Path analytical study of the short version of the WHO Quality of Life Instrument

BACKGROUND: Using confirmatory factor analysis, we have shown that the 8 factors we derived from the responses of 118 Nigerian psychiatric patients to the short version of the WHO Quality of Life Instrument had greater structural integrity than the 4- and 6-domain models of the WHO. OBJECTIVES: Using path analysis to assess the structural integrity of the model we generated from the relationships among the 8 factors, we proposed a model of QOL from which targets for subjective QOL interventions could be delineated. METHOD: The model was generated by multiple regression analysis with the item on overall QOL (OQOL) as dependent variable and the 8 domains as predictors. Path analysis was done by Analysis of Moment Structures, with a maximum likelihood ratio as method of estimation. RESULTS: Our model had high Cronbach's alphas and met the criteria for the following fit indices: relative chi2 (1.9), goodness of fit (0.92) and comparative fit index (0.91). Hence, we propose that subjective QOL is primarily mediated by satisfaction with life, informational need, opportunity for experience, and instrumental need. CONCLUSION: Subjective QOL encompasses satisfaction with life circumstances, fulfillment of needs, and opportunity for experience, which should be targets for QOL interventions.     

A confirmatory factor analytic evaluation of the pentagonal PANSS model

The positive and negative syndrome scale (PANSS) is widely used in psychiatric research. Reflecting this common use, considerable attention has been applied to the psychometric properties of this instrument. However, despite the publication of numerous studies and analyses, it remains uncertain how best data from the PANSS should be analysed to best model the symptoms of schizophrenia. A resolution to these concerns seemed to be offered following the publication in 1997 of a large multisite factor analysis that produced the 'pentagonal model', which has subsequently been included in the 2000 revision of the PANSS user manual. However, to date, an independent confirmatory analysis of this model has not yet been published. The aim of this study was to test this model in a new independent sample with confirmatory factor analysis (CFA). Independent confirmation of the fit of the model is required to ensure that its implementation is informed by confirmation of its psychometric properties. CFA was performed in a sample of 347 subjects with schizophrenia. The analysis found that the model had inadequate goodness of fit. The use of the pentagonal model has similar difficulties as earlier models and more research is required to ascertain the optimal method for measuring symptom dimensions in research and clinical settings.     

Reliability,Validity, and Unidimensionality of the Korean Version of the Pornography Craving Questionnaire Based on the Classical Test Theory and Item Response Theory

ObjectiveThis study aimed to evaluate the reliability and validity of the Korean version of the Pornography Craving Questionnaire (K-PCQ) using classical test theory and item response theory. MethodsThe goodness of fit test and differential item functioning (DIF) analysis based on the Rasch model, confirmatory factor analysis (CFA), exploratory factor analysis (EFA), and correlation analysis were used to test its reliability and validity. ResultsResponse data from 226 students were analyzed. According to the goodness of fit test, the outfit mean square value of only one item, Item 11, was greater than 2. The CFA results revealed that all items of the K-PCQ measured a single construct. The EFA results revealed that the K-PCQ had excellent internal reliability. The DIF analysis results showed that the measurement of pornography craving using the K-PCQ did not differ based on gender. The result of Poly-DIMTEST supported the unidimensionality of the K-PCQ. The cut-off value of pornography craving was suggested as a measure of -0.0908 which corresponds to 46 (54.8%) out of a maximum score of 84. ConclusionThe items of the K-PCQ are unidimensional and have good reliability and validity. The K-PCQ will be useful in clinical practice and research as a screening tool for pornography craving.     

Subjective quality of life in a nationwide sample of Kuwaiti subjects using the short version of the WHO quality of life instrument

Objectives  The usefulness of quality of life (QOL) as an outcome measure in medicine has inspired general population studies to establish normative values. The objectives of the study were to: (1) highlight the pattern of satisfaction with aspects of life circumstances among a nationwide sample of Kuwaiti subjects, using the 26-item WHOQOL Instrument (WHOQOL-Bref); (2) establish the QOL domain normative values; (3) highlight the relationship of QOL with socio-demographic variables and scores on scales for anxiety and depression; and (4) assess the relationship between domains of QOL. Method  A one-in-three systematic random proportionate sample of consenting Kuwaiti nationals attending the large cooperative stores and municipal government offices in the six governorates, were requested to complete the questionnaires anonymously. Results  There were 3,303 participants (44.8% m, 55.2% f, mean age 35.4, SD 11.9; range, 16–87). As a group, they were only moderately satisfied with their life circumstances. The domain scores for physical health (14.6 or 66.2%) and psychological health (14.2 or 63.9%) were at the middle of the range for the WHO 23-country report, while the social relations (15.0 or 68.8%) and environment (14.5 or 65.4%) domains were at the upper end of the WHO range. The general facet (GF) score (15.5 or 71.6%) was significantly higher than all domains. Diminished QOL was significantly associated with female gender, older age, social disadvantage, and high scores on anxiety/depression. Depression was the most important predictor of QOL, accounting for over 77% of total variance. Conclusion  QOL was sensitive to distressing and unfulfilled life circumstances. Hence, coupled with the difficulty of conducting house-to-house surveys in such a conservative society, a cost effective way of tracking societal distress is by including a brief and responsive measure of QOL during national census exercises. Clinicians need to be aware of QOL issues because QOL is associated with clinical and social variables. The differences between GF (representing subjective well-being) and the domains, has implications for QOL theory.     

Apathy and depression: separate factors in Parkinson's disease

The objective of this study was to test the hypothesis that apathy and depression are dissociable in Parkinson disease (PD) by conducting a confirmatory factor analysis (CFA) of items from two commonly used mood scales. A total of 161 non-demented PD patients (age = 64.1; ± 8.4 years) were administered the Apathy Scale and the Beck Depression Inventory-II. Items were hypothesized to load onto four factors: (1) an apathy factor representing loss of motivation, (2) dysphoric mood factor representing sadness and negativity, (3) loss of interest/pleasure factor representing the features common to both apathy and depression, and (4) a somatic factor representing bodily complaints. Results indicated a good fit for the overall CFA model, χ2 (128, N = 146) = 194.9; p<.01. RMSEA was .060 (p = .16). The four-factor model was significantly better than all alternative nested models at p < .001, including an overarching single factor model, representing "depression." Results support the concept that apathy and depression are discrete constructs. We suggest a "factor based" scoring of the Apathy Scale and Beck Depression Inventory-II that disentangles symptoms related to apathy, depression, overlapping symptoms, and somatic complaints. Such scoring may be important in providing useful information regarding differential treatment options.     

Developing an African youth psychosocial assessment: an application of item response theory

This study aimed to refine a dimensional scale for measuring psychosocial adjustment in African youth using item response theory (IRT). A 60‐item scale derived from qualitative data was administered to 667 war‐affected adolescents (55% female). Exploratory factor analysis (EFA) determined the dimensionality of items based on goodness‐of‐fit indices. Items with loadings less than 0.4 were dropped. Confirmatory factor analysis (CFA) was used to confirm the scale's dimensionality found under the EFA. Item discrimination and difficulty were estimated using a graded response model for each subscale using weighted least squares means and variances. Predictive validity was examined through correlations between IRT scores (θ) for each subscale and ratings of functional impairment. All models were assessed using goodness‐of‐fit and comparative fit indices. Fisher's Information curves examined item precision at different underlying ranges of each trait. Original scale items were optimized and reconfigured into an empirically‐robust 41‐item scale, the African Youth Psychosocial Assessment (AYPA). Refined subscales assess internalizing and externalizing problems, prosocial attitudes/behaviors and somatic complaints without medical cause. The AYPA is a refined dimensional assessment of emotional and behavioral problems in African youth with good psychometric properties. Validation studies in other cultures are recommended. Copyright © 2014 John Wiley & Sons, Ltd.     

Depression and quality of life in first-episode psychosis

AimQuality of life (QOL) has gained recognition as a valid measure of outcome in first-episode psychosis (FEP). This study aimed to determine the influence of specific groups of depressive symptoms on separate domains of subjectively appraised QOL.MethodsWe assessed 208 individuals with first-episode non-affective psychosis using measures of diagnosis (Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition), symptoms (Scale for the Assessment of Positive Symptoms, Scale for the Assessment of Negative Symptoms, and Calgary Depression Scale for Schizophrenia), functioning (Global Assessment of Functioning), insight (Birchwood Scale), duration of untreated psychosis (Beiser Scale), and QOL World Health Organisation Quality of Life Instrument (WHOQOL-Bref). We used multiple regression to determine the contribution of depressive symptoms to QOL domains while controlling for socio-demographic and other clinical characteristics.ResultsThere were complete data for 146 individuals with FEP. Quality-of-life domains were consistently predicted by depressive symptoms including depressive mood and hopelessness rather than biological symptoms of depression with those experiencing more depressive symptoms reporting worse QOL. Those who were treated as in-patients reported improved QOL, and hospitalization was an independent predictor of most QOL domains. In-patients displayed greater levels of positive symptoms with those involuntarily detained displaying greater levels of bizarre behavior, thought disorder, and delusions.ConclusionsThese findings suggest that QOL is heavily influenced by depressive symptoms at initial presentation; however, as QOL domains are also influenced by admission status with in-patients being more symptomatic in terms of positive symptoms, subjective QOL assessment may be compromised during the acute phase of illness by both positive and depressive symptom severity.     

Quality of life and its correlates in patients with bipolar disorder stabilized on lithium prophylaxis

The quality of life (QOL) of 50 bipolar disorder patients in remission (stabilized on lithium prophylaxis) was assessed and compared with that of clinically stable patients with schizophrenia (n = 20) and healthy subjects (n = 20). World Health Organization Quality of Life-Bref (WHOQOL-BREF) and Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q) were used to assess QOL in the three groups of subjects. The factors that contribute or influence QOL (i.e. stressful life events, social support, daily hassles) were also studied using standardized instruments in the study group. It was found that, compared to schizophrenia group, the bipolar group had significantly better QOL in all the domains of Q-LES-Q and the domains of general well-being, physical health and psychological health of the WHOQOL-Bref. The bipolar group had similar QOL scores in all other domains and higher scores in leisure time activity domain of Q-LES-Q, in comparison to the healthy group. The QOL in the bipolar group was better in patients who were younger and had a lesser severity of daily hassle. The present findings suggest that euthymic patients with bipolar disorder have a QOL that is comparable to that of healthy subjects. In contrast, patients with clinically stable schizophrenia have a poorer QOL. Occurrence of daily hassles contributes significantly to QOL in patients with bipolar disorder. However, the relatively limited variance explained by the independent variables included in the study, suggests the need to examine other (perhaps non-clinical) factors that may affect QOL.     

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 Cerebral Palsy Quality of Life for Children (CP QOL-Child): Evidence of construct validity

The Cerebral Palsy Quality of Life for Children (CP QOL-Child) is the first health condition-specific questionnaire designed for measuring QOL in children with cerebral palsy (CP). However, its construct validity has not yet been confirmed by confirmatory factor analysis (CFA). Hence, this study assessed the construct validity of the caregiver proxy-report version of the Chinese version of the CP QOL-Child in children with CP using CFA.A total of 312 children with CP (mean age: 8.59 years, SD: 2.52 years) and their caregivers participated in this study. The Chinese version of the CP QOL-Child was completed by the caregivers of children with CP. Then, CFA was applied to evaluate the seven-factor measurement structure of the CP QOL-Child. The seven-factor CFA model had an adequate fit to our data as judged by χ² statistic and various goodness-of-fit (GOF) indices, including the root mean square error of approximation (RMSEA). This study provided empirical evidence of the construct validity of the CP QOL-Child to support its use with children with CP in the Chinese speaking society.     

A comparison of cognitive structure in schizophrenia patients and healthy controls using confirmatory factor analysis

There is evidence that cognitive task performance breaks down into the same broad domains in schizophrenia as in healthy populations. However, this does not mean that the domains are independent of one another or that the interrelationships among domains are the same between groups. We used confirmatory factor analysis (CFA) to compare the latent structure of a broad neuropsychological battery in schizophrenia patients (n = 148) and healthy controls (n = 157). Main analyses examined the fit of a hierarchical six-factor model, in which associations among the factors were assumed to reflect their strong shared relationship to a general cognitive ability factor. The model incorporated the factors of verbal comprehension, perceptual organization, verbal memory, spatial memory, processing speed, and executive/working memory. The hierarchical model provided a good overall fit to data from both groups. However multiple groups CFA revealed significant differences in factor loadings between groups, reflecting a more generalized latent structure of cognitive ability in schizophrenia. This was also evident in higher bivariate correlations among cognitive domain composite scores calculated from the observed test data. Cognitive ability, as reflected in test performance, appears to be more unitary in schizophrenia than in healthy subjects. This finding may have measurement and treatment implications.     

The impact of epilepsy on quality of life: a qualitative analysis

The assessment and understanding of epilepsy's impact on an individual's quality of life (QOL) is increasingly being recognized as an important component of clinical care. Because the impact of epilepsy can span a range of clinically important functional and psychosocial domains, QOL as a model for understanding epilepsy's impact should be inclusive of the many life domains that are important to the individual. In this study a community-based sample of 46 adults with epilepsy were surveyed to identify the QOL domains that are important to persons with epilepsy, the factors that contribute to and detract from QOL, and the ways that epilepsy is perceived to impact QOL. A multidomain structure of quality of life emerged from the qualitative data analysis. Epilepsy was seen as having both a direct and an indirect impact on QOL, by directly affecting QOL domains and by affecting those factors that contribute to QOL.     

A comparison of quality-of-life in schizophrenia and affective disorder patients in a Nigerian tertiary hospital

This study determined the degree of satisfaction with various aspects of life in patients with affective disorders and schizophrenia in a Nigerian tertiary hospital. We compared quality-of-life (QOL) at onset-of-illness (first episode) with QOL at time of study and identified sociodemographic and clinical variables that may predict QOL. All consenting patients with ICD-10 compatible diagnosis of schizophrenia (n = 100) and affective disorders (n = 35) receiving treatment in the study center during the study period were interviewed. The WHOQOL-Bref was used to assess respondents' subjective QOL, and a data-collection sheet assessed objective domains of QOL. Respondents with schizophrenia and affective disorders had a good outcome in terms of objective QOL scores. In both groups, however, the subjective ratings were poor as the illness progresses. We conclude that in Nigerian hospital cases, patients with schizophrenia andaffective disorders have a good outcome in terms of objective QOL scores, which are not in consonance with their subjective ratings. Marital status and employment status are predictive of QOL.     

Quality of life in substance abuse and dependency

Substance abuse and substance dependency are diagnosed not only through the extent a drug is used but the effects--emotional, medical, social and behavioural--the drug has on the (ab)user. These effects incorporate many of the domains that may be systematically examined through using quality of life (QOL) measures. The assessment of QOL may therefore be used both as an evaluation and a diagnostic tool. A comprehensive literature review was completed to examine: (1) what QOL research has been conducted and in what context, (2) how different constructs of QOL are used, and (3) what patterns of results in QOL ratings are evident across different substance abusing or dependent populations. The data relates to individuals who misuse alcohol or drugs, the dual diagnosis population of substance abusing individuals with comorbid psychiatric disorders, and 'hidden populations' such as individuals who abuse legal drugs. Comparisons are made complex by the use of two different constructs, the generic construct QOL which examines satisfaction with life, and the more specialized construct of health-related QOL (HRQOL). Results suggest the potential diagnostic importance of QOL, and the need for detailed analysis of patterns of QOL scores in clinical subpopulations and the wider substance using population. Concluding comments address the paucity of existing studies, and the need for regular incorporation of the measure within substance abuse and dependency research and practice.     

Development and validation of the Subjective Awareness of Neuropsychological Deficits Questionnaire for Children (SAND-C)

Although lowered awareness of abilities has been associated with poorer outcome in adults with neurological compromise, a dearth of research exists examining whether lowered awareness exists in younger populations. Using findings from recent literature and expert opinion, a 47-item Subjective Awareness of Neuropsychological Deficits Questionnaire for Children (SAND-C) was created to assess awareness of cognitive functioning in 6 domains (attention, psychomotor, visual-spatial, language, memory, and executive functioning). Confirmatory factor analysis (CFA) of the SAND-C was conducted on a sample consisting of 365 healthy children and 48 children with epilepsy. The SAND-C was found to have strong reliability. Factor analysis confirmed the a priori 6 factor model, but the 6-factor model was only marginally better than a more parsimonious 1-factor solution. Post-hoc exploratory factor analyses indicate that the SAND-C may measure more constructs for adolescents than for younger children. The difference between younger and older children may reflect developmental changes in metacognitive awareness and abstraction about their own abilities.     

A confirmatory factor analysis of combined models of the Harvard Trauma Questionnaire and the Inventory of Complicated Grief-Revised: Are we measuring complicated grief or posttraumatic stress?

The aim of this study was to assess the factorial structure of complicated grief (CG) and investigate the relationship between CG and posttraumatic stress disorder (PTSD) through the assessment of models combining both constructs. The questionnaire was completed by elderly, married respondents with a history of at least one significant, interpersonal loss (145 males and 147 females, 60–81 years). Confirmatory factor analysis (CFA) supported a two-factor model of separation and traumatic distress in CG. To investigate the relationship between CG and PTSD three combined models were specified and estimated using CFA. A model where all five factors, the two factors of CG and the three factors of PTSD, as defined by the DSM-IV, were allowed to correlate provided the best fit. The results indicated a considerable overlap between the dimensions of CG and PTSD, and complicated grief is construct that appears to be largely accounted for by especially the intrusive component of PTSD.     

Quality of life for people with intellectual disabilities in China: a cross-culture perspectives study

Background The concept of quality of life (QOL) is explained on the basis of traditional Chinese culture and contemporary social and cultural trends. Method The importance of internationally recognized QOL domains and indicators was determined for three respondent groups: consumers, parents of the consumers, and teachers and rehabilitation professionals working with the clients. Results Principal component analysis confirmed seven factors influencing QOL for people with intellectual disabilities (ID) in China. These seven components are conceptually equivalent to the eight domains found in the international QOL literature. Conclusion The concept of QOL has become one of the most sensitive issues in present Chinese society and peoples’ lives, and an important theoretical framework for the education and rehabilitation for people with ID in several ways: curriculum development, service delivery models, education and rehabilitation practices, and employment models.     

Validation and normalization of the General Health Questionnaire 30 in parents with primary school children in China

ObjectivesParenting can be a stressful experience. Higher levels of parenting stress are predictive of parents' negative appraisal of children's behavior, the use of physical discipline, and poor child outcomes across a variety of domains. Assessment of parenting depression is needed in China. This study aims to standardize the Chinese version of the General Health Questionnaire (GHQ-30) for parents of primary school children.MethodStratified randomly selected parents of primary school children were selected from the cities of Nanjing and Shenyang in China. The Chinese version of the General Health Questionnaire 30 was administered to 7615 parents of primary school students aged between 8 and 12 years. A high response rate was achieved, with 6672 parents (88%) responding to the survey.ResultsExploratory factor analysis with a 5-factor solution showed that 5 factors were extracted from the scale, namely, depression, anxiety, inadequate coping, social dysfunctioning, and sleep disturbance. The 5-factor structures were confirmed by using confirmatory factor analysis (CFA). Overall, the 5-factor structure had a high level of reliability for each individual dimension. Confirmatory factor analysis showed that the 5-factor structure abstracted from this study had a good model fit.ConclusionsThe 5-factor structure derived from the present sample of parents, with good model fit in the CFA analysis, suggests that a 5-factor solution can be used to assess parent psychopathological symptoms in mainland Chinese parents of primary school children.     

Validation of the Quality of Life Inventory for patients with anxiety and depression

BACKGROUND: In 1992, Frisch et al (Psychol Assess. 1992;4:92-101) developed the Quality of Life Inventory (QOLI) to measure the concept of quality of life (QOL) because it has long been thought to be related to both physical and emotional well-being. However, the psychometric properties of the QOLI in clinical populations are still in debate. The present study examined the factor structure of QOLI and reported its validity and reliability in a clinical sample. METHOD: Two hundred seventeen patients with anxiety and depressive disorders completed the QOLI, and additional questionnaires measuring symptoms (Zung Self-rating Depression Scale, Beck Anxiety Inventory, Fear Questionnaire, Depression Anxiety Stress Scale-Stress) and subjective well-being (Satisfaction With Life Scale) were also used. RESULTS: Exploratory factor analysis via the principal components method, with oblique rotation, revealed a 2-factor structure that accounted for 42.73% of the total variance, and a subsequent confirmatory factor analysis suggested a moderate fit of the data to this model. The 2 factors appeared to describe self-oriented QOL and externally oriented QOL. The Cronbach alpha coefficients were 0.85 for the overall QOLI score, 0.81 for the first factor, and 0.75 for the second factor. CONCLUSION: Consistent evidence was also found to support the concurrent, discriminant, predictive, and criterion-related validity of the QOLI.     

Effects of ignoring clustered data structure in confirmatory factor analysis of ordered polytomous items: a simulation study based on PANSS

Statistical theory indicates that hierarchical clustering by interviewers or raters needs to be considered to avoid incorrect inferences when performing any analyses including regression, factor analysis (FA) or item response theory (IRT) modelling of binary or ordinal data. We use simulated Positive and Negative Syndrome Scale (PANSS) data to show the consequences (in terms of bias, variance and mean square error) of using an analysis ignoring clustering on confirmatory factor analysis (CFA) estimates. Our investigation includes the performance of different estimators, such as maximum likelihood, weighted least squares and Markov Chain Monte Carlo (MCMC). Our simulation results suggest that ignoring clustering may lead to serious bias of the estimated factor loadings, item thresholds, and corresponding standard errors in CFAs for ordinal item response data typical of that commonly encountered in psychiatric research. In addition, fit indices tend to show a poor fit for the hypothesized structural model. MCMC estimation may be more robust against clustering than maximum likelihood and weighted least squares approaches but further investigation of these issues is warranted in future simulation studies of other datasets. Copyright © 2015 John Wiley & Sons, Ltd.