Browsing by Subject "Psychometrics"
- ItemOpen AccessA comparative multidisciplinary investigation into two hypothetical altered states of consciousness(1975) Doxey, Neville Charles Stephen; Abramovitz, Arnold; Beumont, Peter
- ItemOpen AccessConstruct validity and factor structure of the Kessler-10 in South Africa(2022-07-18) Hoffman, Jacob; Cossie, Qhama; Ametaj, Amantia A; Kim, Hannah H; James, Roxanne; Stroud, Rocky E; Stevenson, Anne; Zingela, Zukiswa; Stein, Dan J; Gelaye, BizuBackground The Kessler Psychological Distress Scale (K-10) is a short screening tool developed to identify, with good sensitivity, non-specific psychological distress in the general population. Sensitivity and specificity of the K-10 have been examined in various clinical populations in South Africa; however, other psychometric properties, such as construct validity and factor structure, have not been evaluated. We present evidence of the prevalence and severity of psychological distress in an outpatient setting in South Africa and evaluate the internal reliability, construct validity, and factor structure of the K-10 in this population. Methods We explored prevalence estimates of psychological distress using previously established cutoffs and assessed the reliability (consistency) of the K-10 by calculating Cronbach’s alpha, item-total correlations and omega total and hierarchical coefficients. Construct validity and factor structure of the K-10 were examined through split-sample exploratory factor analysis (EFA) followed by confirmatory factor analysis (CFA), comparing several theoretical models and the EFA. Results Overall, there was low prevalence of psychological distress in our sample of 2591 adults, the majority of whom were between the ages of 18–44 (77.7%). The K-10 showed good construct validity and reliability, with a Cronbach’s alpha of 0.84 and omega total of 0.88. EFA yielded a four-factor solution with likely measurement artifacts. CFA showed that the four-factor model from EFA displayed the best comparative fit indices, but was likely overfitted. The unidimensional model with correlated errors was deemed the best fitting model based on fit indices, prior theory, and previous studies. Conclusion The K-10 displays adequate psychometric properties, good internal reliability, and good fit with a unidimensional-factor structure with correlated errors. Further work is required to determine appropriate cutoff values in different populations and clinical subgroups within South Africa to aid in determining the K-10’s clinical utility.
- ItemOpen AccessAn investigation into the validity and clinical usefulness of the five-element rank order repertory grid with children(1975) Swart, Wessel Cornelius; Van der Spuy, H I JThe main objective of this project was to investigate some aspects of the diagnostic and prognostic validity of the five-element rank order repertory grid (REP 5). This has been attempted at various levels of analysis with 48 nocturnal enuretic boys, aged 8 to 14, undergoing highly standardized hypnotherapy. REP 5, with neutral elements (photographs) and supplied constructs, was administered 5 times over an 8 month period, i.e. at the pretherapy; mid-therapy; end-therapy; 6 week and the 6 month follow-up stages. Each subject acted as his mm control and in addition a nontreatment control group awaiting similar therapy was used. On the basis of current theory and relevant adult research findings, certain hypotheses were formulated to assess the validity of REP 5. This provided a framework within which the task was to determine whether REP 5 could register (a) in a predictable and meaningful way the expected relationships between the relevant variables; and (b) changes in these relationships. The grid performances were also validated against an empirical criterion which was objectively measurable, i.e. nights dry. Results indicated that the REP 5 was reasonably effective in registering in a meaningful way the status and changes in variables during and after therapy. It appeared that the REP 5 has a significant diagnostic and prognostic utility value. Its efficacy as an instrument seems to be mainly limited by the ability of its designer to match the test design with the purposes for which it was intended.
- ItemOpen AccessMeasuring evidence-based practice knowledge and skills in occupational therapy—a brief instrument(2015) Buchanan, Helen; Jelsma, Jennifer; Siegfried, NandiBackgroundValid and reliable instruments are required to measure the effect of educational interventions to improve evidence-based practice (EBP) knowledge and skills in occupational therapy. The aims of this paper are to: 1) describe amendments to the Adapted Fresno Test of Competence in EBP (AFT), and 2) report the psychometric properties of the modified instrument when used with South African occupational therapists.MethodsThe clinical utility of the AFT was evaluated for use with South African occupational therapists and modifications made. The modified AFT was used in two studies to assess its reliability and validity. In Study 1 a convenience sample of 26 occupational therapists in private practice or government-funded health facilities in a South African province were recruited to complete the modified AFT on two occasions 1week apart. Completed questionnaires were scored independently by two raters. Inter-rater, test-retest reliability and internal consistency were determined. Study 2 was a pragmatic randomised controlled trial involving occupational therapists in four Western Cape Department of Health district municipalities (n = 58). Therapists were randomised in matched pairs to one of two educational interventions (interactive or didactic), and completed the modified AFT at baseline and 12weeks after the intervention. An intention-to-treat analysis was performed. Data were not normally distributed, thus non-parametric statistics were used.ResultsIn Study 1, 21 of 26 participants completed the questionnaire twice. Test-retest (ICC = 0.95, 95% CI = 0.88–0.98) and inter-rater reliability (Time 1: ICC = 0.995, 95% CI = 0.99–0.998; Time 2: ICC = 0.99, 95% CI = 0.97–0.995) were excellent for total scores. Internal consistency based on time 1 scores was satisfactory (α = 0.70). In Study 2, 28 participants received an interactive educational intervention and completed the modified AFT at baseline and 12weeks later. Median total SAFT scores increased significantly from baseline to 12-weeks (Z = −4.078, p < 0.001) with a moderate effect size (r = 0.55).ConclusionThe modified AFT has demonstrated validity for detecting differences in EBP knowledge between two groups. It also has excellent test-retest and inter-rater reliability. The instrument is recommended for contexts where EBP is an emerging approach and time is at a premium.Trial registrationPan African Controlled Trials Register PACTR201201000346141. Registered 31 January 2012.Clinical Trials NCT01512823. Registered 1 February 2012.South African National Clinical Trial Register DOH2710093067. Registered 27 October 2009.
- ItemOpen AccessPain in amaXhosa women living with HIV/AIDS: a cross-sectional study of ambulant outpatients(2017) Parker, Romy; Jelsma, Jennifer; Stein, Dan JBACKGROUND: Pain is one of the most commonly reported symptoms in people living with HIV/AIDS, whether or not they are receiving anti-retroviral therapy. A recent systematic review identified a paucity of studies exploring pain in women in low and middle income countries. The prevalence and characteristics of pain in women living with HIV/AIDS may differ from that of men as many chronic pain conditions are more prevalent in women. The aims of this study were to establish pain prevalence, characteristics and management in amaXhosa women living with HIV/AIDS. In addition, we aimed to identify whether there were associations between pain in this population and the psychosocial factors of employment, education, self-efficacy, depression, post-traumatic stress disorder, health related quality of life and childhood trauma. METHODS: A cross-sectional study of 229 women who had undergone HIV testing and were registered patients at a community health centre was conducted. Data were collected by interview with a demographic questionnaire, the Brief Pain Inventory-Xhosa, Childhood Trauma Questionnaire-Xhosa, Harvard Trauma Questionnaire-Xhosa for PTSD, Self-Efficacy for Managing Chronic Disease 6-Item Scale-Xhosa; the EQ-5D health related quality of life instrument, and the Beck Depression Inventory. RESULTS: 170 of the women had pain, a prevalence rate of 74.24% (95%CI 68.2 - 79.47%). The women reported significant pain with pain severity of 5.06 ± 1.57 and pain interference of 6.39 ± 1.96 out of 10. Only two women were receiving adequate pain management according to the pain management index. Participants reported a mean of 2.42 ± 1.21 different anatomical sites of pain. There were more unemployed participants in the group with pain and they had significantly fewer years of schooling. Those with pain had lower self-efficacy; health related quality of life and increased depression and PTSD symptom severity. CONCLUSION: This study highlights that pain is a common problem for amaXhosa women living with HIV/AIDS. These data emphasise the need to prioritise pain assessment and management in amaXhosa women living with HIV/AIDS. Routinely assessing for the presence of pain in women with HIV/AIDS has the potential to improve pain management and minimise the impact of pain on function.
- ItemOpen AccessPsychometric properties of the child PTSD checklist in a community sample of South African children and adolescents(Public Library of Science, 2012) Boyes, Mark E; Cluver, Lucie D; Gardner, FrancesObjective The current study assessed the basic psychometric properties of the Child PTSD Checklist and examined the structure of symptoms of posttraumatic stress disorder (PTSD) in a large sample of South African youth. METHODOLOGY: The checklist was completed by 1025 (540 male; 485 female) South African youth (aged between 10 and 19 years). The factor structure of the scale was assessed with a combination of confirmatory and exploratory techniques. Internal consistencies for the full scale and all subscales were evaluated with Cronbach's alpha and McDonald's omega. Validity was assessed by comparing PTSD scores obtained by children who had and had not experienced a traumatic event, and by examining associations between total PTSD scores and known correlates of PTSD. RESULTS: Scores on the Child PTSD Checklist clearly discriminated between youth who had experienced a traumatic event and those who had not. Internal consistencies for the full scale (and all subscales) were acceptable to good and hypothesized correlations between PTSD, depression, anxiety, somatic symptoms, and age were observed. Two of the reported fit statistics for the tripartite DSM-IV-TR model of PTSD did not meet traditional criteria and further exploratory analyses revealed a four-factor structure (broadly consistent with Simms and colleagues' Dysphoria Model of PTSD symptoms) which provided a better fit to the observed data. CONCLUSION: Given the continued use of the Child PTSD Checklist in South Africa, findings offer an important first step in establishing the reliability and validity of the checklist for use with South African youth. However, further evaluation of the checklist in South African samples is clearly required before conclusions regarding its use as diagnostic tool in this context can be made.
- ItemOpen AccessThe use of the EQ-5D-Y health related quality of life outcome measure in children in the Western Cape, South Africa: psychometric properties, feasibility and usefulness - a longitudinal, analytical study(2017) Scott, Des; Ferguson, Gillian D; Jelsma, JenniferAbstract Background The EQ-5D-Y, an outcome measure of Health Related Quality of Life (HRQoL) in children, was developed by an international task team in 2010. The multinational feasibility, reliability and validity study which followed was undertaken with mainly healthy children. The aim of this study was to investigate the psychometric properties of the EQ-5D-Y when used to assess the HRQoL of children with different health states. Method A sample of 224 children between eight and twelve years were grouped according to their health state. The groups included 52 acutely ill children, 67 children with either a chronic health condition or disability and 105 mostly healthy, mainstream school children as a comparator. They were assessed at baseline, at three months and at six months. An analysis of the psychometric properties was performed to assess the reliability, validity and responsiveness of the EQ-5D-Y in the different groups of children. Cohen’s kappa, the intraclass correlation coefficient, Pearson Chi-square, Kruskal-Wallis ANOVA and effect size of Wilcoxon Signed-rank test were used to determine the reliability, validity and responsiveness of the instrument. Results The EQ-5D-Y dimensions were found to be reliable on test-retest (kappa varying from 0.365 to 0.653), except for the Usual Activities dimension (kappa 0.199). The Visual Analogue Scale (VAS) was also reliable (ICC = 0.77). Post-hoc analysis indicated that dimensions were able to discriminate between acutely ill and healthy children (all differences p < 0.001). The acutely ill children had the lowest ranked VAS (median 50, range 0–100), indicating worst HRQoL and was the only group significantly different from the other three groups (p < 0.001 in all cases). Convergent validity between all similar EQ-5D-Y and PedsQL, WeeFIM and Faces Pain Scale dimensions was only evident in the acutely ill children. As expected the largest treatment effect was also observed in these children (Wilcoxon Signed-rank test for VAS was 0.43). Six of the nine therapists who took part in the study, found the measure quick and easy to apply, used the information in the management of the child and would continue to use it in future. Conclusions The EQ-5D-Y could be used with confidence as an outcome measure for acutely-ill children, but demonstrated poorer psychometric properties in children with no health condition or chronic conditions. It appears to be feasible and useful to include the EQ-5D-Y in routine assessments of children.
- ItemOpen AccessValidation of the 10-item Centre for Epidemiological Studies Depression Scale (CES-D-10) in Zulu, Xhosa and Afrikaans populations in South Africa(2017) Baron, Emily Claire; Davies, Thandi; Lund, CrickAbstract Background The 10-item Centre for Epidemiological Studies Depression Scale (CES-D-10) is a depression screening tool that has been used in the South African National Income Dynamics Study (NIDS), a national household panel study. This screening tool has not yet been validated in South Africa. This study aimed to establish the reliability and validity of the CES-D-10 in Zulu, Xhosa and Afrikaans. The CES-D-10’s psychometric properties were also compared to the Patient Health Questionnaire (PHQ-9), a depression screening tool already validated in South Africa. Methods Stratified random samples of Xhosa, Afrikaans and Zulu-speaking participants aged 15 years or older (N = 944) were recruited from Cape Town Metro and Ethekwini districts. Face-to-face interviews included socio-demographic questions, the CES-D-10, Patient Health Questionnaire (PHQ-9), and WHO Disability Assessment Schedule 2.0 (WHODAS). Major depression was determined using the Mini International Neuropsychiatric Interview. All instruments were translated and back-translated to English. Construct validity was examined using exploratory factor analysis with varimax rotation. Receiver Operating Characteristics (ROC) curves were used to investigate the CES-D-10 and PHQ-9’s criterion validity, and compared using the DeLong method. Results Overall, 6.6, 18.0 and 6.9% of the Zulu, Afrikaans and Xhosa samples were diagnosed with depression, respectively. The CES-D-10 had acceptable internal consistency across samples (α = 0.69–0.89), and adequate concurrent validity, when compared to the PHQ-9 and WHODAS. The CES-D-10 area under the Receiver Operator Characteristic curve was good to excellent: 0.81 (95% CI 0.71–0.90) for Zulu, 0.93 (95% CI 0.90–0.96) for Afrikaans, and 0.94 (95% CI 0.89–0.99) for Xhosa. A cut-off of 12, 11 and 13 for Zulu, Afrikaans and Xhosa, respectively, generated the most balanced sensitivity, specificity and positive predictive value (Zulu: 71.4, 72.6% and 16.1%; Afrikaans: 84.6%, 84.0%, 53.7%; Xhosa: 81.0%, 95.0%, 54.8%). These were slightly higher than those generated for the PHQ-9. The CES-D-10 and PHQ-9 otherwise performed similarly across samples. Conclusions The CES-D-10 is a valid, reliable screening tool for depression in Zulu, Xhosa and coloured Afrikaans populations.