scholarly journals Meta-Analysis of Correlation Coefficients: A Cautionary Tale on Treating Measurement Error

2021 ◽  
Author(s):  
Qian Zhang
Keyword(s):  
Measurement Error ◽  
Coverage Probability ◽  
Meta Analysis ◽  
Correlation Coefficients ◽  
Coefficient Alpha ◽  
Estimation Accuracy ◽  
Score Distribution ◽  
Scale Scores ◽  
The Mean ◽  
Correlation Estimate

Abstract: A scale to measure a psychological construct is subject to measurement error. When meta-analyzing correlations obtained from scale scores, many researchers recommend correcting measurement error. We considered three caveats when conducting meta-analysis of correlations: (1) the distribution of true scores can be non-normal, resulting in a violation of the normality assumption for raw correlations and Fisher's z transformed correlations; (2) coefficient alpha is often used as the reliability, but correlations corrected for measurement error using alpha can be inaccurate when some assumptions (e.g., tau-equivalence) of alpha are violated; and (3) item scores are often ordinal, making the disattenuation formula potentially problematic. Via three simulation studies, we examined the performance of two meta-analysis approaches with raw correlations and z scores. In terms of estimation accuracy and coverage probability of the mean correlation, results showed that (1) the true score distribution alone had slight influence; (2) when the tau-equivalence assumption was violated and coefficient alpha was used for correcting measurement error, the mean correlation estimate can be biased and coverage probability can be low; and (3) discretization of continuous items can result in under-coverage of the mean correlation even when tau-equivalence was satisfied. With more categories and/or items on a scale, results can improve when tau-equivalence was met or not. Based on these findings, we then gave recommendations when conducting meta-analysis of correlations.

scholarly journals Controlling for baseline telomere length biases estimates of the rate of telomere attrition

2019 ◽  
Vol 6 (10) ◽  
pp. 190937 ◽  
Author(s):  
Melissa Bateson ◽  
Dan T. A. Eisenberg ◽  
Daniel Nettle
Keyword(s):  
Measurement Error ◽  
Telomere Length ◽  
Statistical Models ◽  
Meta Analysis ◽  
Regression To The Mean ◽  
Inference Models ◽  
Telomere Attrition ◽  
The Mean ◽  
Invalid Inference ◽  
Over Time

Longitudinal studies have sought to establish whether environmental exposures such as smoking accelerate the attrition of individuals' telomeres over time. These studies typically control for baseline telomere length (TL) by including it as a covariate in statistical models. However, baseline TL also differs between smokers and non-smokers, and telomere attrition is spuriously linked to baseline TL via measurement error and regression to the mean. Using simulated datasets, we show that controlling for baseline TL overestimates the true effect of smoking on telomere attrition. This bias increases with increasing telomere measurement error and increasing difference in baseline TL between smokers and non-smokers. Using a meta-analysis of longitudinal datasets, we show that as predicted, the estimated difference in telomere attrition between smokers and non-smokers is greater when statistical models control for baseline TL than when they do not, and the size of the discrepancy is positively correlated with measurement error. The bias we describe is not specific to smoking and also applies to other exposures. We conclude that to avoid invalid inference, models of telomere attrition should not control for baseline TL by including it as a covariate. Many claims of accelerated telomere attrition in individuals exposed to adversity need to be re-assessed.

scholarly journals Evaluating the effect of measurement error when using one or two 24 h dietary recalls to assess eating out: a study in the context of the HECTOR project

2013 ◽  
Vol 110 (6) ◽  
pp. 1107-1117 ◽  
Author(s):  
Philippos Orfanos ◽  
Sven Knüppel ◽  
Androniki Naska ◽  
Jennifer Haubrock ◽  
Antonia Trichopoulou ◽  
...  
Keyword(s):  
Measurement Error ◽  
Energy Intake ◽  
Partial Correlation ◽  
Correlation Coefficients ◽  
Personal Characteristics ◽  
Inverse Association ◽  
Short Term ◽  
Precise Data ◽  
The Mean ◽  
Eating Out

Eating out is often recorded through short-term measurements and the large within-person variability in intakes may not be adequately captured. The present study aimed to understand the effect of measurement error when using eating-out data from one or two 24 h dietary recalls (24hDR), in order to describe intakes and assess associations between eating out and personal characteristics. In a sample of 366 adults from Potsdam, Germany, two 24hDR and a FFQ were collected. Out-of-home intakes were estimated based on either one 24hDR or two 24hDR or the Multiple Source Method (MSM) combining the two 24hDR and the questionnaire. The distribution of out-of-home intakes of energy, macronutrients and selected foods was described. Multiple linear regression and partial correlation coefficients were estimated to assess associations between out-of-home energy intake and participants' characteristics. The mean daily out-of-home intakes estimated from the two 24hDR were similar to the usual intakes estimated through the MSM. The out-of-home energy intake, estimated through either one or two 24hDR, was positively associated with total energy intake, inversely with age and associations were stronger when using the two 24hDR. A marginally significant inverse association between out-of-home energy intake and physical activity at work was observed only on the basis of the two 24hDR. After applying the MSM, all significant associations remained and were more precise. Data on eating out collected through one or two 24hDR may not adequately describe intake distributions, but significant associations between eating out and participants' characteristics are highly unlikely to appear when in reality these do not exist.

Response Rates in Online Surveys With Affective Disorder Participants

2020 ◽  
Vol 228 (1) ◽  
pp. 14-24 ◽  
Author(s):  
Tanja Burgard ◽  
Michael Bošnjak ◽  
Nadine Wedderhoff
Keyword(s):  
Meta Analysis ◽  
Response Rates ◽  
Contact Mode ◽  
General Anxiety Disorder ◽  
General Anxiety ◽  
Face To Face ◽  
Survey Participation ◽  
The Mean ◽  
Design Characteristics ◽  
E Mail

Abstract. A meta-analysis was performed to determine whether response rates to online psychology surveys have decreased over time and the effect of specific design characteristics (contact mode, burden of participation, and incentives) on response rates. The meta-analysis is restricted to samples of adults with depression or general anxiety disorder. Time and study design effects are tested using mixed-effects meta-regressions as implemented in the metafor package in R. The mean response rate of the 20 studies fulfilling our meta-analytic inclusion criteria is approximately 43%. Response rates are lower in more recently conducted surveys and in surveys employing longer questionnaires. Furthermore, we found that personal invitations, for example, via telephone or face-to-face contacts, yielded higher response rates compared to e-mail invitations. As predicted by sensitivity reinforcement theory, no effect of incentives on survey participation in this specific group (scoring high on neuroticism) could be observed.

The Effect of Desmopressin on Reducing Blood Loss in Cardiac Surgery – A Meta-Analysis of Double-Blind, Placebo-Controlled Trials

1995 ◽  
Vol 74 (04) ◽  
pp. 1064-1070 ◽  
Author(s):  
Marco Cattaneo ◽  
Alan S Harris ◽  
Ulf Strömberg ◽  
Pier Mannuccio Mannucci
Keyword(s):  
Cardiac Surgery ◽  
Blood Loss ◽  
Meta Analysis ◽  
Postoperative Blood Loss ◽  
Controlled Trials ◽  
Double Blind ◽  
Double Blind Placebo ◽  
Transfusion Requirements ◽  
The Mean ◽  
Excessive Blood Loss

SummaryThe effect of desmopressin (DDAVP) on reducing postoperative blood loss after cardiac surgery has been studied in several randomized clinical trials, with conflicting outcomes. Since most trials had insufficient statistical power to detect true differences in blood loss, we performed a meta-analysis of data from relevant studies. Seventeen randomized, double-blind, placebo-controlled trials were analyzed, which included 1171 patients undergoing cardiac surgery for various indications; 579 of them were treated with desmopressin and 592 with placebo. Efficacy parameters were blood loss volumes and transfusion requirements. Desmopressin significantly reduced postoperative blood loss by 9%, but had no statistically significant effect on transfusion requirements. A subanalysis revealed that desmopressin had no protective effects in trials in which the mean blood loss in placebo-treated patients fell in the lower and middle thirds of distribution of blood losses (687-1108 ml/24 h). In contrast, in trials in which the mean blood loss in placebo-treated patients fell in the upper third of distribution (>1109 ml/24 h), desmopressin significantly decreased postoperative blood loss by 34%. Insufficient data were available to perform a sub-analysis on transfusion requirements. Therefore, desmopressin significantly reduces blood loss only in cardiac operations which induce excessive blood loss. Further studies are called to validate the results of this meta-analysis and to identify predictors of excessive blood loss after cardiac surgery.

A Meta Analytic Review of the Relationship between Emotional Intelligence and Leadership Effectiveness

2019 ◽  
Vol 118 (9) ◽  
pp. 118-126
Author(s):  
Augusty P. A ◽  
Jain Mathew
Keyword(s):  
Systematic Review ◽  
Emotional Intelligence ◽  
Direct Relationship ◽  
Effective Leadership ◽  
Leadership Effectiveness ◽  
Meta Analysis ◽  
Correlation Coefficients ◽  
Review Of Literature ◽  
Analytic Review ◽  
The Relationship

The study evaluates the relationship between Emotional Intelligence and Leadership Effectiveness through a Systematic Review of Literature. The relationship has been evaluated in two steps. First, a Systematic review of literature was done to provide a theoretical framework to link the dimensions of Emotional Intelligence to the elements of effective leadership. Meta-analysis was then used to consolidate empirical evidence of the relationship. The studies for the meta-analysis were sourced from Pro Quest and EBSCO and the correlation coefficients of the studies were analysed. Only articles that presented the direct relationship between the variables were included in the study. The results of the analysis revealed a strong, statistically significant relationship between emotional intelligence and effective leadership. The findings of the study provide evidence for the proposition that Emotional Intelligence and Leadership Effectiveness are interrelated.

scholarly journals Outcomes of Oblique Lateral Interbody Fusion for Adult Spinal Deformity: A Systematic Review and Meta-Analysis

2021 ◽  
pp. 219256822097914
Author(s):  
Lei Zhu ◽  
Jun-Wu Wang ◽  
Liang Zhang ◽  
Xin-Min Feng
Keyword(s):  
Systematic Review ◽  
Lumbar Lordosis ◽  
Interbody Fusion ◽  
Perioperative Complications ◽  
Adult Spinal Deformity ◽  
Meta Analysis ◽  
Fusion Rate ◽  
The Mean ◽  
Oblique Lateral Interbody Fusion ◽  
Lateral Interbody

Study Design: A systematic review and meta-analysis. Objectives: To evaluate clinical and radiographic outcomes, and perioperative complications of oblique lateral interbody fusion (OLIF) for adult spinal deformity (ASD). Methods: We performed a systematic review and meta-analysis of related studies reporting outcomes of OLIF for ASD. The clinical outcomes were assessed by visual analogue scale (VAS) and Oswestry Disability Index (ODI). The radiographic parameters were evaluated by sagittal vertical axis (SVA), pelvic tilt (PT), sacral slope (SS), thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence-lumbar lordosis (PI-LL), Cobb angle and fusion rate. A random effects model and 95% confidence intervals (CI) were performed to investigate the results. Results: A total of 16 studies involving 519 patients were included in the present study. The mean difference of VAS-back score, VAS-leg score and ODI score before and after surgery was 5.1, 5.0 and 32.3 respectively. The mean correction of LL was 20.6°, with an average of 6.9° per level and the mean correction of Cobb was 16.4°, with an average of 4.7° per level. The mean correction of SVA, PT, SS, TK and PI-LL was 59.3 mm, 11.7°, 6.9°, 9.4° and 20.6° respectively. The mean fusion rate was 94.1%. The incidence of intraoperative and postoperative complications was 4.9% and 29.6% respectively. Conclusions: OLIF is an effective and safe surgery method in the treatment of mild or moderate ASD and it has advantages in less intraoperative blood loss and lower perioperative complications.

scholarly journals Outpatient Total Hip Arthroplasty: A Meta-Analysis

2021 ◽  
Vol 11 (15) ◽  
pp. 6853
Author(s):  
Filippo Migliorini ◽  
Lucio Cipollaro ◽  
Francesco Cuozzo ◽  
Francesco Oliva ◽  
Andrea Valerio Marino ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Meta Analysis ◽  
Readmission Rates ◽  
Total Hip ◽  
Vein Thrombosis ◽  
Outpatient Group ◽  
Operative Planning ◽  
The Mean ◽  
And Gender

Introduction: Outpatient total hip arthroplasty (THA) is increasingly popular. This meta-analysis investigated the potential advantages of outpatient regimes for THA. Methods: This study followed the PRISMA guidelines. PubMed, Web of Science, Google Scholar, Embase, and Scopus databases were accessed in June 2021. All clinical studies investigating outpatient THA were considered. The outcomes of interest were pain, infection, mortality, revision, dislocation, readmission rates, and deep vein thrombosis (DVT). Results: Data from 102,839 patients were included. A total of 52% (153,168 of 102,839 patients) were women. The mean age of patients was 62.6 ± 4.6 years, the mean BMI was 29.1 ± 1.8 kg/m2. Good comparability was found in age, BMI, and gender (p > 0.1). No difference was found in pain (p = 0.4), infections (p = 0.9), mortality (p = 0.9), rate of revision (p = 0.1), dislocation (p = 0.9), and readmission (p = 0.8). The outpatient group demonstrated a greater rate of DVT (OR 3.57; 95% CI 2.47 to 5.18; p < 0.0001). Conclusions: In selected patients, outpatient THA can be performed safely with optimal outcomes comparable with inpatient THA. Clear and comprehensive pre-operative planning should involve a multi-disciplinary group composed of orthopaedic surgeons, anaesthesia and rehabilitation specialists, and physiotherapists. Each centre performing outpatient THA should implement continuous homecoming welfare activity, to supervise physiotherapy and monitor anticoagulant therapy.

scholarly journals The quality of life in Chinese juvenile idiopathic arthritis patients: psychometric properties of the pediatric quality of life inventor generic core scales and rheumatology module

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Hua-hong Wu ◽  
Feng-qi Wu ◽  
Yang Li ◽  
Jian-ming Lai ◽  
Gai-xiu Su ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Juvenile Idiopathic Arthritis ◽  
Reliability And Validity ◽  
Correlation Coefficients ◽  
Active Period ◽  
Generic Core Scale ◽  
Remission Period ◽  
Pedsql 4.0 ◽  
The Mean

Abstract Background Juvenile idiopathic arthritis (JIA) may seriously affects patients’ quality of life (QoL), but it was rarely focused and studied in China, so we explore JIA children’s QoL using Chinese version of the PedsQL4.0 Generic Core and PedsQL3.0 Rheumatology Module scale, and analyzed the psychometric properties of these two Scales among Chinese JIA children. Methods We recruited 180 JIA patients from Children's Hospital Affiliated to Capital Institute of Pediatrics and Hebei Yanda Hospital from July 2018 to August 2019. The questionnaires include information related on JIA, PedsQL4.0 generic core and PedsQL3.0 Rheumatology Module scales. According to the disease type, onset age of and course of JIA, we divided them into different groups, then compared the QoL status among different groups. Moreover, we analyzed the reliability and validity of these two scales in these 180 JIA children. Results The mean score of PedsQL4.0 generic core scale on these 180 patients was 82.85 ± 14.82, for these in active period was 72.05 ± 15.29, in remission period was 89.77 ± 9.23; the QoL score of systemic, polyarticular and oligoarticular JIA patients were 77.05 ± 19.11, 84.33 ± 12.46 and 87.12 ± 10.23. The mean score of PedsQL3.0 Rheumatology Module scale on 180 patients was 91.22 ± 9.45, for these in active period was 84.70 ± 11.37, in remission period was 95.43 ± 4.48; the QoL score of systemic, polyarticular and oligoarticular JIA patients were 89.41 ± 11.54, 89.38 ± 10.08 and 93.71 ± 6.92. In the PedsQL 4.0 Generic Core scale, the α coefficients of total scale and almost every dimension are all greater than 0.8 except for the school activity dimension of 0.589; the correlation coefficients of 22 items’ scores (total 23 items) with the scores of dimensions they belong to are greater than 0.5 (maximum value is 0.864), and the other one is 0.406. In PedsQL3.0 Rheumatology Module scale, except for the treatment and worry dimensions of 0.652 and 0.635, the α coefficients of other dimensions and the total scale are all greater than 0.7; the correlation coefficients of all items’ score were greater than 0.5 (the maximum is 0.933, the minimum is 0.515). Conclusions The QoL of Chinese JIA children is worse than their healthy peers, these in active period and diagnosed as systemic type were undergoing worst quality of life. The reliability and validity of PedsQL 4.0 Generic Core and PedsQL3.0 Rheumatology Module scale in Chinese JIA children are satisfactory, and can be used in clinical and scientific researches.

The Cagey C-test Construct: Some Evidence from a Meta-analysis of Correlation Coefficients

System ◽  
2021 ◽  
pp. 102526
Author(s):  
Todd H. McKay ◽  
Yasser Teimouri ◽  
Ayşenur Sağdiç ◽  
Bradford Salen ◽  
Derek Reagan ◽  
...  
Keyword(s):  
Meta Analysis ◽  
Correlation Coefficients

The analgesic efficacy of liposomal bupivacaine compared with bupivacaine hydrochloride for the prevention of postoperative pain: a systematic review and meta-analysis with trial sequential analysis

2021 ◽  
pp. rapm-2020-102427
Author(s):  
Hanns-Christian Dinges ◽  
Thomas Wiesmann ◽  
Berit Otremba ◽  
Hinnerk Wulf ◽  
Leopold H Eberhart ◽  
...  
Keyword(s):  
Systematic Review ◽  
Postoperative Pain ◽  
Pain Score ◽  
Meta Analysis ◽  
End Points ◽  
Liposomal Bupivacaine ◽  
Bupivacaine Hydrochloride ◽  
Pain Scores ◽  
Score Difference ◽  
The Mean

Background/ImportanceLiposomal bupivacaine (LB) is a prolonged release formulation of conventional bupivacaine designed for prolonging local or peripheral regional single injection anesthesia. To this day, the benefit of the new substance on relevant end points is discussed controversial.ObjectiveThe objective was to determine whether there is a difference in postoperative pain scores and morphine consumption between patients treated with LB and bupivacaine hydrochloride in a systematic review and meta-analysis.Evidence reviewRandomized controlled trials (RCT) were identified in Embase, CENTRAL, MEDLINE and Web of Science up to May 2020. Risk of bias was assessed using Cochrane methodology. Primary end points were the mean pain score difference and the relative morphine equivalent (MEQ) consumption expressed as the ratio of means (ROM) 24 and 72 hours postoperatively.Findings23 RCTs including 1867 patients were eligible for meta-analysis. The mean pain score difference at 24 hours postoperatively was significantly lower in the LB group, at −0.37 (95% CI −0.56 to −0.19). The relative MEQ consumption after 24 hours was also significantly lower in the LB group, at 0.85 (0.82 to 0.89). At 72 hours, the pain score difference was not significant at −0.25 (−0.71 to 0.20) and the MEQ ratio was 0.85 (0.77 to 0.95).ConclusionThe beneficial effect on pain scores and opioid consumption was small but not clinically relevant, despite statistical significance. The effect was stable among all studies, indicating that it is independent of the application modality.

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