Soccer and Vocational Training are Ineffective Delivery Strategies to Prevent HIV and Substance Abuse by Young, South African Men: A Cluster Randomized Controlled Trial.

HIV and substance abuse are common among young men, associated with a cluster of risk behaviors. Yet, most services addressing these challenges are delivered in setting underutilized by men and are often inconsistent with male identity. This cluster randomized controlled trial aimed to reduce multiple risk behaviors found among young men township areas on the outskirts of Cape Town, South Africa. Young men aged 18-29 years (N = 1193) across 27 neighborhoods were randomized by area to receive HIV-related skills training during either: (1) a 12-month soccer league (SL) intervention; (2) 6-month SL followed by 6 months of vocational training (VT) intervention (SL/VT, n = 9); or 3) a control condition (CC). Bayesian longitudinal mixture models were used to evaluate behaviors over time. Because we targeted multiple outcomes as our primary outcome, we analyzed if the number of significantly different outcomes between conditions exceeded chance for 13 measures over 18 months (with 83%, 76%, and 61% follow-up). Only if there were three significant benefits favoring the SL/VT over the SL would benefits be significant. Outcome measures included substance use, HIV-testing, protective sexual behaviors, violence, community engagement and mental health. Consistent participation in the SL was typically around 45% over time across conditions, however, only 17% of men completed SL/VT. There were no significant differences between conditions over time based on the number of study outcomes. These structural interventions were ineffective in addressing young men's substance abuse and risk for HIV.Clinical Trial Registration: This trial was prospectively registered on 24 November 2014 with ClinicalTrials.gov (NCT02358226).

Utilizing Soccer for Delivery of HIV and Substance Use Prevention for Young South African Men: 6-Month Outcomes of a Cluster Randomized Controlled Trial.

Young men in South Africa face the intersecting epidemics of HIV, substance use and endemic poverty. We tested the effectiveness of a behavioral intervention using soccer training to reduce the cluster of risks associated with HIV and substance use. This cluster randomized controlled trial was conducted with men aged 18-29 years old in 27 neighborhoods in the townships of Cape Town, South Africa. Neighborhoods were randomized to receive for 6 months either: (1) Soccer League (SL; n = 18 neighborhoods, n = 778 men) who attended soccer three times weekly (72 sessions; 94% uptake, 45.5% weekly attendance rate), combined with an HIV/substance use, cognitive-behavioral intervention; or (2) a Control Condition (CC; n = 9; 415 men) who received educational materials and referrals at 3 month intervals. The primary outcome was the number of significant changes in a cluster of outcomes including HIV-related risks, substance abuse, employment/income, mental health, violence, and community engagement. There was only one significant difference on the rapid diagnostic tests for mandrax at 6 months, an insufficient number of changes to indicate a successful intervention. A group-based behavioral intervention was ineffective in addressing multiple risk behaviors among at-risk young men, similar to the findings of several recent soccer-related interventions. Early adulthood may be too late to alter well-established patterns of risk behaviors.Clinical Trial Registration This trial was prospectively registered on 24 November 2014 with ClinicalTrials.gov NCT02358226.

A general semiparametric Bayesian discrete-time recurrent events model.

Event time variables are often recorded in a discrete fashion, especially in the case of patient-reported outcomes. This work is motivated by a study of illicit drug users, in which time to drug use cessation has been recorded as a number of whole months. Existing approaches for handling such discrete data include treating the survival times as continuous (with adjustments for inevitable tied outcomes), or using discrete models that omit important features like random effects. We provide a general Bayesian discrete-time proportional hazards model, incorporating a number of features popular in continuous-time models such as competing risks and frailties. Our model also provides flexible baseline hazards for time effects, as well as generalized additive models style semiparametric incorporation of other time-varying covariates. Our specific modeling choices enable efficient Markov chain Monte Carlo inference algorithms, which we provide to the user in the form of a freely available R package called $\texttt{brea}$. We demonstrate that our model performs better on our motivating substance abuse application than existing approaches. We also present a reproducible application of the $\texttt{brea}$ software to a freely available data set from a clinical trial of anesthesia administration methods.

Association of early migration with child growth, cognition and behaviour in South Africa.

OBJECTIVE: The main objective of the study was to examine the association of migration with child growth, cognition and behaviour in South Africa. METHODS: Secondary analysis assessing effects of migration on child outcomes among a population cohort of women and children (n = 1238) recruited in Cape Town, South African townships and repeatedly assessed from birth to age eight. Logistic regression models analysed sociodemographic predictors of migration and longitudinal models assessed the association of child migration, with or without their mother, on child growth, cognition and behavioural outcomes. RESULTS: By 8 years post-birth, 41% of children born in the townships in Cape Town had migrated to the rural Eastern Cape. Staying in Cape Town, or not migrating, was associated with having an older mother. Children who migrated with their mothers were shorter and weighed less than those who did not migrate. Children who migrated had larger vocabularies and those who migrated with their mothers had fewer behavioural problems than children who stayed in Cape Town. CONCLUSION: Migration in South Africa between peri-urban Cape Town and rural Eastern Cape areas during a child's early years is common and is associated with both positive and negative child outcomes.

Angiosarcoma of the Uterus: A Systematic Review.

Primary uterine angiosarcoma is an extremely rare neoplasm. Due to its rarity, knowledge regarding this malignancy is limited to a few scattered case reports. To better understand the prognostic factors and optimal management of these neoplasms, we have performed a systematic analysis of the disease. A systematic literature search of this entity yielded 25 reported cases of this entity. In addition, we searched the National Cancer Institute Surveillance, Epidemiology, and End Results database to find 4 additional cases and added a case diagnosed in our institution. We analyzed the patients' demographic characteristics and the different treatment protocols utilized to treat this malignancy. Patients were primarily treated by surgery with or without adjuvant chemotherapy and radiotherapy. Survival analysis was performed to examine the role of various factors in the outcome for the patients. There was no correlation with age of diagnosis, or treatment modality used, however, better outcomes were seen in patients presenting with smaller sized tumors. Our study is the first attempt to systematically study this rare malignancy in hopes of leading to a more standardized, evidence-based, and improved treatment protocol.

Characteristics and Longitudinal Patterns of Erectile Dysfunction Drug Use Among Men Who Have Sex with Men in the U.S.

We investigated the longitudinal relationship between erectile dysfunction (ED) drug use with behavioral factors, including substance use and sexual activities in men who have sex with men from the Multicenter AIDS Cohort Study during 1998-2016 (n = 1636). We used a bivariate random-intercept model to evaluate ED drug use along with other behavioral factors to assess relationships between the two outcomes over time on a population level and also at the individual level. Average ED drug use among men who have sex with men (MSM) with HIV was positively correlated with average use of marijuana (r = .19), poppers (r = .27), and stimulants (r = .25). In this group, testosterone use (r = .32), multiple partners (r = .41), insertive anal intercourse with condom (r = .40), and insertive anal intercourse without condom (r = .43) all showed moderate correlations over time with average ED use (p < .001). Associations among MSM without HIV were similar, with average marijuana use (r = .19) and stimulant use (r = .22) being positively correlated with average ED drug use, and were also correlated with having multiple partners (r = .36), insertive anal intercourse with condom (r = .22), and insertive anal intercourse without condom (r = .18) over time. Positive within-individual associations between ED drug use and multiple partners and insertive anal intercourse with and without condom were observed regardless of HIV serostatus. This study showed that MSM who reported use of ED drugs were also, on average, more likely to use recreational drugs and engage in sexual activities, such as having multiple partners and insertive anal intercourse. Within individuals, average ED drug use was also positively correlated with sexual behaviors.

Impact of pathologic lymph node-positive renal cell carcinoma on survival in patients without metastasis: Evidence in support of expanding the definition of stage IV kidney cancer.

BACKGROUND: Stage III renal cell carcinoma (RCC) encompasses both lymph node-positive (pT1-3N1M0) and lymph node-negative (pT3N0M0) disease. However, prior institutional studies have indicated that among patients with stage III disease, those with lymph node disease have worse oncologic outcomes and experience survival that is similar to that of patients with American Joint Committee on Cancer (AJCC) stage IV disease. The objective of the current study was to validate these findings using a large, nationally representative sample of patients with kidney cancer. METHODS: Patients with AJCC stage III or stage IV RCC were identified using the National Cancer Data Base (NCDB). Patients were categorized as having lymph node-positive stage III (pT1-3N1M0), lymph node-negative stage III (pT3N0M0), or stage IV metastatic (pT1-3 N0M1) disease. Cox proportional hazards models compared outcomes while adjusting for comorbidities. Kaplan-Meier estimates illustrated relative survival when comparing staging groups. RESULTS: A total of 8988 patients met the inclusion criteria, with 6587 patients classified as having lymph node-negative stage III disease, 2218 as having lymph node-positive stage III disease, and 183 as having stage IV disease. Superior survival was noted among patients with lymph node-negative stage III disease, but similar survival was noted between patients with lymph node-positive stage III and stage IV RCC, with 5-year survival rates of 61.9% (95% confidence interval [95% CI], 60.3%-63.4%), 22.7% (95% CI, 20.6%-24.9%), and 15.6% (95% CI, 11.1%-23.8%), respectively. CONCLUSIONS: Current RCC staging systems group pT1-3N1M0 and pT3N0M0 disease as stage III disease. However, the results of the current validation study suggest the need for further stratification and even placement of patients with pT1-3N1M0 disease into the stage IV category. Staging that accurately reflects oncologic prognosis may help clinicians better counsel and select patients who might derive the most benefit from lymphadenectomy, adjuvant systemic therapy, more rigorous imaging surveillance, and clinical trial participation.

Risk Stratification of Older Adults Who Present to the Emergency Department With Syncope: The FAINT Score.

STUDY OBJECTIVE: Older adults with syncope are commonly treated in the emergency department (ED). We seek to derive a novel risk-stratification tool to predict 30-day serious cardiac outcomes. METHODS: We performed a prospective, observational study of older adults (≥60 years) with unexplained syncope or near syncope who presented to 11 EDs in the United States. Patients with a serious diagnosis identified in the ED were excluded. We collected clinical and laboratory data on all patients. Our primary outcome was 30-day all-cause mortality or serious cardiac outcome. RESULTS: We enrolled 3,177 older adults with unexplained syncope or near syncope between April 2013 and September 2016. Mean age was 73 years (SD 9.0 years). The incidence of the primary outcome was 5.7% (95% confidence interval [CI] 4.9% to 6.5%). Using Bayesian logistic regression, we derived the FAINT score: history of heart failure, history of cardiac arrhythmia, initial abnormal ECG result, elevated pro B-type natriuretic peptide, and elevated high-sensitivity troponin T. A FAINT score of 0 versus greater than or equal to 1 had sensitivity of 96.7% (95% CI 92.9% to 98.8%) and specificity 22.2% (95% CI 20.7% to 23.8%), respectively. The FAINT score tended to be more accurate than unstructured physician judgment: area under the curve 0.704 (95% CI 0.669 to 0.739) versus 0.630 (95% CI 0.589 to 0.670). CONCLUSION: Among older adults with syncope or near syncope of potential cardiac cause, a FAINT score of zero had a reasonably high sensitivity for excluding death and serious cardiac outcomes at 30 days. If externally validated, this tool could improve resource use for this common condition.

The Accuracy of Interqual Criteria in Determining the Observation versus Inpatient Status in Older Adults with Syncope.

BACKGROUND: McKesson's InterQual criteria are widely used in hospitals to determine if patients should be classified as observation or inpatient status, but the accuracy of the criteria is unknown. OBJECTIVE: We sought to determine whether InterQual criteria accurately predicted length of stay (LOS) in older patients with syncope. METHODS: We conducted a secondary analysis of a cohort study of adults ≥60 years of age who had syncope. We calculated InterQual criteria and classified the patient as observation or inpatient status. Outcomes were whether LOS were less than or greater than 2 midnights. RESULTS: We analyzed 2361 patients; 1227 (52.0%) patients were male and 1945 (82.8%) were white, with a mean age of 73.2 ± 9.0 years. The median LOS was 32.6 h (interquartile range 24.2-71.8). The sensitivity of InterQual criteria for LOS was 60.8% (95% confidence interval 57.9-63.6%) and the specificity was 47.8% (95% confidence interval 45.0-50.5%). CONCLUSIONS: In older adults with syncope, those who met InterQual criteria for inpatient status had longer LOS compared with those who did not; however, the accuracy of the criteria to predict length of stay over 2 days is poor, with a sensitivity of 60% and a specificity of 48%. Future research should identify criteria to improve LOS prediction.

Clinical Benefit of Hospitalization for Older Adults With Unexplained Syncope: A Propensity-Matched Analysis.

STUDY OBJECTIVE: Many adults with syncope are hospitalized solely for observation and testing. We seek to determine whether hospitalization versus outpatient management for older adults with unexplained syncope is associated with a reduction in postdisposition serious adverse events at 30 days. METHODS: We performed a propensity score analysis using data from a prospective, observational study of older adults with unexplained syncope or near syncope who presented to 11 emergency departments (EDs) in the United States. We enrolled adults (≥60 years) who presented with syncope or near syncope. We excluded patients with a serious diagnosis identified in the ED. Clinical and laboratory data were collected on all patients. The primary outcome was rate of post-ED serious adverse events at 30 days. RESULTS: We enrolled 2,492 older adults with syncope and no serious ED diagnosis from April 2013 to September 2016. Mean age was 73 years (SD 8.9 years), and 51% were women. The incidence of serious adverse events within 30 days after the index visit was 7.4% for hospitalized patients and 3.19% for discharged patients, representing an unadjusted difference of 4.2% (95% confidence interval 2.38% to 6.02%). After propensity score matching on risk of hospitalization, there was no statistically significant difference in serious adverse events at 30 days between the hospitalized group (4.89%) and the discharged group (2.82%) (risk difference 2.07%; 95% confidence interval -0.24% to 4.38%). CONCLUSION: In our propensity-matched sample of older adults with unexplained syncope, for those with clinical characteristics similar to that of the discharged cohort, hospitalization was not associated with improvement in 30-day serious adverse event rates.

Comparison of 30-Day Serious Adverse Clinical Events for Elderly Patients Presenting to the Emergency Department With Near-Syncope Versus Syncope.

STUDY OBJECTIVE: Controversy remains in regard to the risk of adverse events for patients presenting with syncope compared with near-syncope. The purpose of our study is to describe the difference in outcomes between these groups in a large multicenter cohort of older emergency department (ED) patients. METHODS: From April 28, 2013, to September 21, 2016, we conducted a prospective, observational study across 11 EDs in adults (≥60 years) with syncope or near-syncope. A standardized data extraction tool was used to collect information during their index visit and at 30-day follow-up. Our primary outcome was the incidence of 30-day death or serious clinical events. Data were analyzed with descriptive statistics and multivariate logistic regression analysis adjusting for relevant demographic or historical variables. RESULTS: A total of 3,581 patients (mean age 72.8 years; 51.6% men) were enrolled in the study. There were 1,380 patients (39%) presenting with near-syncope and 2,201 (61%) presenting with syncope. Baseline characteristics revealed a greater incidence of congestive heart failure, coronary artery disease, previous arrhythmia, nonwhite race, and presenting dyspnea in the near-syncope compared with syncope cohort. There were no differences in the primary outcome between the groups (near-syncope 18.7% versus syncope 18.2%). A multivariate logistic regression analysis identified no difference in 30-day serious outcomes for patients with near-syncope (odds ratio 0.94; 95% confidence interval 0.78 to 1.14) compared with syncope. CONCLUSION: Near-syncope confers risk to patients similar to that of syncope for the composite outcome of 30-day death or serious clinical event.

Long term surgical outcomes for infective endocarditis in people who inject drugs: a systematic review and meta-analysis.

BACKGROUND: In recent years, the number of infective endocarditis (IE) cases associated with injection drug use has increased. Clinical guidelines suggest deferring surgery for IE in people who inject drugs (PWID) due to a concern for worse outcomes in comparison to non-injectors (non-PWID). We performed a systematic review and meta-analysis of long-term outcomes in PWID who underwent cardiac surgery and compared these outcomes to non-PWID. METHODS: We systematically searched for studies reported between 1965 and 2018. We used an algorithm to estimate individual patient data (eIPD) from Kaplan-Meier (KM) curves and combined it with published individual patient data (IPD) to analyze long-term outcomes after cardiac surgery for IE in PWID. Our primary outcome was survival. Secondary outcomes were reoperation and mortality at 30-days, one-, five-, and 10-years. Random effects Cox regression was used for estimating survival. RESULTS: We included 27 studies in the systematic review and 19 provided data (KM or IPD) for the meta-analysis. PWID were younger and more likely to have S. aureus than non-PWID. Survival at 30-days, one-, five-, and 10-years was 94.3, 81.0, 62.1, and 56.6% in PWID, respectively; and 96.4, 85.0, 70.3, and 63.4% in non-PWID. PWID had 47% greater hazard of death (HR 1.47, 95% CI, 1.05-2.05) and more than twice the hazard of reoperation (HR 2.37, 95% CI, 1.25-4.50) than non-PWID. CONCLUSION: PWID had shorter survival that non-PWID. Implementing evidence-based interventions and testing new modalities are urgently needed to improve outcomes in PWID after cardiac surgery.

Orthostatic vital signs do not predict 30 day serious outcomes in older emergency department patients with syncope: A multicenter observational study.

BACKGROUND: Syncope is a common chief complaint among older adults in the Emergency Department (ED), and orthostatic vital signs are often a part of their evaluation. We assessed whether abnormal orthostatic vital signs in the ED are associated with composite 30-day serious outcomes in older adults presenting with syncope. METHODS: We performed a secondary analysis of a prospective, observational study at 11 EDs in adults ≥ 60 years who presented with syncope or near syncope. We excluded patients lost to follow up. We used the standard definition of abnormal orthostatic vital signs or subjective symptoms of lightheadedness upon standing to define orthostasis. We determined the rate of composite 30-day serious outcomes, including those during the index ED visit, such as cardiac arrhythmias, myocardial infarction, cardiac intervention, new diagnosis of structural heart disease, stroke, pulmonary embolism, aortic dissection, subarachnoid hemorrhage, cardiopulmonary resuscitation, hemorrhage/anemia requiring transfusion, with major traumatic injury from fall, recurrent syncope, and death) between the groups with normal and abnormal orthostatic vital signs. RESULTS: The study cohort included 1974 patients, of whom 51.2% were male and 725 patients (37.7%) had abnormal orthostatic vital signs. Comparing those with abnormal to those with normal orthostatic vital signs, we did not find a difference in composite 30-serious outcomes (111/725 (15.3%) vs 184/1249 (14.7%); unadjusted odds ratio, 1.05 [95%CI, 0.81-1.35], p = 0.73). After adjustment for gender, coronary artery disease, congestive heart failure (CHF), history of arrhythmia, dyspnea, hypotension, any abnormal ECG, physician risk assessment, medication classes and disposition, there was no association with composite 30-serious outcomes (adjusted odds ratio, 0.82 [95%CI, 0.62-1.09], p = 0.18). CONCLUSIONS: In a cohort of older adult patients presenting with syncope who were able to have orthostatic vital signs evaluated, abnormal orthostatic vital signs did not independently predict composite 30-day serious outcomes.

QTc prolongation as a marker of 30-day serious outcomes in older patients with syncope presenting to the Emergency Department.

BACKGROUND: Syncope is a common chief complaint in the ED, and the electrocardiogram (ECG) is a routine diagnostic tool in the evaluation of syncope. We assessed whether increasingly prolonged QTc intervals are associated with composite 30-day serious outcomes in older adults presenting to the ED with syncope. METHODS: This is a secondary analysis of a prospective, observational study at 11 EDs in adults 60 years or older who presented with syncope or near syncope. We excluded patients presenting without an ECG, measurement of QTc, non-sinus rhythm, bundle branch block or those without 30-day follow-up. We categorized QTc cutoffs into values of <451; 451-470; 471-500, and >500 ms. We determined the rate of composite 30-day serious outcomes including ED serious outcomes and 30-day arrhythmias not identified in ED. RESULTS: The study cohort included 2609 patients. There were 1678 patients (64.3%) that had QTc intervals <451 ms; 544 (20.8%) were 451-470 ms; 302 (11.6%) were 471-500 ms, and 85 (3.3%) had intervals >500 ms. Composite 30-day serious outcomes was associated with increasingly prolonged QTc intervals (13.0%, 15.3%, 18.2%, 22.4%, p = 0.01), but this association did not persist in multivariate analysis. CONCLUSIONS: In a cohort of older patients presenting with syncope, increased QTc interval was a marker of but was not independently predictive of composite 30-day serious outcomes.

Recurrent syncope is not an independent risk predictor for future syncopal events or adverse outcomes.

Almost 20% of patients with syncope will experience another event. It is unknown whether recurrent syncope is a marker for a higher or lower risk etiology of syncope. The goal of this study is to determine whether older adults with recurrent syncope have a higher likelihood of 30-day serious clinical events than patients experiencing their first episode. METHODS: This study is a pre-specified secondary analysis of a multicenter prospective, observational study conducted at 11 emergency departments in the US. Adults 60 years or older who presented with syncope or near syncope were enrolled. The primary outcome was occurrence of 30-day serious outcome. The secondary outcome was 30-day serious cardiac arrhythmia. In multivariate analysis, we assessed whether prior syncope was an independent predictor of 30-day serious events. RESULTS: The study cohort included 3580 patients: 1281 (35.8%) had prior syncope and 2299 (64.2%) were presenting with first episode of syncope. 498 (13.9%) patients had 1 prior episode while 771 (21.5%) had >1 prior episode. Those with recurrent syncope were more likely to have congestive heart failure, coronary artery disease, previous diagnosis of arrhythmia, and an abnormal ECG. Overall, 657 (18.4%) of the cohort had a serious outcome by 30 days after index ED visit. In multivariate analysis, we found no significant difference in risk of events (adjusted odds ratio 1.09; 95% confidence interval 0.90-1.31; p = 0.387). CONCLUSION: In older adults with syncope, a prior history of syncope within the year does not increase the risk for serious 30-day events.

Does HIV pre-exposure prophylaxis use lead to a higher incidence of sexually transmitted infections? A case-crossover study of men who have sex with men in Los Angeles, California.

BACKGROUND: Pre-exposure prophylaxis (PrEP) is an effective method for reducing HIV incidence among at-risk populations. However, concerns exist over the potential for an increase in STIs following PrEP initiation. The objective of this study is to compare the STI incidence before and after PrEP initiation within subjects among a cohort of men who have sex with men in Los Angeles, California. METHODS: The present study used data from patients who initiated PrEP services at the Los Angeles LGBT Center between October 2015 and October 2016 (n=275). A generalised linear mixed model was used with a case-crossover design to determine if there was a significant difference in STIs within subjects 365 days before (before-PrEP period) and 365 days after PrEP initiation (after-PrEP period). RESULTS: In a generalised linear mixed model, there were no significant differences in urethral gonorrhoea (P=0.95), rectal gonorrhoea (P=0.33), pharyngeal gonorrhoea (P=0.65) or urethral chlamydia (P=0.71) between periods. There were modest increases in rectal chlamydia (rate ratio (RR) 1.83; 95% CI 1.13 to 2.98; P=0.01) and syphilis diagnoses (RR 2.97; 95% CI 1.23 to 7.18; P=0.02). CONCLUSIONS: There were significant increases in rectal chlamydia and syphilis diagnoses when comparing the periods directly before and after PrEP initiation. However, only 28% of individuals had an increase in STIs between periods. Although risk compensation appears to be present for a segment of PrEP users, the majority of individuals either maintain or decrease their sexual risk following PrEP initiation.

App-Based Sexual Partner Seeking and Sexually Transmitted Infection Outcomes: A Cross-Sectional Study of HIV-Negative Men Who Have Sex With Men Attending a Sexually Transmitted Infection Clinic in Los Angeles, California.

BACKGROUND: Gay, bisexual, and other men who have sex with men (MSM) face higher rates of sexually transmitted infections (STIs) compared with the general population. The association between venues where sexual partners are met and STI transmission is dynamic and poorly understood, especially among those who use geosocial networking (GSN) apps. This study aimed to determine whether there is a difference in STI incidence between MSM who met their last sexual partner through a GSN app and MSM who met their last partner via other venues. METHODS: Data were analyzed from HIV-negative MSM attending the Los Angeles LBGT Center between August 2015 and July 2016 (n = 9499). Logistic regression models were used to investigate the relationship between STI incidence and whether or not an individual met his last partner through a GSN app. RESULTS: No relationship was detected between STI incidence and whether one's last sexual partner was met via GSN app. However, an association was detected between STI incidence and having used GSN apps to meet sexual partners in the past 3 months. A dose-response relationship was observed between the number of venues used to meet partners and testing positive for any STI (adjusted odds ratio, 1.08; 95% confidence interval, 1.02-1.14). CONCLUSIONS: The relationship between how people meet sexual partners and STI acquisition is much more nuanced than previously thought. Geosocial networking apps do not inherently expose users to high-risk reservoirs of STIs, but further understanding of the complexity of sexual networks and networking methods is warranted, given increasing rates of STIs.

A Bayesian confirmatory factor model for multivariate observations in the form of two-way tables of data.

Researchers collected multiple measurements on patients with schizophrenia and their relatives, as well as control subjects and their relatives, to study vulnerability factors for schizophrenics and their near relatives. Observations across individuals from the same family are correlated, and also the multiple outcome measures on the same individuals are correlated. Traditional data analyses model outcomes separately and thus do not provide information about the interrelationships among outcomes. We propose a novel Bayesian family factor model (BFFM), which extends the classical confirmatory factor analysis model to explain the correlations among observed variables using a combination of family-member and outcome factors. Traditional methods for fitting confirmatory factor analysis models, such as full-information maximum likelihood (FIML) estimation using quasi-Newton optimization (QNO), can have convergence problems and Heywood cases (lack of convergence) caused by empirical underidentification. In contrast, modern Bayesian Markov chain Monte Carlo handles these inference problems easily. Simulations compare the BFFM to FIML-QNO in settings where the true covariance matrix is identified, close to not identified, and not identified. For these settings, FIML-QNO fails to fit the data in 13%, 57%, and 85% of the cases, respectively, while MCMC provides stable estimates. When both methods successfully fit the data, estimates from the BFFM have smaller variances and comparable mean-squared errors. We illustrate the BFFM by analyzing data on data from schizophrenics and their family members.

Bayesian methods for analysis of biosimilar phase III trials.

A biologic is a product made from living organisms. A biosimilar is a new version of an already approved branded biologic. Regulatory guidelines recommend a totality-of-the-evidence approach with stepwise development for a new biosimilar. Initial steps for biosimilar development are (a) analytical comparisons to establish similarity in structure and function followed by (b) potential animal studies and a human pharmacokinetics/pharmacodynamics equivalence study. The last step is a phase III clinical trial to confirm similar efficacy, safety, and immunogenicity between the biosimilar and the biologic. A high degree of analytical and pharmacokinetics/pharmacodynamics similarity could provide justification for an eased statistical threshold in the phase III trial, which could then further facilitate an overall abbreviated approval process for biosimilars. Bayesian methods can help in the analysis of clinical trials, by adding proper prior information into the analysis, thereby potentially decreasing required sample size. We develop proper prior information for the analysis of a phase III trial for showing that a proposed biosimilar is similar to a reference biologic. For the reference product, we use a meta-analysis of published results to set a prior for the probability of efficacy, and we propose priors for the proposed biosimilar informed by the strength of the evidence generated in the earlier steps of the approval process. A simulation study shows that with few exceptions, the Bayesian relative risk analysis provides greater power, shorter 90% credible intervals with more than 90% frequentist coverage, and better root mean squared error.