Quantitative Economic Evaluations of HIV-Related Prevention and Treatment Services: A Review

Dr. Holtgrave and colleagues at the CDC set forth an extensive taxonomy of HIV prevention and treatment services and review reports of efforts to subject some of those services to formal economic evaluation. They find few services thus far to have been so evaluated, no evaluation to have focused solely upon behavioral outcomes and most economic evaluations to lack formal quantitative analyses

Health chatbots acceptability moderated by perceived stigma and severity: A cross-sectional survey

Background: Chatbots and virtual voice assistants are increasingly common in primary care without sufficient evidence for their feasibility and effectiveness. We aimed to assess how perceived stigma and severity of various health issues are associated with the acceptability for three sources of health information and consultation: an automated chatbot, a General Practitioner (GP), or a combination of both. Methods: Between May and June 2019, we conducted an online study, advertised via Facebook, for UK citizens. It was a factorial simulation experiment with three within-subject factors (perceived health issue stigma, severity, and consultation source) and six between-subject covariates. Acceptability rating for each consultation source was the dependant variable. A single mixed-model ANOVA was performed. Results: Amongst 237 participants (65% aged over 45 years old, 73% women), GP consultations were seen as most acceptable, followed by GP-chatbot service. Chatbots were seen least acceptable as a consultation source for severe health issues, while the acceptability was significantly higher for stigmatised health issues. No associations between participants’ characteristics and acceptability were found. Conclusions: Although healthcare professionals are perceived as the most desired sources of health information, chatbots may be useful for sensitive health issues in which disclosure of personal information is challenging. However, chatbots are less acceptable for health issues of higher severity and should not be recommended for use within that context. Policymakers and digital service designers need to recognise the limitations of health chatbots. Future research should establish a set of health topics most suitable for chatbot-led interventions and primary healthcare services

Scaling limit of a non-relativistic model

I calculate the structure function for scattering from the two-body bound state in its lowest level in a non-relativistic model of confined scalar ``quarks'' of masses $m_A$ and $m_B$. The scaling limit in $x={\bf q}^2/2(m_A+m_B)q^0$ exists and is non-vanishing only for the values $x=m_A/(m_A+m_B)$ and $x=m_B/(m_A+m_B)$ which correspond to the fractions of the momentum of the two-body system carried by each of the ``quarks.'' In the scaling limit, the interference from scattering off of the two ``quarks'' vanishes. Thus the scaling limit of this model agrees with the parton picture.Comment: 10 pages, 3 figures not included, in LaTex, UMD 92-22

Notes On Some Common Misconceptions In Input-Output Impact Methodology

The methodology in many studies involving input-output analysis appears to be often misunderstood, particularly in the way multipliers are used. The preoccupation with multipliers has led in many cases to incorrect analytical procedures; for example, there is a temptation to first derive a multiplier and then use this multiplier to calculate the total impact on the economy. This paper demonstrates that this approach is often erroneous and can result in significant errors. In addition, the importance of determining how imports are treated when using input-output in empirical situations is discussed. This is particularly relevant when using input-output tables in developing countries. Other issues which are clarified include the use of output multipliers, state versus regional multipliers and impacts, expenditure switching and table balancing

Little Groups of Preon Branes

Little groups for preon branes (i.e. configurations of branes with maximal (n-1)/n fraction of survived supersymmetry) for dimensions d=2,3,...,11 are calculated for all massless, and partially for massive orbits. For massless orbits little groups are semidirect product of d-2 translational group $T_{d-2}$ on a subgroup of (SO(d-2) $\times$ R-invariance) group. E.g. at d=9 the subgroup is exceptional $G_2$ group. It is also argued, that 11d Majorana spinor invariants, which distinguish orbits, are actually invariant under d=2+10 Lorentz group. Possible applications of these results include construction of field theories in generalized space-times with brane charges coordinates, different problems of group's representations decompositions, spin-statistics issues.Comment: LaTeX, 11 page

HypTrails: A Bayesian Approach for Comparing Hypotheses About Human Trails on the Web

When users interact with the Web today, they leave sequential digital trails on a massive scale. Examples of such human trails include Web navigation, sequences of online restaurant reviews, or online music play lists. Understanding the factors that drive the production of these trails can be useful for e.g., improving underlying network structures, predicting user clicks or enhancing recommendations. In this work, we present a general approach called HypTrails for comparing a set of hypotheses about human trails on the Web, where hypotheses represent beliefs about transitions between states. Our approach utilizes Markov chain models with Bayesian inference. The main idea is to incorporate hypotheses as informative Dirichlet priors and to leverage the sensitivity of Bayes factors on the prior for comparing hypotheses with each other. For eliciting Dirichlet priors from hypotheses, we present an adaption of the so-called (trial) roulette method. We demonstrate the general mechanics and applicability of HypTrails by performing experiments with (i) synthetic trails for which we control the mechanisms that have produced them and (ii) empirical trails stemming from different domains including website navigation, business reviews and online music played. Our work expands the repertoire of methods available for studying human trails on the Web.Comment: Published in the proceedings of WWW'1

Face masks to prevent community transmission of viral respiratory infections: A rapid evidence review using Bayesian analysis [Preprint, version 1]

Background: Face masks have been proposed as an important way of reducing transmission of viral respiratory infections, including SARS-CoV-2. / Objective: To assess the likelihood that wearing face masks in community settings reduces transmission of viral respiratory infections. / Methods: We conducted a rapid evidence review and used a Bayesian statistical approach to analysing experimental and observational studies conducted in community-dwelling children and adults that assessed the effectiveness of face mask wearing (vs. no face masks) on self-reported, laboratory-confirmed, or clinically diagnosed viral respiratory infections. / Results: Eleven RCTs and 10 observational studies met the inclusion criteria. The calculation of Bayes factors and cumulative posterior odds from the RCTs showed a moderate likelihood of a small effect of wearing surgical face masks in community settings in reducing self-reported influenza-like illness (ILI) (cumulative posterior odds = 3.61). However, the risk of reporting bias was high and evidence of reduction of clinically- or laboratory-confirmed infection was equivocal (cumulative posterior odds = 1.07 and 1.22, respectively). Observational studies yielded evidence of a negative association between face mask wearing and ILI but with high risk of confounding and reporting bias. / Conclusions: Available evidence from RCTs is equivocal as to whether or not wearing face masks in community settings results in a reduction in clinically- or laboratory-confirmed viral respiratory infections. No relevant studies concerned SARS-CoV-2 or were undertaken in community settings in the UK

Face masks to prevent community transmission of viral respiratory infections: A rapid evidence review using Bayesian analysis [Preprint, version 1]

Background: Face masks have been proposed as an important way of reducing transmission of viral respiratory infections, including SARS-CoV-2. / Objective: To assess the likelihood that wearing face masks in community settings reduces transmission of viral respiratory infections. / Methods: We conducted a rapid evidence review and used a Bayesian statistical approach to analysing experimental and observational studies conducted in community-dwelling children and adults that assessed the effectiveness of face mask wearing (vs. no face masks) on self-reported, laboratory-confirmed, or clinically diagnosed viral respiratory infections. / Results: Eleven RCTs and 10 observational studies met the inclusion criteria. The calculation of Bayes factors and cumulative posterior odds from the RCTs showed a moderate likelihood of a small effect of wearing surgical face masks in community settings in reducing self-reported influenza-like illness (ILI) (cumulative posterior odds = 3.61). However, the risk of reporting bias was high and evidence of reduction of clinically- or laboratory-confirmed infection was equivocal (cumulative posterior odds = 1.07 and 1.22, respectively). Observational studies yielded evidence of a negative association between face mask wearing and ILI but with high risk of confounding and reporting bias. / Conclusions: Available evidence from RCTs is equivocal as to whether or not wearing face masks in community settings results in a reduction in clinically- or laboratory-confirmed viral respiratory infections. No relevant studies concerned SARS-CoV-2 or were undertaken in community settings in the UK

The effects of the small t properties of hadronic scattering amplitude on the determination its real part

Taking into account the different forms of the Coulomb-hadron interference phase and the possible spin-flip contribution the new analysis of the experimental data of the proton-antiproton elastic scattering at $3.8 < p_L <6.0 \$GeV/c and small momentum transfer is carried out. It is shown that the size of the spin-flip amplitude can be determined from the form of the differential cross sections at small $t$, and the deviation of $\rho(s,t)$ obtained from the examined experimental data of the $p\bar{p}$ scattering from the analysis \cite{Kroll}, based on the dispersion relations, is conserved in all xamined assumptions. The analysis of the proton-proton elastic scattering at $9 < p_L < 70 \$GeV/c also shows the impact of the examined effects on the form of the differential cross sections.Comment: 13 pages, 3 figure