Creating and sustaining effective pipeline initiatives to increase diversity in biostatistics: the ENAR Fostering Diversity in Biostatistics Workshop

Biostatisticians with advanced degrees are highly sought after. Employment opportunities in the fields of mathematics and statistics are expected to increase dramatically by 2028. Underrepresentation of minorities in biostatistics has been a persistent problem, yielding a demographic landscape that differs substantially from the general US population. In some instances, students may have the appropriate quantitative skills, but are unaware of biostatistics and in other instances, students may not yet have the appropriate quantitative background, but are intellectually capable and willing to shore up those skills once they learn about biostatistics as a viable, exciting career option. Therefore, in order to ensure robust scientific advancement, there must be a concerted effort to increase the pipeline of intellectually talented persons available with exposure to the appropriate quantitative skills who are interested in careers in biostatistics. The overarching goal of this paper is to discuss the development, implementation, and impact of a federally funded pipeline initiative aimed at increasing the number of underrepresented minorities successful in graduate training and professional careers in biostatistics as well as establishing effective mentoring and networking relationships. Our findings provide a roadmap for the development of sustainable initiatives to promote diversity in biostatistics and STEM fields more broadly.

Early plasma soluble receptor for advanced glycation end-product levels are associated with bronchiolitis obliterans syndrome

Early epithelial injury after lung transplantation may contribute to development of bronchiolitis obliterans syndrome (BOS). We evaluated the relationship between early postoperative soluble receptor for advanced glycation end-product (sRAGE) levels, a marker of type I alveolar cell injury and BOS. We performed a cohort study of 106 lung transplant recipients between 2002 and 2006 at the University of Pennsylvania with follow-up through 2010. Plasma sRAGE was measured 6 and 24 h after transplantation. Cox proportional hazards models were used to evaluate the association between sRAGE and time to BOS, defined according to ISHLT guidelines. Sixty (57%) subjects developed BOS. The average time to BOS was 3.4 years. sRAGE levels measured at 6 h (HR per SD of sRAGE: 1.69, 95% CI: 1.11, 2.57, p = 0.02) and 24 h (HR per SD of sRAGE: 1.74, 95% CI: 1.14, 2.65, p = 0.01) were associated with an increased hazard of BOS. Multivariable Cox regression indicated this relationship was independent of potential confounders. Elevated plasma sRAGE levels measured in the immediate postoperative period are associated with the development of BOS. Early epithelial injury after transplantation may contribute to the development of fibrosis in BOS.

Plasma cytokines and chemokines in primary graft dysfunction post-lung transplantation

Primary graft dysfunction (PGD) after lung transplantation causes significant morbidity and mortality. We aimed to determine the role of cytokines and chemokines in PGD. This is a multicenter case-control study of PGD in humans. A Luminex analysis was performed to determine plasma levels of 25 chemokines and cytokines before and at 6, 24, 48 and 72 h following allograft reperfusion in 25 cases (grade 3 PGD) and 25 controls (grade 0 PGD). Biomarker profiles were evaluated using a multivariable logistic regression and generalized estimating equations. PGD cases had higher levels of monocyte chemotactic protein-1 (MCP-1)/chemokine CC motif ligand 2 (CCL2) and interferon (IFN)-inducible protein (IP-10)/chemokine CXC motif ligand 10 (CXCL10) (both p < 0.05), suggesting recruitment of monocytes and effector T cells in PGD. In addition, PGD cases had lower levels of interleukin (IL-13) (p = 0.05) and higher levels of IL-2R (p = 0.05). Proinflammatory cytokines, including tumor necrosis factor (TNF)-alpha, and IFN-gamma decreased to very low levels after transplant in both PGD cases and controls, exhibiting no differences between the two groups. These findings were independent of clinical variables including diagnosis in multivariable analyses, but may be affected by cardiopulmonary bypass. Profound injury in clinical PGD is distinguished by the upregulation of selected chemokine pathways, which may useful for the prediction or early detection of PGD if confirmed in future studies.

Plasma intercellular adhesion molecule-1 and von Willebrand factor in primary graft dysfunction after lung transplantation

Primary graft dysfunction (PGD), a form of acute lung injury occurring within 72 h following lung transplantation, is characterized by pulmonary edema and diffuse alveolar damage. We hypothesized that higher concentrations of intercellular adhesion molecule-1 (ICAM-1) and von Willebrand factor (vWF) would be associated with the occurrence of PGD. A total of 128 lung transplant recipients among 7 lung transplant centers were enrolled in a multicenter, prospective, cohort study. Blood specimens were collected preoperatively and at 6, 24, 48 and 72 h following lung transplantation. The primary outcome was Grade 3 PGD at 72 h after transplant. Logistic regression and generalized estimating equations (GEE) were used to analyze plasma ICAM-1 and vWF. At each postoperative timepoint, mean plasma ICAM-1 concentrations were higher for patients with PGD versus no PGD. The GEE contrast estimate for the association of plasma ICAM-1 with PGD was 107.5 ng/mL (95% CI 38.7, 176.3), p = 0.002. In the multivariate analyses, this finding was independent of all clinical variables except pulmonary artery pressures prior to transplant. There was no association between plasma vWF levels and PGD. We conclude that higher levels of plasma ICAM-1 are associated with PGD following lung transplantation.

Vaginal symptoms and bacterial vaginosis (BV): how useful is self-report? Development of a screening tool for predicting BV status

Vaginal complaints compel an evaluation of bacterial vaginosis (BV), however, many cases of BV are asymptomatic. We evaluated the sensitivity and specificity of vaginal symptoms in the diagnosis of BV and examined the utility of creating a BV screening tool using clinical, behavioural and demographic characteristics. A total of 1916 pregnant women were included in this analysis. In total, 757 women screened positive for BV and over one third of BV-positive women presented without any lower genital tract symptoms (39.4%). African American race, abnormal vaginal odour, and smoking were independently related to BV positivity. A BV screening tool including these three factors was fairly predictive of BV status with the area under the ROC curve equal to 0.669. This three-item prediction rule may be useful in identifying high- risk pregnant women in need of BV screening and, given the high specificity, accurately identify the group of BV-negative pregnant women.

Analysis of dichotomous outcome data for community intervention studies

Community intervention trials are becoming increasingly popular as a tool for evaluating the effectiveness of health education and intervention strategies. Typically, units such as households, schools, towns, counties, are randomized to receive either intervention or control, then outcomes are measured on individuals within each of the units of randomization. It is well recognized that the design and analysis of such studies must account for the clustering of subjects within the units of randomization. Furthermore, there are usually both subject level and cluster level covariates that must be considered in the modelling process. While suitable methods are available for continuous outcomes, data analysis is more complicated when dichotomous outcomes are measured on each subject. This paper will compare and contrast several of the available methods that can be applied in such settings, including random effects models, generalized estimating equations and methods based on the calculation of 'design effects', as implemented in the computer package SUDAAN. For completeness, the paper will also compare these methods of analysis with more simplistic approaches based on the summary statistics. All the methods will be applied to a case study based on an adolescent anti-smoking intervention in Australia. The paper concludes with some general discussion and recommendations for routine design and analysis.

On the Morinaga Misalignment Illusion

The Morinaga illusion is the apparent misalignment of the aligned apexes of oppositely facing angles. It is also called the Morinaga paradox because its direction is opposite to that intuitively expected from the Müller-Lyer illusion. Six experiments are reported. The first showed that the illusion is greater when the apexes are aligned obliquely than when aligned vertically or horizontally (the oblique effect); the second showed that the illusion is undiminished when the two outer angles are replaced with single lines coincident with the arms of the angles; and the third showed that the illusion is undiminished when the central apex is replaced by a dot but diminished by about half when the two outer apexes are each replaced by dots. The fourth experiment showed that the illusion also occurs with the aligned ends of parallel lines and edges of squares but not with the aligned tangential points of circles of about the same size. Experiments 5 and 6 showed that the effect is markedly greater with small, widely spaced elements. Explanations in terms of perceptual normalization to a line and perceptual assimilation have been considered. The latter explanation is the more plausible of the two, although it is conceivable that both processes contribute to the effect.