Validity and reliability of the Caregiver Reaction Assessment scale among primary informal caregivers for older persons in Singapore

Previous studies evaluating the validity and reliability of the Caregiver Reaction Assessment (CRA) scale (24 items; five subscales: schedule, health, finances, family support, and esteem) in different countries are not fully congruent. This article assesses the validity and reliability of the CRA among informal caregivers of older persons in Singapore. Data from a national survey of 1190 primary informal caregivers of Singaporeans aged ≥75 years with ≥1 activity of daily living limitation was analyzed. Fit of the five-factor model was tested in half of the sample using confirmatory factor analysis (CFA) and the other half subjected to exploratory factor analysis (EFA). The CRA was modified accordingly and again subjected to CFA. The CRA's measurement equivalence/invariance (ME/I) across language of administration (Chinese/English/Malay) was assessed. CFA showed a poor fit for the five-factor model. EFA suggested the presence of four factors, three items to have neither sufficient nor unique factor loadings and items on two of the subscales to load on a single factor. CFA of the ‘modified’ CRA (21 items; four subscales: schedule and health, finances, family support, and esteem) suggested a better fit for the four-factor model than for the five-factor model. ME/I analysis supported partial invariance of the CRA across language of administration. The CRA scale should be assessed for relevance in Asian settings. With the suggested modifications, it is suitable for assessing negative and positive effects of caregiving among informal caregivers of older persons with activity limitations in Singapore.     

Principal components analysis of obsessive-compulsive disorder symptoms in children and adolescents.

BACKGROUND: Obsessive-compulsive disorder (OCD) has a broadly diverse clinical expression that may reflect etiologic heterogeneity. Several adult studies have identified consistent symptom dimensions of OCD. The purpose of this study was to conduct an exploratory principal components analysis of obsessive-compulsive (OC) symptoms in children and adolescents with OCD to identify improved phenotypes for future studies. METHODS: This study examined lifetime occurrence of OC symptoms included in the 13 symptom categories of the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and the Children's Yale-Brown Obsessive-Compulsive Scale (CY-BOCS). Principal components analysis with promax rotation was performed on 231 children and adolescents with OCD and compared with results of similar adult studies. RESULTS: A four-factor solution emerged explaining 59.8% of symptom variance characterized by 1) symmetry/ordering/repeating/checking; 2) contamination/cleaning/aggressive/somatic; 3) hoarding; and 4) sexual/religious symptoms. All factors included core symptoms that have been consistently observed in adult studies of OCD. CONCLUSIONS: In children and adolescents, OCD is a multidimensional disorder. Symptom dimensions are predominantly congruent with those described in similar studies of adults with OCD, suggesting fairly consistent covariation of OCD symptoms through the developmental course. Future work is required to understand changes in specific symptom dimensions observed across the life span.     

Psychometric properties of the Screen for Child Anxiety Related Emotional Disorders (SCARED) in the general adolescent population

OBJECTIVE: This study examined the psychometric properties of the Screen for Child Anxiety Related Emotional Disorders (SCARED) in a large sample of adolescents from the general population. METHOD: In 2001, 1,340 junior high and high school adolescents in the Netherlands completed the SCARED. The SCARED is a questionnaire that purports to measure five child and adolescent anxiety symptom dimensions. The factor structure of the SCARED was investigated by means of confirmatory factor analyses that were conducted for males and females, early (10-13 years) and middle (14-18 years) adolescent groups, and for Dutch and ethnic minorities. Analyses of variance were carried out to compare mean scores for the various groups. RESULTS: The five-factor structure of the SCARED not only had the best fit for the general adolescent population but also for the age, gender, and ethnic groups. It was also found that the SCARED scores of the adolescent subgroups differed from one another in agreement with previous studies on adolescent anxiety disorder symptoms. CONCLUSIONS: The findings of this study support the claim that the SCARED has a five-factor structure. The usefulness of the SCARED was also demonstrated.     

Further development of YBOCS dimensions in the OCD Collaborative Genetics study: symptoms vs. categories

Despite progress in identifying homogeneous subphenotypes of obsessive-compulsive disorder (OCD) through factor analysis of the Yale Brown Obsessive-Compulsive Scale Symptom Checklist (YBOCS-SC), prior solutions have been limited by a reliance on presupposed symptom categories rather than discrete symptoms. Furthermore, there have been few attempts to evaluate the familiality of OCD symptom dimensions. The purpose of this study was to extend prior work by this collaborative group in category-based dimensions by conducting the first-ever exploratory dichotomous factor analysis using individual OCD symptoms, comparing these results to a refined category-level solution, and testing the familiality of derived factors. Participants were 485 adults in the six-site OCD Collaborative Genetics Study, diagnosed with lifetime OCD using semi-structured interviews. YBOCS-SC data were factor analyzed at both the individual item and symptom category levels. Factor score intraclass correlations were calculated using a subsample of 145 independent affected sib pairs. The item- and category-level factor analyses yielded nearly identical 5-factor solutions. While significant sib-sib associations were found for four of the five factors, Hoarding and Taboo Thoughts were the most robustly familial (r ICC>or=0.2). This report presents considerable converging evidence for a five-factor structural model of OCD symptoms, including separate factor analyses employing individual symptoms and symptom categories, as well as sibling concordance. The results support investigation of this multidimensional model in OCD genetic linkage studies.     

Factor analysis of the Yale-Brown Obsessive Compulsive Scale in a family study of obsessive-compulsive disorder

Our objective in this study was to determine whether symptoms of obsessive-compulsive disorder (OCD) cluster into groups that can usefully subclassify OCD. Psychiatrists or psychologists interviewed 221 subjects using the Lifetime Anxiety Version of the Schedule for Affective Disorders and Schizophrenia (SADS-LA) for the diagnosis of DSM-IV disorders, and the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) for OCD symptoms. We analyzed 16 symptom categories from the Y-BOCS using exploratory factor analysis to identify latent symptom dimensions. The relationship between these symptom dimensions and clinical characteristics and familiality was investigated. A four-factor model emerged as the best classification of OCD symptoms in the Y-BOCS. These factors were labeled Pure Obsessions, Contamination, Symmetry/Order, and Hoarding. The contamination factor was least likely to be associated with other Axis I disorders. Whereas no significant relationship was found between the factor scores of probands and the presence of OCD in their first-degree relatives, the Symmetry/Order and Hoarding factors did breed true. Hoarding was found to predict poorer treatment response. A four-factor classification of OCD features best describes the symptom patterns of a sample of patients with OCD. There were specific clinical correlates for these factors, and significant intrafamilial sib-sib correlations were found for the Symmetry/Order and Hoarding factors.     

Obsessive-compulsive disorder symptom dimensions show specific relationships to psychiatric comorbidity

The goals of this study were to examine relationships among symptom categories in obsessive-compulsive disorder (OCD), to establish OCD symptom dimensions by factor- and cluster-analytic analyses, and to explore associations between OCD symptom dimensions and comorbid neuropsychiatric conditions. A total of 317 OCD participants underwent a systematic diagnostic interview using the Structured Clinical Interview for DSM-IV. OCD symptoms assessed by the Yale-Brown Obsessive-Compulsive Scale Symptom Checklist (N=169) and by the Thoughts and Behaviors Inventory (N=275) were subjected to factor and cluster analyses. An identical four-factor solution emerged in two different data sets from overlapping samples, in agreement with most smaller factor-analytic studies employing the YBOCS checklist alone. The cluster analysis confirmed the four-factor solution and provided additional information on the similarity among OCD symptom categories at five different levels. OCD symptom dimensions showed specific relationships to comorbid psychiatric disorders: Factor I (aggressive, sexual, religious and somatic obsessions, and checking compulsions) was broadly associated with comorbid anxiety disorders and depression; Factor II (obsessions of symmetry, and repeating, counting and ordering/arranging compulsions) with bipolar disorders and panic disorder/agoraphobia; and Factor III (contamination obsessions and cleaning compulsions) with eating disorders. Factors I and II were associated with early onset OCD. This study encourages the use of cluster analyses as a supplementary method to factor analyses to establish psychiatric symptom dimensions. The frequent co-occurrence of OCD with other psychiatric disorders and the relatively specific association patterns between OCD symptom dimensions and comorbid disorders support the importance of OCD subtyping for treatment, genetic, and other research studies of this heterogeneous disorder.     

A cross-national factor analytic comparison of three models of PANSS symptoms in schizophrenia

The 30-item Positive and Negative Syndrome Scale (PANSS) is used worldwide in the assessment of symptom severity in schizophrenia. The present study uses confirmatory factor analysis (CFA) to compare three different factorial models and to evaluate the best-fitting representation of schizophrenia symptom structure on the PANSS across four samples of patients diagnosed with schizophrenia from the US (the CATIE schizophrenia trial), São Paulo, Brazil, and from Beijing and Changsha, China. We examine the goodness of fit of several previously proposed models. The traditional trifactorial model for the PANSS and two five-factor models were evaluated using absolute and incremental indices. Single group CFA found that the five-factor model proposed by NIMH researchers based on an extensive literature review demonstrates the best fit in each of the four samples. This model used 20 of the 30 PANSS items grouped into five factors: positive, negative, disorganized, excited, and depressed symptoms. Subgroups defined by age, gender, nationality, hospitalization status, and severity of illness also did not differ in overall symptom structure as assessed by several standard indices. Our findings suggest that the five factor NIMH model showed the best representation among all four samples from different countries and potentially contrasting cultures.     

The subscale structure of the Inventory of Depressive Symptomatology Self Report (IDS-SR) in older persons

BackgroundUsing symptom dimensions may be more effective than using categorical subtypes when investigating clinical outcome and underlying mechanisms of late-life depression. Therefore, this study aims to identify both the factor and subscale structure of late-life depression underlying the Inventory of Depressive Symptomatology Self Report (IDS-SR) in older persons.MethodIDS-SR data of 423 participants in the Netherlands Study of Depression in Older Persons (NESDO) were analyzed by exploratory (EFA) and confirmatory factor analysis (CFA). The best-fitting factor solution in a group of older persons with a major depressive disorder diagnosis in the last month (n = 229) was replicated in a control group of older persons with no or less severe depression (n = 194). Multiple group (MG-CFA) was performed to evaluate generalizability of the best-fitting factor solution across subgroups, and internal consistency coefficients were calculated for each factor.ResultsEFA and CFA show that a 3-factor model fits best to the data [comparative fit index (CFI) = 0.98; Tucker Lewis Index (TLI) = 0.99; and root mean square error of approximation (RMSEA) = 0.052], consisting of a ‘mood’, ‘motivation’ and ‘somatic’ factor with adequate internal consistencies (alpha coefficient 0.93, 0.83 and 0.70, respectively). MG-CFA shows a structurally similar factor model across subgroups.ConclusionThe IDS-SR can be used to measure three homogeneous symptom dimensions that are specific to older people. Application of these dimensions that may serve as subscales of the IDS-SR may benefit both clinical practice and scientific research.     

Exploratory Structural Equation Modeling Analysis of the Social Network Site Use Motives Scale

Objective Social Network Site Use Motives Scale (SUMS) was developed under the assumption that it consists of six factors, but only four factors were extracted as a result of Exploratory Factor Analysis. The goal of the present study was to investigate whether SUMS consists of four or six factors using Confirmatory Factor Analysis (CFA) and Exploratory Structural Equation Modeling (ESEM) approach. Methods A Korean college student sample (n=600; mean age, 21 years; 58% female) filled out the SUMS and the Social Network Site Addiction Proneness Scale. CFA and ESEM were used to assess the factor structure of the SUMS. ResultsResults indicated that a four-factor solution to the SUMS had inadequate fit in the sample examined using both CFA and ESEM and a six-factor solution to the SUMS had insufficient fit using CFA, whereas fit was optimal using ESEM for the six-factor model. In addition, the scale showed adequate convergent validity and reliability. Conclusion These findings support the six-factor model of SNS use motives and suggest that ESEM is a more appropriate method than CFA for examining the factor structure of the SUMS. The results displayed the usefulness of the ESEM framework in the investigation of use motives.     

The contribution of guilt sensitivity in the prediction of obsessive-compulsive disorder symptom dimensions: Replication and extension

BackgroundObsessive-compulsive disorder (OCD) is associated with particular cognitive processes, such as beliefs about the importance of intrusive thoughts. The present study examined the explanatory power of guilt sensitivity to OCD symptom dimensions after controlling for well-established cognitive predictors.Methods164 patients with OCD completed self-reported measures of OCD and depressive symptoms, obsessive beliefs, and guilt sensitivity. Bivariate correlations were examined, and latent profile analysis (LPA) was used to generate groups based on symptom severity scores. Differences in guilt sensitivity were examined across latent profiles.ResultsGuilt sensitivity was most strongly associated with unacceptable thoughts and responsibility for harm OCD symptoms, and moderately with symmetry. After controlling for depression and obsessive beliefs, guilt sensitivity added explanatory power to the prediction of unacceptable thoughts. LPA identified 3 profiles; profile-based subgroups significantly differed from one another in terms of guilt sensitivity, depression, and obsessive beliefs.ConclusionsGuilt sensitivity is relevant to various OCD symptom dimensions. Above and beyond depression and obsessive beliefs, guilt sensitivity contributed to the explanation of repugnant obsessions. Theory, research, and treatment implications are discussed.     

Childhood,adolescent and adult age at onset and related clinical correlates in obsessive–compulsive disorder: a report from the International College of Obsessive–Compulsive Spectrum Disorders (ICOCS)

Objective: Many studies suggest that age at onset (AAO) is an important factor for clinically differentiating patients with juvenile and adult onset of obsessive–compulsive disorder (OCD). The present international study aimed to assess the prevalence of different AAO groups and compare related socio-demographic and clinical features in a large sample of OCD patients.

Methods: A total of 431 OCD outpatients, participating in the ICOCS network, were first categorised in groups with childhood (≤12 years), adolescent (13–17 years) and adult-onset (≥18 years), then in pre-adult and adult onset (≥18 years) and their socio-demographic and clinical features compared.

Results: Twenty-one percent (n?=?92) of the sample reported childhood onset, 36% (n?=?155) adolescent onset, and 43% (n?=?184) adult onset. Patients with adult onset showed a significantly higher proportion of females compared with the other subgroups (χ^2?=^?10.9, pχ^2?=^?11.5; p?Conclusions: The present international multicentre study confirms that OCD onset occurs more frequently before adult age, with approximately one out of five patients showing childhood onset. Pre-adult onset was associated with higher rate of CBT, while adult onset was more prevalent in females.     

Validation of the Spanish version of the Dimensional Yale–Brown Obsessive–Compulsive Scale (DYBOCS) in children and adolescents

BackgroundObsessive–compulsive disorder (OCD) is best understood as a complex overlap of obsessive–compulsive (OC) symptom dimensions with specific clinical and etiological characteristics. The Dimensional Yale–Brown Obsessive–Compulsive Scale (DYBOCS) was developed to assess the presence and severity of each of these OC symptom dimensions. Despite showing excellent psychometric properties in adults, the psychometric properties of the DYBOCS have not been widely investigated in children and adolescents.MethodsWe examined the psychometric properties of the DYBOCS Spanish version in a sample of 97 OCD children and adolescents.ResultsThe results of the psychometric analyses were excellent overall. The internal consistency for each OC symptom dimension was high, although somewhat lower than in previous studies with adult samples. The DYBOCS showed overall good convergent and divergent validity. Factors obtained from a principal component analysis corresponded with the five DYBOCS dimensions (aggressive; sexual/religious; contamination; symmetry; and hoarding) and each one accounted for approximately 20% of the variance.ConclusionsThe DYBOCS is a valid instrument for assessing the frequency and severity of OC symptom dimensions in children and adolescents with OCD. The principal component analysis supported the division of OC symptoms into five dimensions. OCD is a heterogeneous disorder, and a dimensional approach can help to understand its clinical, etiological and treatment response characteristics.     

Neural Correlates of Symptom Dimensions in Pediatric Obsessive-Compulsive Disorder: A Functional Magnetic Resonance Imaging Study

ObjectiveNeuroimaging studies have identified distinct neural correlates of obsessive-compulsive disorder (OCD) symptom dimensions in adult subjects and may be related to functional abnormalities in different cortico-striatal-thalamic neural systems underlying cognition and affective processing. Similar symptom dimensions are apparent in childhood and adolescence, but their functional neural correlates remain to be elucidated.MethodPediatric subjects with OCD (n = 18) and matched controls (n = 18), ages 10 to 17 years, were recruited for two functional magnetic resonance imaging experiments. They were scanned while viewing alternating blocks of symptom provocation (contamination-related or symmetry-related) and neutral pictures and imagining scenarios related to the content of each picture type.ResultsThe subjects with OCD demonstrated reduced activity in the right insula, putamen, thalamus, dorsolateral prefrontal cortex, and left orbitofrontal cortex (contamination experiment) and in the right thalamus and right insula (symmetry experiment). Higher scores on OCD symptom-related measures (contamination and total severity) were significantly predictive of reduced neural activity in the right dorsolateral prefrontal cortex during the contamination experiment.ConclusionsOur findings indicate reduced activity in neural regions underlying emotional processing, cognitive processing, and motor performance in pediatric subjects with OCD compared with the controls. These between-group differences are present during both contamination and symmetry provocation experiments and during symptom provocation as well as viewing neutral pictures. The direction of activity is in contrast to adult findings in the insula and in components of cortico-striatal thalamic neural systems. Our findings suggest developmental effects on neural systems underlying symptom dimensions in pediatric OCD.     

Factor structure of the CES-D scale among older adults in Chennai,India

To examine the psychometric properties of the 20-item Centre for Epidemiological Studies – Depression scale (CES-D). Data were collected from 400 community-dwelling older adults aged 65 years and above, residing in Chennai, India. The instruments including the CES-D scale were translated into Tamil language. The sample was randomly split for exploratory factor analysis (EFA) and confirmatory factor analysis (CFA), respectively. EFA on a subsample (n?=?200) yielded two factors, depressed affect and positive affect. CFA with another subsample (n?=?200) indicated a good fit for the two-factor structure. In addition, the two-factor model evinced a superior fit to one-, three- and four-factor models. The internal consistency was high for the total scale and its subscales. The convergent validity of the scale was supported by significant correlations with theoretically related measures. The results indicate acceptable measurement properties of the CES-D scale. However, some items appear to be problematic for Indian older adults. Therefore, there is a need for further studies among Indian older adults.     

Latent structure of posttraumatic stress disorder symptoms in an adolescent sample one month after an earthquake

Increasing empirical studies suggest that the tripartite posttraumatic stress disorder (PTSD) model described in the DSM-IV does not accurately account for the underlying PTSD factor structure, and several alternative models have been proposed. The present study investigated a newly refined, five-factor model of PTSD symptoms in a sample of Chinese adolescent survivors of an earthquake. A total of 1198 middle school students (653 females, 526 males) with a mean age of 14.4 years (SD = 1.1, range: 11–18) participated in this study one month after an earthquake. The novel five-factor model comprised of intrusion, avoidance, numbing, dysphoric arousal, and anxious arousal demonstrated significantly better fit than two alternative four-factor models. Further analyses revealed differentiable relations between the PTSD factors and external measures of anxiety and depression. These findings provide empirical support for the robustness of five-factor model, and carry implications for further reorganization of PTSD criteria.     

Independent validation of the Dimensional Yale-Brown Obsessive-Compulsive Scale (DY-BOCS)

IntroductionObsessive-compulsive disorder (OCD) is a clinically heterogeneous condition characterized by a few consistent, temporally stable symptom dimensions. The Dimensional Yale-Brown Obsessive-Compulsive Scale (DY-BOCS) is a recently developed instrument that allows patient and clinician ratings of dimension-specific symptom severity, as well as estimates of global symptom severity in patients with OCD.MethodsWe examined the psychometric properties of the DY-BOCS in a sample of 128 European adult patients with OCD.ResultsThe results of the psychometric analyses were overall excellent. The internal consistency across the domains of time, distress and interference for each dimension was high. The subscales of the DY-BOCS were largely independent from one another. The convergent and discriminant validity of the DY-BOCS subscales were adequate. The Global Severity and Interference scales were largely intercorrelated, suggesting that they may be redundant. The level of agreement between self-report and expert ratings was adequate although somewhat lower than in the original validation study.ConclusionThe results of the present study confirm the excellent psychometric properties of the DY-BOCS reported in the original validation study.     

Evaluating WAIS–IV structure through a different psychometric lens: structural causal model discovery as an alternative to confirmatory factor analysis

Abstract

Objective: Since the publication of the WAIS–IV in the U.S. in 2008, efforts have been made to explore the structural validity by applying factor analysis to various samples. This study aims to achieve a more fine-grained understanding of the structure of the Dutch language version of the WAIS–IV (WAIS–IV–NL) by applying an alternative analysis based on causal modeling in addition to confirmatory factor analysis (CFA). The Bayesian Constraint-based Causal Discovery (BCCD) algorithm learns underlying network structures directly from data and assesses more complex structures than is possible with factor analysis. Method: WAIS–IV–NL profiles of two clinical samples of 202 patients (i.e. patients with temporal lobe epilepsy and a mixed psychiatric outpatient group) were analyzed and contrasted with a matched control group (N = 202) selected from the Dutch standardization sample of the WAIS–IV–NL to investigate internal structure by means of CFA and BCCD. Results: With CFA, the four-factor structure as proposed by Wechsler demonstrates acceptable fit in all three subsamples. However, BCCD revealed three consistent clusters (verbal comprehension, visual processing, and processing speed) in all three subsamples. The combination of Arithmetic and Digit Span as a coherent working memory factor could not be verified, and Matrix Reasoning appeared to be isolated. Conclusions: With BCCD, some discrepancies from the proposed four-factor structure are exemplified. Furthermore, these results fit CHC theory of intelligence more clearly. Consistent clustering patterns indicate these results are robust. The structural causal discovery approach may be helpful in better interpreting existing tests, the development of new tests, and aid in diagnostic instruments.     

Confirmatory factor analysis of the wechsler memory scale-revised in a mixed clinical population

Abstract

Previous exploratory factor analyses (EFA) of the Wechsler Memory Scale-Revised (WMS-R) have yielded highly disparate factor structures, while the few reported confirmatory factor analyses (CFA) of this instrument have been more consistent. The present study employed a CFA approach to identify the factor structure of the WMS-R in a mixed clinical sample of 306 patients, the majority of whom had sustained mild, diffuse brain injury. Consistent with previous CFA studies, the present study found that a three-factor solution (attention/concentration, immediate memory, delayed recall) fit the data significantly better than competing models. The validity of separate verbal and visual memory indices was not supported, perhaps because of the heterogeneity of the sample.     

Preliminary analysis of positive and negative syndrome scale in ketamine-associated psychosis in comparison with schizophrenia

ObjectiveStudies of the effects of the N-methyl-d-aspartate (NMDA) glutamate receptor antagonist, ketamine, have suggested similarities to the symptoms of schizophrenia. Our primary goal was to evaluate the dimensions of the Positive and Negative Syndrome Scale (PANSS) in ketamine users (acute and chronic) compared to schizophrenia patients (early and chronic stages).MethodWe conducted exploratory factor analysis for the PANSS from four groups: 135 healthy subject administrated ketamine or saline, 187 inpatients of ketamine abuse; 154 inpatients of early course schizophrenia and 522 inpatients of chronic schizophrenia. Principal component factor analyses were conducted to identify the factor structure of the PANSS.ResultsFactor analysis yielded five factors for each group: positive, negative, cognitive, depressed, excitement or dissociation symptoms. The symptom dimensions in two schizophrenia groups were consistent with the established five-factor model (Wallwork et al., 2012). The factor structures across four groups were similar, with 19 of 30 symptoms loading on the same factor in at least 3 of 4 groups. The factors in the chronic ketamine group were more similar to the factors in the two schizophrenia groups rather than to the factors in the acute ketamine group. Symptom severities were significantly different across the groups (Kruskal–Wallis χ²(4) = 540.6, p < 0.0001). Symptoms in the two ketamine groups were milder than in the two schizophrenia groups (Cohen's d = 0.7).ConclusionOur results provide the evidence of similarity in symptom dimensions between ketamine psychosis and schizophrenia psychosis. The interpretations should be cautious because of potential confounding factors.