scholarly journals Determination of the effect size of an observed factor based on a multi-variate model for evaluating practical significance of differences between two groups of case-control design

2020 ◽  
Author(s):  
Liu Hui
Keyword(s):  
Effect Size ◽  
Control Design ◽  
Substantial Effect ◽  
Case Control ◽  
Practical Significance ◽  
Size Difference ◽  
Intensity Level ◽  
Positive Ratio ◽  
The Difference ◽  
Clinically Significant

Abstract Background To determine the effect size of an observed factor for a disease by using consistency in a cohort study (CRC) for evaluating practical significance of differences between two groups of case-control design. Methods A model of multiple pathogenic factors was established by analyzing the number and distribution of observed factors in a study population. The difference in the incidence between two groups (exposed and unexposed) was calculated according to the model as CRC. The relationship of Youden’s index and true and false-positive ratio (TFR) in case-control design were observed with CRC. Results The CRC was able to correctly reflect the number of factors combined in the models, and therefore, indicates that CRC is a reasonable indicator of effect size. Difference scores <0.25 indicate that one of four or more factors plays a role in a disease; scores >0.50 indicate one of two factors plays a role in disease and implies a high intensity level of the factor. TFR could correctly reflect CRC. Accordingly, a factor with an effect size (i.e., CRC) less than 6.0 should not be considered a clinically significant factor, even if the observed difference is statistically significant. Conclusions A CRC over 0.25 OR TFR over 6.0 is suggested as an indicator of a substantial effect size.

scholarly journals Determination of the effect size of an observed factor based on a multi-variate model for evaluating practical significance of differences between two groups of case-control design

2020 ◽  
Author(s):  
Liu Hui
Keyword(s):  
Effect Size ◽  
Control Design ◽  
Substantial Effect ◽  
Case Control ◽  
Practical Significance ◽  
Size Difference ◽  
Intensity Level ◽  
Positive Ratio ◽  
The Difference ◽  
Clinically Significant

Abstract Background: To determine the effect size of an observed factor for a disease by using consistency in a cohort study (CRC) for evaluating practical significance of differences between two groups of case-control design. Methods: A model of multiple pathogenic factors was established by analyzing the number and distribution of observed factors in a study population. The difference in the incidence between two groups (exposed and unexposed) was calculated according to the model as CRC. The relationship of Youden’s index and true and false-positive ratio (TFR) in case-control design were observed with CRC. Results: The CRC was able to correctly reflect the number of factors combined in the models, and therefore, indicates that CRC is a reasonable indicator of effect size. Difference scores <0.25 indicate that one of four or more factors plays a role in a disease; scores >0.50 indicate one of two factors plays a role in disease and implies a high intensity level of the factor. TFR could correctly reflect CRC. Accordingly, a factor with an effect size (i.e., TFR) less than 6.0 should not be considered a clinically significant factor, even if the observed difference is statistically significant. Conclusions: A CRC over 0.25 OR TFR over 6.0 is suggested as an indicator of a substantial effect size.

scholarly journals Evaluating differences in disease occurrence between two groups to determine the effect size of an observed factor based on a multi-variate model

2019 ◽  
Author(s):  
Hui Liu
Keyword(s):  
Effect Size ◽  
Disease Incidence ◽  
Substantial Effect ◽  
Size Difference ◽  
Intensity Level ◽  
Number Of Factors ◽  
Disease Occurrence ◽  
Pathogenic Factors ◽  
Two Factors ◽  
The Difference

Abstract Background To describe a method to determine the effect size of an observed factor for a disease by evaluating the difference in the frequency of disease occurrence between exposed and unexposed groups.Methods A model of multiple pathogenic factors was established by analyzing the number and distribution of observed factors in a study population. The difference in the incidence between two groups (exposed and unexposed) was calculated according to the model.Results The distribution of observed factors in the population did not influence the difference in disease incidence between the two groups. However, the difference in incidence between the two groups was able to correctly reflect the number of factors combined in the models, and therefore, indicates that group differences in incidence is a reasonable indicator of effect size. Difference scores <0.25 indicate that one of four or more factors plays a role in a disease; scores >0.50 indicate one of two factors plays a role in disease and implies a high intensity level of the factor.Conclusions A difference in incidence between two groups over 0.25 is suggested as an indicator of a substantial effect size.

scholarly journals Practical significance of the difference in means

2000 ◽  
Vol 26 (3) ◽  
Author(s):  
H. S. Steyn
Keyword(s):  
Effect Size ◽  
Practical Importance ◽  
Practical Significance ◽  
Population Means ◽  
Two Samples ◽  
Significant Difference ◽  
Standard Deviations ◽  
The Difference

It is shown how the standardised difference (the effect size) between two population means can be used to establish significance when the populations are observed in totality. When dealing with two samples methods are given to determine the practical importance of a statistically significant difference. The usual effect size formula is adapted to deal with cases where populations have different standard deviations. Opsomming Dit word aangetoon hoe die gestandaardiseerde verskil (die effekgrootte) tussen twee populasiegemiddeldes gebruik kan word om beduidenheid t.o.v. volledig waargenome populasies te bepaal. In die geval van twee steekproewe word metodes gegee om die praktiese belangrikheid van 'n statistiese beduidende verskil vas te stel. Die gewone effekgrootte formule word aangepas ten einde gevalle waar populasies verskillende standaardafwykings het te hanteer.

PrePrint - Exploring Perceptions of Meaningful Relationships

2018 ◽  
Author(s):  
Nataly Beribisky ◽  
Heather Davidson ◽  
Rob Cribbie
Keyword(s):  
Effect Size ◽  
Mean Difference ◽  
Practical Significance ◽  
Equivalence Testing ◽  
Significant Variability ◽  
Meaningful Relationship ◽  
Meaningful Relationships ◽  
Context Free

Researchers often need to consider the practical significance of a relationship. For example, interpreting the magnitude of an effect size or establishing bounds in equivalence testing requires knowledge of the meaningfulness of a relationship. However, there has been little research exploring the degree of relationship among variables (e.g., correlation, mean difference) necessary for an association to be interpreted as meaningful or practically significant. In this study, we presented statistically trained and untrained participants with a collection of figures that displayed varying degrees of mean difference between groups or correlations among variables and participants indicated whether or not each relationship was meaningful. The results suggest that statistically trained and untrained participants differ in their qualification of a meaningful relationship, and that there is significant variability in how large a relationship must be before it is labeled meaningful. The results also shed some light on what degree of relationship is considered meaningful by individuals in a context-free setting.

scholarly journals 688 Pediatric Obstructive Sleep Apnea (OSA) and COVID-19-Related Adverse Clinical Outcomes

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A269-A269
Author(s):  
Vaishal Shah ◽  
Nancy Foldvary-Schaefer ◽  
Lu Wang ◽  
Lara Jehi ◽  
Cynthia Pena Obrea ◽  
...  
Keyword(s):  
High Risk ◽  
Clinical Outcome ◽  
Clinical Outcomes ◽  
Pediatric Patients ◽  
Control Design ◽  
Supplemental Oxygen ◽  
Case Control ◽  
World Health ◽  
Invasive Ventilation ◽  
High Flow Oxygen

Abstract Introduction The relationship of OSA and human coronavirus (COVID-19) in the pediatric population is unknown. We postulate that OSA is associated with SARS-CoV-2 positivity and with adverse COVID-19 outcomes in children. Methods A retrospective review of 120 consecutive patients (&lt;18 years) with prior polysomnogram (PSG) and COVID-19 testing from the Cleveland Clinic COVID-19 registry was conducted. Using a case control design of SARS-CoV-2 positive and negative pediatric patients, we examined COVID-19 and pre-existing OSA (dichotomized AHI≥1) using logistic (OR,95%CI) regression and as continuous measures: AHI, oxygen(SpO2) nadir, %time SpO2&lt;90%) using linear regression(beta+/-SE). In those positive for SARS-CoV-2(cases only), we assessed the association of OSA and World Health Organization(WHO) COVID-19 clinical outcome composite score (hospitalization, requiring supplemental oxygen, non-invasive ventilation/high-flow oxygen, invasive ventilation/ECMO or death) using Wilcoxon rank sum test for ordinal data. Results Cases (n=36) were 11.8±4.4 years, 61% male, 27.8% black and 88.9% with OSA, while 85.7% of controls (n=84) had OSA. OSA was not associated with increased SARS-CoV-2 positivity: OR=1.33(0.40, 4.45,p=0.64). No significant difference between cases and controls for mean AHI 3.7(1.5,6.0) vs 3.5(1.5,7.1),p=0.91,SpO2 nadir 88.6±5.4 vs 89.1±4.4,p=0.58,%time SpO2&lt;90% 0.05[0.00,1.00) vs 0.10 (0.00,1.00, p=0.65) respectively was noted. WHO-7 COVID-19 clinical outcome did not meet statistical significance in relation to OSA due to the low event frequency (p=0.49). Of note, those with OSA vs without OSA had a higher WHO-7 outcome score of 2 vs 0 and prevalence of hospitalization: 12.5 vs 0% respectively. Of hospitalized patients, the following was observed: 23% had moderate/severe OSA vs 4.3% mild OSA, 50% required supplemental oxygen and 25% required intubation/invasive ventilation. No deaths or readmissions were reported. High risk conditions included: 75% obesity, 50% asthma, 25% sickle cell disease and 25% hypoplastic left heart. Conclusion In this first report of which we are aware focused on COVID-19 in pediatric OSA, we use a case control design leveraging COVID-19 and sleep laboratory registries. Albeit not statistically significant, pediatric patients with OSA had a higher percentage of worse clinical outcomes. Larger network studies are needed to clarify whether poorer COVID-19 outcomes may be attributable to OSA or modulated via high risk health conditions. Support (if any):

Serum otolin-1 as a biomarker for benign paroxysmal positional vertigo: a case-control study

2021 ◽  
pp. 1-4
Author(s):  
D V K Irugu ◽  
A Singh ◽  
H Yadav ◽  
H Verma ◽  
R Kumar ◽  
...  
Keyword(s):  
Serum Level ◽  
Benign Paroxysmal Positional Vertigo ◽  
Case Control Study ◽  
Serum Levels ◽  
Case Control ◽  
Control Group ◽  
Positional Vertigo ◽  
The Difference ◽  
Control Study ◽  
Paroxysmal Positional Vertigo

Abstract Objectives This study aimed to evaluate serum otolin-1 levels in patients with benign paroxysmal positional vertigo and to compare these levels with healthy individuals. Method This was a case-control study. After obtaining institutional ethical committee clearance, the serum level of otolin-1 was calculated in adult individuals (18–75 years old) who were divided into group 1 (patients presenting with benign paroxysmal positional vertigo) and group 2 (healthy patients without benign paroxysmal positional vertigo as the control group). Data analysis was carried out to compare the serum levels in the cases and controls. A p-value less than 0.05 was considered significant. Results A total of 70 age-matched individuals (cases, n = 40; controls, n = 30) were included in the study. The mean serum level of otolin-1 was 636.8 pg/ml (range, 259–981 pg/ml) in the group of patients with benign paroxysmal positional vertigo and 236.2 pg/ml (range, 189–370 pg/ml) in the control group. The difference was statistically significant (p = 0.0000). Conclusion The serum levels of otolin-1 in patients with benign paroxysmal positional vertigo are significantly higher compared with individuals without benign paroxysmal positional vertigo.

scholarly journals Transdiagnostic comparison of visual working memory capacity in bipolar disorder and schizophrenia

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Catherine V. Barnes-Scheufler ◽  
Caroline Passow ◽  
Lara Rösler ◽  
Jutta S. Mayer ◽  
Viola Oertel ◽  
...  
Keyword(s):  
Bipolar Disorder ◽  
Working Memory ◽  
Visual Working Memory ◽  
Effect Size ◽  
Working Memory Capacity ◽  
Memory Capacity ◽  
Medium Effect ◽  
Full Spectrum ◽  
Small Effect Size ◽  
The Difference

Abstract Background Impaired working memory is a core cognitive deficit in both bipolar disorder and schizophrenia. Its study might yield crucial insights into the underpinnings of both disorders on the cognitive and neurophysiological level. Visual working memory capacity is a particularly promising construct for such translational studies. However, it has not yet been investigated across the full spectrum of both disorders. The aim of our study was to compare the degree of reductions of visual working memory capacity in patients with bipolar disorder (PBD) and patients with schizophrenia (PSZ) using a paradigm well established in cognitive neuroscience. Methods 62 PBD, 64 PSZ, and 70 healthy controls (HC) completed a canonical visual change detection task. Participants had to encode the color of four circles and indicate after a short delay whether the color of one of the circles had changed or not. We estimated working memory capacity using Pashler’s K. Results Working memory capacity was significantly reduced in both PBD and PSZ compared to HC. We observed a small effect size (r = .202) for the difference between HC and PBD and a medium effect size (r = .370) for the difference between HC and PSZ. Working memory capacity in PSZ was also significantly reduced compared to PBD with a small effect size (r = .201). Thus, PBD showed an intermediate level of impairment. Conclusions These findings provide evidence for a gradient of reduced working memory capacity in bipolar disorder and schizophrenia, with PSZ showing the strongest degree of impairment. This underscores the importance of disturbed information processing for both bipolar disorder and schizophrenia. Our results are compatible with the cognitive manifestation of a neurodevelopmental gradient affecting bipolar disorder to a lesser degree than schizophrenia. They also highlight the relevance of visual working memory capacity for the development of both behavior- and brain-based transdiagnostic biomarkers.

scholarly journals Morphological consistency of bilateral hip joints in adults based on the X-ray and CT data

2021 ◽  
Author(s):  
Ran Zhao ◽  
Hong Cai ◽  
Hua Tian ◽  
Ke Zhang
Keyword(s):  
Hip Joint ◽  
Morphological Difference ◽  
Medullary Cavity ◽  
Size Difference ◽  
Single Plane ◽  
X Ray ◽  
Stem Size ◽  
The Difference ◽  
Ct Data ◽  
Anatomical Parameters

Abstract Purpose The application of the anatomical parameters of the contralateral hip joint to guide the preoperative template of the affected side relies on the bilateral hip symmetry. We investigated the bilateral hip symmetry and range of anatomical variations by measurement and comparison of bilateral hip anatomical parameters. Methods This study included 224 patients (448 hips) who were diagnosed with osteoarthritis (OA) and avascular necrosis (AVN) of the femur head, and underwent bilateral primary total hip arthroplasty (THA) in our hospital from January 2012 to August 2020. Imaging data included 224 patients X-ray and 30 CT data at the end of the cohort. Anatomical parameters, including the acetabular abduction angle and trochanteric height, were measured using the Noble method. Postoperative measurements included stem size, difference of leg length and offset. Results Except for the isthmus width, there were no significant differences in the anatomical morphology of the hip joint. Among the demographic factors, there was a correlation between body weight and NSA. Among various anatomical parameters, a correlation was present between medullary cavity widths of T + 20, T, and T − 20. The difference in the use of stem size is not due to the morphological difference of bilateral medullary cavity, but due to the different of 1- or 2-stage surgery. Conclusion Bilateral symmetry was present among the patients with normal morphology of the hip medullary cavity, theoretically confirming the feasibility of structural reconstruction of the hip joint using the hip joint on the uninjured side. Additionally, the difference in the morphology of the hip medullary cavity is not present in a single plane but is synergistically affected by multiple adjacent planes.

scholarly journals The bowel and beyond: extracolonic findings from CT colonography

2021 ◽  
Author(s):  
Gerard Lambe ◽  
Peter Hughes ◽  
Louise Rice ◽  
Caoimhe McDonnell ◽  
Mark Murphy ◽  
...  
Keyword(s):  
Ct Colonography ◽  
Surgical Intervention ◽  
Potential Significance ◽  
Age And Gender ◽  
Abdominal Aortic ◽  
Life Threatening ◽  
Extracolonic Findings ◽  
The Difference ◽  
Clinically Significant ◽  
And Gender

AbstractCT colonography has emerged as the investigation of choice for suspected colorectal cancer in patients when a colonoscopy in incomplete, is deemed high risk or is declined because of patient preference. Unlike a traditional colonoscopy, it frequently reveals extracolonic as well as colonic findings. Our study aimed to determine the prevalence, characteristics and potential significance of extracolonic findings on CT colonography within our own institution. A retrospective review was performed of 502 patients who underwent CT colonography in our institution between January 1, 2010 and January 4, 2015. Of 502 patients, 60.63% had at least one extracolonic finding. This was close to other similar-sized studies (Kumar et al. Radiology 236(2):519–526, 2005). However, our rate of E4 findings was significantly higher than that reported in larger studies at 5.3%(Pooler et al. AJR 206:313–318, 2016). The difference may be explained by our combination of symptomatic/screening patients or by the age and gender distribution of our population. Our study lends support to the hypothesis that CT colonography may be particularly useful in identifying clinically significant extracolonic findings in symptomatic patients. CT colonography may allow early identification of extracolonic malignancies and life-threatening conditions such as an abdominal aortic aneurysm at a preclinical stage when they are amenable to medical or surgical intervention. However, extracolonic findings may also result in unnecessary investigations for subsequently benign findings.

4971Blood viscosity and its relevance to the diagnosis and management of pulmonary hypertension: a new elephant in the cathlab

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
A Kempny ◽  
K Dimopoulos ◽  
A E Fraisse ◽  
G P Diller ◽  
L C Price ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Cardiac Catheterization ◽  
Clinical Decision Making ◽  
Clinical Decision ◽  
Pulmonary Vasculature ◽  
Pulmonary Vascular Disease ◽  
Significant Difference ◽  
The Difference ◽  
Clinically Significant ◽  
The Relationship

Abstract Background Pulmonary vascular resistance (PVR) is an essential parameter assessed during cardiac catheterization. It is used to confirm pulmonary vascular disease, to assess response to targeted pulmonary hypertension (PH) therapy and to determine the possibility of surgery, such as closure of intra-cardiac shunt or transplantation. While PVR is believed to mainly reflect the properties of the pulmonary vasculature, it is also related to blood viscosity (BV). Objectives We aimed to assess the relationship between measured (mPVR) and viscosity-corrected PVR (cPVR) and its impact on clinical decision-making. Methods We assessed consecutive PH patients undergoing cardiac catheterization. BV was assessed using the Hutton method. Results We included 465 patients (56.6% female, median age 63y). The difference between mPVR and cPVR was highest in patients with abnormal Hb levels (anemic patients: 5.6 [3.4–8.0] vs 7.8Wood Units (WU) [5.1–11.9], P<0.001; patients with raised Hb: 10.8 [6.9–15.4] vs. 7.6WU [4.6–10.8], P<0.001, respectively). Overall, 33.3% patients had a clinically significant (>2.0WU) difference between mPVR and cPVR, and this was more pronounced in those with anemia (52.9%) or raised Hb (77.6%). In patients in the upper quartile for this difference, mPVR and cPVR differed by 4.0WU [3.4–5.2]. Adjustment of PVR required Conclusions We report, herewith, a clinically significant difference between mPVR and cPVR in a third of contemporary patients assessed for PH. This difference is most pronounced in patients with anemia, in whom mPVR significantly underestimates PVR, whereas in most patients with raised Hb, mPVR overestimates it. Our data suggest that routine adjustment for BV is necessary.

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