Physical activity (PA) offers numerous physical and mental health benefits. Unfortunately, most people struggle to lead an active lifestyle, particularly when they are concurrently striving to balance other pursuits that may interfere with their engagement in PA. The self-regulatory strategies of action planning (AP) and coping planning (CP) have been proposed as a means of helping people initiate and maintain PA, though inconsistent findings have been observed to this effect. The primary objectives of the present dissertation, achieved by way of two original articles, were to (a) review the extant planning for PA literature in order to summarize and synthesize knowledge in the area to date, and (b) examine AP and CP in relation to more than one goal at a time, while testing the relevant moderator of academic goal conflict. The first article comprised a meta-analysis of correlational (k = 19) and experimental (k = 21) studies on planning for PA, which revealed a medium-to-large summary effect for correlational studies, and a small summary effect for experimental studies. Furthermore, AP and CP emerged as partial mediators in the relation between behavioural intention and PA. Numerous moderators were also found. Among other key findings, this article cast light on the fact that, despite multiple goal pursuit being the rule rather than the exception, most studies reviewed examined a single goal in isolation. Further, the summary effects found were more modest than expected and highly heterogeneous, pointing to the value to testing relevant moderators. Thus, the second article contained two studies that examined the moderating role of academic goal conflict on the relations between AP and CP with PA using samples of university students concurrently pursuing an academic and a PA goal. Study 1 (N = 317) used a 6-week prospective design, and Study 2 (N = 97) used a 1-week daily diary design and measures of self-reported PA behaviour and goal progress. Across both studies, it was found that academic goal conflict moderated the influence of planning on PA outcomes. AP and CP were found to play differential roles in predicting PA when students were experiencing goal conflict: AP related to better PA outcomes at lower levels of academic goal conflict, whereas CP related to better PA outcomes at higher levels of academic goal conflict. These two self-regulatory strategies appear to play a different, yet complementary role in the goal pursuit process. Overall, the present dissertation contributes to knowledge synthesis in the area of planning for PA. In addition, novel research findings are presented which specifically target identified gaps in the literature. Theoretical, methodological, and practical implications are discussed, and future research avenues are proposed.

There is little head-to-head evidence comparing interventions available for juvenile idiopathic arthritis (JIA). This review involved a series of systematic reviews and network meta-analyses (NMAs) to evaluate the comparative efficacy and safety of pharmacological and non-pharmacological interventions among patients with JIA. Outcomes were the American College of Rheumatology Pediatric 30 (ACR Pedi 30) (disease response), its six composite outcomes, pain relief, health-related quality of life, and physical and emotional functioning. There was some evidence that etanercept had greater reduction in the number of joints with active arthritis compared to abatacept for polyarticular-course JIA and that canakinumab had improved ACR Pedi 30 over rilonacept. Non-pharmacological interventions showed no significant results for efficacy but were safe overall. Most included studies were low-quality and many were excluded from analysis because of unclear reporting or no results for outcomes of interest. As more studies are conducted this will improve the estimates from the NMAs.

The introduction of species outside of their native ranges has been extensively studied in ecology. Particular attention has been paid to examining interactions between alien and native plants, and a large proportion of this attention has focused on pollinator-mediated interactions. In order to interact through pollinators, plants must co-occur, coflower, and share pollinators; studies investigating pollinator-mediated interactions between alien and native plants frequently make fundamental assumptions about the definition of these prerequisites to pollinator-mediated interaction. The present analysis examines assumptions about plant co-occurrence and the effects that these assumptions have on study outcomes. In Chapter 2, I present the results of a meta-analysis of 76 studies which overturns previous findings that pollinator-mediated interactions between plants can be predicted on the basis of whether the neighbour is an alien, phylogenetic distance, or floral trait similarity. Moreover, I demonstrate that the spatial definition of the control group (i.e. the distance between the group of focal plants that ‘do not co-occur’ with the alien/alternate neighbour species and the nearest individuals of that neighbour species), and the spatial arrangements of plants within their treatment groups (i.e. the relative placement of the group of focal plants that ‘co-occurr’ with the neighbour species), both have a significant impact on the outcome of pollinator-mediated interactions between alien and native plants. I also emphasize evidence of bias in the selection of study systems and in the process of publication. In Chapter 3, I present the results of a field experiment testing the role of distance between interacting plants in determining patterns of visitation by insects. The results of this analysis are suggestive of visitor functional group-dependent effects but limited by low power. In both Chapter 2 and Chapter 3, I show that heretofore unexamined assumptions about definitions of co-occurrence of plants may be introducing bias into studies of pollinator-mediated interactions between plants, and that facilitation and competition between plants for visitation may be linked across different spatial scales.

Pancreatic cancer is the fourth leading cause of cancer death in Canada. Significant advancements in chemotherapy for advanced pancreatic cancer have resulted in the need for a quantitative comparison between these treatments on a relative scale. Therefore, a systematic review and Bayesian network meta-analysis of randomized clinical trials was conducted using gemcitabine, the standard treatment, as the reference comparator. Based on results from the network meta-analysis, in which optimal treatments were identified and side effects of each treatment evaluated, an Internet-based patient decision aid was developed in order to present the benefits and risks of each therapy option: (1) Best supportive care (2) gemcitabine (3) FOLFIRINOX. The objective of the decision aid was to guide patients through the decision-making process based on their individual preferences and values. The decision aid was deemed to be acceptable and feasible based on results from a pilot study conducted at The Ottawa Hospital Cancer Centre.

Background: A compilation of high quality systematic reviews (SRs) on lifestyle factors associated with adult glioma and meningioma was developed. Methods and Materials: Phase 1 consisted of a systematic overview of existing SRs. For Phase 2, high quality SRs were incorporated in an update. Moderate or low quality SRs which had not been considered in a high quality review were eligible for a de-novo synthesis. Results: Phase 1 resulted in seven moderate to low quality reviews. From this, in Phase 2, smoking, mobile phone and hair dye use were subjected to de-novo reviews. For smoking, it was suggestive that past smokers had an increased risk. For mobile phone use, there was no overall association, however it was suggestive that ipsilateral and high cumulative call time were associated with slight increased risk. No association was observed for personal hair dye use. Conclusions: Despite these null associations, rigorous SR methods were used providing confidence in conveying these results.

Nowell (1976) first proposed that unless cytotoxic cancer therapy eradicates all tumor cells, genetic or heritable variation within heterogeneous tumors will inevitably lead to the evolution of chemotherapeutic resistance through clonal selection. This evolutionary hypothesis was formalized by Goldie and Coldman (1979), who developed one of the earliest mathematical kinetic models of resistance evolution in neoplasms. Their model predicted that the likelihood of response and cure would be increased in combination vs single agent cytotoxic therapies. In a later study, Gardner (2002) developed a computational kinetic model to predict chemotherapeutic combinations, doses, and schedules most likely to result in patient response and prolonged life. This model predicts that combination therapy involving both cytotoxic and cytostatic drugs will be more effective than combination therapy involving only cytotoxic drugs. Thus far, no systematic evaluation of the Goldie and Coldman and Gardner hypotheses have been conducted in the metastatic clinical trial setting. Here I test these hypotheses using the results of over 700 phase II, III and II/III clinical trials. I show that, as predicted by Goldie and Coldman, both overall response rate and overall survival were greater in combination arms. Moreover, median duration of response – the key indicator of the rate of resistance evolution - was also greater in combination vs single agent arms. These results suggest that generally combination chemotherapy is more effective than single agent therapy for advanced solid tumors as predicted by Goldie and Coldman (1979) hypothesis and that, at least in the metastatic setting, the potential disadvantages of combination therapy with respect to accelerated resistance evolution are outweighed by the greater waiting times for resistance mutations to arise. By contrast, although combination cytotoxic and cytostatic therapy is associated with a greater average overall response rate than multi agent cytotoxic therapy, this is not the case for both median duration of response and overall survival. Hence, there is no evidence that, in contrast to the predictions of the Gardner (2002) model, combination cytotoxic and cytostatic therapy decreases the rate of resistance evolution relative to that obtaining under combination cytotoxic therapy.

The aim of the thesis is to broaden the research in the field of housing economics using the statistical tool of meta-analysis. The thesis examines the relationship between the selling price of a house and the time the house spends at the housing market. Although the research investigating this relation is of a wide comprehension, the results arising from various primary studies differ a lot. The goal of the thesis is to explain the source of this heterogeneity and determine the factors causing this variation. According to the results, it can be concluded that the effect size is influenced mainly by number of observations, modelling technique and specification of the model. Median income or location are other factors also determining the size of estimated coefficients. Also publication bias has been investigated although its presence is not confirmed in this thesis.

Developing effective literacy skill has become an increasingly critical skill in today's information age. Students with emotional/behavioral disorders (E/BD) routinely lack these skills and are not being taught how to read effectively. The field of special education needs more comprehensive and specific information about how to most effectively teach reading skills to students with E/BD. When reading interventions are conducted using student with E/BD, the interventions are generally drawn from the LD field. The assumption is that the reading interventions that have worked with students with LD will work equally well with the E/BD population. This study performed a meta-analysis to examine whether reading interventions are equally effective on the E/BD and LD populations. In addition, it will examine whether the instruction mode (e. g., peer, self, or teacher directed), gender, or grade group affects the success of the intervention. The meta-analysis found that the reading interventions for both disability groups had high effect sizes. In addition, neither disability group, teaching method, gender, nor grades were predictive of the variance in the effect size. These results indicate that reading programs that have been designed for students with LD are also effective for students with E/BD and furthermore, reading programs can improve the academic achievement of students with behavioral disorders. Recommendations for teacher training and future research are given based on these results.

Longitudinal methods have become an improved and essential means of measuring intra-individual change over time. Yet one of the greatest and most hazardous drawbacks studying participants over multiple sessions can be the loss of participants over time. This study attempts to illuminate the problem of attrition in longitudinal research by estimating the mean effect sizes for participant loss across 57 studies published in 13 prestigious journals which regularly use older participants. Results estimate overall attrition to be around 34% of the original sample. The subsequent break down of attrition into its subtypes yield mean effect sizes for attrition due to Refusal (8%), Loss of contact (10%), Illness (6%), and Death (14%) in studies sampling from adults 50 years or older. Analyses were then conducted via meta-analytic one-way ANOVA and weighted regression to identify possible moderators of overall attrition and their four subtypes.

This study examined, via a meta-analysis, the relations among stressors, social support, and stress reactions. Unexpectedly, small to medium negative, but robust effect sizes were found for the stressors-social support relation. As expected the stressor-stress reaction relation was positive, and the social support-stress reaction relation was negative. Both relations had small to medium effect sizes that ranged from weak to very robust. The direct effect of social support on the stressor-stress reaction was generally supported, whereas the suppressor and mediating models were not supported. Furthermore, the findings were inconclusive for the moderator effect of social support. Non-interpersonal traumas appear different in the stressor-social support and social support-stress reaction relations compared to other trauma types. These findings have important clinical implications.