scholarly journals Sample size calculation for active-arm trial with counterfactual incidence based on recency assay

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Fei Gao ◽  
David V. Glidden ◽  
James P. Hughes ◽  
Deborah J. Donnell
Keyword(s):  
Sample Size ◽  
Sample Size Calculation ◽  
Standard Of Care ◽  
Sub Saharan Africa ◽  
Control Group ◽  
Sample Sizes ◽  
Delivery Methods ◽  
Sub Saharan ◽  
Sex With Men ◽  
Exposure Prophylaxis

Abstract Objectives The past decade has seen tremendous progress in the development of biomedical agents that are effective as pre-exposure prophylaxis (PrEP) for HIV prevention. To expand the choice of products and delivery methods, new medications and delivery methods are under development. Future trials of non-inferiority, given the high efficacy of ARV-based PrEP products as they become current or future standard of care, would require a large number of participants and long follow-up time that may not be feasible. This motivates the construction of a counterfactual estimate that approximates incidence for a randomized concurrent control group receiving no PrEP. Methods We propose an approach that is to enroll a cohort of prospective PrEP users and aug-ment screening for HIV with laboratory markers of duration of HIV infection to indicate recent infections. We discuss the assumptions under which these data would yield an estimate of the counterfactual HIV incidence and develop sample size and power calculations for comparisons to incidence observed on an investigational PrEP agent. Results We consider two hypothetical trials for men who have sex with men (MSM) and transgender women (TGW) from different regions and young women in sub-Saharan Africa. The calculated sample sizes are reasonable and yield desirable power in simulation studies. Conclusions Future one-arm trials with counterfactual placebo incidence based on a recency assay can be conducted with reasonable total screening sample sizes and adequate power to determine treatment efficacy.

scholarly journals “I wish to remain HIV negative”: Pre-exposure prophylaxis adherence and persistence in transgender women and men who have sex with men in coastal Kenya

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0244226
Author(s):  
Makobu Kimani ◽  
Elise M. van der Elst ◽  
Oscar Chirro ◽  
Elizabeth Wahome ◽  
Fauz Ibrahim ◽  
...  
Keyword(s):  
Risk Behaviour ◽  
Healthcare Services ◽  
Transgender Women ◽  
Situational Factors ◽  
Sub Saharan Africa ◽  
Sexual Risk Behaviour ◽  
Sub Saharan ◽  
Sex With Men ◽  
Hiv Acquisition ◽  
Exposure Prophylaxis

Background Transgender women (TGW) and men who have sex with men (MSM) in sub-Saharan Africa have high HIV acquisition risks and can benefit from daily pre-exposure prophylaxis (PrEP). We assessed PrEP adherence by measuring tenofovir-diphosphate (TFV-DP) levels and explore motives for PrEP persistence in TGW and MSM. Methods Participants were enrolled in a one-year PrEP programme and made quarterly visits irrespective of whether they were still using PrEP. At their month 6 visit, participants provided a dried blood spot to test for TFV-DP levels; protective levels were defined as those compatible with ≥4 pills per week (700–1249 fmol/punch). Before TFV-DP levels were available, a sub-set of these participants were invited for an in-depth interview (IDI). Semi-structured IDI topic guides were used to explore motives to uptake, adhere to, and discontinue PrEP. IDI data were analyzed thematically. Results Fifty-three participants (42 MSM and 11 TGW) were enrolled. At month 6, 11 (20.7%) participants (8 MSM and 3 TGW) were lost to follow up or stopped taking PrEP. Any TFV-DP was detected in 62.5% (5/8) of TGW vs. 14.7% of MSM (5/34, p = 0.01). Protective levels were detected in 37.5% of TGW (3/8), but not in any MSM. Nineteen IDI were conducted with 7 TGW and 9 MSM on PrEP, and 1 TGW and 2 MSM off PrEP. Unplanned or frequent risky sexual risk behaviour were the main motives for PrEP uptake. Among participants on PrEP, TGW had a more complete understanding of the benefits of PrEP. Inconsistent PrEP use was attributed to situational factors. Motives to discontinue PrEP included negative reactions from partners and stigmatizing healthcare services. Conclusion While MSM evinced greater adherence challenges in this PrEP programme, almost 40% of TGW were protected by PrEP. Given high HIV incidences in TGW these findings hold promise for TGW PrEP programming in the region.

scholarly journals Continuing high levels of HIV diagnoses in men who have sex with men in the United Kingdom

2008 ◽  
Vol 13 (14) ◽  
pp. 3-4
Author(s):  
B Rice ◽  
A Nardone ◽  
N Gill ◽  
V Delpech
Keyword(s):  
United Kingdom ◽  
Confidence Intervals ◽  
Sub Saharan Africa ◽  
Newly Diagnosed ◽  
The United Kingdom ◽  
Reporting Delays ◽  
Sub Saharan ◽  
Sex With Men ◽  
The Uk ◽  
Almost All

The latest HIV data for 2007 has recently been published for the United Kingdom (UK). During the year, an estimated 6,840 (95% confidence intervals 6,600-7,050) persons (adjusted for reporting delays) were newly diagnosed with HIV in the UK. This represents a 12% decline from a peak of new HIV diagnoses reported in 2005 (7,800). Almost all this decline in new HIV diagnoses was in HIV-infected heterosexuals from sub-Saharan Africa who were probably infected in their country of origin.

scholarly journals Barriers to and enablers of uptake of antiretroviral therapy in integrated HIV and tuberculosis treatment programmes in sub-Saharan Africa: a systematic review and meta-analysis

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Benjamin Momo Kadia ◽  
Christian Akem Dimala ◽  
Noah T. Fongwen ◽  
Adrian D. Smith
Keyword(s):  
Systematic Review ◽  
Antiretroviral Therapy ◽  
Health System ◽  
Sample Size ◽  
Meta Analysis ◽  
Sub Saharan Africa ◽  
System Level ◽  
Comprehensive Treatment ◽  
Barriers And Enablers ◽  
Sub Saharan

Abstract Introduction Programmes that merge management of Human Immunodeficiency Virus (HIV) and tuberculosis (TB) aim to improve HIV/TB co-infected patients’ access to comprehensive treatment. However, several reports from sub-Saharan Africa (SSA) indicate suboptimal uptake of antiretroviral therapy (ART) even after integration of HIV and TB treatment. This study assessed ART uptake, its barriers and enablers in programmes integrating TB and HIV treatment in SSA. Method A systematic review was performed. Seven databases were searched for eligible quantitative, qualitative and mixed-methods studies published from March 2004 through July 2019. Random-effects meta-analysis was used to obtain pooled estimates of ART uptake. A thematic approach was used to analyse and synthesise data on barriers and enablers. Results Of 5139 references identified, 27 were included in the review: 23/27 estimated ART uptake and 10/27 assessed barriers to and/or enablers of ART uptake. The pooled ART uptake was 53% (95% CI: 42, 63%) and between-study heterogeneity was high (I2 = 99.71%, p < 0.001). WHO guideline on collaborative TB/HIV activities and sample size were associated with heterogeneity. There were statistically significant subgroup effects with high heterogeneity after subgroup analyses by region, guideline on collaborative TB/HIV activities, study design, and sample size. The most frequently described socioeconomic and individual level barriers to ART uptake were stigma, low income, and younger age group. The most frequently reported health system-related barriers were limited staff capacity, shortages in medical supplies, lack of infrastructure, and poor adherence to or lack of treatment guidelines. Clinical barriers included intolerance to anti-TB drugs, fear of drug toxicity, and contraindications to antiretrovirals. Health system enablers included good management of the procurement, supply, and dispensation chain; convenience and accessibility of treatment services; and strong staff capacity. Availability of psychosocial support was the most frequently reported enabler of uptake at the community level. Conclusions In SSA, programmes integrating treatment of TB and HIV do not, in general, achieve high ART uptake but we observe a net improvement in uptake after WHO issued the 2012 guidelines on collaborative TB/HIV activities. The recurrence of specific modifiable system-level and patient-level factors in the literature reveals key intervention points to improve ART uptake in these programmes. Systematic review registration: CRD42019131933.

scholarly journals Prevalence and Correlates of Pregnancy Self-Testing Among Pregnant Women Attending Antenatal Care in Western Kenya

2020 ◽  
Author(s):  
Nina Njeri Nganga ◽  
Julia Dettinger ◽  
John Kinuthia ◽  
Jared Baeten ◽  
Grace John-Stewart ◽  
...  
Keyword(s):  
Antenatal Care ◽  
Pregnant Women ◽  
Sub Saharan Africa ◽  
Future Research ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Western Kenya ◽  
Self Testing ◽  
Sub Saharan ◽  
Exposure Prophylaxis

Abstract In sub-Saharan Africa little is known about how often women use pregnancy self-tests or characteristics of these women despite evidence that pregnancy self-testing is associated with early antenatal care (ANC) attendance. Understanding the characteristics of women who use pregnancy self-tests may facilitate early access to ANC and preventive interventions in pregnancy. We conducted a cross-sectional survey on an ongoing pre-exposure prophylaxis (PrEP) implementation study which enrolled pregnant women to determine the prevalence and factors associated with pregnancy self-testing among women in western Kenya. Overall in our study population, the prevalence of pregnancy self-testing was 22% and higher among women who were employed, currently in school, had previous pregnancy complications, received services from urban health facilities, and had partners who had at least attended secondary school. The most reported reasons for non-use of pregnancy self-tests included not thinking it was necessary, lack of knowledge, and lack of money to pay for the test. Future research should focus on understanding the knowledge and attitudes of women toward pregnancy self-testing.

Health system adaptations and considerations to facilitate optimal oral pre-exposure prophylaxis scale-up in sub-Saharan Africa

2021 ◽  
Author(s):  
Daniel K Were ◽  
Abednego Musau ◽  
Kaitlyn Atkins ◽  
Prakriti Shrestha ◽  
Jason Reed ◽  
...  
Keyword(s):  
Health System ◽  
Scale Up ◽  
Sub Saharan Africa ◽  
Sub Saharan ◽  
Exposure Prophylaxis

Mental health needs of transgender women, gay men, and other men who have sex with men across sub-Saharan Africa.

2020 ◽  
pp. 153-166
Author(s):  
Carolyn Brown ◽  
Keletso Makofane ◽  
Kevin Rebe ◽  
L. Leigh Ann van der Merwe ◽  
Bhekie Sithole ◽  
...  
Keyword(s):  
Mental Health ◽  
Gay Men ◽  
Transgender Women ◽  
Health Needs ◽  
Sub Saharan Africa ◽  
Mental Health Needs ◽  
Sub Saharan ◽  
Sex With Men

scholarly journals Design and analysis of a clinical trial using previous trials as historical control

2019 ◽  
Vol 16 (5) ◽  
pp. 531-538 ◽  
Author(s):  
David Alan Schoenfeld ◽  
Dianne M Finkelstein ◽  
Eric Macklin ◽  
Neta Zach ◽  
David L Ennist ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Amyotrophic Lateral Sclerosis ◽  
Sample Size ◽  
Standard Error ◽  
Controlled Trial ◽  
Sample Size Calculation ◽  
Control Group ◽  
Controlled Trials ◽  
Number Of Patients ◽  
Lateral Sclerosis

Background/AimsFor single arm trials, a treatment is evaluated by comparing an outcome estimate to historically reported outcome estimates. Such a historically controlled trial is often analyzed as if the estimates from previous trials were known without variation and there is no trial-to-trial variation in their estimands. We develop a test of treatment efficacy and sample size calculation for historically controlled trials that considers these sources of variation.MethodsWe fit a Bayesian hierarchical model, providing a sample from the posterior predictive distribution of the outcome estimand of a new trial, which, along with the standard error of the estimate, can be used to calculate the probability that the estimate exceeds a threshold. We then calculate criteria for statistical significance as a function of the standard error of the new trial and calculate sample size as a function of difference to be detected. We apply these methods to clinical trials for amyotrophic lateral sclerosis using data from the placebo groups of 16 trials.ResultsWe find that when attempting to detect the small to moderate effect sizes usually assumed in amyotrophic lateral sclerosis clinical trials, historically controlled trials would require a greater total number of patients than concurrently controlled trials, and only when an effect size is extraordinarily large is a historically controlled trial a reasonable alternative. We also show that utilizing patient level data for the prognostic covariates can reduce the sample size required for a historically controlled trial.ConclusionThis article quantifies when historically controlled trials would not provide any sample size advantage, despite dispensing with a control group.

scholarly journals How men who have sex with men experience HIV health services in Kampala, Uganda

2020 ◽  
Vol 5 (4) ◽  
pp. e001901
Author(s):  
Rachel King ◽  
Zubayiri Sebyala ◽  
Moses Ogwal ◽  
George Aluzimbi ◽  
Rose Apondi ◽  
...  
Keyword(s):  
Hiv Prevention ◽  
Health Services ◽  
Healthcare Access ◽  
Healthcare Services ◽  
Sub Saharan Africa ◽  
Health Staff ◽  
Structural Factors ◽  
Structural Barriers ◽  
Sub Saharan ◽  
Sex With Men

In sub-Saharan Africa, men who have sex with men (MSM) are socially, largely hidden and face disproportionate risk for HIV infection. Attention to HIV epidemics among MSM in Uganda and elsewhere in sub-Saharan Africa has been obscured by repressive governmental policies, criminalisation, stigma and the lack of basic epidemiological data describing these epidemics. In this paper, we aim to explore healthcare access, experiences with HIV prevention services and structural barriers to using healthcare services in order to inform the acceptability of a combination HIV prevention package of services for men who have sex with men in Uganda. We held focus group discussions (FGDs) with both MSM and healthcare providers in Kampala, Uganda, to explore access to services and to inform prevention and care. Participants were recruited through theoretical sampling with criteria based on ability to answer the research questions. Descriptive thematic coding was used to analyse the FGD data. We described MSM experiences, both negative and positive, as they engaged with health services. Our findings showed that socio-structural factors, mediated by psychological and relational factors impacted MSM engagement in care. The socio-structural factors such as stigma, homophobia and policy issues emerged strongly as did the mediating factors such as relations with specific health staff and a social support structure. A combination intervention addressing structural, social and psychological barriers could have an impact even in the precarious policy environment where this study was conducted.

scholarly journals Cytokine profile and clinical correlates in HIV-exposed infants with severe (hypoxic) pneumonia

2016 ◽  
Vol 22 (1) ◽  
pp. 3 ◽  
Author(s):  
Robin Green ◽  
A Terclanche ◽  
P Becker ◽  
P Rheeder ◽  
D F Wittenberg ◽  
...  
Keyword(s):  
Severe Pneumonia ◽  
Sub Saharan Africa ◽  
Control Group ◽  
Clinical Correlates ◽  
Sub Saharan ◽  
Paired Serum ◽  
Hiv Exposed ◽  
Host Inflammatory Response ◽  
Severe Lung Disease ◽  
Severe Lung

<p><strong>Introduction. </strong>Severe pneumonia in infants who are HIV-infected is a common problem in many parts of the developing world, especially sub-Saharan Africa. What has been missing from previous studies of severe pneumonia in HIV-infected infants, however, is a description of the host inflammatory response and cytokine/chemokine profile that accompanies this disease.</p><p><strong>Objective.</strong> To describe the cytokine profiles associated with severe hypoxic pneumonia in HIV-infected infants</p><p class="Body1"><strong>Methods. </strong>In a cohort of HIV-infected children diagnosed clinically with severe hypoxic pneumonia, paired serum and sputum cytokines were tested. A control group of HIV-infected children with bronchiectasis contributed matching controls.</p><p><strong>Results.</strong> A total of 100 infants (mean age 2.8 months) with a clinical diagnosis of severe hypoxic pneumonia were included in this study. IP-10 was markedly elevated in both sputum (mean 560.77pg/ml) and serum (mean 9091.14pg/ml), while IP-10 was elevated in serum (mean 39.55 pg/ml), with both these cytokines being significantly higher than in stable children with HIV-related bronchiectasis.</p><p><strong>Conclusion. </strong>This study of HIV-infected infants with severe hypoxic pneumonia suggests that IL-10 and IP-10 are associated with more severe lung disease. However, further investigation of this association is required.</p>

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