Factor structure of psychosis screening questionnaire in Ugandan adults.

BACKGROUND: Psychotic disorders are common and contribute significantly to morbidity and mortality of people with psychiatric diseases. Therefore, early screening and detection may facilitate early intervention and reduce adverse outcomes. Screening tools that lay persons can administer are particularly beneficial in low resource settings. However, there is limited research evaluating the validity of psychosis screening instruments in Uganda. We aimed to assess the construct validity and psychometric properties of the Psychosis Screening Questionnaire (PSQ) in Uganda in a population with no history of a psychotic disorder. METHODS: The sample consisted of 2101 Ugandan adults participating as controls in a larger multi-country case-control study on psychiatric genetics who were recruited between February 2018 and March 2020. Participants were individuals seeking outpatient general medical care, caretakers of individuals seeking care, and staff or students recruited from five medical facilities that were age 18 years or older and able to provide consent. Individuals were excluded who had acute levels of alcohol or substance use, including being under inpatient hospitalization or acute medical care for one of these conditions. We used confirmatory factor analysis (CFA) and item response theory (IRT) to evaluate the factor structure and item properties of the PSQ. RESULTS: The overall prevalence screening positive for psychotic symptoms was 13.9% 95% CI (12.4,15.4). "Strange experiences" were the most endorsed symptoms 6.6% 95% CI (5.6,7.8). A unidimensional model seemed to be a good model or well-fitting based on fit indices including the root mean square error of approximation (RMSEA of 0.00), comparative fit index (CFI of 1.000), and Tucker-Lewis Index (TLI of 1.000). The most discriminating items along the latent construct of psychosis were items assessing thought disturbance followed by items assessing paranoia, with a parameter (discrimination) value of 2.53 and 2.40, respectively. CONCLUSION: The PSQ works well in Uganda as an initial screening tool for moderate to high-level of psychotic symptoms.

Psychometric properties of the mini international neuropsychiatric interview (MINI) psychosis module: a Sub-Saharan Africa cross country comparison.

BACKGROUND: The Mini International Neuropsychiatric Inventory 7.0.2 (MINI-7) is a widely used tool and known to have sound psychometric properties; but very little is known about its use in low and middle-income countries (LMICs). This study aimed to examine the psychometric properties of the MINI-7 psychosis items in a sample of 8609 participants across four countries in Sub-Saharan Africa. METHODS: We examined the latent factor structure and the item difficulty of the MINI-7 psychosis items in the full sample and across four countries. RESULTS: Multiple group confirmatory factor analyses (CFAs) revealed an adequate fitting unidimensional model for the full sample; however, single group CFAs at the country level revealed that the underlying latent structure of psychosis was not invariant. Specifically, although the unidimensional structure was an adequate model fit for Ethiopia, Kenya, and South Africa, it was a poor fit for Uganda. Instead, a 2-factor latent structure of the MINI-7 psychosis items provided the optimal fit for Uganda. Examination of item difficulties revealed that MINI-7 item K7, measuring visual hallucinations, had the lowest difficulty across the four countries. In contrast, the items with the highest difficulty were different across the four countries, suggesting that MINI-7 items that are the most predictive of being high on the latent factor of psychosis are different for each country. CONCLUSIONS: The present study is the first to provide evidence that the factor structure and item functioning of the MINI-7 psychosis vary across different settings and populations in Africa.

Psychosis screening questionnaire: Exploring its factor structure among South African adults.

Background: Early detection of psychosis improves treatment outcomes, but there is limited research evaluating the validity of psychosis screening instruments, particularly in low-resourced countries. Aim: This study aims to assess the construct validity and psychometric properties of the psychosis screening questionnaire (PSQ) in South Africa. Setting: This study was conducted at several health centres in the Western and Eastern Cape provinces in South Africa. Methods: The sample consisted of 2591 South African adults participating as controls in a multi-country case-control study of psychiatric genetics. Using confirmatory factor analysis and item response theory, we evaluated the psychometric properties of the PSQ. Results: Approximately 11% of the participants endorsed at least one psychotic experience on the PSQ, and almost half of them (49%) occurred within the last 12 months. A unidimensional model demonstrated good fit (root mean square error of approximation [RMSEA] = 0.023, comparative fit index [CFI] = 0.977 and Tucker-Lewis Index [TLI] = 0.954). The mania item had the weakest association with a single latent factor (standardised factor loading = 0.14). Model fit improved after removing the mania item (RMSEA = 0.025, CFI = 0.991 and TLI = 0.972). With item response theory analysis, the PSQ provided more information at higher latent trait levels. Conclusion: Consistent with prior literature, the PSQ demonstrated a unidimensional factor structure among South Africans. In our study, the PSQ in screening for psychosis performed better without the mania item, but future criterion validity studies are warranted. Contribution: This study highlights that PSQ can be used to screen for early psychosis.

Frequency and source of worries in an International sample of pregnant and postpartum women during the Covid-19 pandemic.

BACKGROUND: Pregnant and postpartum women face unique challenges and concerns during the COVID-19 pandemic. Thus far, no studies have explored the factors associated with increased levels of worry in this population globally. The current study sought to assess the frequency and sources of worry during the COVID-19 pandemic in an international sample of pregnant and postpartum women. METHODS: We conducted an anonymous, online, cross-sectional survey in 64 countries between May and June 2020. The survey was available in 12 languages and hosted on the Pregistry platform for COVID-19 studies. Participants were sought mainly on social media platforms and online parenting forums. The survey included questions related to demographics, level of worry, support, stress, COVID-19 exposure, frequency of media usage, and mental health indicators. RESULTS: The study included 7561 participants. Eighty-three percent of all participants indicated that they were either 'somewhat' or 'very' worried. Women 13-28 weeks pregnant were significantly more likely to indicate that they were 'very worried' compared to those who were postpartum or at other stages of pregnancy. When compared with women living in Europe, those in Africa, Asia and Pacific, North America and South/Latin America were more likely to have increased levels of worry, as were those who more frequently interacted with social media. Different forms of support and stress also had an impact upon level of worry, while indicators of stress and anxiety were positively associated with worry level. CONCLUSION: Pregnant and postpartum women are vulnerable to the changes in societal norms brought about by the COVID-19 pandemic. Understanding the factors associated with levels of worry within this population will enable society to address potential unmet needs and improve the current and future mental health of parents and children.

Bioresponsive polymer coated drug nanorods for breast cancer treatment.

Ineffective drug release at the target site is among the top challenges for cancer treatment. This reflects the facts that interaction with the physiological condition can denature active ingredients of drugs, and low delivery to the disease microenvironment leads to poor therapeutic outcomes. We hypothesize that depositing a thin layer of bioresponsive polymer on the surface of drug nanoparticles would not only protect drugs from degradation but also allow the release of drugs at the target site. Here, we report a one-step process to prepare bioresponsive polymer coated drug nanorods (NRs) from liquid precursors using the solvent diffusion method. A thin layer (10.3 ± 1.4 nm) of poly(ε-caprolactone) (PCL) polymer coating was deposited on the surface of camptothecin (CPT) anti-cancer drug NRs. The mean size of PCL-coated CPT NRs was 500.9 ± 91.3 nm length × 122.7 ± 10.1 nm width. The PCL polymer coating was biodegradable at acidic pH 6 as determined by Fourier transform infrared spectroscopy. CPT drugs were released up to 51.5% when PCL coating dissolved into non-toxic carboxyl and hydroxyl groups. Trastuzumab (TTZ), a humanized IgG monoclonal antibody, was conjugated to the NR surface for breast cancer cell targeting. Combination treatments using CPT and TTZ decreased the HER-2 positive BT-474 breast cancer cell growth by 66.9 ± 5.3% in vitro. These results suggest effective combination treatments of breast cancer cells using bioresponsive polymer coated drug delivery.

An Item Response Theory Analysis of the Psychosis Screening Questionnaire in Ethiopia.

AIM: Few psychosis screening instruments have been tested for use in Africa, yet appropriate tools can increase the detection of self-reported psychotic symptoms, improve the detection of psychosis and impact its prognosis. METHOD: The construct validity and factor structure of Psychosis Screening Questionnaire (PSQ) were tested with confirmatory factor analysis (CFA) and item response theory (IRT) in a sample of 1928 Ethiopian adults without any history of psychosis. We tested a unidimensional model with and without an item on mania. For IRT, unidimensional latent structure one-parameter logistic (1PL) and two-parameter (2PL) logistic models were tested and compared for relative fit using a likelihood-ratio test. RESULT AND DISCUSSION: The prevalence of lifetime positive screens was 2.8% in an Ethiopian sample of adults from a general medical setting. A unidimensional model demonstrated good fit for the PSQ, (CFI = 0.993, TLI = 0.986 and RMSEA = 0.025). For IRT, a 2PL model was the best fitting one. IRT tests of item difficulty and discrimination parameters showed that paranoia had the highest discrimination α = 4.59 $$ \left(\alpha =4.59\right) $$ and lowest difficulty ( ß = 2.53 $$ \beta =2.53 $$ ), likely to be endorsed at low levels of psychotic features. Thought insertion had the highest item difficulty ( ß = 2.98 $$ \beta =2.98 $$ ). Overall, the measure captures the psychosis construct at higher levels of the latent trait and may be suited for detecting moderate to severe levels of psychosis. CONCLUSION: The PSQ is found to have good construct validity in screening for psychosis among Ethiopian adults. Future studies may focus on the diagnostic validity of the PSQ comparing it with a structured clinical interview.

Physical symptoms and brain morphology: a population neuroimaging study in 12,286 pre-adolescents.

Physical symptoms, also known as somatic symptoms, are those for which medical examinations do not reveal a sufficient underlying root cause (e.g., pain and fatigue). The extant literature of the neurobiological underpinnings of physical symptoms is largely inconsistent and primarily comprises of (clinical) case-control studies with small sample sizes. In this cross-sectional study, we studied the association between dimensionally measured physical symptoms and brain morphology in pre-adolescents from two population-based cohorts; the Generation R Study (n = 2649, 10.1 ± 0.6 years old) and ABCD Study (n = 9637, 9.9 ± 0.6 years old). Physical symptoms were evaluated using continuous scores from the somatic complaints syndrome scale from the parent-reported Child Behavior Checklist (CBCL). High-resolution structural magnetic resonance imaging (MRI) was collected using 3-Tesla MRI systems. Linear regression models were fitted for global brain metrics (cortical and subcortical grey matter and total white matter volume) and surface-based vertex-wise measures (surface area and cortical thickness). Results were meta-analysed. Symptoms of anxiety/depression were studied as a contrasting comorbidity. In the meta-analyses across cohorts, we found negative associations between physical symptoms and surface area in the (i) left hemisphere; in the lateral orbitofrontal cortex and pars triangularis and (ii) right hemisphere; in the pars triangularis, the pars orbitalis, insula, middle temporal gyrus and caudal anterior cingulate cortex. However, only a subset of regions (left lateral orbitofrontal cortex and right pars triangularis) were specifically associated with physical symptoms, while others were also related to symptoms of anxiety/depression. No significant associations were observed for cortical thickness. This study in preadolescents, the most representative and well-powered to date, showed that more physical symptoms are modestly related to less surface area of the prefrontal cortex mostly. While these effects are subtle, future prospective research is warranted to understand the longitudinal relationship of physical symptoms and brain changes over time. Particularly, to elucidate whether physical symptoms are a potential cause or consequence of distinct neurodevelopmental trajectories.

Construct Validity of the Psychosis Screening Questionnaire in Ugandan Adults.

Background: Psychotic disorders are common and contribute significantly to morbidity and mortality of people with psychiatric diseases. Therefore, early screening and detection may facilitate early intervention and reduce adverse outcomes. Screening tools that lay persons can administer are particularly beneficial in low resource settings. However, there is limited research evaluating the validity of psychosis screening instruments in Uganda. We aimed to assess the construct validity and psychometric properties of the Psychosis Screening Questionnaire (PSQ) in Uganda in a population with no history of a psychotic disorder. Methods: The sample consisted of 2101 Ugandan adults participating as controls in a larger multi-country case-control study on psychiatric genetics. We used confirmatory factor analysis (CFA) and item response theory (IRT) to evaluate the factor structure and item properties of the PSQ. Results: The overall prevalence screening positive for psychotic symptoms was 13.9%. "Strange experiences" were the most endorsed symptoms (6.6%). A unidimensional factor was the best fitting model based on the fit indices including the root mean square error of approximation (RMSEA of 0.00), comparative fit index (CFI of 1.000), and Tucker-Lewis Index (TLI of 1.000). The most discriminating items along the latent construct of psychosis were items assessing thought disturbance followed by items assessing paranoia, with a parameter (discrimination) value of 2.53 and 2.40, respectively. Conclusion: The PSQ works well in Uganda as an initial screening tool for moderate to high-level of psychotic symptoms.

Racial and Ethnic Differences in Drug Disposition and Response: Review of New Molecular Entities Approved Between 2014 and 2019.

Race and ethnicity can contribute to differences in drug exposure and/or response. Here, we report that about 10% of the new molecular entities (NMEs) approved between 2014 and 2019 by the US Food and Drug Administration's Center for Drug Evaluation and Research showed differences in exposure and/or response based on race/ethnicity or pharmacogenetic factors known to vary in frequency across global populations. Fewer NMEs (10%) reported differences in the labeling in 2014 to 2019 when compared to about 21% of NMEs approved between 2008 and 2013 that had differences in pharmacokinetics, safety, response, and/or pharmacogenetics. Understanding the underlying mechanisms that lead to such differences and adequate enrollment of racial and ethnic subgroups is essential to obtain sufficient information on exposure and response. Though drug development is global, when heterogeneous populations are not adequately enrolled, the risk-benefit assessments can remain incomplete for certain subgroups. Consequently, this can result in regional differences in drug approval, population-specific prescribing recommendations, or need for additional postmarketing studies to address concerns related to exposure, response, or lack of representation that lead to gaps in information.

Regulation of endothelial nitric oxide synthase in cardiac remodeling.

OBJECTIVES: Our previous study demonstrated that endothelial nitric oxide synthase (eNOS) gene serves as a candidate for modifiers of hypertrophic cardiomyopathy (HCM), which alters severity of HCM phenotypes. Herein, we sought to further elucidate the role of eNOS on cardiac myocyte hypertrophy and fibrosis, the major phenotypes of HCM. METHODS: Male eNOS-deficient mice (eNOS-/-) and wild type control mice (eNOS+/+, C57B1/6 J) were used in this study. Myocyte size was analyzed in hematoxylin/eosin stained sections using an image analyzing system. Cardiac ß-myosin heavy chain (ß-MHC) and α-skeletal actin (α-SKA) levels, markers of myocyte hypertrophy were evaluated by Western blot. Cardiac collagen volume fraction (CVF) was examined in picrosirius red stained section using an image analyzing system. Cardiac expression of tissue inhibitor of metalloproteinase 1 (TIMP-1) and transforming growth factor beta 1 (TGF-ß1), markers of fibrosis, were determined by Western blot. RESULTS: Compared to eNOS+/+ mice, we found that; 1) myocyte size was significantly increased in eNOS-/- mice; 2) cardiac expression of ß-MHC was markedly elevated, while α-SKA levels remained unchanged in eNOS-/- mice; 3) cardiac total and interstitial CVF levels were significantly higher in eNOS-/- mice; and 4) cardiac TIMP-1 levels were significantly greater in eNOS-/- mice, however, cardiac TGF-ß1 was not differently expressed between the two groups. CONCLUSION: The current study revealed that eNOS plays a beneficial role in cardiac remodeling, preventing the heart from development of myocyte hypertrophy and cardiac fibrosis. These findings support our previous report that eNOS may modify the severity of HCM phenotypes.

Differences in cortical morphology and child internalizing or externalizing problems: Accounting for the co-occurrence.

Background: Childhood internalizing and externalizing problems frequently co-occur. Many studies report neural correlates of either internalizing or externalizing problems, but few account for their co-occurrence. We aimed to assess specific cortical substrates of these psychiatric problems. Methods: We used data from 9635 children aged 9-11 years in the baseline Adolescent Brain Cognitive Development Study. Internalizing and externalizing problem composite scales scores were derived from the Child Behavior Checklist. We standardized FreeSurfer-derived volumes of 68 cortical regions. We examined internalizing and externalizing problems separately and jointly (covariate-adjustment) in relation to cortical volumes, with and without adjusting for total brain volume (TBV) in multivariate linear regressions adjusted for demographics and multiple comparisons. We fit bifactor models to confirm the consistency of patterns exploring specific internalizing and specific externalizing problems. Sensitivity analyses included a vertex-wide analysis and a replication in another large population-based study. Results: In separate TBV-unadjusted analyses, externalizing and internalizing problems were associated with smaller cortical volumes. If adjusted for externalizing behavior, however, larger cortical volumes were associated with internalizing problems, while smaller cortical volumes remained associated with externalizing problems after adjustment for internalizing problems. The bifactor model produced similar results, which were consistently replicated in another pre-adolescent neuroimaging sample. These associations likely represent global effects: adjusting for TBV rendered most associations non-significant. Vertex-wise analyses confirmed global patterns. Conclusion: Our results suggest that internalizing and externalizing problems have globally opposing, and non-specific associations with cortical morphology in childhood, which are only apparent if analyses account for their co-occurrence.

Poverty, Cortical Structure, and Psychopathologic Characteristics in Adolescence.

Importance: Childhood poverty has been associated with increased internalizing and externalizing problems in adolescence, a period of peak onset for psychiatric problems. The underlying neural mechanisms remain unclear because longitudinal studies of poverty, brain structure, and changes in psychiatric symptoms are lacking. Objective: To examine whether structural differences in cortical regions mediate the association between household poverty and change in psychiatric symptoms in early adolescence. Design, Setting, and Participants: This longitudinal cohort study used baseline and 1-year follow-up data from the Adolescent Brain Cognitive Development Study. Children aged 9 to 10 years in the US were enrolled between September 1, 2016, and October 15, 2018. Data analysis was performed from August 13, 2021, to September 30, 2022. Exposures: Household poverty as measured by income-to-needs ratio, which incorporates family income and adjusts for family size as a percentage of the federal poverty level. Main Outcomes and Measures: Mediators were children's cortical surface area, thickness, and volume, obtained using magnetic resonance imaging. Internalizing and externalizing problems at 1-year follow-up were outcomes measured by maternal report using the Child Behavior Checklist. Analyses were adjusted for baseline psychiatric problems and sociodemographic variables, including sex, race and ethnicity, parental educational level, and study site. Results: Of the 7569 children (mean [SD] age, 9.91 [0.62] years; 3970 boys [52.5%]) included in the analysis, 1042 children (13.8%) lived below the poverty threshold between 2016 and 2018. Poverty was associated with increased externalizing symptoms score at 1-year follow-up (b = 1.57; 95% CI, 1.14-1.99), even after adjustment for baseline externalizing symptoms (b = 0.35; 95% CI, 0.06-0.64). The longitudinal associations of poverty with increases in externalizing problems over time were mediated by reductions in surface area in multiple cortical regions that support executive functioning (middle frontal gyrus), decision-making (lateral orbitofrontal cortex), visual processing (fusiform gyrus), auditory processing (transverse temporal gyrus), and emotion and language processing (superior temporal gyrus). Conclusions and Relevance: The findings of this study suggest that childhood poverty is associated with increases in externalizing problems, but not internalizing problems, over time in early adolescence. This association is mediated by reductions in cortical surface area across numerous brain regions. These findings highlight potential neurobiological mechanisms underlying the link between poverty and the emergence of externalizing problems during early adolescence.

Attention-deficit hyperactivity disorder symptoms and brain morphology: Examining confounding bias.

Background: Associations between attention-deficit/hyperactivity disorder (ADHD) and brain morphology have been reported, although with several inconsistencies. These may partly stem from confounding bias, which could distort associations and limit generalizability. We examined how associations between brain morphology and ADHD symptoms change with adjustments for potential confounders typically overlooked in the literature (aim 1), and for the intelligence quotient (IQ) and head motion, which are generally corrected for but play ambiguous roles (aim 2). Methods: Participants were 10-year-old children from the Adolescent Brain Cognitive Development (N = 7722) and Generation R (N = 2531) Studies. Cortical area, volume, and thickness were measured with MRI and ADHD symptoms with the Child Behavior Checklist. Surface-based cross-sectional analyses were run. Results: ADHD symptoms related to widespread cortical regions when solely adjusting for demographic factors. Additional adjustments for socioeconomic and maternal behavioral confounders (aim 1) generally attenuated associations, as cluster sizes halved and effect sizes substantially reduced. Cluster sizes further changed when including IQ and head motion (aim 2), however, we argue that adjustments might have introduced bias. Conclusions: Careful confounder selection and control can help identify more robust and specific regions of associations for ADHD symptoms, across two cohorts. We provided guidance to minimizing confounding bias in psychiatric neuroimaging. Funding: Authors are supported by an NWO-VICI grant (NWO-ZonMW: 016.VICI.170.200 to HT) for HT, LDA, SL, and the Sophia Foundation S18-20, and Erasmus University and Erasmus MC Fellowship for RLM.

Construct validity and factor structure of the K-10 among Ugandan adults.

BACKGROUND: Psychological distress is often used as a proxy measure for the mental health of a population. The Kessler Psychological Distress Scale (K-10) is a widely used brief screening tool for psychological distress, yet few studies have evaluated its utility in sub-Saharan Africa. We evaluated its construct validity and factor structure in Uganda. METHODS: We used data from an ongoing case-control study. Participants in the present study were patients seeking general medical outpatient services and caretakers of mentally ill persons. Demographic data were collected using a structured questionnaire, and psychological distress was assessed using the K-10. K-10 construct validity and factorial structure were assessed through exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). RESULTS: A total of 2104 participants were included in this analysis, these were controls from a general medical setting. The mean K-10 score was 2.34 with an internal consistency of 0.86. EFA resulted in a two-factor solution that accounted for 78.37% of the variance. CFA revealed that a unidimensional model of psychological distress with correlated errors between some of K-10 items was superior, with a comparative fit index of 0.95, Tucker-Lewis index of 0.93, and a root mean square error of approximation of 0.08. LIMITATIONS: The study was limited to evaluating internal consistency and construct validity. Future studies are warranted to examine criterion validity and establish cut-offs for psychological distress. CONCLUSIONS: The K-10 had good psychometric properties in this population and may be useful for measuring broad psychological distress in general medical settings.

A Systematic Review of Cost-Effectiveness Analyses for Hepatocellular Carcinoma Treatment.

BACKGROUND: Hepatocellular carcinoma (HCC) is associated with significant financial burden for patients and payers. The objective of this study was to review economic models to identify, evaluate, and compare cost-effectiveness estimates for HCC treatments. METHODS: A systematic search of the PubMed, Embase, and Cochrane Library databases to identify economic evaluations was performed and studies that modeled treatments for HCC reporting costs and cost effectiveness were included. Risk of bias was assessed qualitatively, considering costing approach, reported study perspective, and funding received. Intervention costs were adjusted to 2021 US dollars for comparison. For studies reporting quality-adjusted life-years (QALYs), we conducted analyses stratified by comparison type to assess cost effectiveness at the time of the analysis. RESULTS: A total of 27 studies were included. Non-curative versus non-curative therapy comparisons were used in 20 (74.1%) studies, curative versus curative comparisons were used in 5 (18.5%) studies, and curative versus non-curative comparisons were used in 2 (7.4%) studies. Therapy effectiveness was estimated using a QALY measure in 20 (74.1%) studies, while 7 (25.9%) studies only assessed life-years gained (LYG). A health sector perspective was used in 26 (96.3%) of the evaluations, with only 1 study including costs beyond this perspective. Median intervention cost was $53,954 (range $4550-$4,760,835), with a median incremental cost of $6546 (range - $72,441 to $1,279,764). In cost-utility analyses, 11 (55%) studies found the intervention cost effective using a $100,000/QALY threshold at the time of the study, with an incremental cost-effectiveness ratio (ICER) ranging from - $1,176,091 to $1,152,440 when inflated to 2021 US dollars. CONCLUSION: The majority of HCC treatments were found to be cost effective, but with significant variation and with few studies considering indirect costs. Standards for value assessment for HCC treatments may help improve consistency and comparability.

Psychometric properties and factor structure of the Kessler-10 among Ethiopian adults.

BACKGROUND: Many common mental disorders are underdiagnosed and undertreated in low-resource countries. The ten-item Kessler Psychological Distress Scale (K10) is a brief screening tool widely used to assess psychological distress. We evaluated the K10's performance in an Ethiopian population by assessing internal consistency and construct validity through factor structure. METHODS: K10 survey responses and sociodemographic data were collected from 1928 adults, including patients and caregivers from a general medical setting, who served as controls of a large epidemiological study. RESULTS: The K10 had good internal consistency, with a Cronbach's alpha of 0.83. Results from exploratory factor analyses showed that the K10 had a two-factor solution that accounted for approximately 66% of the variance. Confirmatory factor analyses demonstrated that a unidimensional model with correlated errors, informed by a theoretical model, was the best fitting model for the setting (comparative fit index of 0.90 and root mean square error of approximation of 0.10). LIMITATIONS: We did not assess the K10's test-retest reliability or its criterion validity (i.e., agreement with a reference measure). CONCLUSIONS: Based on internal consistency and construct validity, the K10 can effectively assess psychological distress among Ethiopian adults for population-based research and potentially clinical screening, consistent with previous findings in this setting. Further studies are needed to test its criterion validity against a reference measure of psychological distress.

Factor structure and item response of psychosis symptoms among Kenyan adults.

BACKGROUND: The aim of this study was to evaluate the construct validity of the psychosis module of the Mini International Neuropsychiatric Interview version 7.0.2 (MINI-7). METHOD: We utilized data collected from 2738 participants with a primary psychotic or bipolar disorder. Participants were drawn from two Kenyan sites of a large multi-center neuropsychiatric genetic study. The factor structure of the MINI-7 psychosis items were explored using confirmatory factor analyses (CFA) and Item Response Theory approach, for the full sample and by gender. RESULTS: The CFA revealed that a 1-factor model provided adequate fit for the MINI-7 psychosis items for the full sample (x2 = 397.92, df = 35, p < .0001; RMSEA = 0.06; CFI = 0.92; TLI = 0.90) as well as for the female (x2 = 185.16.92, df = 35, p < .0001; RMSEA = 0.06; CFI = 0.93; TLI = 0.91) and male groups (x2 = 242.09, df = 35, p < .0001; RMSEA = 0.06; CFI = 0.92; TLI = 0.89). Item thresholds for the full sample, and female and male groups were highest for 'odd beliefs' (-1.42, -1.33, and -1.51 respectively) and lowest for 'visual hallucinations' (-0.03, -0.04, and -0.01 respectively). LIMITATIONS: Our study used a hospital-based population, which may have excluded patients with milder psychotic symptoms. Findings may therefore not be generalizable to the community setting. CONCLUSIONS: Our findings indicate good construct validity of the MINI-7 psychosis module, and provides support for use of the tool in diagnosing psychotic disorders in clinical settings in Kenya.

Construct validity and factor structure of the Kessler-10 in South Africa.

BACKGROUND: 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.

Cross-country variations in the reporting of psychotic symptoms among sub-Saharan African adults: A psychometric evaluation of the Psychosis Screening Questionnaire.

BACKGROUND: Self-reporting of psychotic symptoms varies significantly between cultures and ethnic groups. Yet, limited validated screening instruments are available to capture such differences in the African continent. METHODOLOGY: Among 9,059 individuals participating as controls in a multi-country case-control study of the genetic causes of psychosis, we evaluated the psychometric properties of the Psychosis Screening Questionnaire (PSQ). We applied multi-group confirmatory factor analysis and item response theory to assess item parameters. RESULTS: The overall positive endorsement of at least one item assessing psychotic symptoms on the PSQ was 9.7%, with variability among countries (Uganda 13.7%, South Africa 11%, Kenya 10.2%, and Ethiopia 2.8%). A unidimensional model demonstrated good fit for the PSQ (root mean square error of approximation = 0.009; comparative fit index = 0.997; and Tucker-Lewis Index = 0.995). Hypomania had the weakest association with single latent factor (standardized factor loading 0.62). Sequential multi-group confirmatory factor analysis demonstrated that PSQ items were measured in equivalent ways across the four countries. PSQ items gave more information at higher levels of psychosis, with hypomania giving the least discriminating information. LIMITATIONS: Participants were recruited from general medical facilities, so findings may not be generalizable to the general population. CONCLUSION: The PSQ demonstrated a unidimensional factor structure in these samples. Items were measured equivalently across all study settings, suggesting that differences in prevalence of psychotic symptoms between countries were less likely to represent measurement artifact. The PSQ is more reliable in screening for psychosis in individuals with higher degrees of psychotic experiences-hypomania excluded-and might decrease the false-positive rate from mild nonspecific psychotic experiences.