| 1. |
- Fang, Lanyan, et al.
(author)
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Model-Informed Drug Development and Review for Generic Products : Summary Of FDA Public Workshop
- 2018
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In: Clinical Pharmacology and Therapeutics. - : Wiley. - 0009-9236 .- 1532-6535. ; 104:1, s. 27-30
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Journal article (peer-reviewed)abstract
- On October 2nd and 3rd, 2017, the US Food and Drug Administration (FDA) hosted a public workshop titled “Leveraging Quantitative Methods and Modeling to Modernize Generic Drug Development and Review.”1 This report summarizes Session 2 of the public workshop: “Model Informed Drug Development and Review for Generic Products.” The session focused on the application of quantitative methods and modeling in modernizing the generic drug development and review.
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| 2. |
- Haghighi, Mona, et al.
(author)
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A Comparison of Rule-based Analysis with Regression Methods in Understanding the Risk Factors for Study Withdrawal in a Pediatric Study
- 2016
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Journal article (peer-reviewed)abstract
- Regression models are extensively used in many epidemiological studies to understand the linkage between specific outcomes of interest and their risk factors. However, regression models in general examine the average effects of the risk factors and ignore subgroups with different risk profiles. As a result, interventions are often geared towards the average member of the population, without consideration of the special health needs of different subgroups within the population. This paper demonstrates the value of using rule-based analysis methods that can identify subgroups with heterogeneous risk profiles in a population without imposing assumptions on the subgroups or method. The rules define the risk pattern of subsets of individuals by not only considering the interactions between the risk factors but also their ranges. We compared the rule-based analysis results with the results from a logistic regression model in The Environmental Determinants of Diabetes in the Young (TEDDY) study. Both methods detected a similar suite of risk factors, but the rule-based analysis was superior at detecting multiple interactions between the risk factors that characterize the subgroups. A further investigation of the particular characteristics of each subgroup may detect the special health needs of the subgroup and lead to tailored interventions.
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| 3. |
- Kilburn, Kelly N., et al.
(author)
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Conditional cash transfers and the reduction in partner violence for young women : an investigation of causal pathways using evidence from a randomized experiment in South Africa (HPTN 068)
- 2018
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In: Journal of the International AIDS Society. - : JOHN WILEY & SONS LTD. - 1758-2652. ; 21
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Journal article (peer-reviewed)abstract
- IntroductionEvidence has shown that the experience of violence by a partner has important influences on women's risk of HIV acquisition. Using a randomized experiment in northeast South Africa, we found that a conditional cash transfer (CCT) targeted to poor girls in high school reduced the risk of physical intimate partner violence (IPV) in the past 12months by 34%. The purpose of this analysis is to understand the pathways through which the CCT affects IPV. MethodsHPTN 068 was a phase 3, randomized controlled trial in rural Mpumalanga province, South Africa. Eligible young women (aged 13-20) and their parents or guardians were randomly assigned (1:1) to either receive a monthly cash transfer conditional on monthly high school attendance or no cash transfer. Between 2011 and 2015, participants (N=2,448) were interviewed at baseline, then at annual follow-up visits at 12, 24 and 36months. The total effect of the CCT on IPV was estimated using a GEE log-binomial regression model. We then estimated controlled direct effects to examine mediation of direct effects through intermediate pathways. Mediators include sexual partnership measures, the sexual relationship power scale, and household consumption measures. ResultsWe found evidence that the CCT works in part through delaying sexual debut or reducing the number of sexual partners. The intervention interacts with these mediators leading to larger reductions in IPV risk compared to the total effect of the CCT on any physical IPV [RR 0.66, CI(95%):0.59-0.74]. The largest reductions are seen when we estimate the controlled direct effect under no sexual debut [RR 0.57, CI(95%):0.48-0.65] or under no sexual partner in the last 12months [RR 0.53, CI(95%):0.46-0.60]. ConclusionsResults indicate that a CCT for high school girls has protective effects on their experience of IPV and that the effect is due in part to girls choosing not to engage in sexual partnerships, thereby reducing the opportunity for IPV. As a lower exposure to IPV and safer sexual behaviours also protect against HIV acquisition, this study adds to the growing body of evidence on how cash transfers may reduce young women's HIV risk.
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| 4. |
- Stoner, Marie C. D., et al.
(author)
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Does Partner Selection Mediate the Relationship Between School Attendance and HIV/Herpes Simplex Virus-2 Among Adolescent Girls and Young Women in South Africa : An Analysis of HIV Prevention Trials Network 068 Data
- 2018
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In: Journal of Acquired Immune Deficiency Syndromes. - : Lippincott Williams & Wilkins. - 1525-4135 .- 1944-7884. ; 79:1, s. 20-27
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Journal article (peer-reviewed)abstract
- Objective: School attendance prevents HIV and herpes simplex virus-2 (HSV-2) in adolescent girls and young women, but the mechanisms to explain this relationship remain unclear. Our study assesses the extent to which characteristics of sex partners, partner age, and number mediate the relationship between attendance and risk of infection in adolescent girls and young women in South Africa.Design: We use longitudinal data from the HIV Prevention Trials Network 068 randomized controlled trial in rural South Africa, where girls were enrolled in early adolescence and followed in the main trial for more than 3 years. We examined older partners and the number of partners as possible mediators.Methods: We used the parametric g-formula to estimate 4-year risk differences for the effect of school attendance on the cumulative incidence of HIV/HSV-2 overall and the controlled direct effect (CDE) for mediation. We examined mediation separately and jointly for the mediators of interest.Results: We found that young women with high attendance in school had a lower cumulative incidence of HIV compared with those with low attendance (risk difference = -1.6%). Partner age difference (CDE = -1.2%) and the number of partners (CDE = -0.4%) mediated a large portion of this effect. In fact, when we accounted for the mediators jointly, the effect of schooling on HIV was almost removed, showing full mediation (CDE = -0.3%). The same patterns were observed for the relationship between school attendance and cumulative incidence of HSV-2 infection.Conclusion: Increasing school attendance reduces the risk of acquiring HIV and HSV-2. Our results indicate the importance of school attendance in reducing partner number and partner age difference in this relationship.
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| 5. |
- Stoner, Marie C. D., et al.
(author)
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Effect of schooling on age-disparate relationships and number of sexual partners among young women in rural South Africa enrolled in HPTN 068
- 2017
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In: Journal of Acquired Immune Deficiency Syndromes. - : Wolters Kluwer Health. - 1525-4135 .- 1944-7884. ; 76:5, s. E107-E114
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Journal article (peer-reviewed)abstract
- Background: Attending school may have a strong preventative association with sexually transmitted infections among young women, but the mechanism for this relationship is unknown. One hypothesis is that students who attend school practice safer sex with fewer partners, establishing safer sexual networks that make them less exposed to infection.Setting: We used longitudinal data from a randomized controlled trial of young women aged 13-20 years in the Bushbuckridge district, South Africa, to determine whether the percentage of school days attended, school dropout, and grade repetition are associated with having a partner 5 or more years older (age-disparate) and with the number of sexual partners in the previous 12 months.Methods: Risks of having an age-disparate relationship and number of sexual partners were compared using inverse probability of exposure weighted Poisson regression models. Generalized estimating equations were used to account for repeated measures.Results: Young women who attended fewer school days (<80%) and who dropped out of school were more likely to have an age-disparate relationship (risk difference 9.9%, 95% confidence interval [CI]: 3.9% to 16.0%; risk difference (%) dropout 17.2%, 95% CI: 5.4% to 29.0%) and those who dropped out reported having fewer partners (count difference dropout 0.343, 95% CI: 0.192 to 0.495). Grade repetition was not associated with either behavior.Conclusion: Young women who less frequently attend school or who drop out are more likely to have an age-disparate relationship. Young women who drop out have overall more partners. These behaviors may increase the risk of exposure to HIV infection in young women out of school.
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| 6. |
- Stoner, Marie C. D., et al.
(author)
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The effect of school attendance and school dropout on incident HIV and HSV-2 among young women in rural South Africa enrolled in HPTN 068
- 2017
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In: AIDS. - : LIPPINCOTT WILLIAMS & WILKINS. - 0269-9370 .- 1473-5571. ; 31:15, s. 2127-2134
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Journal article (peer-reviewed)abstract
- Objective: To estimate the association between school attendance, school dropout, and risk of incident HIV and herpes simplex virus type 2 (HSV-2) infection among young women.Design: We used longitudinal data from a randomized controlled trial in rural Mpumalanga province, South Africa, to assess the association between school days attended, school dropout, and incident HIV and HSV-2 in young women aged 13-23 years.Methods: We examined inverse probability of exposure weighted survival curves and used them to calculate 1.5, 2.5, and 3.5-year risk differences and risk ratios for the effect of school attendance on incident HIV and HSV-2. A marginal structural Cox model was used to estimate hazard ratios for the effect of school attendance and school dropout on incident infection.Results: Risk of infection increased over time as young women aged, and was higher in young women with low school attendance (<80% school days) compared with high (>= 80% school days). Young women with low attendance were more likely to acquire HIV [hazard ratio (HR): 2.97; 95% confidence interval (CI): 1.62, 5.45] and HSV-2 (HR: 2.47; 95% CI: 1.46, 4.17) over the follow-up period than young women with high attendance. Similarly, young women who dropped out of school had a higher weighted hazard of both HIV (HR 3.25 95% CI: 1.67, 6.32) and HSV-2 (HR 2.70; 95% CI 1.59, 4.59).Conclusion: Young women who attend more school days and stay in school have a lower risk of incident HIV and HSV-2 infection. Interventions to increase frequency of school attendance and prevent dropout should be promoted to reduce risk of infection.
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| 7. |
- Stoner, Marie C. D., et al.
(author)
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The Relationship Between School Dropout and Pregnancy Among Adolescent Girls and Young Women in South Africa : A HPTN 068 Analysis
- 2019
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In: Health Education & Behavior. - : Sage Publications. - 1090-1981 .- 1552-6127. ; 46:4, s. 559-568
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Journal article (peer-reviewed)abstract
- Background. Prevention of both school dropout and teen pregnancy represent clear public health priorities for South Africa, yet their complex and potentially cyclical relationship has not been fully explored. Objective. To further understand how this relationship operates, we analyzed data from a randomized trial of young women aged 13 to 20 years enrolled in school in rural South Africa to estimate the association between pregnancy and subsequent dropout and between dropout and subsequent pregnancy. Method. We examined inverse probability (IP) of exposure-weighted survival curves for school dropout by pregnancy and for pregnancy by school dropout. We used weighted curves to calculate 1-, 2-, and 3-year risk differences and risk ratios. Additionally, we used an IP-weighted marginal structural cox model to estimate a hazard ratio (HR) for each relationship. Results. Dropout from school was associated with subsequent pregnancy (HR 3.58; 95% confidence interval [CI] [2.04, 6.28]) and pregnancy was associated with subsequent school dropout (HR 2.36; 95% CI [1.29, 4.31]). Young women who attended school but attended fewer days had a higher hazard of pregnancy than those who attended more school (HR 3.64; 95% CI [2.27, 5.84]). Conclusion. Pregnancy is both a cause and a consequence of school dropout. Consideration of school attendance and academic performance could ultimately enhance pregnancy prevention efforts in this population. Programs should be tailored differently for (1) girls who have dropped out of school, (2) those who are in school and at risk for pregnancy, and (3) those who are in school and become pregnant.
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