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The International Journal of Behavioral... Jul 2017Well-designed research trials are critical for determining the efficacy and effectiveness of nutrition education interventions. To determine whether behavioral and/or... (Review)
Review
BACKGROUND
Well-designed research trials are critical for determining the efficacy and effectiveness of nutrition education interventions. To determine whether behavioral and/or cognition changes can be attributed to an intervention, the experimental design must include a control or comparison condition against which outcomes from the experimental group can be compared. Despite the impact different types of control groups can have on study outcomes, the treatment provided to participants in the control condition has received limited attention in the literature.
METHODS
A systematic review of control groups in nutrition education interventions was conducted to better understand how control conditions are described in peer-reviewed journal articles compared with experimental conditions. To be included in the systematic review, articles had to be indexed in CINAHL, PubMed, PsycINFO, WoS, and/or ERIC and report primary research findings of controlled nutrition education intervention trials conducted in the United States with free-living consumer populations and published in English between January 2005 and December 2015. Key elements extracted during data collection included treatment provided to the experimental and control groups (e.g., overall intervention content, tailoring methods, delivery mode, format, duration, setting, and session descriptions, and procedures for standardizing, fidelity of implementation, and blinding); rationale for control group type selected; sample size and attrition; and theoretical foundation.
RESULTS
The search yielded 43 publications; about one-third of these had an inactive control condition, which is considered a weak study design. Nearly two-thirds of reviewed studies had an active control condition considered a stronger research design; however, many failed to report one or more key elements of the intervention, especially for the control condition. None of the experimental and control group treatments were sufficiently detailed to permit replication of the nutrition education interventions studied.
CONCLUSIONS
Findings advocate for improved intervention study design and more complete reporting of nutrition education interventions.
Topics: Control Groups; Diet; Health Education; Humans; Research
PubMed: 28693581
DOI: 10.1186/s12966-017-0546-3 -
Missouri Medicine 2014Osteoporosis and related fractures cause significant morbidity and mortality worldwide and result in enormous costs to affected individuals and society. Lifestyle... (Review)
Review
Osteoporosis and related fractures cause significant morbidity and mortality worldwide and result in enormous costs to affected individuals and society. Lifestyle choices across the lifespan impact osteoporosis and fracture risk. Physical activity is a viable strategy for the prevention and treatment of low bone mass.
Topics: Bone Density; Fractures, Bone; Humans; Life Style; Motor Activity; Osteoporosis; Resistance Training; Risk Factors
PubMed: 24645301
DOI: No ID Found -
PloS One 2015Important considerations for exercise trials in cancer patients are contamination and differential drop-out among the control group members that might jeopardize the... (Review)
Review
PURPOSE
Important considerations for exercise trials in cancer patients are contamination and differential drop-out among the control group members that might jeopardize the internal validity. This systematic review provides an overview of different control groups design characteristics of exercise-oncology trials and explores the association with contamination and drop-out rates.
METHODS
Randomized controlled exercise-oncology trials from two Cochrane reviews were included. Additionally, a computer-aided search using Medline (Pubmed), Embase and CINAHL was conducted after completion date of the Cochrane reviews. Eligible studies were classified according to three control group design characteristics: the exercise instruction given to controls before start of the study (exercise allowed or not); and the intervention the control group was offered during (any (e.g., education sessions or telephone contacts) or none) or after (any (e.g., cross-over or exercise instruction) or none) the intervention period. Contamination (yes or no) and excess drop-out rates (i.e., drop-out rate of the control group minus the drop-out rate exercise group) were described according to the three design characteristics of the control group and according to the combinations of these three characteristics; so we additionally made subgroups based on combinations of type and timing of instructions received.
RESULTS
40 exercise-oncology trials were included based on pre-specified eligibility criteria. The lowest contamination (7.1% of studies) and low drop-out rates (excess drop-out rate -4.7±9.2) were found in control groups offered an intervention after the intervention period. When control groups were offered an intervention both during and after the intervention period, contamination (0%) and excess drop-out rates (-10.0±12.8%) were even lower.
CONCLUSIONS
Control groups receiving an intervention during and after the study intervention period have lower contamination and drop-out rates. The present findings can be considered when designing future exercise-oncology trials.
Topics: Control Groups; Exercise; Humans; Neoplasms; Quality of Life; Randomized Controlled Trials as Topic; Research Design; Survivors
PubMed: 25815479
DOI: 10.1371/journal.pone.0120996 -
JAMA Network Open Jul 2022Nonspecific effects, particularly placebo effects, are thought to contribute significantly to the observed effect in surgical trials. (Meta-Analysis)
Meta-Analysis
IMPORTANCE
Nonspecific effects, particularly placebo effects, are thought to contribute significantly to the observed effect in surgical trials.
OBJECTIVE
To estimate the proportion of the observed effect of surgical treatment that is due to nonspecific effects (including the placebo effect).
DATA SOURCES
Published Cochrane reviews and updated, extended search of MEDLINE, Embase, and CENTRAL until March 2019.
STUDY SELECTION
Published randomized placebo-controlled surgical trials and trials comparing the effect of the same surgical interventions with nonoperative controls (ie, no treatment, usual care, or exercise program).
DATA EXTRACTION AND SYNTHESIS
Pairs of authors independently screened the search results, assessed full texts to identify eligible studies and the risk of bias of included studies, and extracted data. The proportion of all nonspecific effects was calculated as the change in the placebo control divided by the change in the active surgery and pooled in a random-effect meta-analysis. To estimate the magnitude of the placebo effect, we pooled the difference in outcome between placebo and nonoperative controls and used metaregression to estimate the association between the type of control group and the treatment effect (difference between the groups), adjusting for risk of bias, sample size, and type of outcome.
MAIN OUTCOMES AND MEASURES
Between- and within-group effect sizes expressed as Hedges g.
RESULTS
In this review, 100 trials were included comprising data from 62 trials with placebo controls (3 also included nonoperative controls), and 38 trials with nonoperative controls (32 interventions; 10 699 participants). Risk of bias across trials was comparable except for performance and detection bias, which was high in trials with nonoperative controls. The mean nonspecific effects accounted for 67% (95% CI, 61% to 73%) of the observed change after surgery; however, this varied widely between different procedures. The estimated surgical placebo effect had a standardized mean difference (SMD) of 0.13 (95% CI, -0.26 to 0.51). Trials with placebo and nonoperative controls found comparable treatment effects (SMD, -0.09 [95% CI, -0.35 to 0.18]; 15 interventions; 73 between-group effects; adjusted analysis: SMD, -0.11 [95% CI, -0.37 to 0.15]).
CONCLUSIONS AND RELEVANCE
In this review, the change in health state after surgery was composed largely of nonspecific effects, but no evidence supported a large placebo effect. Placebo-controlled surgical trials may be redundant when trials with nonoperative controls consistently report no substantial association from surgery compared with nonoperative treatment.
Topics: Control Groups; Exercise; Humans; Placebo Effect
PubMed: 35895060
DOI: 10.1001/jamanetworkopen.2022.23903 -
Seminars in Arthritis and Rheumatism Aug 2021To assess how patient characteristics and study design influence the effectiveness of control interventions in hand OA trials. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
To assess how patient characteristics and study design influence the effectiveness of control interventions in hand OA trials.
METHODS
The study protocol was registered in PROSPERO (CRD42020163473). Two authors independently searched four electronic databases from their inception to December 31, 2019. Randomized and non-randomized controlled hand OA trials were included if pain intensity was assessed using a validated scale. We allocated control groups into one of the following: placebo, add-on treatment, no treatment, or active treatment. The standardized mean differences (d) of pain, as well as subjective function and hand strength, were pooled with 95% confidence intervals (CI) and 90% prediction intervals using random-effects models. Meta-regression and post-hoc subgroup analyses were performed to investigate which factors potentially impacted placebo analgesia and between-study heterogeneity.
RESULTS
Thirty-one placebo, 11 add-on, 12 no-treatment, and 10 active-treatment controls were included in meta-analyses. Effective pain relief was observed in placebo (d = -0.50, 95% CI -0.63 to -0.37), add-on (d = -0.35, 95% CI -0.59 to -0.12), and active-treatment (d = -0.92, 95% CI -1.35 to -0.48) groups. In subjective function, these treatments had smaller but beneficial effects; hand strength, contrastingly, was not improved. Placebo effects were larger when flare designs were used (d = -0.96) and more homogeneous when minimum pain thresholds were set (d = -0.46, 90% prediction intervals -0.79 to -0.14).
CONCLUSION
Placebo, add-on, and active control treatments were more effective than the no treatment control in relieving hand pain and improving subjective function. By choosing minimum pain thresholds and flare requirements at patient enrollment, moderate pain relief may be replicated among control participants in future randomized placebo-controlled trials.
Topics: Control Groups; Hand; Humans; Osteoarthritis; Pain; Randomized Controlled Trials as Topic
PubMed: 34146952
DOI: 10.1016/j.semarthrit.2021.04.006 -
Proceedings of the National Academy of... Jul 2022To understand the cortical neuronal dynamics behind movement generation and control, most studies have focused on tasks where actions were planned and then executed...
To understand the cortical neuronal dynamics behind movement generation and control, most studies have focused on tasks where actions were planned and then executed using different instances of visuomotor transformations. However, to fully understand the dynamics related to movement control, one must also study how movements are actively inhibited. Inhibition, indeed, represents the first level of control both when different alternatives are available and only one solution could be adopted and when it is necessary to maintain the current position. We recorded neuronal activity from a multielectrode array in the dorsal premotor cortex (PMd) of monkeys performing a countermanding reaching task that requires, in a subset of trials, them to cancel a planned movement before its onset. In the analysis of the neuronal state space of PMd, we found a subspace in which activities conveying temporal information were confined during active inhibition and position holding. Movement execution required activities to escape from this subspace toward an orthogonal subspace and, furthermore, surpass a threshold associated with the maturation of the motor plan. These results revealed further details in the neuronal dynamics underlying movement control, extending the hypothesis that neuronal computation confined in an "output-null" subspace does not produce movements.
Topics: Animals; Macaca mulatta; Motor Activity; Motor Cortex; Neurons; Psychomotor Performance
PubMed: 35867763
DOI: 10.1073/pnas.2122395119 -
Journal of Applied Physiology... Aug 2011Acute coronary syndromes (ACS) are common, life-threatening cardiac disorders that typically are triggered by rupture or erosion of an atherosclerotic plaque. Platelet... (Review)
Review
Acute coronary syndromes (ACS) are common, life-threatening cardiac disorders that typically are triggered by rupture or erosion of an atherosclerotic plaque. Platelet deposition and activation of the blood coagulation cascade in response to plaque disruption lead to the formation of a platelet-fibrin thrombus, which can grow rapidly, obstruct coronary blood flow, and cause myocardial ischemia and/or infarction. Several clinical studies have examined the relationship between physical activity and ACS, and numerous preclinical and clinical studies have examined specific effects of sustained physical training and acute physical activity on atherosclerotic plaque rupture, platelet function, and formation and clearance of intravascular fibrin. This article reviews the available literature regarding the role of physical activity in determining the incidence of atherosclerotic plaque rupture and the pace and extent of thrombus formation after plaque rupture.
Topics: Acute Coronary Syndrome; Atherosclerosis; Blood Coagulation; Coronary Disease; Coronary Thrombosis; Fibrinolysis; Humans; Motor Activity; Plaque, Atherosclerotic; Platelet Aggregation
PubMed: 21596926
DOI: 10.1152/japplphysiol.00017.2011 -
Journal of Neurophysiology Nov 2018Successful performance in many everyday tasks requires compensating unexpected mechanical disturbance to our limbs and body. The long-latency reflex plays an important... (Review)
Review
Successful performance in many everyday tasks requires compensating unexpected mechanical disturbance to our limbs and body. The long-latency reflex plays an important role in this process because it is the fastest response to integrate sensory information across several effectors, like when linking the elbow and shoulder or the arm and body. Despite the dozens of studies on inter-effector long-latency reflexes, there has not been a comprehensive treatment of how these reveal the basic control organization that sets constraints on any candidate model of neural feedback control such as optimal feedback control. We considered three contrasting ways that controllers can be organized: multiple independent controllers vs. a multiple-input multiple-output (MIMO) controller, a continuous feedback controller vs. an intermittent feedback controller, and a direct MIMO controller vs. a state feedback controller. Following a primer on control theory and review of the relevant evidence, we conclude that continuous state feedback control best describes the organization of inter-effector coordination by the long-latency reflex.
Topics: Animals; Feedback, Physiological; Humans; Motor Activity; Muscle, Skeletal; Reaction Time; Reflex
PubMed: 30133376
DOI: 10.1152/jn.00205.2018 -
Physiological Reports Sep 2021Rhythmic motor activities such as breathing, locomotion, tremor, or mastication are organized by groups of interconnected neurons. Most synapses in the central nervous... (Review)
Review
Rhythmic motor activities such as breathing, locomotion, tremor, or mastication are organized by groups of interconnected neurons. Most synapses in the central nervous system are in close apposition with processes belonging to astrocytes. Neurotransmitters released from neurons bind to receptors expressed by astrocytes, activating a signaling pathway that leads to an increase in calcium concentration and the release of gliotransmitters that eventually modulate synaptic transmission. It is therefore likely that the activation of astrocytes impacts motor control. Here we review recent studies demonstrating that astrocytes inhibit, modulate, or trigger motor rhythmic behaviors.
Topics: Animals; Astrocytes; Efferent Pathways; Humans; Locomotion; Mastication; Motor Activity; Respiration
PubMed: 34558208
DOI: 10.14814/phy2.15029 -
NeuroImage Oct 2023Is there a way improve our ability to understand the minds of others? Towards addressing this question, here, we conducted a single-arm, proof-of-concept study to...
Is there a way improve our ability to understand the minds of others? Towards addressing this question, here, we conducted a single-arm, proof-of-concept study to evaluate whether real-time fMRI neurofeedback (rtfMRI-NF) from the temporo-parietal junction (TPJ) leads to volitional control of the neural network subserving theory of mind (ToM; the process by which we attribute and reason about the mental states of others). As additional aims, we evaluated the strategies used to self-regulate the network and whether volitional control of the ToM network was moderated by participant characteristics and associated with improved performance on behavioral measures. Sixteen participants underwent fMRI while completing a task designed to individually-localize the TPJ, and then three separate rtfMRI-NF scans during which they completed multiple runs of a training task while receiving intermittent, activation-based feedback from the TPJ, and one run of a transfer task in which no neurofeedback was provided. Region-of-interest analyses demonstrated volitional control in most regions during the training tasks and during the transfer task, although the effects were smaller in magnitude and not observed in one of the neurofeedback targets for the transfer task. Text analysis demonstrated that volitional control was most strongly associated with thinking about prior social experiences when up-regulating the neural signal. Analysis of behavioral performance and brain-behavior associations largely did not reveal behavior changes except for a positive association between volitional control in RTPJ and changes in performance on one ToM task. Exploratory analysis suggested neurofeedback-related learning occurred, although some degree of volitional control appeared to be conferred with the initial self-regulation strategy provided to participants (i.e., without the neurofeedback signal). Critical study limitations include the lack of a control group and pre-rtfMRI transfer scan, which prevents a more direct assessment of neurofeedback-induced volitional control, and a small sample size, which may have led to an overestimate and/or unreliable estimate of study effects. Nonetheless, together, this study demonstrates the feasibility of training volitional control of a social cognitive brain network, which may have important clinical applications. Given the study's limitations, findings from this study should be replicated with more robust experimental designs.
Topics: Humans; Magnetic Resonance Imaging; Theory of Mind; Learning; Control Groups; Brain
PubMed: 37591479
DOI: 10.1016/j.neuroimage.2023.120334