Last data update: Jun 24, 2024. (Total: 47078 publications since 2009)
Records 1-8 (of 8 Records) |
Query Trace: Niska R [original query] |
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Analysis of false-negative HIV rapid tests performed on oral fluid in three international clinical research studies
Curlin ME , Gvetadze R , Leelawiwat W , Martin M , Rose C , Niska RW , Segolodi TM , Choopanya K , Tongtoyai J , Holtz TH , Samandari T , McNicholl JM . Clin Infect Dis 2017 64 (12) 1663-1669 Objective: The OraQuick Advance Rapid HIV-1/2 Test is a point-of-care test capable of detecting HIV-specific antibodies in blood and oral fluid. To understand test performance and factors contributing to false-negative (FN) results in longitudinal studies, we examined results of participants enrolled in the TDF2 study, the Bangkok Tenofovir Study, and the Bangkok MSM Cohort Study (BMCS), three separate clinical studies of high-risk, HIV-negative persons conducted in Botswana and Thailand. Design: Retrospective observational analysis. Methods: We compared oral fluid OraQuick (OFOQ) results among participants becoming HIV-infected to results obtained retrospectively using enzyme immunoassay and nucleic acid amplification tests on stored specimens. We categorized negative OFOQ results as true-negative or false-negative relative to NAAT and/or EIA, and determined the delay in OFOQ conversion relative to the estimated time of infection. We used generalized estimating equations to examine the association between FN results and participant, clinical and testing-site factors. Results: Two-hundred and thirty-three FN OFOQ results occurred in 80 of 287 seroconverting individuals. Estimated OFOQ conversion delay ranged from 14.5-547.5 (median 98.5) days. Delayed OFOQ conversion was associated with clinical site and test operator (p<0.05), pre-exposure prophylaxis (p=0.01), low plasma viral load (p<0.02) and time to kit expiration (p<0.01). Participant age, gender, and HIV subtype were not associated with FN results. Long OFOQ conversion delay time was associated with antiretroviral exposure and low PVL. Conclusions: Failure of OFOQ to detect HIV-1 infection was frequent, and multifactorial in origin. In longitudinal trials, negative oral fluid results should be confirmed by testing blood samples. |
Normal laboratory reference intervals among healthy adults screened for a HIV pre-exposure prophylaxis clinical trial in Botswana
Segolodi TM , Henderson FL , Rose CE , Turner KT , Zeh C , Fonjungo PN , Niska R , Hart C , Paxton LA . PLoS One 2014 9 (4) e93034 INTRODUCTION: Accurate clinical laboratory reference values derived from a local or regional population base are required to correctly interpret laboratory results. In Botswana, most reference intervals used to date are not standardized across clinical laboratories and are based on values derived from populations in the United States or Western Europe. METHODS: We measured 14 hematologic and biochemical parameters of healthy young adults screened for participation in the Botswana HIV Pre-exposure Prophylaxis Study using tenofovir disoproxil fumarate and emtricitabine (TDF/FTC) (TDF2 Study). Reference intervals were calculated using standard methods, stratified by gender, and compared with the site-derived reference values used for the TDF2 study (BOTUSA ranges), the Division of AIDS (DAIDS) Grading Table for Adverse Events, the Botswana public health laboratories, and other regional references. RESULTS: Out of 2533 screened participants, 1786 met eligibility criteria for participation in study and were included in the analysis. Our reference values were comparable to those of the Botswana public health system except for amylase, blood urea nitrogen (BUN), phosphate, total and direct bilirubin. Compared to our reference values, BOTUSA reference ranges would have classified participants as out of range for some analytes, with amylase (50.8%) and creatinine (32.0%) producing the highest out of range values. Applying the DAIDS toxicity grading system to the values would have resulted in 45 and 18 participants as having severe or life threatening values for amylase and hemoglobin, respectively. CONCLUSION: Our reference values illustrate the differences in hematological and biochemical analyte ranges between African and Western populations. Thus, the use of western-derived reference laboratory values to screen a group of Batswana adults resulted in many healthy people being classified as having out-of-range blood analytes. The need to establish accurate local or regional reference values is apparent and we hope our results can be used to that end in Botswana. |
Bone mineral density changes among HIV-uninfected young adults in a randomised trial of pre-exposure prophylaxis with tenofovir-emtricitabine or placebo in Botswana
Kasonde M , Niska RW , Rose C , Henderson FL , Segolodi TM , Turner K , Smith DK , Thigpen MC , Paxton LA . PLoS One 2014 9 (3) e90111 BACKGROUND: Tenofovir-emtricitabine (TDF-FTC) pre-exposure prophylaxis (PrEP) has been found to be effective for prevention of HIV infection in several clinical trials. Two studies of TDF PrEP among men who have sex with men showed slight bone mineral density (BMD) loss. We investigated the effect of TDF and the interaction of TDF and hormonal contraception on BMD among HIV-uninfected African men and women. METHOD: We evaluated the effects on BMD of using daily oral TDF-FTC compared to placebo among heterosexual men and women aged 18-29 years enrolled in the Botswana TDF2 PrEP study. Participants had BMD measurements at baseline and thereafter at 6-month intervals with dual-energy X-ray absorptiometry (DXA) scans at the hip, spine, and forearm. RESULTS: A total of 220 participants (108 TDF-FTC, 112 placebo) had baseline DXA BMD measurements at three anatomic sites. Fifteen (6.8%) participants had low baseline BMD (z-score of <-2.0 at any anatomic site), including 3/114 women (2.6%) and 12/106 men (11.3%) (p = 0.02). Low baseline BMD was associated with being underweight (p = 0.02), having high blood urea nitrogen (p = 0.02) or high alkaline phosphatase (p = 0.03), and low creatinine clearance (p = 0.04). BMD losses of >3.0% at any anatomic site at any time after baseline were significantly greater for the TDF-FTC treatment group [34/68 (50.0%) TDF-FTC vs. 26/79 (32.9%) placebo; p = 0.04]. There was a small but significant difference in the mean percent change in BMD from baseline for TDF-FTC versus placebo at all three sites at month 30 [forearm -0.84% (p = 0.01), spine -1.62% (p = 0.0002), hip -1.51% (p = 0.003)]. CONCLUSION: Use of TDF-FTC was associated with a small but statistically significant decrease in BMD at the forearm, hip and lumbar spine. A high percentage (6.8%) of healthy Batswana young adults had abnormal baseline BMD. Further evaluation is needed of the longer-term use of TDF in HIV-uninfected persons. TRIAL REGISTRATION: ClinicalTrials.gov NCT00448669. |
CD4+ cell count, viral load, and drug resistance patterns among heterosexual breakthrough HIV infections in a study of oral preexposure prophylaxis
Chirwa LI , Johnson JA , Niska RW , Segolodi TM , Henderson FL , Rose CE , Li JF , Thigpen MC , Matlhaba O , Paxton LA , Brooks JT . AIDS 2013 28 (2) 223-6 We examined CD4 cell count and plasma viral load patterns among Botswana TDF/FTC Oral HIV Prophylaxis Trial (TDF2 study) participants who seroconverted, comparing participants assigned to receive tenofovir/emtricitabine with participants assigned to receive placebo. We also evaluated for antiretroviral drug resistance among the breakthrough HIV infections. Among nine seroconverters assigned to tenofovir/emtricitabine and 24 to placebo, there were no significant differences in their CD4 cell count or viral load profiles over time. Of the four participants who seroconverted on-study while receiving tenofovir/emtricitabine, none became infected as a result of drug-resistant HIV; moreover, no resistance mutations emerged following seroconversion. |
Hospital preparedness for emergency response: United States, 2008
Niska RW , Shimizu IM . Natl Health Stat Report 2011 (37) 1-14 OBJECTIVE: This report is a summary of hospital preparedness for responding to public health emergencies, including mass casualties and epidemics of naturally occurring diseases such as influenza. METHODS: Data are from an emergency response preparedness supplement to the 2008 National Hospital Ambulatory Medical Care Survey, which uses a national probability sample of nonfederal general and short-stay hospitals in the United States. Sample data were weighted to produce national estimates. |
National Hospital Ambulatory Medical Care Survey: 2007 emergency department summary
Niska R , Bhuiya F , Xu J . Natl Health Stat Report 2010 (26) 1-31 OBJECTIVE: This report presents data on U.S. emergency department (ED) visits in 2007, with statistics on hospital, patient, and visit characteristics. METHODS: Data are from the 2007 National Hospital Ambulatory Medical Care Survey, which uses a national probability sample of visits to emergency departments of nonfederal general and short-stay hospitals in the United States. Sample data were weighted to produce annual national estimates. RESULTS: In 2007, there were about 117 million ED visits in the United States. About 25 percent of visits were covered by Medicaid or the State Children's Health Insurance Program (SCHIP). About one-fifth of ED visits by children younger than 15 years of age were to pediatric EDs. There were 121 ED visits for asthma per 10,000 children under 5 years of age. The leading injury-related cause of ED visits was unintentional falls. Two percent of visits resulted in admission to an observation unit. Electronic medical records were used in 62 percent of EDs. |
Research using emergency department-related data sets: current status and future directions
Hirshon JM , Warner M , Irvin CB , Niska RW , Andersen DA , Smith GS , McCaig LF . Acad Emerg Med 2009 16 (11) 1103-9 The 2009 Academic Emergency Medicine consensus conference focused on "Public Health in the ED: Surveillance, Screening and Intervention." One conference breakout session discussed the significant research value of health-related data sets. This article represents the proceedings from that session, primarily focusing on emergency department (ED)-related data sets and includes examples of the use of a data set based on ED visits for research purposes. It discusses types of ED-related data sets available, highlights barriers to research use of ED-related data sets, and notes limitations of these data sets. The paper highlights future directions and challenges to using these important sources of data for research, including identification of five main needs related to enhancing the use of ED-related data sets. These are 1) electronic linkage of initial and follow-up ED visits and linkage of information about ED visits to other outcomes, including costs of care, while maintaining de-identification of the data; 2) timely data access with minimal barriers; 3) complete data collection for clinically relevant and/or historical data elements, such as the external cause-of-injury code; 4) easy access to data that can be parsed into smaller jurisdictions (such as states) for policy and/or research purposes, while maintaining confidentiality; and 5) linkages between health survey data and health claims data. ED-related data sets contain much data collected directly from health care facilities, individual patient records, and multiple other sources that have significant potential impact for studying and improving the health of individuals and the population. |
The use of antiplatelet agents for secondary prevention of ischemic stroke in U.S. ambulatory care settings
Niska R , Han B . J Health Care Poor Underserved 2009 20 (3) 831-9 INTRODUCTION: We examined stroke prevention with antiplatelet agents by U.S. nonfederal office physicians and hospital outpatient departments from 2005-2006. METHODS: The nationally representative dataset used a multistage (112 primary sampling units, physicians/ hospitals, patient medical records) random sample of 1,702 visits by patients 20 years or older with cerebrovascular disease (national estimate: 15.4 million annual visits). Dependent variable: use of antiplatelet agents for patients without contraindications. Independent variables: age, sex, race/ethnicity, payment, primary care provider, prior visits in last year, comorbidities. Logistic regression was used to investigate associations with recommended interventions. RESULTS: Antiplatelet agents were prescribed at 31.1% of visits. Positive predictors: seeing the patient's primary care provider and having five or more comorbidities. Negative predictors: non-Hispanic Black race/ethnicity and having six or more prior visits in the last year. CONCLUSION: Variations by visit characteristics suggest that improvement in using antiplatelet agents is possible, especially for non-Hispanic Black patients. |
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