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Two-Step Approach to Partial Factorial Invariance: Selecting a reference variable and Identifying the Source of Noninvariance

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STRUCTURAL EQUATION MODELING-A MULTIDISCIPLINARY JOURNAL 2017年第1期24卷 65-79页

作者： Jung, Eunju Yoon, Myeongsun Indiana Univ Bloomington IN USA Texas A&M Univ College Stn TX 77843 USA

To date, no effective empirical method has been available to identify a truly invariant reference variable (RV) in testing measurement invariance under a multiple-group confirmatory factor analysis. This study proposes a method that, in selecting an RV, uses the smallest modification index (min-mod). The method's performance is evaluated using 2 models: (a) a full invariance model, and (b) a partial invariance model. Results indicate that for both models the min-mod successfully identifies a truly invariant RV (Study 1). In Study 2, we use the RV found in Study 1 to further evaluate the performance of item-by-item Wald tests at locating a noninvariant variable. The results indicate that Wald tests overall performed better with an RV selected in a partial invariance model than an RV selected in a full invariance model, although in certain conditions their performances were rather similar. Implications and limitations of the study are also discussed.

关键词： modification index multiple-group confirmatory factor analysis partial factorial invariance reference variable

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Detecting the violation of factorial invariance with an unknown reference variable

Detecting the violation of factorial invariance with an unkn...

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作者： Jung, Eunju Texas A&M University

学位级别：Ph.D.

A widely used tool for testing measurement invariance is multi-group confirmatory factor analysis (MCFA). Identification of MCFA models is usually done by imposing invariance constraints on parameters of chosen reference variables (RV). If the chosen RVs were not actually invariant, one could draw invalid conclusions regarding the source of noninvariance. How can an invariant RV be selected accurately? To our knowledge, no method is yet available, yet two approaches have been suggested to detect non-invariant (or invariant) items without choosing specific RVs. One is the factor-ratio test (FR-T), and the other is the use of the largest modification index (Max-Mod). These two approaches have yet to be directly compared under the same conditions. To address unsolved problems in partial measurement invariance testing, two studies were conducted. The first aimed to identify a truly invariant RV using the smallest modification index. The second aimed to directly compare the performances of FR-T and the backward approach using the Max-Mod in correctly specifying the source of noninvariance. The second study also proposes a new method—the forward approach facilitated by the bias-corrected bootstrapping confidence intervals. The performances of the three methods was compared in terms of perfect recovery rates, model-level Type I error rates, and model-level Type II error rates. The results of the first study indicated that the Min-Mod successfully identify a truly invariant RV across all conditions. In the second study, overall, the backward approach also showed best performance under 99% confidence level (α = 0.01) in both partial metric invariance (PMI) and partial scalar invariance (PSI) conditions. The performance of the forward approach was comparable with that of the backward approach only in PMI conditions. The factor-ratio test had the poorest performance. Limitations and future directions are also discussed.

关键词： Measurement Invariance Factorial Invariance reference variable Thesis

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An adaptive polynomial dimensional decomposition method and its application in reliability analysis

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ENGINEERING COMPUTATIONS 2022年第7期39卷 2755-2780页

作者： Sheng, Xiangqian Fan, Wenliang Zhang, Qingbin Li, Zhengling Chongqing Univ Sch Civil Engn Chongqing Peoples R China Chongqing Univ Minist Educ Key Lab New Technol Construct Cities Mt Area Chongqing Peoples R China

Purpose The polynomial dimensional decomposition (PDD) method is a popular tool to establish a surrogate model in several scientific areas and engineering disciplines. The selection of appropriate truncated polynomials is the main topic in the PDD. In this paper, an easy-to-implement adaptive PDD method with a better balance between precision and efficiency is proposed. Design/methodology/approach First, the original random variables are transformed into corresponding independent reference variables according to the statistical information of variables. Second, the performance function is decomposed as a summation of component functions that can be approximated through a series of orthogonal polynomials. Third, the truncated maximum order of the orthogonal polynomial functions is determined through the nonlinear judgment method. The corresponding expansion coefficients are calculated through the point estimation method. Subsequently, the performance function is reconstructed through appropriate orthogonal polynomials and known expansion coefficients. Findings Several examples are investigated to illustrate the accuracy and efficiency of the proposed method compared with the other methods in reliability analysis. Originality/value The number of unknown coefficients is significantly reduced, and the computational burden for reliability analysis is eased accordingly. The coefficient evaluation for the multivariate component function is decoupled with the order judgment of the variable. The proposed method achieves a good trade-off of efficiency and accuracy for reliability analysis.

关键词： Polynomial dimensional decomposition Reliability reference variable Orthogonal polynomials Nonlinearity judgment

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Importance of Measuring Hand and Foot Function Over the Disease Course in Rheumatoid Arthritis: An Eight-Year Follow-Up Study

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ARTHRITIS CARE & RESEARCH 2019年第2期71卷 166-172页

作者： Bremander, Ann Forslind, Kristina Eberhardt, Kerstin Andersson, Maria L. E. Lund Univ Lund Sweden Halmstad Univ Halmstad Sweden Spenshult Res & Dev Ctr Backagardsvagen 47 SE-30274 Halmstad Sweden

Objective To assess function using the Signals of Functional Impairment (SOFI) instrument over 8 years, to study clinical variables associated with the change, and to study change over time of the SOFI items. Methods In total, 1,223 patients with early rheumatoid arthritis (RA) from the Better Anti-Rheumatic Farmacotherapy (BARFOT) cohort (mean +/- SD age 56.9 +/- 15.4 years, 67% women) were included in the analysis. Data from baseline and from 1 and 8 years were studied. The SOFI instrument includes measures of range of motion in the hand, shoulder/arm, and lower extremity (range 0-44, best to worst). The effects of baseline variables (sociodemographic, disease activity, joint destruction, and function) on change in SOFI scores were studied by linear regression analysis. Results During the first year, the improvement in mean +/- SD SOFI scores was 2.7 +/- 5.7 (P < 0.001). Worse scores in the Disease Activity Score in 28 joints and Health Assessment Questionnaire score at baseline were associated with this improvement (r(2) <= 0.11). During the next 7 years, the deterioration in SOFI scores was mean +/- SD 1.5 +/- 4.9 (P < 0.001). Based on change scores, we found that finger flexion, pincer grip, and toe-standing were the most important items to measure, explaining 58-61% of the total SOFI score, and these items were also associated with radiographic changes at the 8-year follow-up. Conclusion Function as assessed with SOFI scores improved during the first year in patients with early RA, but it deteriorated slowly thereafter. Impaired hand and foot function was associated with joint destruction at the 8-year follow-up. Measures of hand and foot function will complement self-reported and medical data, both in clinical work and in long-term research studies.

关键词： joint destruction health assessment questionnaire Hand disease activity score time-dependent reference variable BASELINE Rheumatoid Arthritis Follow-Up Studies Disease Progression

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Prevalence, Temporal Evolution, and Impact on Survival of Ventricular Conduction Blocks in Patients With Acute Coronary Syndrome and Cardiogenic Shock

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AMERICAN JOURNAL OF CARDIOLOGY 2018年第2期122卷 199-205页

作者： Tolppanen, Heli Javanainen, Tuija Sans-Rosello, Jordi Parenica, Jiri Nieminen, Tuomo Pavlusova, Marie Masip, Josep Kober, Lars Banaszewski, Marek Sionis, Alessandro Spinar, Jindrich Harjola, Veli-Pekka Jurkko, Raija Lassus, Johan Helsinki Univ Hosp Heart & Lung Ctr Helsinki Finland Univ Helsinki Helsinki Finland Paijat Hame Cent Hosp Heart Ctr Lahti Finland Univ Autonoma Barcelona Hosp Santa Creu & St Pau Biomed Res Inst IIB St Pau Intens Cardiac Care UnitCardiol Dept Barcelona Spain Univ Hosp Brno Dept Internal Med & Cardiol Brno Czech Republic Helsinki Univ Hosp Dept Internal Med Lappeenranta Finland Univ Helsinki South Karelia Cent Hosp Lappeenranta Finland Hosp Sanitas CIMA Cardiol Dept Barcelona Spain Consorci Sanitari Integral Dept Intens Care Barcelona Spain Univ Copenhagen Rigshosp Dept Cardiol Copenhagen Denmark Inst Cardiol Intens Cardiac Therapy Clin Warsaw Poland Helsinki Univ Hosp Dept Emergency Med & Serv Helsinki Finland

Changes in QRS duration and pattern are regarded to reflect severe ischemia in acute coronary syndromes (ACS), and ventricular conduction blocks (VCBs) are recognized high-risk markers in both ACS and acute heart failure. Our aim was to evaluate the prevalence, temporal evolution, association with clinical and angiographic parameters, and impact on mortality of VCBs in ACS-related cardiogenic shock (CS). Data of 199 patients with ACS-related CS from a prospective multinational cohort were evaluated with electrocardiogram data from baseline and day 3. VCBs including left or right bundle branch block, right bundle branch block and hemiblock, isolated hemiblocks, and unspecified intraventricular conduction delay were assessed. Fifty percent of patients had a VCB at baseline;these patients were older, had poorer left ventricular function and had more often left main disease compared with those without VCB. One-year mortality was over 2-fold in patients with VCB compared with those without VCB (68% vs 32%, p<0.001). All types of VCBs at baseline were associated with increased mortality, and the predictive value of a VCB was independent of baseline variables and coronary angiography findings. Interestingly, 37% of the VCBs were transient, i.e., disappeared before day 3. However, 1-year mortality was much higher in these patients (69%) compared to patients with persistent (38%) or no VCB (15%, p<0.001). Indeed, a transient VCB was a strong independent predictor of 1-year mortality. In conclusion, our findings propose that any VCB in baseline electrocardiogram, even if transient, identifies very early patients at particularly high mortality risk in ACS-related CS. (C) 2018 Elsevier Inc. All rights reserved.

关键词： qrs interval acute heart failure Cardiogenic Shock Mortality Acute Coronary Syndrome Right Bundle-Branch Block Patients BASELINE reference variable

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Upscaling instantaneous to daily evapotranspiration using modelled daily shortwave radiation for remote sensing applications: an artificial neural network approach

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HYDROLOGY AND EARTH SYSTEM SCIENCES 2017年第1期21卷 197-215页

作者： Wandera, Loise Mallick, Kaniska Kiely, Gerard Roupsard, Olivier Peichl, Matthias Magliulo, Vincenzo Luxembourg Inst Sci & Technol Dept ERIN Remote Sensing & Ecohydrol Modeling Belvaux Luxembourg Univ Twente Dept ITC Water Resources Enschede Netherlands Univ Coll Cork Dept Civil & Environm Engn Cork Ireland Univ Coll Cork Environm Res Inst Cork Ireland CIRAD UMR Eco & Sols 2 Pl Viala Montpellier France CATIE Turrialba Cartago Costa Rica Swedish Univ Agr Sci Dept Forest Ecol & Management Umea Sweden CNR ISAFOM Naples Italy

Upscaling instantaneous evapotranspiration retrieved at any specific time-of-day (ETi) to daily evapotranspiration (ETd) is a key challenge in mapping regional ET using polar orbiting sensors. Various studies have unanimously cited the shortwave incoming radiation (R-S) to be the most robust reference variable explaining the ratio between ETd and ETi. This study aims to contribute in ETi upscaling for global studies using the ratio between daily and instantaneous incoming shortwave radiation (R-Sd/R-Si) as a factor for converting ETi to ETd. This paper proposes an artificial neural network (ANN) machine-learning algorithm first to predict R-Sd from R-Si followed by using the R-Sd / R-Si ratio to convert ETi to ETd across different terrestrial ecosystems. Using R-Si and R-Sd observations from multiple sub-networks of the FLUXNET database spread across different climates and biomes (to represent inputs that would typically be obtainable from remote sensors during the overpass time) in conjunction with some astronomical variables (e.g. solar zenith angle, day length, exoatmospheric shortwave radiation), we developed the ANN model for reproducing R-Sd and further used it to upscale ETi to ETd. The efficiency of the ANN is evaluated for different morning and afternoon times of day, under varying sky conditions, and also at different geographic locations. R-S-based upscaled ETd produced a significant linear relation (R-2 = 0.65 to 0.69), low bias (-0.31 to 0.56 MJ m(-2) d(-1);approx. 4 %), and good agreement (RMSE 1.55 to 1.86 MJ m(-2) d(-1);approx. 10 %) with the observed ETd, although a systematic overestimation of ETd was also noted under persistent cloudy sky conditions. Inclusion of soil moisture and rainfall information in ANN training reduced the systematic overestimation tendency in predominantly overcast days. An intercomparison with existing upscaling method at daily, 8-day, monthly, and yearly temporal resolution revealed a robust performance of the ANN-driven

关键词： Daily high temperature and high humidity drying short wave radiation Radiation evapotranspiration reference variable

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Can Matching-Adjusted Indirect Comparison Methods Mitigate Placebo Response Differences Among Patient Populations in Adjunctive Trials of Brivaracetam and Levetiracetam?

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CNS DRUGS 2017年第10期31卷 899-910页

作者： Swallow, Elyse Fang, Anna Signorovitch, James Plumb, Jonathan Borghs, Simon Anal Grp Inc 111 Huntington AveFloor 14 Boston MA USA UCB Pharma Allee Rech 60 B-1070 Brussels Belgium UCB Pharma Ltd 208 Bath Rd Slough SL1 3WE Berks England

Background and objective Patients with focal seizures recruited into adjunctive antiepileptic drug (AED) trials have become more refractory and severe over time;concurrently, placebo responses have increased. To attempt to account for heterogeneity among trials, propensity-score weighted patient-level data were used to indirectly compare placebo responses reported in brivaracetam and levetiracetam trials. Methods Patient-level data from randomised, placebo-controlled brivaracetam (recruited 2007-2014) and levetiracetam (1993-1998) trials were pooled. Consistent inclusion/exclusion criteria were applied and outcomes were defined consistently. Potentially confounding baseline characteristics were adjusted for using propensity score weighting. Weighting success was assessed using placebo response. Results In total, 707 and 473 active drug and 399 and 253 placebo patients comprised the brivaracetam and levetiracetam groups, respectively. Before weighting, several baseline variables were significantly different between groups;after weighting, prior vagal nerve stimulation, comorbid depression and co-morbid anxiety remained different. Before weighting, median seizure frequency reduction was 21.7 and 3.9% in the brivaracetam and levetiracetam placebo arms, respectively;after weighting, median reduction was 15.0 and 6.0%. The comparison of non-randomised groups could be biased by unobserved confounding factors and region of residence. Lifetime AED history was unavailable in the brivaracetam trials and excluded from analysis. Conclusions Placebo responses remained different between brivaracetam and levetiracetam trials after propensity score weighting, indicating the presence of residual confounding factors associated with placebo response in these trials. It therefore remains problematic to conduct reliable indirect comparisons of brivaracetam and levetiracetam given the current evidence base, which may apply to comparisons between other AED trials.

关键词： Trials Brivaracetam Propensity Score levetiracetam experimentation Placebos reference variable

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Long-term electrical stimulation of bed nucleus of stria terminalis for obsessive-compulsive disorder

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MOLECULAR PSYCHIATRY 2017年第6期22卷 931-934页

作者： Raymaekers, S. Vansteelandt, K. Luyten, L. Bervoets, C. Demyttenaere, K. Gabriels, L. Nuttin, B. Katholieke Univ Leuven Res Grp Psychiat Herestr 49 B-3000 Leuven Belgium Z ORG UPC KU Leuven Leuven Belgium Katholieke Univ Leuven Res Grp Psychol Learning & Expt Psychopathol Leuven Belgium Katholieke Univ Leuven Res Grp Expt Neurosurg & Neuroanat Leuven Belgium UZ Leuven Dept Neurosurg Leuven Belgium

We previously reported that bilateral electrical stimulation in the anterior limb of the internal capsule/bed nucleus of the stria terminalis (IC/BST) effectively reduces symptoms in severe treatment-resistant obsessive-compulsive disorder (OCD) patients. Here we used a linear mixed model to investigate the evolution of symptomatic and functional status of our patients (n=24) and examined if baseline variables could predict this evolution. Data were collected during routine, clinical psychiatric visits. Our analysis showed a long-term, sustained effect of electrical stimulation in the IC/BST. After a fast initial decline of OCD symptoms, these symptoms remain relatively stable. In addition, we found a strong ON/OFF effect of stimulation (e.g., due to battery depletion). Our data also show that it is not the surgical procedure but rather the electrical stimulation that drives the improvement in Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) scores. The Beck Depression Inventory (BDI) at baseline was the only predictor significantly related to the evolution of the Y-BOCS. A higher BDI at baseline seemed to be related to a smaller decrease of the Y-BOCS over time. In conclusion, electrical stimulation in the IC/BST has a fast and sustained effect on OCD and comorbid symptoms and functional status of patients.

关键词： Anxiety Disorders Level of function Nucleus of Stria Terminalis Stria terminalis Beck Depression Inventory Obsessive-Compulsive Disorder Electric Stimulation reference variable BASELINE

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Using Citizen Science Reports to Evaluate Estimates of Surface Precipitation Type

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BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY 2016年第2期97卷 187-193页

作者： Chen, Sheng Gourley, Jonathan J. Hong, Yang Cao, Qing Carr, Nicholas Kirstetter, Pierre-Emmanuel Zhang, Jian Flamig, Zac Univ Oklahoma Adv Radar Res Ctr Natl Weather Ctr Norman OK 73019 USA Univ Oklahoma Sch Civil Engn & Environm Sci Norman OK 73019 USA Univ Oklahoma NOAA Natl Severe Storms Lab Norman OK 73019 USA Univ Oklahoma Sch Meteorol Norman OK 73019 USA Enterprise Elect Corp Res & Innovat Enterprise AL USA Natl Weather Ctr Adv Radar Res Ctr Norman OK 73072 USA NOAA Natl Severe Storms Lab Norman OK 73069 USA Univ Oklahoma Cooperat Inst Mesoscale Meteorol Studies Adv Radar Res Ctr Natl Weather Ctr Norman OK USA

In meteorological investigations, the reference variable or ground truth typically comes from an instrument. This study uses human observations of surface precipitation types to evaluate the same variables that are estimated from an automated algorithm. The NOAA/National Severe Storms Laboratory's Multi-Radar Multi-Sensor (MRMS) system relies primarily on observations from the Next Generation Radar (NEXRAD) network and model analyses from the Earth System Research Laboratory's Rapid Refresh (RAP) system. Each hour, MRMS yields quantitative precipitation estimates and surface precipitation types as rain or snow. To date, the surface precipitation type product has received little attention beyond case studies. This study uses precipitation type reports collected by citizen scientists who have contributed observations to the meteorological Phenomena Identification Near the Ground (mPING) project. Citizen scientist reports of rain and snow during the winter season from 19 December 2012 to 30 April 2013 across the United States are compared to the MRMS precipitation type products. Results show that while the mPING reports have a limited spatial distribution (they are concentrated in urban areas), they yield similar critical success indexes of MRMS precipitation types in different cities. The remaining disagreement is attributed to an MRMS algorithmic deficiency of yielding too much rain, as opposed to biases in the mPING reports. The study also shows reduced detectability of snow compared to rain, which is attributed to lack of sensitivity at S band and the shallow nature of winter storms. Some suggestions are provided for improving the MRMS precipitation type algorithm based on these findings.

关键词： Snow Snowfall precipitation (meteorology) spatial distribution reporting reference variable winter season Winter rain

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Effect of Heart Rate and Use of Beta Blockers on Mortality After Heart Transplantation

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AMERICAN JOURNAL OF CARDIOLOGY 2016年第12期118卷 1916-1921页

作者： Ciarka, Agnieszka Lund, Lars H. Van Cleemput, Johan Voros, Gabor Droogne, Walter Vanhaecke, Johan Katholieke Univ Leuven Dept Cardiovasc Dis Leuven Belgium Karolinska Inst Dept Med Stockholm Sweden

Heart transplantation (HT) recipients may have tachycardia secondary to cardiac denervation. As higher heart rate predicts worse outcomes in cardiovascular disease, we hypothesized that tachycardia and nonuse of beta blockers are associated with increased mortality after HT. All patients who underwent HT at our institution from 1987 to 2010 were included. The association of heart rate 3 months after HT and beta-blocker use during follow-up to mortality was assessed using Kaplan Meier and multivariate Cox proportional hazards regression analyses adjusting for clinically relevant baseline variables. From 1987 to 2010, there were 493 HT. After excluding 29 who died within 3 months and 3 with follow-up <3 months, 461 HT recipients (50 +/- 2 years;20% women) were included. Over a follow-up of 12 +/- 7 years, selected important univariate predictors of post-HT mortality were older age, male gender, higher body mass index, ischemic cardiomyopathy, longer post-HT intensive care unit stay, and hospitalization and at 3 months, increased mean pulmonary artery pressure, right atrial pressure and pulmonary capillary occlusion pressure, higher heart rate, and nonuse of beta blockers during follow-up. In multivariate analysis, older ager, longer hospitalization, higher mean pulmonary artery pressure, higher heart rate at 3 months (hazard ratio 1.02 per beat, 95% confidence interval 1.008 to 1.035, p = 0.02) and nonuse of beta blockers (hazard ratio 1.43, 95% confidence interval 1.002 to 2.031, p <0.05) were associated with mortality. In conclusion, in a large single-center cohort of HT recipients, higher heart rate and nonuse of beta blockers were independently associated with higher mortality. (C) 2016 Elsevier Inc. All rights reserved.

关键词： Mortality Tachycardia Adrenergic beta-Antagonists Vital Signs Heart Transplantation right atrial pressure Heart Rate reference variable

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