Using generalizability theory with continuous latent response variables.

In this article, we illustrate ways in which generalizability theory (G-theory) can be used with continuous latent response variables (CLRVs) to address problems of scale coarseness resulting from categorization errors caused by representing ranges of continuous variables by discrete data points and transformation errors caused by unequal interval widths between those data points. The mechanism to address these problems is applying structural equation modeling (SEM) as a tool in deriving variance components needed to estimate indices of score consistency and validity. Illustrations include quantification of multiple sources of measurement error, use of non-nested and nested designs, derivation of indices of consistency for norm- and criterion-referenced interpretation of scores, estimation of effects when changing measurement procedures and designs, and disattenuation of correlation coefficients for measurement error.

Using Generalizability Theory to Disattenuate Correlation Coefficients for Multiple Sources of Measurement Error.

Over the years, research in the social sciences has been dominated by reporting of reliability coefficients that fail to account for key sources of measurement error. Use of these coefficients, in turn, to correct for measurement error can hinder scientific progress by misrepresenting true relationships among the underlying constructs being investigated. In the research reported here, we addressed these issues using generalizability theory (G-theory) in both traditional and new ways to account for the three key sources of measurement error (random-response, specific-factor, and transient) that affect scores from objectively scored measures.

Interchangeability of Results From Computerized and Traditional Administration of the BIDR: Convenience Can Match Reality.

Although interchangeability of results across computer and paper modes of administration is commonly assumed, recent meta-analyses and individual studies continue to reveal mean differences in scores for measures of socially desirable responding (SDR). Results from these studies have also failed to include new methods of scoring and crucial aspects of scaling, reliability, validity, and administration emphasized in professional standards for assessment that are essential in establishing equivalence. We addressed these shortcomings in a comprehensive, repeated measures investigation for 6 ways of scoring the Balanced Inventory of Desirable Responding (BIDR), one of the most frequently administered companion measures of SDR in research and practice.

Practical Applications of Generalizability Theory for Designing, Evaluating, and Improving Psychological Assessments.

In this article, we illustrate how generalizability theory (G-theory) can extend traditional assessment methods for designing, improving, and evaluating results from both objectively and subjectively scored measures of individual differences. Our illustrations include quantification of multiple sources of measurement error, derivation of unique indexes of consistency for norm- and criterion-referenced interpretations of scores, estimation of score consistency when changing a measurement procedure, and disattenuation of correlation coefficients for measurement error. We also expand G-theory analyses beyond the item level to include parcels and split measures and highlight linkages among G-theory, classical test theory, and structural equation modeling.

Applications of generalizability theory and their relations to classical test theory and structural equation modeling.

Although widely recognized as a comprehensive framework for representing score reliability, generalizability theory (G-theory), despite its potential benefits, has been used sparingly in reporting of results for measures of individual differences. In this article, we highlight many valuable ways that G-theory can be used to quantify, evaluate, and improve psychometric properties of scores. Our illustrations encompass assessment of overall reliability, percentages of score variation accounted for by individual sources of measurement error, dependability of cut-scores for decision making, estimation of reliability and dependability for changes made to measurement procedures, disattenuation of validity coefficients for measurement error, and linkages of G-theory with classical test theory and structural equation modeling.

Development of the Classism Attitudinal Profile (CAP).

Despite increasing interest in social class issues within psychology, there are a limited number of theoretically rooted instruments to measure subjective social class, particularly related to classism. The purpose of this project was to create a brief, psychometrically sound, and theoretically grounded instrument, called the Classism Attitudinal Profile (CAP), designed to measure 2 aspects of classism (downward and upward) defined in Liu's (2011) Social Class World View Model Revised (SCWM-R). Data from 2 independent samples (n = 608, n = 199) provided evidence in support of the consistency (alpha and test-retest coefficients), anticipated factor structure, and convergent/discriminant validity of CAP subscale scores.

Using G-Theory to Enhance Evidence of Reliability and Validity for Common Uses of the Paulhus Deception Scales.

We applied a new approach to Generalizability theory (G-theory) involving parallel splits and repeated measures to evaluate common uses of the Paulhus Deception Scales based on polytomous and four types of dichotomous scoring. G-theory indices of reliability and validity accounting for specific-factor, transient, and random-response measurement error supported use of polytomous over dichotomous scores as contamination checks; as control, explanatory, and outcome variables; as aspects of construct validation; and as indexes of environmental effects on socially desirable responding. Polytomous scoring also provided results for flagging faking as dependable as those when using dichotomous scoring methods.

Pharmacokinetic interaction between pyronaridine-artesunate and metoprolol.

The objectives of this study were to characterize any drug-drug interaction between the antimalarial Pyramax (pyronaridine-artesunate [PA]) and the CYP2D6 probe substrate metoprolol and to assess the safety of 60-day or 90-day PA redosing, particularly with regard to liver biochemistry parameters. Healthy adult subjects were randomized to arm A (n = 26) or arm B (n = 30), with the arm A subjects administered 100 mg metoprolol tartrate in the first period, 100 mg metoprolol tartrate with the third of three daily doses of PA in the second period, and three daily doses of PA alone in the 90-day redosing period. The arm B subjects received the three-day PA regimen in the first period, with redosing of the regimen after 60 days in the second period.

Mass balance and metabolism of the antimalarial pyronaridine in healthy volunteers.

This was a single dose mass balance and metabolite characterization study of the antimalarial agent pyronaridine. Six healthy male adults were administered a single oral dose of 720 mg pyronaridine tetraphosphate with 800 nCi of radiolabeled (14)C-pyronaridine. Urine and feces were continuously collected through 168 h post-dose, with intermittent 48 h collection periods thereafter through 2064 h post-dose.

Effects of body size and gender on the population pharmacokinetics of artesunate and its active metabolite dihydroartemisinin in pediatric malaria patients.

Despite the important role of the antimalarial artesunate and its active metabolite dihydroartemisinin (DHA) in malaria treatment efforts, there are limited data on the pharmacokinetics of these agents in pediatric patients. This study evaluated the effects of body size and gender on the pharmacokinetics of artesunate-DHA using data from pediatric and adult malaria patients. Nonlinear mixed-effects modeling was used to obtain a base model consisting of first-order artesunate absorption and one-compartment models for artesunate and for DHA.

Comparison of brain structural variables, neuropsychological factors, and treatment outcome in early-onset versus late-onset late-life depression.

Objective: To compare differences in gray matter volumes, white matter and subcortical gray matter hyperintensities, neuropsychological factors, and treatment outcome between early- and late-onset late-life depressed (LLD) subjects.

Methods: We conducted a prospective, nonrandomized, controlled trial at the outpatient clinics at Washington University and Duke University on 126 subjects, aged 60 years or older, who met Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for major depression, scored 20 or more on the Montgomery-Asberg Depression Rating Scale (MADRS), and received neuropsychological testing and magnetic resonance imaging. Subjects were excluded for cognitive impairment or severe medical disorders.

Treatment course with antidepressant therapy in late-life depression.

Objective: In order to assess the effect of gray matter volumes and cortical thickness on antidepressant treatment response in late-life depression, the authors examined the relationship between brain regions identified a priori and Montgomery-Åsberg Depression Rating Scale (MADRS) scores over the course of an antidepressant treatment trial.

Method: In a nonrandomized prospective trial, 168 patients who were at least 60 years of age and met DSM-IV criteria for major depression underwent MRI and were enrolled in a 12-week treatment study. Exclusion criteria included cognitive impairment or severe medical disorders.

Alzheimer's disease multiple intervention trial (ADMIT): study protocol for a randomized controlled clinical trial.

Background: Given the current lack of disease-modifying therapies, it is important to explore new models of longitudinal care for older adults with dementia that focus on improving quality of life and delaying functional decline. In a previous clinical trial, we demonstrated that collaborative care for Alzheimer's disease reduces patients' neuropsychiatric symptoms as well as caregiver stress. However, these improvements in quality of life were not associated with delays in subjects' functional decline.

Drug-drug interaction analysis of pyronaridine/artesunate and ritonavir in healthy volunteers.

A multiple dose, parallel group study was conducted to assess for a drug-drug interaction between the pyronaridine/artesunate (PA) combination antimalarial and ritonavir. Thirty-four healthy adults were randomized (1:1) to receive PA for 3 days or PA with ritonavir (100 mg twice daily for 17 days, PA administered on Days 8-10). Pharmacokinetic parameters for pyronaridine, artesunate, and its active metabolite dihydroartemisinin (DHA) were obtained after the last PA dose and for ritonavir on Days 1 and 10.

The role of bimatoprost eyelash gel in chemotherapy-induced madarosis: an analysis of efficacy and safety.

Objectives: Breast cancer patients suffer from madarosis (loss of eyelashes) due to chemotherapy side effects. An effective treatment or prevention for alopecia or madarosis induced by chemotherapy is not available. Potential drug side effects of bimatoprost solution include increased eyelash length, darkness, and number.

Review of the clinical pharmacokinetics of artesunate and its active metabolite dihydroartemisinin following intravenous, intramuscular, oral or rectal administration.

Artesunate (AS) is a clinically versatile artemisinin derivative utilized for the treatment of mild to severe malaria infection. Given the therapeutic significance of AS and the necessity of appropriate AS dosing, substantial research has been performed investigating the pharmacokinetics of AS and its active metabolite dihydroartemisinin (DHA). In this article, a comprehensive review is presented of AS clinical pharmacokinetics following administration of AS by the intravenous (IV), intramuscular (IM), oral or rectal routes.

A histological analysis of the Müllerectomy: redefining its mechanism in ptosis repair.

Background: The goals of this study were to determine whether the surgical target amount of Müller's muscle removed is consistent with the histological amount obtained, to assess the clinical outcome of ptosis repair based on these amounts, and to evaluate the role of the levator aponeurosis in the procedure.

Methods: The Müllerectomy procedure was performed on eight eyelids of four cadavers and eight eyelids of seven patients (six unilateral, one bilateral). Histologically, the dimensions of the Müller and levator muscles were measured in the specimens removed.

Population pharmacokinetics of artesunate and dihydroartemisinin in pregnant and non-pregnant women with malaria.

Background: The World Health Organization endorses the use of artemisinin-based combination therapy for treatment of acute uncomplicated falciparum malaria in the second and third trimesters of pregnancy. However, the effects of pregnancy on the pharmacokinetics of artemisinin derivatives, such as artesunate (AS), are poorly understood. In this analysis, the population pharmacokinetics of oral AS, and its active metabolite dihydroartemisinin (DHA), were studied in pregnant and non-pregnant women at the Kingasani Maternity Clinic in the DRC.

Development of a community mobility skills course for people who use mobility devices.

Objective: We assessed mobility device skills in a lived-in environment on a community mobility skills course (CMSC) and related those skills to previously demonstrated skills in a controlled environment on an inside mobility skills course (IMSC).

Method: Six mobility device users were selected from 91 adults who had previously completed the IMSC. Each of the following device groups was represented: power wheelchair, manual wheelchair, scooter, cane, crutch, and walker.

Enhanced enlargement of silicone ocular prostheses achieved by silicone gel (MED-361).

Recently, silicone prostheses have been used instead of acrylic ocular prostheses. The authors sought to assess the ability of silicone gel to facilitate the growth of an ocular silicone prosthesis and to determine the best application modality to achieve maximal possible growth. Two ocular prostheses with similar baseline dimensions and contour were used for comparison of growth environment.

Cosmetic surgery survey of american society of oculoplastic and reconstructive surgery members and a 6-year comparison.

Purpose: To examine the current cosmetic practices of American Society of Oculoplastic and Reconstructive Surgery members using a survey and compare those results with a similar survey that was performed 6 years prior, and to determine the types and breadth of cosmetic procedures that are currently performed within the field of ophthalmic plastic and reconstructive surgery.

Methods: A 49-question survey was sent to members of American Society of Oculoplastic and Reconstructive Surgery by post mail and/or electronic mail in 2007. The questions covered surgeon demographics, cosmetic practice design, and preferences for aesthetic procedures and commercial equipment and products.

Analysis of the anatomic changes of the aging facial skeleton using computer-assisted tomography.

Purpose: The bony skeleton serves as the scaffolding for the soft tissues of the face; however, age-related changes of bony morphology are not well defined. This study sought to compare the anatomic relationships of the facial skeleton and soft tissue structures between young and old men and women.

Methods: A retrospective review of CT scans of 100 consecutive patients imaged at Duke University Medical Center between 2004 and 2007 was performed using the Vitrea software package.

The allocation of time in decision-making.

We study the allocation of time across decision problems. If a decision-maker (1) has noisy estimates of value, (2) improves those estimates the longer he or she analyzes a choice problem, and (3) allocates time optimally, then the decision-maker should spend less time choosing when the difference in value between two options is relatively large. To test this prediction we ask subjects to make 27 binary incentive-compatible intertemporal choices, and measure response time for each decision.

Influence of a Consumer-Directed Personal Assistance Services Program on the lives of persons with mobility impairments.

Objective: To examine the effects of a consumer-directed personal assistance services (CDPAS) program on the lives of persons with disabilities.

Methods: Thirteen individuals receiving paid agency-directed PAS services before enrollment in a CDPAS program (Agency Group) and 40 individuals receiving only unpaid PAS before enrollment (Informal Group) participated in this prospective study. In-home interviews were conducted just prior to CDPAS enrollment and again 6 months after CDPAS enrollment.

Intraocular pressure change in orbital disease.

Intraocular pressure change has been found concurrent with many orbital pathologies, particularly those involving proptosis. The objective of this review is to offer an inclusive classification of orbital disease-related intraocular pressure change, not only for oculoplastics and glaucoma specialists, but also for general ophthalmologists. Various orbital conditions associated with increased intraocular pressure and glaucoma are comprehensively summarized, and pathophysiology, clinical manifestations, and treatment options of these diseases are discussed.