Browsing by Author "McLeod, Kevin"

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    Evaluating treatments in health care: The instability of a one-legged stool
    (BMC Medical Research Methodology, 2011) Kaplan, Bonnie; Giesbrecht, Gerald; Shannon, Scott; McLeod, Kevin
    Background: Both scientists and the public routinely refer to randomized controlled trials (RCTs) as being the 'gold standard' of scientific evidence. Although there is no question that placebo-controlled RCTs play a significant role in the evaluation of new pharmaceutical treatments, especially when it is important to rule out placebo effects, they have many inherent limitations which constrain their ability to inform medical decision making. The purpose of this paper is to raise questions about over-reliance on RCTs and to point out an additional perspective for evaluating healthcare evidence, as embodied in the Hill criteria. The arguments presented here are generally relevant to all areas of health care, though mental health applications provide the primary context for this essay. Discussion: This article first traces the history of RCTs, and then evaluates five of their major limitations: they often lack external validity, they have the potential for increasing health risk in the general population, they are no less likely to overestimate treatment effects than many other methods, they make a relatively weak contribution to clinical practice, and they are excessively expensive (leading to several additional vulnerabilities in the quality of evidence produced). Next, the nine Hill criteria are presented and discussed as a richer approach to the evaluation of health care treatments. Reliance on these multi-faceted criteria requires more analytical thinking than simply examining RCT data, but will also enhance confidence in the evaluation of novel treatments. Summary: Excessive reliance on RCTs tends to stifle funding of other types of research, and publication of other forms of evidence. We call upon our research and clinical colleagues to consider additional methods of evaluating data, such as the Hill criteria. Over-reliance on RCTs is similar to resting all of health care evidence on a one-legged stool.
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    Fronto-striatal Network Dysfunction in Children with Developmental Coordination Disorder and Attention-Deficit/Hyperactivity Disorder
    (2015-04-06) McLeod, Kevin; Goodyear, Bradley; Dewey, Deborah
    Developmental coordination disorder (DCD) and attention-deficit/hyperactivity disorder (ADHD) are common neurodevelopmental disorders that significantly impact a child’s physical and mental health. Importantly, DCD and ADHD frequently co-occur. Behavioral, genetic and neuroimaging research have identified commonalities between children with these disorders. This thesis used resting-state functional magnetic resonance imaging (rs-fMRI) to determine the functional connections of the motor network of children with DCD, ADHD, and combined DCD and ADHD, in comparison to healthy children. In the first study, common and distinct alterations in the functional connections with the left motor cortex were identified in children with these disorders, including regions involved in sensorimotor processing and motor control. In the second study, differences in the hemispherical asymmetry of functional connections within the motor networks were also identified. These findings suggest that common brain functional networks are involved in DCD and ADHD, and that rs-fMRI is a valuable tool for furthering our understanding of the neurological underpinnings of these disorders.
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    Red Bull: Effects on cardiovascular function and development in the chick embryo
    (2009) McLeod, Kevin; Choi, May; Tang, Angela; Truong, Kathy