1,721,131 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Investigating Vaccine Hesitancy in Canada: A Quantitative and Qualitative Description of Vaccine Attitudes, Beliefs, and Perceptions of the Seasonal Influenza Vaccine.
No full textThe overarching objective of this thesis was to investigate the phenomenon of vaccine hesitancy in Canada and examine relationships among vaccine beliefs, socio-demographic characteristics, and seasonal influenza immunization. Quantitative findings were derived from a national health risk perception survey administered to adults across Canada (N = 1,125). Respondents were asked to provide their level of agreement (1 = do not agree at all to 5 = agree completely) with 2 vaccine-related behaviour statements and 21 vaccine-related beliefs statements. A principal components analysis was performed to reduce the number of belief statements into meaningful components. Two components were retained and reflected negative beliefs about ‘vaccine safety’ and positive beliefs about ‘vaccine regulation and benefits’. \ud
Descriptive results presented in the first study indicated a heightened uncertainty about the long-term side effects of vaccination, particularly with respect to the purported link between the Measles-Mumps-Rubella vaccine and the development of autism, among survey respondents. Multivariate analyses identified differences in the endorsement of numerous vaccine beliefs according to age and educational attainment. Findings revealed that older respondents and respondents without a university education demonstrated more negative attitudes towards vaccination, whereas younger respondents and respondents with a university education demonstrated more positive vaccine attitudes, respectively. Finally, both components of vaccine beliefs were significant predictors of vaccine-related behaviours, including discussing information about vaccines with others and reported receipt of the seasonal influenza vaccine. \ud
The second study investigated interrelationships among components of vaccine beliefs, socio-demographic characteristics, and reported receipt of the seasonal influenza vaccine. A mediation analysis revealed that higher levels of agreement with the statement ‘I usually get the seasonal flu vaccine’ among older adults was associated with lower levels of agreement with negative beliefs about vaccine safety in conjunction with higher levels of agreement with positive beliefs about the regulation and benefits of vaccines, whereas the opposite was true for younger adults. Also, a significant moderation analysis revealed that among respondents with greater concern about vaccine safety, those with higher educational attainment reported lower levels of agreement with the statement ‘I usually get the seasonal flu vaccine’ compared to those with lower educational attainment. \ud
Recognizing the limitations of quantitative findings, a qualitative investigation was undertaken to provide more in-depth insight on the factors driving influenza immunization among healthy adults. A thematic analysis was performed on transcripts from 6 semi-structured focus group discussions with a total of 18 participants residing in Ottawa, Ontario. Findings identified 7 themes and 8 sub-themes related to contextual, vaccine specific, and individual determinants of vaccine hesitancy. Participants predominantly discussed themes related to individual determinants of vaccine hesitancy (perceived severity, susceptibility, and likelihood of contracting the influenza virus; personal interests; interactions with healthcare professionals). The perceived novelty, severity and effectiveness of the influenza vaccine, as well as a lack of information and discontent with communication by government health authorities and the media were also discussed. Overall, findings identified salient themes informing vaccine decision-making and behaviours among a sample of educated adults, which can inform subsequent studies investigating influenza immunization in a more representative sample of Canadian adults
Pharmacotherapies in Parkinson Disease: Investigating Trends and Adverse Health Outcomes
No full textParkinson disease (PD) is the second most common neurodegenerative disease worldwide, with estimates suggesting that PD prevalence and incidence will increase with aging populations. Therapeutic options and clinical guidelines for PD have significantly changed over the past 15 years; however, pharmacoepidemiology data in PD are lacking, especially regarding adverse effects of non-ergot dopamine agonists (DAs) and outcomes associated with anticholinergic burden. The objectives of this doctoral research are threefold: 1) examine patterns of antiparkinson drug use in relation to clinical guideline publication, drug availability, and emerging safety concerns; 2) determine whether PD patients treated with non-ergot DAs are at increased risk of adverse cardiovascular or cerebrovascular outcomes; and 3) determine whether anticholinergic burden is associated with adverse outcomes in PD. Specific research questions were investigated using epidemiological methods and electronic health data from Cerner Health Facts®, an electronic medical record database that stores time-stamped patient records for more than 300 Cerner subscribing facilities across the United States. Findings from this work are reported in a series of manuscripts, all of which have been published. Key findings include: 1) DA use began declining in 2007, from 34% to 27% in 2012. The decline followed publication of the American Academy of Neurology’s practice parameter refuting levodopa toxicity, pergolide withdrawal, and pramipexole label revisions; 2) heart failure was the only adverse cardiovascular or cerebrovascular outcome that demonstrated a significant association with non-ergot DA use, mainly pramipexole; and 3) anticholinergic burden in PD was associated with the diagnosis of fracture and delirium, and significantly increased the risk of emergency department visit and readmission post inpatient discharge. Reported antiparkinson prescribing trends suggest that safety and best practice information may be communicated effectively in PD. Although findings warrant replication, individuals with PD and independent risk factors for or a history of heart failure may benefit from limited use of pramipexole. Similarly, individuals with PD may benefit from substituting non-PD medications with anticholinergic effects for equally effective non-anticholinergic agents. Additional pharmacovigilance studies are needed to better understand health risks and the impact of population health interventions in PD
Pharmacotherapies in Parkinson Disease: Investigating Trends and Adverse Health Outcomes
No full textParkinson disease (PD) is the second most common neurodegenerative disease worldwide, with estimates suggesting that PD prevalence and incidence will increase with aging populations. Therapeutic options and clinical guidelines for PD have significantly changed over the past 15 years; however, pharmacoepidemiology data in PD are lacking, especially regarding adverse effects of non-ergot dopamine agonists (DAs) and outcomes associated with anticholinergic burden. The objectives of this doctoral research are threefold: 1) examine patterns of antiparkinson drug use in relation to clinical guideline publication, drug availability, and emerging safety concerns; 2) determine whether PD patients treated with non-ergot DAs are at increased risk of adverse cardiovascular or cerebrovascular outcomes; and 3) determine whether anticholinergic burden is associated with adverse outcomes in PD. Specific research questions were investigated using epidemiological methods and electronic health data from Cerner Health Facts®, an electronic medical record database that stores time-stamped patient records for more than 300 Cerner subscribing facilities across the United States. Findings from this work are reported in a series of manuscripts, all of which have been published. Key findings include: 1) DA use began declining in 2007, from 34% to 27% in 2012. The decline followed publication of the American Academy of Neurology’s practice parameter refuting levodopa toxicity, pergolide withdrawal, and pramipexole label revisions; 2) heart failure was the only adverse cardiovascular or cerebrovascular outcome that demonstrated a significant association with non-ergot DA use, mainly pramipexole; and 3) anticholinergic burden in PD was associated with the diagnosis of fracture and delirium, and significantly increased the risk of emergency department visit and readmission post inpatient discharge. Reported antiparkinson prescribing trends suggest that safety and best practice information may be communicated effectively in PD. Although findings warrant replication, individuals with PD and independent risk factors for or a history of heart failure may benefit from limited use of pramipexole. Similarly, individuals with PD may benefit from substituting non-PD medications with anticholinergic effects for equally effective non-anticholinergic agents. Additional pharmacovigilance studies are needed to better understand health risks and the impact of population health interventions in PD
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Interrupted Time Series Analysis Techniques in Pharmacovigilance
No full textThis thesis considers an approach to evaluate the effectiveness of risk communications for prescription drugs by performing interrupted time series analysis of prescription drug volumes prior to and after the risk communication date.
The paper presents methods for detecting change in the presence of autocorrelation and techniques to reduce bias in estimation. Statistical results and data plots are presented for 63 data series. Size and power of the statistical techniques are considered, and a correspondence analysis between these statistical techniques and a small group of physicians is performed.
The methods considered in this thesis correspond weakly with physician sentiment, and exhibit inflated type I errors in the presence of significant autocorrelation
Investigations Into the Effects of Gestational Exposure to Environmental Phthalates on Maternal and Perinatal Outcomes and the Role of Inflammation Biomarkers as Potential Mediators
No full textObjectives The aims of this thesis were to (1) investigate the association of gestational exposure to environmental phthalates with maternal and perinatal outcomes, and (2) explore phthalate-induced changes to maternal inflammatory responses as potential mediators of possible health effects.
Methods A systematic review was performed to summarize existing evidence on the association of gestational exposure to phthalates with obstetrical outcomes, including pre-eclampsia (PE), pregnancy-induced hypertension (PIH), gestational diabetes mellitus (GDM), intrauterine growth restriction (IUGR), birth weight (BW), head circumference (HC), gestational age (GA), preterm birth (PB), and Apgar scores (AS). Additionally, a secondary analysis of data from the MIREC Study was conducted to evaluate the association of phthalate metabolites with clinical outcomes in the mother and infant using multiple linear and logistic regression, and with inflammatory biomarkers using multinomial logistic regression.
Results The systematic review identified a total of 24 articles, and observed inconsistent evidence on BW, HC, GA, and PB, a paucity of research on IUGR, PE, GDM, and AS, and a lack of studies on PIH. However, among studies with statistically significant (p<0.05) results, most suggest an association of phthalates with decreased BW and GA, and increased HC and PB. Findings from the MIREC Study indicate a significant (p<0.01) positive association between MBP and HC among female infants; however, null results were identified for BW, GA, PB, AS, and PIH. In relation to the exposure to phthalates, general trends among suggestive associations (p<0.05) for head circumference showed consistent increases in females and decreases in males, and for gestational age displayed decreases in both stratums. Additionally, a significant positive association of MBzP and ∑DEHP was observed with high MMP-2 and low VCAM levels, respectively. Results approaching statistical significance demonstrated a positive association of ∑DEHP with low MCP1 and ICAM levels, MCPP with low GMCSF levels, MBzP with low CRP and high ICAM levels, and MEP with high MMP-7 and IL-2 levels.
Conclusion From the systematic review, the effects of phthalates on maternal and perinatal health remain unclear, possibly due to sources of heterogeneity and challenges in exposure assessment. In the MIREC Study cohort, phthalate levels were associated with GA and HC in infants in a sex-specific manner. Phthalates also appear to influence the circulating inflammatory marker levels, possibly explaining the observed adverse effects. Future research is needed to validate these findings
NextGen Decision-Making for Health and Environmental Risks
No full textRisk decision-making has evolved from specifying the main steps involved in risk assessment and how this links to the overall analysis and governance of risks, to complex and fully integrated risk science frameworks. With the advancement in science and technology, there has also been a significant change in the types of evidence available for identifying and characterizing hazards, determining potential exposure profiles, and evaluating the probability of health and environmental risks. These efforts have resulted in several publications focused on providing precision on specific areas within the risk assessment-management process and new approaches for undertaking risk assessments. There has also been a transition to more complex and holistic risk science frameworks, methodologies, and guidelines. The term next generation risk decision-making is used to capture these contemporary approaches. Further, while there is specific guidance for a particular approach, limited attention has been paid to the underlying considerations for developing these contemporary and more complex and holistic approaches to risk decision-making.
In this thesis, we address this knowledge gap through an embedded research model designed to determine the ongoing modernization efforts and approaches to next generation risk decision-making within both the Canadian and international regulatory context (national and federal level). The embedded research model is coupled with an independent knowledge mobilization and transfer strategy that relies on the engagement and collaboration, with diverse experts and thought leaders, to determine fundamental risk and ethical principles for risk decision-making. Further, a scoping review provides a mechanism to visualize the evolution in risk science over the last fifty years, and characterize best practices and ten key attributes for risk decision-making. To help integrate our findings, we rely on a realist paradigm to generate an a priori theoretical construct and kaleidoscope model, which translates the principles, best practices, and attributes into key considerations for developing an approach to next generation risk decision-making. Our findings are widely applicable to any organization or governmental body interested in learning about next generation risk decision-making, including adapting or developing their own approach to risk decision-making, informed by the results presented in this thesis. The embedded research model, knowledge mobilization and transfer strategy, realist paradigm, and publication in open science, peer-reviewed journals ensures that our findings are available for the broader community interested in next generation risk decision-making
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