Evaluating Prognostic Bias of Critical Illness Severity Scores Based on Age, Sex, and Primary Language in the United States: A Retrospective Multicenter Study.

OBJECTIVES: Although illness severity scoring systems are widely used to support clinical decision-making and assess ICU performance, their potential bias across different age, sex, and primary language groups has not been well-studied. DESIGN SETTING AND PATIENTS: We aimed to identify potential bias of Sequential Organ Failure Assessment (SOFA) and Acute Physiology and Chronic Health Evaluation (APACHE) IVa scores via large ICU databases. SETTING/PATIENTS: This multicenter, retrospective study was conducted using data from the Medical Information Mart for Intensive Care (MIMIC) and eICU Collaborative Research Database. SOFA and APACHE IVa scores were obtained from ICU admission. Hospital mortality was the primary outcome. Discrimination (area under receiver operating characteristic [AUROC] curve) and calibration (standardized mortality ratio [SMR]) were assessed for all subgroups. INTERVENTIONS: Not applicable. MEASUREMENTS AND MAIN RESULTS: A total of 196,310 patient encounters were studied. Discrimination for both scores was worse in older patients compared with younger patients and female patients rather than male patients. In MIMIC, discrimination of SOFA in non-English primary language speakers patients was worse than that of English speakers (AUROC 0.726 vs. 0.783, p < 0.0001). Evaluating calibration via SMR showed statistically significant underestimations of mortality when compared with overall cohort in the oldest patients for both SOFA and APACHE IVa, female patients (1.09) for SOFA, and non-English primary language patients (1.38) for SOFA in MIMIC. CONCLUSIONS: Differences in discrimination and calibration of two scores across varying age, sex, and primary language groups suggest illness severity scores are prone to bias in mortality predictions. Caution must be taken when using them for quality benchmarking and decision-making among diverse real-world populations.

From education to action: Development and evaluation of a student-directed service learning program.

PURPOSE: Service learning consists of service activities that respond to community-identified concerns, active learning about the population being served, and self-reflecting on the experience. The Service Learning Program (SLP) is a novel, student-led, longitudinal volunteering experience designed to address social determinants of health (SDOH) education in the undergraduate medical school curriculum. In this program, medical students complete requirements in three domains of service, education, and self-reflection over the span of one academic year. METHODS AND MATERIALS: Participating students are sent surveys prior to and after a year of participation in SLP, which are aimed to measure changes in their perceived knowledge, attitudes, and skills in multiple domains related to service learning and social determinants of health. RESULTS: Over the course of the 2019-2020 year, 110 students who participated in SLP responded to both pre- and post-surveys. These students reported significant improvements in their confidence in various knowledge and skills related to SDOH, such as identifying vulnerable populations and assessing community needs. They also were more likely to report that learning about social determinants of health was 'very important' after participating the program. CONCLUSIONS: Medical students participating in a longitudinal service learning program focused on SDOH can acquire knowledge and skills that will empower them to understand, advocate, and care for underserved populations as future physicians. This program provides a model for integrating service learning into undergraduate medical education.

A Split Methyl Halide Transferase AND Gate That Reports by Synthesizing an Indicator Gas.

Monitoring microbial reactions in highly opaque or autofluorescent environments like soils, seawater, and wastewater remains challenging. To develop a simple approach for observing post-translational reactions within microbes situated in environmental matrices, we designed a methyl halide transferase (MHT) fragment complementation assay that reports by synthesizing an indicator gas. We show that backbone fission within regions of high sequence variability in the Rossmann domain yields split MHT (sMHT) AND gates whose fragments cooperatively associate to synthesize CH3Br. Additionally, we identify a sMHT whose fragments require fusion to pairs of interacting partner proteins for maximal activity. We also show that sMHT fragments fused to FKBP12 and the FKBP-rapamycin binding domain of mTOR display significantly enhanced CH3Br production in the presence of rapamycin. This gas production is reversed in the presence of the competitive inhibitor of FKBP12/FKPB dimerization, indicating that sMHT is a reversible reporter of post-translational reactions. This sMHT represents the first genetic AND gate that reports on protein-protein interactions via an indicator gas. Because indicator gases can be measured in the headspaces of complex environmental samples, this assay should be useful for monitoring the dynamics of diverse molecular interactions within microbes situated in hard-to-image marine and terrestrial matrices.