measurement precision and missing data.

Background: Despite several decades of research, the relevance of body fat and body fat distribution to the risk of cardiovascular disease remains unclear. This thesis aims to investigate associations of body-mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR) with risk of first-onset cardiovascular disease under a range of different circumstances. Methods: This thesis used individual records from the Emerging Risk Factors Collaboration to calculate risk ratios, and measures of discrimination and reclassification. 118 prospective studies, involving 1,064,541 participants without known history of cardiovascular disease, had information on BMI at baseline examination. 58 of these studies, involving 221,934 participants, had additional information on waist and hip circumference at baseline examination. Serial measurements made in 42,300 participants from 12 studies with concomitant information on these adiposity measures enabled quantification of within-person variability in BMI, WC and WHR. Results: Cross-sectional analyses demonstrated that although the correlations of adiposity measures differed with one another, BMI, WC and WHR were similarly and importantly associated with mediating cardiovascular risk factors, such as blood pressure, fasting glucose and lipids. Within-person variability was lower in BMI (regression dilution ratio: 0.96) than in WC (0.88) and WHR (0.66). The variability of adiposity measures was not materially influenced by several characteristics, although the variability of WHR varied somewhat by sex, diabetes status and baseline WHR values. 1,064,541 individuals with information on BMI recorded 161,903 deaths or non-fatal cardiovascular outcomes during 15.0 million person-years of follow-up. In analyses adjusted for age, sex and smoking status, BMI had positive and nearly loge-linear associations with coronary heart disease and ischaemic stroke (except at BMI values below 20 kg/m2), which were largely explained by the intermediate risk factors noted above. The association between BMI and non-vascular mortality was curvilinear. Data on 221,934 individuals with complete information on weight, height, and waist and hip circumference (14,297 incident cardiovascular outcomes; 1.87 million person-years of follow-up) demonstrated that BMI, WC and WHR were substantially and similarly related to risk of coronary heart disease and ischaemic stroke. For cardiovascular risk prediction, additional information on BMI, WC or WHR to a prediction model containing conventional risk factors did not importantly improve risk discrimination, nor classification of participants to risk categories of predicted 10-year risk. Conclusions: BMI, WC and WHR are similarly associated with risk of cardiovascular disease, with much of the risk explained by intermediate risk factors. These clinical measures of adiposity do not importantly improve cardiovascular risk prediction when additional information is available on blood pressures, history of diabetes and lipids.

With the growing number of older adults in the general population, there is also a concomitant rise in the number of older adults who require mental health services, making the measurement of psychological conditions in later life a priority. However, due to a lack of measures created for older adults, researchers and clinicians must often rely on measures created for younger populations. Three studies were designed to add to the field of evidence-based assessment and determine which anxiety measures possess strong evidence when used with older adults to warrant their use with this specific population. In the first study, I systematically reviewed the literature to identify the anxiety measures most commonly used with older adults. I reviewed each measure to examine its psychometric properties (e.g., internal consistency, test-retest reliability, inter-rater reliability, concurrent and discriminant validity) and the availability of age-appropriate norms in order to evaluate whether the instruments are appropriate for use with older adults. In the second study, I conducted a reliability generalization meta-analysis to estimate the mean reliability of each commonly used anxiety measure identified in the first study. Finally, in the third study, I examined whether the anxiety measures commonly used with an older population can be consistently and accurately categorized as evidence-based. The literature review and the reliability generalization study both revealed that most of the most commonly used measures lacked sufficient evidence to warrant their use with older adults. However, three measures (Beck Anxiety Inventory, Penn State Worry Questionnaire, and Geriatric Mental Status Examination) showed psychometric properties sufficient to justify the use of these instruments when assessing anxiety in older adults. In addition, two measures developed specifically for older adults (Worry Scale and Geriatric Anxiety Inventory) were also found to be appropriate for use with older adults. This suggests that based on their overall level of reliability and previous psychometric evidence, both researchers and clinicians assessing anxiety in a geriatric population should consider these measures as likely to be the best currently available.

Osteoporosis is a growing cause of morbidity and mortality in aging populations worldwide, especially in postmenopausal women. Bisphosphonates are widely prescribed for fracture prevention in osteoporosis. Meta-analyses have been performed for alendronate, risedronate, and etidronate, examining their effectiveness versus placebo in fracture prevention. Total withdrawals and adverse event withdrawals were examined as safety outcomes. Systematic reviews were performed for two other bisphosphonates, ibandronate and zoledronic acid and the results combined with previously obtained data for the other bisphosphonates. Indirect treatment comparisons of the drugs against each other and versus placebo were performed using Bayesian and frequentist methods. Both types of analyses yielded almost identical results: zoledronic acid and alendronate were the most effective bisphosphonates for preventing vertebral fractures. No differences were found regarding withdrawals. Subgroup analyses found that fracture prevention was generally more effective with longer therapy (greater than or longer than 3 years).

The development of competency in clinical supervision is becoming an increasingly important element of training and practice in professional psychology. To assist students in developing supervisory competencies, knowledge of relevant research and effective training methods is required. Three studies were designed to add to the field of supervisor development research. In the first study, I conducted a systematic review to examine the extent to which theoretical models of supervisor development have been used in empirical studies of supervisor development within professional psychology. This study revealed that studies rarely employ theory, and when they do, the Supervisor Complexity Model is the most often used theory, likely because it is the only one with an associated measure, the Psychotherapy Supervisor Development Scale (PSDS; Watkins, Schneider, Haynes, & Nieberding, 1995). Building on the findings of this systematic review, in the second study I conducted a reliability and validity generalization on the PSDS. Reliability and validity generalizations are meta-analytic methods that allow reliability and validity data from a measure to be summarized across studies. Results indicate the PSDS has a history of excellent reliability, and higher scores are found with increased supervisory training and experience, evidence of the scale’s validity. The third study is a meta-analysis of the supervisor development literature, in order to assess the effect sizes of training and experience on supervisory development and self-efficacy. Results indicate that training and experience have significant positive effect sizes, though they do not differ from one another. Based on results from these studies I provide recommendations about: the samples with which the PSDS tool is appropriately used, and how researchers might increase reliability within their own future studies, and evidence based recommendations for competency based education efforts.

Testosterone products comprise a multi-billion dollar industry; however, Health Canada and the United States Food and Drug Administration have issued statements of concern about their safety, and their benefits are unclear. In the first phase of this study, we performed a systematic review of the current evidence for the benefits of testosterone replacement therapy. In the second phase, we analyzed the evidence from randomized controlled trials for the benefits of testosterone replacement therapy (depression, quality of life, erectile function, libido, total testosterone level). In the third phase, we analyzed data for harms (cardiovascular death, myocardial infarction, stroke, newly diagnosed prostate cancer, coronary artery disease or diabetes, serious adverse events, withdrawals due to adverse events, erythrocytosis) from randomized controlled trials and non-randomized studies. In general, most included studies had a short duration and were poorly reported. Additional high-quality research into the long-term safety of testosterone products is needed.

As the HIV-positive population ages, managing non-AIDS-related comorbidities such as cardiovascular disease (CVD) complicates HIV care. Effectively treating risk factors for CVD will help reduce its burden in the HIV-infected population. However, the evidence base for the efficacy of statins as lipid-lowering therapies in HIV-infected patients has yet to be synthesized. Most trials do not compare statins directly to each other. In the absence of head-to-head evidence, the relative treatment effects of different statins can be indirectly obtained through a network meta-analysis (NMA). This NMA aims to evaluate the use of statins for treating dyslipidemia in HIV-infected individuals. Bayesian methods were used for obtaining treatment effect estimates and probabilistic rankings of treatments. Among lipid-lowering therapies, statins were most effective in treating dyslipidemia. All statins were found to offer the same treatment benefits. To our knowledge, this is the first NMA on this topic. It provides clinicians, health economists, and policy decision-makers with precise and reliable estimates for making definitive recommendations for the use of statins in dyslipidemic HIV-positive patients.

Class of 2008 Abstract / Objectives: To assess the effect of treatment with placebo on weight loss in obese patients. Methods: The placebo groups from nine orlistat and three sibutramine weight loss studies, as identified from the Padwal meta-analysis, were analyzed for: weight loss in kilograms; change in BMI; type of nutrition and exercise interventions; and bias. The means and standard deviations for weight loss were entered into the Stata meta-analysis program to obtain a forest plot to determine an overall estimate of weight loss. The Potential for Methodological Bias Assessment Tool (PMBAT) was used to create a bias score for each study. Results: Overall, subjects in the placebo group lost 3.8 kg (p<0.001). Placebo subjects in the orlistat trials lost significantly more weight (4.3 kg) than did subjects in the sibutramine trials (1.1 kg, p=0.014). The subjects in the sibutramine studies did not lose a significant amount of weight (p=0.397). There were distinct differences between the sibutramine and orlistat studies with regard to nutrition and exercise interventions. The mean score on the PMBAT was 16.7 ± 3.6; and no study scored higher than 25 out of 45 total points. Conclusions: Overall subjects in the placebo group in the combined orlistat and sibutramine studies lost a significant amount of weight. Differences in study design, bias, and the Hawthorne effect may have contributed to this weight loss.

Despite the large volume of research in the area of loyalty-repurchase-satisfaction, the findings on the relationship between these variables are conflicting. It seems that links between loyalty, repurchase, and satisfaction are not fully understood yet. The study provided the theoretical background on loyalty, repurchase, satisfaction, and their interrelationships. The Theory of Planned Behavior and the Expectation Confirmation Theory were discussed. The loyalty-repurchase differentiation with five contributing factors was addressed. From the literature review nine hypotheses were proposed. The study was conducted in three phases. The purpose of the first phase was to statistically identify the magnitude and the direction of relationships: loyalty-satisfaction, repurchase-satisfaction, and loyalty-repurchase by providing a quantitative review. A Hunter and Schmidt (1990) meta-analysis technique was employed. The results demonstrated that those three constructs have positive, strong relationships. However, the relationships were moderated by a number of factors, including the geographic region of the collected sample, the category (products versus service), and the business setting (B2B versus B2C). The purpose of the second phase was to statistically identify relationships between the research constructs, such as loyalty dimensions (commitment, trust, involvement, and word of mouth), repurchase/repurchase intent, and satisfaction, by conducting a field study with customers of apparel products. A structural equation modeling technique was employed to test the proposed hypotheses. Eight hypotheses were supported. The results indicated that although positive relationships between the research constructs exist, not all relationships are significantly strong. The purpose of the third phase was to compare the meta-analysis results, obtained from the large number of independent empirical studies, with the field study results, obtained from surveying consumers of apparel products. The overall findings of this research indicated that while meta-analysis and the field study results agree on positive relationships between the research constructs, the differences lay within the strength of the investigated relationships. The possible explanation was provided based on the theoretical foundation from the literature review. The study contributes to the growing knowledge of the relationships between loyalty, repurchase, and satisfaction by assessing the current state of the empirical research on those three variables. This research addresses the existing gap in the literature, and attempts to resolve the existing mixed views on the studied concepts. The mixed results of meta-analysis and the field study in terms of the strength of the investigated relationships indicate the need to expand this area of research further.

The purpose of the meta-analysis was to address the varied and somewhat stratified study results within the area of singing ability and instruction by statistically summarizing the data of related studies. An analysis yielded a small overall mean effect size for instruction across 34 studies, 433 unique effects, and 5,497 participants ranging in age from 5- to 11-years old (g = 0.43). The largest overall study effect size across categorical variables included the effects of same and different discrimination techniques on mean score gains. The largest overall effect size across categorical moderator variables included research design: Pretest-posttest 1 group design. Overall mean effects by primary moderator variable ranged from trivial to moderate. Feedback yielded the largest effect regarding teaching condition, 8-year-old children yielded the largest effect regarding age, girls yielded the largest effect regarding gender, the Boardman assessment measure yielded the largest effect regarding measurement instrument, and song accuracy yielded the largest effect regarding measured task. Conclusions address implications for teaching, research pedagogy, and research practice within the field of music education.