Entropy-Based Measures for Person Fit in Item Response Theory.

This article introduces three new variants of entropy to detect person misfit (Ei, EMi , and EMRi ), and provides preliminary evidence that these measures are worthy of further investigation. Previously, entropy has been used as a measure of approximate data-model fit to quantify how well individuals are classified into latent classes, and to quantify the quality of classification and separation between groups in logistic regression models. In the current study, entropy is explored through conceptual examples and Monte Carlo simulation comparing entropy with established measures of person fit in item response theory (IRT) such as lz, lz*, U, and W. Simulation results indicated that EMi and EMRi were successfully able to detect aberrant response patterns when comparing contaminated and uncontaminated subgroups of persons. In addition, EMi and EMRi performed similarly in showing separation between the contaminated and uncontaminated subgroups. However, EMRi may be advantageous over other measures when subtests include a small number of items. EMi and EMRi are recommended for use as approximate person-fit measures for IRT models. These measures of approximate person fit may be useful in making relative judgments about potential persons whose response patterns do not fit the theoretical model.

Neuropsychological Outcomes in Extremely Preterm Preschoolers Exposed to Tiered Low Oxygen Targets: An Observational Study.

An observational study of neuropsychological outcomes at preschool age of tiered lowered oxygen (O2) saturation targets in extremely preterm neonates. We studied 111 three-year-olds born <28 weeks' gestational age. Fifty-nine participants born in 2009-2010 during a time-limited quality improvement initiative each received three-tiered stratification of oxygen rates (83-93% until age 32 weeks, 85-95% until age 35 weeks, and 95% after age 35 weeks), the TieredO2 group. Comparisons were made with 52 participants born in 2007-2008 when pre-initiative saturation targets were non-tiered at 89-100%, the Non-tieredO2 group. Neuropsychological domains included general intellectual, executive, attention, language, visuoperceptual, visual-motor, and fine and gross motor functioning. Descriptive and inferential analyses were conducted. Group comparisons were not statistically significant. Descriptively, the TieredO2 group had better general intellectual, executive function, visual-motor, and motor performance and the Non-tieredO2 group had better language performance. Cohen's d and confidence intervals around d were in similar direction and magnitude across measures. A large effect size was found for recall of digits-forward in participants born at 23 and 24 weeks' gestation, d=0.99 and 1.46, respectively. Better TieredO2 outcomes in all domains except language suggests that the tiered oxygen saturation target method is not harmful and merits further investigation through further studies. Benefit in auditory attention appeared greatest in those born at 23 and 24 weeks. Participants in the tiered oxygen saturation group also had fewer ventilation days and a lower incidence of bronchopulmonary dysplasia, perhaps explanatory for these neuropsychological outcomes at age 3.

Test of visuospatial construction: Validity evidence in extremely low birth weight and late preterm children at early school age.

The Test of Visuospatial Construction (TVSC), a measure of visuoconstruction that does not rely on upper extremity motor response or written production, was administered to extremely low birth weight (ELBW), late preterm (LPT), and term participants at preschool (n = 355) and kindergarten (n = 265) ages. TVSC showed statistically significant weak-to-moderate positive correlations (age 3: r = .118-.303; age 6: r = .138-.348) with Developmental VMI, Differential Ability Scales-II Copying, Matrices, and Pattern Construction subtests, Baron-Hopkins Board Test, and the Purdue Pegboard. One-way ANOVA indicated ELBW performed worse than Term (p = .044) on visuospatial construction at age 3 with a small-to-medium effect size (d = -0.43). No other statistically significant differences were found at age 3 on the TVSC (ELBW/LPT: p = .608, d = -0.17; LPT/Term: p = .116, d = -0.31). At age 6, ELBW participants performed worse than LPT participants (p = .027) and Term participants (p = .012); LPT participants did not differ from Term participants. Small effect sizes at age 3 (ELBW < LPT, d = -0.17; ELBW < Term, d = -0.43) were notably larger at age 6 (ELBW < LPT, d = -0.42; ELBW < Term, d = -0.53). Important practical differences showing LPT participants performed below Term participants (d = -0.31) at age 3 were no longer evident at age 6 (d = -0.097). These findings provide preliminary evidence of TVSC validity supporting its use to detect neuropsychological impairment and to recommend appropriate interventions in young preterm children.

An Entropy-Based Measure for Assessing Fuzziness in Logistic Regression.

This article introduces an entropy-based measure of data-model fit that can be used to assess the quality of logistic regression models. Entropy has previously been used in mixture-modeling to quantify how well individuals are classified into latent classes. The current study proposes the use of entropy for logistic regression models to quantify the quality of classification and separation of group membership. Entropy complements preexisting measures of data-model fit and provides unique information not contained in other measures. Hypothetical data scenarios, an applied example, and Monte Carlo simulation results are used to demonstrate the application of entropy in logistic regression. Entropy should be used in conjunction with other measures of data-model fit to assess how well logistic regression models classify cases into observed categories.

Assessing Spurious Interaction Effects in Structural Equation Modeling: A Cautionary Note.

Several studies have stressed the importance of simultaneously estimating interaction and quadratic effects in multiple regression analyses, even if theory only suggests an interaction effect should be present. Specifically, past studies suggested that failing to simultaneously include quadratic effects when testing for interaction effects could result in Type I errors, Type II errors, or misleading interactions. Research investigating this issue has been limited to multiple regression models. Contrarily, structural equation modeling is a more appropriate analysis when hypotheses include latent variables. The current study utilized Monte Carlo simulation to investigate whether quadratic effects should be included in the latent variable interaction model. Consistent with previous research, it was found that including latent variable quadratic effects in the model successfully reduced the frequency of spurious interaction effects but at a cost of low power to detect true interaction effects, inaccurate parameter estimates, inaccurate standard error estimates, and reduced convergence rates. Based on findings from the current study, we recommend that researchers hypothesizing interactions between latent variables should test for these relations using the latent variable interaction model rather than the interaction quadratic model. If researchers are concerned about spurious interactions, then they may want to consider including quadratic effects in the model, provided that they have sample sizes of at least 500 and high indicator reliability. We caution all researchers to base higher order effects models on theory.

Developmental normative data for the Baron-Hopkins Board test of spatial location memory.

Developmentally appropriate domain-specific tests with strong psychometric properties for preschoolers are lacking and infrequently developed. Baron's modification of the Hopkins Board test (B-HB) to assess spatial location learning and recall in 3- and 6-year-old children has shown promise in the study of young children born prematurely. Current study data were analyzed on 172 typically developing children at age 3 years and 193 at age 6 years, born at term (≥ 37 weeks; ≥ 2500 grams). Statistically significant gender differences were found and data stratification of T-scores and percentile ranks are provided for each of the eight B-HB measures. The B-HB's strong interrater reliability (99.5%), low-to-moderate test-retest reliability across the 3-year age span, Pearson correlations showing criterion validity, and differential functioning from other selective attention and visuospatial/visuoperceptual tests provide initial normative data for this novel measure of spatial location memory in young children.

Latent mean differences in executive function in at-risk preterm children: the delay-deficit dilemma.

OBJECTIVE: To examine whether a one-factor executive function (EF) model fit data for three groups of children differing in birth criteria (extremely low birth weight [ELBW], late preterm [LPT], and Term) at each of two chronological ages, 3 and 6 years, and whether the latent mean amount of EF differed. METHODS: A retrospective observational cohort study of 1,079 participants; 668 aged 3 years born 2000-2009 (93 ELBW, 398 LPT, and 177 Term) and 411 aged 6 years born 1998-2006 (126 ELBW, 102 LPT, and 183 Term). Latent means analysis was conducted using five indicators for EF: noun fluency, action-verb fluency, similarities reasoning, matrices reasoning, and working memory. RESULTS: A one-factor model had acceptable fit for all groups (RMSEA<.06, CFI >0.95, SRMR <0.08). Statistically significant between-groups differences were found for all comparisons except one; there were no statistically significant differences between LPT-Term at age 6. At age 3, ELBW was 0.98 and 1.70 SD below LPT and Term, respectively; LPT was 0.61 SD below Term. At age 6, ELBW was 0.70 and 0.78 SD below LPT and Term, respectively; LPT was 0.10 SD below Term. CONCLUSIONS: Executive deficit identified early in development after preterm birth could represent a transient developmental delay likely to resolve at older age or a more subtle adverse effect likely to persist over the life span. Study at multiple age points should assist in resolving this dilemma, which has important implications for early age neuropsychological screening and intervention.

Subtle adverse effects of late preterm birth: a cautionary note.

OBJECTIVE: Late preterm birth increases risk of perinatal health complications that typically resolve in the short term. Thus, early elective delivery is thought to have no long-term effects. Whether there is increased risk of adverse psychological outcomes that emerge in early childhood remains uncertain. METHOD: The authors compared intellectual, neuropsychological, and behavioral outcomes in 278 late preterm (35-36 weeks) and 192 term (37-41 weeks) participants at age 3 years recruited from a single center, using analysis of variance, analysis of covariance, and regression analyses. Late-preterm participants were further subgrouped by admission to the neonatal intensive care unit (NICU; n = 202) or a well-baby unit (n = 76). Analyses included 132 additional participants born at 34 weeks. RESULTS: Late preterm participants had lower general conceptual ability (GCA; i.e., IQ); lower verbal, nonverbal, spatial, visuomotor, and dexterity scores; and poorer adaptability than term participants (p < .01; -0.271 to -0.511 SDs). Gestational age was the most important predictor of these subtle outcomes, not neonatal medical variables; no differences were found between NICU admitted and nonadmitted late-preterm groups. A 1-week increase in gestational age resulted in a 1.941 increase in GCA (d = 0.127). CONCLUSION: Gestation is a developmental continuum best not interrupted during its natural course. Our data showing subtle but appreciable effects have important implications for obstetric practice and parental decision making regarding early elective delivery in the absence of maternal or fetal adverse indications.

Latent mean comparisons on the BRIEF in preterm children: parent and teacher differences.

Executive function is a heterogeneous construct applied to cognitive capacities that together enable individuals to effectively engage in activities toward a purposive goal. Children born at extremely low birth weight (ELBW) are at risk of executive dysfunction on performance-based measures. In natural contexts, executive function may be described using such parental and teacher questionnaires as the Behavior Rating Inventory of Executive Function (BRIEF). This study examined the factor structure of the BRIEF-parent form in 124 ELBW children and of the BRIEF-teacher form in 90 ELBW children. Although our data showed that the fit of a two-factor structure was adequate for the parent report, a three-factor model provided advantages over the two-factor model across all fit indices and best characterized the data. For teacher report, these data supported a three-factor but not a two-factor model. Using the three-factor model for both groups of informants, we compared parent and teacher reports (n = 90 pairs) between the three identified latent variables. Parents reported significantly more difficulty with Emotional Regulation (p < .05), and teachers reported significantly more difficulty with Behavioral Regulation (p < .05). No significant differences were found between parent and teacher reports for Metacognition.

In vitro fertilization and late preterm preschoolers' neuropsychological outcomes: the PETIT study.

OBJECTIVE: In vitro fertilization (IVF) is considered a generally safe procedure, although associated with a higher incidence of preterm birth. The literature is inconsistent about the psychological impact of IVF, and we found no reports about outcome in late preterm (LPT) children. Our objective was to study neuropsychological and behavioral outcomes in a cohort of preschoolers born LPT between 2004 and 2007. STUDY DESIGN: Participants were 397 LPT children (mean age, 3.8 years) conceived assisted by IVF (n = 105) or non-IVF (n = 292). Standardized performance-based tests of general conceptual ability (intelligence quotient), executive function, focused/selective attention, visual-spatial perception, visual-motor skill, manual dexterity, learning, and memory were administered. Parents completed behavioral and executive function questionnaires. RESULTS: IVF group characteristics included older maternal age (P < .001), lower birthweight (P < .001), and higher maternal education (P < .001). No main-effect significant group differences were found for any variable after controlling for these variables. However, sex differences were demonstrated for the neuropsychological variables in copying (P > .001), nonverbal reasoning (P = .001), manual dexterity (P = .001), and inhibitory capacity (P = .006), all favoring girls. CONCLUSION: Birth following IVF-assisted conception did not increase the risk of intellectual, neuropsychological, or behavioral deficit in LPT preschoolers. As shown in earlier gestational-age participants, girls have selective advantages. These findings should be reassuring for parents who conceive through IVF and deliver infants 1-3 weeks before term gestational age. Future study of these children at elementary school age may detect subtle impairments not yet apparent at age 3 years.

A comparison of methods for estimating quadratic effects in nonlinear structural equation models.

Two Monte Carlo simulations were performed to compare methods for estimating and testing hypotheses of quadratic effects in latent variable regression models. The methods considered in the current study were (a) a 2-stage moderated regression approach using latent variable scores, (b) an unconstrained product indicator approach, (c) a latent moderated structural equation method, (d) a fully Bayesian approach, and (e) marginal maximum likelihood estimation. Of the 5 estimation methods, it was found that overall the methods based on maximum likelihood estimation and the Bayesian approach performed best in terms of bias, root-mean-square error, standard error ratios, power, and Type I error control, although key differences were observed. Similarities as well as disparities among methods are highlight and general recommendations articulated. As a point of comparison, all 5 approaches were fit to a reparameterized version of the latent quadratic model to educational reading data.