Exploring power in response inhibition tasks using the bootstrap: The impact of number of participants, number of trials, effect magnitude, and study design

2019 ◽  
Author(s):  
Curtis D. Von Gunten ◽  
Bruce D. Bartholow
Keyword(s):  
Study Design ◽  
Response Inhibition ◽  
The Impact ◽  
Effect Magnitude

Exploring power in response inhibition tasks using the bootstrap: The impact of number of participants, number of trials, effect magnitude, and study design

2019 ◽  
Author(s):  
Curtis David Von Gunten ◽  
Bruce D Bartholow
Keyword(s):  
Study Design ◽  
Effect Size ◽  
Statistical Power ◽  
Bootstrap Sampling ◽  
Reliable Measure ◽  
Internal Reliability ◽  
The Impact ◽  
Power Analyses ◽  
Effect Magnitude

A primary psychometric concern with laboratory-based inhibition tasks has been their reliability. However, a reliable measure may not be necessary or sufficient for reliably detecting effects (statistical power). The current study used a bootstrap sampling approach to systematically examine how the number of participants, the number of trials, the magnitude of an effect, and study design (between- vs. within-subject) jointly contribute to power in five commonly used inhibition tasks. The results demonstrate the shortcomings of relying solely on measurement reliability when determining the number of trials to use in an inhibition task: high internal reliability can be accompanied with low power and low reliability can be accompanied with high power. For instance, adding additional trials once sufficient reliability has been reached can result in large gains in power. The dissociation between reliability and power was particularly apparent in between-subject designs where the number of participants contributed greatly to power but little to reliability, and where the number of trials contributed greatly to reliability but only modestly (depending on the task) to power. For between-subject designs, the probability of detecting small-to-medium-sized effects with 150 participants (total) was generally less than 55%. However, effect size was positively associated with number of trials. Thus, researchers have some control over effect size and this needs to be considered when conducting power analyses using analytic methods that take such effect sizes as an argument. Results are discussed in the context of recent claims regarding the role of inhibition tasks in experimental and individual difference designs.

scholarly journals Conceptualising natural and quasi experiments in public health

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Frank de Vocht ◽  
Srinivasa Vittal Katikireddi ◽  
Cheryl McQuire ◽  
Kate Tilling ◽  
Matthew Hickman ◽  
...  
Keyword(s):  
Public Health ◽  
Study Design ◽  
Grey Literature ◽  
Public Health Research ◽  
Natural Experiments ◽  
Target Trial ◽  
Design Elements ◽  
Randomized Controlled ◽  
Study Designs ◽  
The Impact

Abstract Background Natural or quasi experiments are appealing for public health research because they enable the evaluation of events or interventions that are difficult or impossible to manipulate experimentally, such as many policy and health system reforms. However, there remains ambiguity in the literature about their definition and how they differ from randomized controlled experiments and from other observational designs. We conceptualise natural experiments in the context of public health evaluations and align the study design to the Target Trial Framework. Methods A literature search was conducted, and key methodological papers were used to develop this work. Peer-reviewed papers were supplemented by grey literature. Results Natural experiment studies (NES) combine features of experiments and non-experiments. They differ from planned experiments, such as randomized controlled trials, in that exposure allocation is not controlled by researchers. They differ from other observational designs in that they evaluate the impact of events or process that leads to differences in exposure. As a result they are, in theory, less susceptible to bias than other observational study designs. Importantly, causal inference relies heavily on the assumption that exposure allocation can be considered ‘as-if randomized’. The target trial framework provides a systematic basis for evaluating this assumption and the other design elements that underpin the causal claims that can be made from NES. Conclusions NES should be considered a type of study design rather than a set of tools for analyses of non-randomized interventions. Alignment of NES to the Target Trial framework will clarify the strength of evidence underpinning claims about the effectiveness of public health interventions.

scholarly journals The Clean pilot study: evaluation of an environmental hygiene intervention bundle in three Tanzanian hospitals

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Giorgia Gon ◽  
Abdunoor M. Kabanywanyi ◽  
Petri Blinkhoff ◽  
Simon Cousens ◽  
Stephanie J. Dancer ◽  
...  
Keyword(s):  
Pilot Study ◽  
Study Design ◽  
Low Income ◽  
High Volume ◽  
Surface Cleaning ◽  
Low Income Countries ◽  
Training Period ◽  
Future Research ◽  
Environmental Hygiene ◽  
The Impact

Abstract Background Healthcare associated infections (HAI) are estimated to affect up to 15% of hospital inpatients in low-income countries (LICs). A critical but often neglected aspect of HAI prevention is basic environmental hygiene, particularly surface cleaning and linen management. TEACH CLEAN is an educational intervention aimed at improving environmental hygiene. We evaluated the effectiveness of this intervention in a pilot study in three high-volume maternity and newborn units in Dar es Salaam, Tanzania. Methods This study design prospectively evaluated the intervention as a whole, and offered a before-and-after comparison of the impact of the main training. We measured changes in microbiological cleanliness [Aerobic Colony Counts (ACC) and presence of Staphylococcus aureus] using dipslides, and physical cleaning action using gel dots. These were analysed with descriptive statistics and logistic regression models. We used qualitative (focus group discussions, in-depth interviews, and semi-structured observation) and quantitative (observation checklist) tools to measure why and how the intervention worked. We describe these findings across the themes of adaptation, fidelity, dose, reach and context. Results Microbiological cleanliness improved during the study period (ACC pre-training: 19%; post-training: 41%). The odds of cleanliness increased on average by 1.33 weekly during the pre-training period (CI = 1.11–1.60), and by 1.08 (CI = 1.03–1.13) during the post-training period. Cleaning action improved only in the pre-training period. Detection of S. aureus on hospital surfaces did not change substantially. The intervention was well received and considered feasible in this context. The major pitfalls in the implementation were the limited number of training sessions at the hospital level and the lack of supportive supervision. A systems barrier to implementation was lack of regular cleaning supplies. Conclusions The evaluation suggests that improvements in microbiological cleanliness are possible using this intervention and can be sustained. Improved microbiological cleanliness is a key step on the pathway to infection prevention in hospitals. Future research should assess whether this bundle is cost-effective in reducing bacterial and viral transmission and infection using a rigorous study design.

scholarly journals P–759 The impact of the COVID–19 pandemic on women seeking fertility treatment in Germany: the patient´s perspective

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
S Wedner-Ross ◽  
F Vo. Versen-Höynck
Keyword(s):  
Study Design ◽  
Online Survey ◽  
Fertility Treatment ◽  
Unborn Child ◽  
Negative Effects ◽  
Cross Sectional ◽  
Professional Societies ◽  
Fertility Treatments ◽  
The Impact

Abstract Study question This cross-sectional survey sought the views of women seeking fertility treatment on the impact of the COVID–19 pandemic on their fertility treatment and attitudes. Summary answer Most respondents worried the recommendations to postpone treatment would reduce their chances of pregnancy and were concerned about negative effects of SARS-Cov–2 infections on pregnancy. What is known already In spring 2020, the recommendations of ESHRE and German professional societies to postpone fertility treatments resulted in limited or closed services from mid-March to early May in many clinics. Previous studies reported that postponing fertility clinic appointments causes psychological distress, with most patients saying they would have preferred to continue treatment. While no similar studies are available from Germany, where COVID–19 incidence was relatively low, concerns of the patients about possible consequences of a treatment delay and a SARS-CoV–2 infection on fertility and pregnancy remain unknown. Study design, size, duration This cross-sectional, anonymous, online questionnaire was completed in June-December 2020 by 249 women attending fertility clinics across Germany. The women were recruited using leaflets, directly by study personnel either in person or by telephone, or via online support group forums for fertility patients. Participants/materials, setting, methods All women seeking treatment in fertility clinics were eligible to participate. The online survey covered questions about the patient’s quality of life, their opinions about the professional societies’ recommendations and their effects as well as any concerns about infection with SARS-CoV–2. Statistical analysis was conducted using SPSS Version 27. Main results and the role of chance Three-quarters of participants disagreed with the pausing of fertility treatments. Women who participated from October-December 2020, when the incidence rate was high, were as likely to disagree as participants that participated from June-September 2020 (73% vs 79%, p = 0.3). Nearly all participants (95%) were concerned that treatment delays would reduce their chances of pregnancy. 72 participants (29%) had their appointments cancelled. Nearly all (97%) reported being upset by this, with 40 (56%) reporting that they were extremely or very disappointed about the cancellation. Women coming for follow-up appointments and women who had to wait 10 weeks or longer were more likely to be upset by the postponement or cancellation of their appointment (p = 0.016 and p = 0.012, respectively). Nearly all (97%) of the participants were worried about possible negative effects a SARS-CoV–2 infection might have related to their fertility, pregnancy or unborn child. Sixty-one percent stated they were very or moderately concerned about the negative influence the infection might have on the womańs own health during pregnancy and 60% were very to moderately concerned about potential negative effects for the unborn child. However, only 26% reported they were very or moderately concerned about the potential negative effects of an infection on fertility. Limitations, reasons for caution The main limitations of this study are the possibility of selection bias as people with strong opinions are more likely to have participated and the lack of information on non-responders due to the study design. Also, the Covid–19 pandemic is evolving continuously meaning that participantś opinions may vary over time. Wider implications of the findings: Postponement of treatments increased distress among patients and should be avoided when possible. If unavoidable, follow-up patients should be prioritised for treatment and the length of postponement should be minimised. Fertility clinics must provide information about the current state of knowledge of SARS-Cov–2 infections in pregnancies and options for immunization. Trial registration number Not applicable

scholarly journals Pneumococcal Conjugate Vaccine impact assessment in Bangladesh

2018 ◽  
Vol 2 ◽  
pp. 21 ◽  
Author(s):  
Abdullah H. Baqui ◽  
Eric D. McCollum ◽  
Samir K. Saha ◽  
Arun K. Roy ◽  
Nabidul H. Chowdhury ◽  
...  
Keyword(s):  
Conjugate Vaccine ◽  
Study Design ◽  
Pneumococcal Conjugate Vaccine ◽  
Case Control Study ◽  
Case Control ◽  
Incident Case ◽  
Vaccine Type ◽  
Before And After ◽  
The Impact ◽  
Control Study

The study examines the impact of the introduction of 10-valent Pneumococcal Conjugate Vaccine (PCV10) into Bangladesh’s national vaccine program. PCV10 is administered to children under 1 year-old; the scheduled ages of administration are at 6, 10, and 18 weeks. The study is conducted in ~770,000 population containing ~90,000 <5 children in Sylhet, Bangladesh and has five objectives: 1) To collect data on community-based pre-PCV incidence rates of invasive pneumococcal diseases (IPD) in 0-59 month-old children in Sylhet, Bangladesh; 2) To evaluate the effectiveness of PCV10 introduction on Vaccine Type (VT) IPD in 3-59 month-old children using an incident case-control study design. Secondary aims include measuring the effects of PCV10 introduction on all IPD in 3-59 month-old children using case-control study design, and quantifying the emergence of Non Vaccine Type IPD; 3) To evaluate the effectiveness of PCV10 introduction on chest radiograph-confirmed pneumonia in children 3-35 months old using incident case-control study design. We will estimate the incidence trend of clinical and radiologically-confirmed pneumonia in 3-35 month-old children in the study area before and after introduction of PCV10; 4) To determine the feasibility and utility of lung ultrasound for the diagnosis of pediatric pneumonia in a large sample of children in a resource-limited setting. We will also evaluate the effectiveness of PCV10 introduction on ultrasound-confirmed pneumonia in 3-35 month-old children using an incident case-control design and to examine the incidence trend of ultrasound-confirmed pneumonia in 3-35 month-old children in the study area before and after PCV10 introduction; and 5) To determine the direct and indirect effects of vaccination status on nasopharyngeal colonization on VT pneumococci among children with pneumonia.  This paper presents the methodology. The study will allow us to conduct a comprehensive and robust assessment of the impact of national introduction of PCV10 on pneumococcal disease in Bangladesh.

scholarly journals The Influence of Response Inhibition Training on Food Consumption and Implicit Attitudes toward Food among Female Restrained Eaters

Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3609
Author(s):  
Noam Weinbach ◽  
Eldad Keha ◽  
Hila Leib ◽  
Eyal Kalanthroff
Keyword(s):  
Food Consumption ◽  
Response Inhibition ◽  
Implicit Attitudes ◽  
Self Control ◽  
Restrained Eaters ◽  
Response Training ◽  
Food Response ◽  
Food Images ◽  
The Impact ◽  
Inhibition Training

Restrained eaters display difficulties engaging in self-control in the presence of food. Undergoing cognitive training to form associations between palatable food and response inhibition was found to improve self-control and influence eating behaviors. The present study assessed the impact of two such response inhibition trainings on food consumption, food-related anxiety, and implicit attitudes toward food among female restrained eaters (Dutch Eating Behavior Questionnaire-restrained eating subscale ≥ 2.5). In Experiment 1, 64 restrained eaters completed either one of two training procedures in which they were asked to classify food vs. non-food images: a food-response training, in which stop cues were always associated with non-food images, or a balanced food-response/inhibition training, in which participants inhibited motor actions to food and non-food stimuli equally. The results revealed reduced snack consumption following the food-response/inhibition training compared to the food-response training. The food-response training was associated with increased levels of food-related anxiety. In Experiment 2, the same training procedures were administered to 47 restrained eaters, and implicit attitudes toward palatable foods were assessed. The results revealed an increase in positive implicit attitudes toward palatable foods in the food-response/inhibition group but not in the food-response training group. The results suggest that balancing response inhibition and execution across food and non-food stimuli may reduce overeating while retaining positive attitudes toward food among female restrained eaters.

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