81 research outputs found

    Substance abuse and HIV risk behaviours amongst primary health care service users in Cape Town

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    Objective: To document prevalence of, and association between, substance use and HIV risk behaviours among primary care patients.Method: Cross-sectional survey. Four primary care clinics in Cape Town. We selected clinics using stratified sampling, and systematically selected 131 patients from attendance logs. We assessed substance use with the Alcohol, Smoking and Substance Involvement Screening Test, and HIV risk with items addressing injection drug use, blood-sharing rituals, and sexual risk behaviours. Results: Substances most used at hazardous levels were tobacco (28.2%) and alcohol (14.8%). Among possible HIV risk factors, highest prevalence was participation in blood-sharing rituals (25%), and having had an STI (19.8%). An association between substance use and sexual risk behaviours was only found among those aged 18-24. Conclusion: In younger patients, presence of substance use or HIV risk behaviours increases the probability that the other is present

    Substance abuse and HIV risk behaviours amongst primary health care service users in Cape Town

    Get PDF
    Objective: To document prevalence of, and association between, substance use and HIV risk behaviours among primary care patients.Method: Cross-sectional survey. Four primary care clinics in Cape Town. We selected clinics using stratified sampling, and systematically selected 131 patients from attendance logs. We assessed substance use with the Alcohol, Smoking and Substance Involvement Screening Test, and HIV risk with items addressing injection drug use, blood-sharing rituals, and sexual risk behaviours. Results: Substances most used at hazardous levels were tobacco (28.2%) and alcohol (14.8%). Among possible HIV risk factors, highest prevalence was participation in blood-sharing rituals (25%), and having had an STI (19.8%). An association between substance use and sexual risk behaviours was only found among those aged 18-24. Conclusion: In younger patients, presence of substance use or HIV risk behaviours increases the probability that the other is present. Keywords: substance abuse, HIV risk behaviours, primary care South African Psychiatry Review Vol. 8(4) 2005: 160-16

    Benzodiazepine and Unhealthy Alcohol Use Among Adult Outpatients

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    OBJECTIVES: Concomitant excessive alcohol consumption and benzodiazepine use is associated with adverse health outcomes. We examined associations of unhealthy alcohol use and other patient characteristics with benzodiazepine use. STUDY DESIGN: A cross-sectional analysis of 2,089,525 Kaiser Permanente of Northern California outpatients screened for unhealthy alcohol use in primary care between November 1, 2014, and December 31, 2016. METHODS: We fit multivariable generalized linear models to estimate the associations between unhealthy alcohol use and benzodiazepine dispensation and, among patients who were dispensed a benzodiazepine, mean doses (in mean lorazepam-equivalent daily doses [LEDDs]) and prescription durations. We controlled for patient sex, age, race/ethnicity, estimated household income, Charlson Comorbidity Index (CCI) score, anxiety disorder, alcohol use disorder, insomnia, musculoskeletal pain, and epilepsy. RESULTS: In the 12 months centered around (6 months before and 6 months after) the first alcohol-screening visit, 7.5% of patients used benzodiazepines. The following characteristics were independently associated with higher rates of benzodiazepine use, higher LEDD, and longer prescription duration: older age, white race/ethnicity, lower estimated household income, higher CCI score, and the presence of an anxiety disorder, insomnia, musculoskeletal pain, or epilepsy. Women and patients with an alcohol use disorder or unhealthy alcohol use, compared with men and patients with low-risk drinking or abstinence, were more likely to use a benzodiazepine; however, their LEDDs were lower and their prescription durations were shorter. CONCLUSIONS: Benzodiazepine use in primary care was associated with older age, female sex, white race/ethnicity, lower socioeconomic status, and unhealthy alcohol use. These findings may be applied to develop policies and interventions to promote judicious benzodiazepine use

    Accounting for quality improvement during the conduct of embedded pragmatic clinical trials within healthcare systems: NIH Collaboratory case studies

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    Embedded pragmatic clinical trials (ePCTs) and quality improvement (QI) activities often occur simultaneously within healthcare systems (HCSs). Embedded PCTs within HCSs are conducted to test interventions and provide evidence that may impact public health, health system operations, and quality of care. They are larger and more broadly generalizable than QI initiatives, and may generate what is considered high-quality evidence for potential use in care and clinical practice guidelines. QI initiatives often co-occur with ePCTs and address the same high-impact health questions, and this co-occurrence may dilute or confound the ability to detect change as a result of the ePCT intervention. During the design, pilot, and conduct phases of the large-scale NIH Collaboratory Demonstration ePCTs, many QI initiatives occurred at the same time within the HCSs. Although the challenges varied across the projects, some common, generalizable strategies and solutions emerged, and we share these as case studies. KEY LESSONS: Study teams often need to monitor, adapt, and respond to QI during design and the course of the trial. Routine collaboration between ePCT researchers and health systems stakeholders throughout the trial can help ensure research and QI are optimally aligned to support high-quality patient-centered care

    The genetic architecture of the human cerebral cortex

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    The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

    Conversion Discriminative Analysis on Mild Cognitive Impairment Using Multiple Cortical Features from MR Images

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    Neuroimaging measurements derived from magnetic resonance imaging provide important information required for detecting changes related to the progression of mild cognitive impairment (MCI). Cortical features and changes play a crucial role in revealing unique anatomical patterns of brain regions, and further differentiate MCI patients from normal states. Four cortical features, namely, gray matter volume, cortical thickness, surface area, and mean curvature, were explored for discriminative analysis among three groups including the stable MCI (sMCI), the converted MCI (cMCI), and the normal control (NC) groups. In this study, 158 subjects (72 NC, 46 sMCI, and 40 cMCI) were selected from the Alzheimer's Disease Neuroimaging Initiative. A sparse-constrained regression model based on the l2-1-norm was introduced to reduce the feature dimensionality and retrieve essential features for the discrimination of the three groups by using a support vector machine (SVM). An optimized strategy of feature addition based on the weight of each feature was adopted for the SVM classifier in order to achieve the best classification performance. The baseline cortical features combined with the longitudinal measurements for 2 years of follow-up data yielded prominent classification results. In particular, the cortical thickness produced a classification with 98.84% accuracy, 97.5% sensitivity, and 100% specificity for the sMCI–cMCI comparison; 92.37% accuracy, 84.78% sensitivity, and 97.22% specificity for the cMCI–NC comparison; and 93.75% accuracy, 92.5% sensitivity, and 94.44% specificity for the sMCI–NC comparison. The best performances obtained by the SVM classifier using the essential features were 5–40% more than those using all of the retained features. The feasibility of the cortical features for the recognition of anatomical patterns was certified; thus, the proposed method has the potential to improve the clinical diagnosis of sub-types of MCI and predict the risk of its conversion to Alzheimer's disease

    Quantitative 18F-AV1451 Brain Tau PET Imaging in Cognitively Normal Older Adults, Mild Cognitive Impairment, and Alzheimer's Disease Patients

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    Recent developments of tau Positron Emission Tomography (PET) allows assessment of regional neurofibrillary tangles (NFTs) deposition in human brain. Among the tau PET molecular probes, 18F-AV1451 is characterized by high selectivity for pathologic tau aggregates over amyloid plaques, limited non-specific binding in white and gray matter, and confined off-target binding. The objectives of the study are (1) to quantitatively characterize regional brain tau deposition measured by 18F-AV1451 PET in cognitively normal older adults (CN), mild cognitive impairment (MCI), and AD participants; (2) to evaluate the correlations between cerebrospinal fluid (CSF) biomarkers or Mini-Mental State Examination (MMSE) and 18F-AV1451 PET standardized uptake value ratio (SUVR); and (3) to evaluate the partial volume effects on 18F-AV1451 brain uptake.Methods: The study included total 115 participants (CN = 49, MCI = 58, and AD = 8) from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Preprocessed 18F-AV1451 PET images, structural MRIs, and demographic and clinical assessments were downloaded from the ADNI database. A reblurred Van Cittertiteration method was used for voxelwise partial volume correction (PVC) on PET images. Structural MRIs were used for PET spatial normalization and region of interest (ROI) definition in standard space. The parametric images of 18F-AV1451 SUVR relative to cerebellum were calculated. The ROI SUVR measurements from PVC and non-PVC SUVR images were compared. The correlation between ROI 18F-AV1451 SUVR and the measurements of MMSE, CSF total tau (t-tau), and phosphorylated tau (p-tau) were also assessed.Results:18F-AV1451 prominently specific binding was found in the amygdala, entorhinal cortex, parahippocampus, fusiform, posterior cingulate, temporal, parietal, and frontal brain regions. Most regional SUVRs showed significantly higher uptake of 18F-AV1451 in AD than MCI and CN participants. SUVRs of small regions like amygdala, entorhinal cortex and parahippocampus were statistically improved by PVC in all groups (p < 0.01). Although there was an increasing tendency of 18F-AV-1451 SUVRs in MCI group compared with CN group, no significant difference of 18F-AV1451 deposition was found between CN and MCI brains with or without PVC (p > 0.05). Declined MMSE score was observed with increasing 18F-AV1451 binding in amygdala, entorhinal cortex, parahippocampus, and fusiform. CSF p-tau was positively correlated with 18F-AV1451 deposition. PVC improved the results of 18F-AV-1451 tau deposition and correlation studies in small brain regions.Conclusion: The typical deposition of 18F-AV1451 tau PET imaging in AD brain was found in amygdala, entorhinal cortex, fusiform and parahippocampus, and these regions were strongly associated with cognitive impairment and CSF biomarkers. Although more deposition was observed in MCI group, the 18F-AV-1451 PET imaging could not differentiate the MCI patients from CN population. More tau deposition related to decreased MMSE score and increased level of CSF p-tau, especially in ROIs of amygdala, entorhinal cortex and parahippocampus. PVC did improve the results of tau deposition and correlation studies in small brain regions and suggest to be routinely used in 18F-AV1451 tau PET quantification
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