Validating the Modified McGill Thyroid Nodule Score for Assessment of Preoperative Risk of Pediatric Thyroid Malignancy.

OBJECTIVE: The McGill Thyroid Nodule Score (MTNS) is a preoperative tool used to predict the risk for well-differentiated thyroid cancer in adults. It was developed by a multidisciplinary team using established evidence-based risk factors for thyroid cancer. The modified McGill Thyroid Nodule Score (mMTNS) was developed to predict malignancy risk in children. A pilot study suggested the mMTNS was able to assess malignancy risk in children with indeterminate cytology on fine needle aspiration (FNA). This study seeks to validate these findings. METHODS: Retrospective chart review identified subjects who underwent FNA biopsy and subsequent resection. Each patient was assigned a score to compare to final pathology. Statistical analysis was performed with SPSS. All tests were 2-tailed and statistical significance defined p < 0.05. Logistic regression used to determine predictive values of scores. RESULTS: 46 patients ≤21 years of age underwent resection of a thyroid nodule. Female predominance of 85% (n = 39). 78% (n = 36) of patients had palpable nodule. 65% (n = 30) found to have benign pathology and 35% (n = 16) found to have malignancy. Malignant nodules associated with greater mean mMTNS compared to benign [13.63 vs 7.23]. An mMTNS greater >12 had sensitivity of 86.7%, specificity of 90.3%, positive predictive value of 81.3%, and negative predictive value of 93.3%. CONCLUSION: Our data suggests the mMTNS continues to be a useful adjunct in predicting malignancy risk of pediatric thyroid nodules. An mMTNS >12 has a high risk for malignancy, which can aid in counseling and clinical decision making, particularly when there is indeterminate cytology on FNA. LEVEL OF EVIDENCE: IV.

Grouped mixtures of air pollutants and seasonal temperature anomalies and cardiovascular hospitalizations among U.S. Residents.

BACKGROUND: Air pollution is a recognized risk factor for cardiovascular disease (CVD). Temperature is also linked to CVD, with a primary focus on acute effects. Despite the close relationship between air pollution and temperature, their health effects are often examined separately, potentially overlooking their synergistic effects. Moreover, fewer studies have performed mixture analysis for multiple co-exposures, essential for adjusting confounding effects among them and assessing both cumulative and individual effects. METHODS: We obtained hospitalization records for residents of 14 U.S. states, spanning 2000-2016, from the Health Cost and Utilization Project State Inpatient Databases. We used a grouped weighted quantile sum regression, a novel approach for mixture analysis, to simultaneously evaluate cumulative and individual associations of annual exposures to four grouped mixtures: air pollutants (elemental carbon, ammonium, nitrate, organic carbon, sulfate, nitrogen dioxide, ozone), differences between summer and winter temperature means and their long-term averages during the entire study period (i.e., summer and winter temperature mean anomalies), differences between summer and winter temperature standard deviations (SD) and their long-term averages during the entire study period (i.e., summer and winter temperature SD anomalies), and interaction terms between air pollutants and summer and winter temperature mean anomalies. The outcomes are hospitalization rates for four prevalent CVD subtypes: ischemic heart disease, cerebrovascular disease, heart failure, and arrhythmia. RESULTS: Chronic exposure to air pollutant mixtures was associated with increased hospitalization rates for all CVD subtypes, with heart failure being the most susceptible subtype. Sulfate, nitrate, nitrogen dioxide, and organic carbon posed the highest risks. Mixtures of the interaction terms between air pollutants and temperature mean anomalies were associated with increased hospitalization rates for all CVD subtypes. CONCLUSIONS: Our findings identified critical pollutants for targeted emission controls and suggested that abnormal temperature changes chronically affected cardiovascular health by interacting with air pollution, not directly.

Extramural US Federal Research Grants For Health Outcomes Associated With Climate Change Inadequate, Too Narrow In Focus.

Climate change causes and exacerbates disease, creates and worsens health disparities, disrupts health care delivery, and imposes a significant disease burden in the US and globally. Critical knowledge gaps hinder an evidence-based response and are perpetuated by scarce federal research funds. We identified and described extramural US federal research funding (that is, grants provided to organizations and institutions outside of federal agencies) that both addressed health outcomes associated with climate change and was awarded between 2010 and 2020. During this eleven-year period, 102 grants met our criteria, totaling approximately $58.7 million, or approximately $5.3 million per year (2020 adjusted US dollars). Federal investments in climate change and health research during this period failed to address the breadth of climate-sensitive exposures, health outcomes, and impacts on vulnerable populations. Moving forward, in addition to increasing investment in climate and health research across all known hazards, critical attention should be placed on vulnerable populations and health equity. To achieve this, increased federal research coordination and cooperation are needed, as well as a mechanism to track this funding.

Ultimate Black Hole Recoil: What is the Maximum High-Energy Collision Kick?

We performed a series of 1381 full numerical simulations of high energy collision of black holes to search for the maximum recoil velocity after their merger. We consider equal mass binaries with opposite spins pointing along their orbital plane and perform a search of spin orientations, impact parameters, and initial linear momenta to find the maximum recoil for a given spin magnitude s. This spin sequence for s=0.4, 0.7, 0.8, 0.85, 0.9 is then extrapolated to the extreme case, s=1, to obtain an estimated maximum recoil velocity of 28,562±342 km/s, thus approximately bounded by 10% of the speed of light.

Additive effects of 10-year exposures to PM2.5 and NO2 and primary cancer incidence in American older adults.

Epidemiologic evidence on the relationships between air pollution and the risks of primary cancers other than lung cancer remained largely lacking. We aimed to examine associations of 10-year exposures to fine particulate matter (PM2.5) and nitrogen dioxide (NO2) with risks of breast, prostate, colorectal, and endometrial cancers. Methods: For each cancer, we constructed a separate cohort among the national Medicare beneficiaries during 2000 to 2016. We simultaneously examined the additive associations of six exposures, namely, moving average exposures to PM2.5 and NO2 over the year of diagnosis and previous 2 years, previous 3 to 5 years, and previous 6 to 10 years, with the risk of first cancer diagnosis after 10 years of follow-up, during which there was no cancer diagnosis. Results: The cohorts included 2.2 to 6.5 million subjects for different cancers. Exposures to PM2.5 and NO2 were associated with increased risks of colorectal and prostate cancers but were not associated with endometrial cancer risk. NO2 was associated with a decreased risk of breast cancer, while the association for PM2.5 remained inconclusive. At exposure levels below the newly updated World Health Organization Air Quality Guideline, we observed substantially larger associations between most exposures and the risks of all cancers, which were translated to hundreds to thousands new cancer cases per year within the cohort per unit increase in each exposure. Conclusions: These findings suggested substantial cancer burden was associated with exposures to PM2.5 and NO2, emphasizing the urgent need for strategies to mitigate air pollution levels.

Seasonal Temperature Variability and Mortality in the Medicare Population.

BACKGROUND: Seasonal temperature variability remains understudied and may be modified by climate change. Most temperature-mortality studies examine short-term exposures using time-series data. These studies are limited by regional adaptation, short-term mortality displacement, and an inability to observe longer-term relationships in temperature and mortality. Seasonal temperature and cohort analyses allow the long-term effects of regional climatic change on mortality to be analyzed. OBJECTIVES: We aimed to carry out one of the first investigations of seasonal temperature variability and mortality across the contiguous United States. We also investigated factors that modify this association. Using adapted quasi-experimental methods, we hoped to account for unobserved confounding and to investigate regional adaptation and acclimatization at the ZIP code level. METHODS: We examined the mean and standard deviation (SD) of daily temperature in the warm (April-September) and cold (October-March) season in the Medicare cohort from 2000 to 2016. This cohort comprised 622,427,230 y of person-time in all adults over the age of 65 y from 2000 to 2016. We used daily mean temperature obtained from gridMET to develop yearly seasonal temperature variables for each ZIP code. We used an adapted difference-in-difference approach model with a three-tiered clustering approach and meta-analysis to observe the relationship between temperature variability and mortality within ZIP codes. Effect modification was assessed with stratified analyses by race and population density. RESULTS: For every 1°C increase in the SD of warm and cold season temperature, the mortality rate increased by 1.54% [95% confidence interval (CI): 0.73%, 2.15%] and 0.69% (95% CI: 0.22%, 1.15%) respectively. We did not see significant effects for seasonal mean temperatures. Participants who were classified by Medicare into an "other" race group had smaller effects than those classified as White for Cold and Cold SD and areas with lower population density had larger effects for Warm SD. DISCUSSION: Warm and cold season temperature variability were significantly associated with increased mortality rates in U.S. individuals over the age of 65 y, even after controlling for seasonal temperature averages. Warm and cold season mean temperatures showed null effects on mortality. Cold SD had a larger effect size for those who were in the racial subgroup other, whereas Warm SD was more harmful for those living in lower population density areas. This study adds to the growing calls for urgent climate mitigation and environmental health adaptation and resiliency. https://doi.org/10.1289/EHP11588.

Weighting of risk factors for low birth weight: a linked routine data cohort study in Wales, UK.

OBJECTIVE: Globally, 20 million children are born with a birth weight below 2500 g every year, which is considered as a low birthweight (LBW) baby. This study investigates the contribution of modifiable risk factors in a nationally representative Welsh e-cohort of children and their mothers to inform opportunities to reduce LBW prevalence. DESIGN: A longitudinal cohort study based on anonymously linked, routinely collected multiple administrative data sets. PARTICIPANTS: The cohort, (N=693 377) comprising of children born between 1 January 1998 and 31 December 2018 in Wales, was selected from the National Community Child Health Database. OUTCOME MEASURES: The risk factors associated with a binary LBW (outcome) variable were investigated with multivariable logistic regression (MLR) and decision tree (DT) models. RESULTS: The MLR model showed that non-singleton children had the highest risk of LBW (adjusted OR 21.74 (95% CI 21.09 to 22.40)), followed by pregnancy interval less than 1 year (2.92 (95% CI 2.70 to 3.15)), maternal physical and mental health conditions including diabetes (2.03 (1.81 to 2.28)), anaemia (1.26 (95% CI 1.16 to 1.36)), depression (1.58 (95% CI 1.43 to 1.75)), serious mental illness (1.46 (95% CI 1.04 to 2.05)), anxiety (1.22 (95% CI 1.08 to 1.38)) and use of antidepressant medication during pregnancy (1.92 (95% CI 1.20 to 3.07)). Additional maternal risk factors include smoking (1.80 (95% CI 1.76 to 1.84)), alcohol-related hospital admission (1.60 (95% CI 1.30 to 1.97)), substance misuse (1.35 (95% CI 1.29 to 1.41)) and evidence of domestic abuse (1.98 (95% CI 1.39 to 2.81)). Living in less deprived area has lower risk of LBW (0.70 (95% CI 0.67 to 0.72)). The most important risk factors from the DT models include maternal factors such as smoking, maternal weight, substance misuse record, maternal age along with deprivation-Welsh Index of Multiple Deprivation score, pregnancy interval and birth order of the child. CONCLUSION: Resources to reduce the prevalence of LBW should focus on improving maternal health, reducing preterm births, increasing awareness of what is a sufficient pregnancy interval, and to provide adequate support for mothers' mental health and well-being.

Autoimmune gene expression profiling of fingerstick whole blood in Chronic Fatigue Syndrome.

BACKGROUND: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating condition that can lead to severe impairment of physical, psychological, cognitive, social, and occupational functions. The cause of ME/CFS remains incompletely understood. There is no clinical diagnostic test for ME/CFS. Although many therapies have been used off-label to manage symptoms of ME/CFS, there are limited, if any, specific therapies or cure for ME/CFS. In this study, we investigated the expression of genes specific to key immune functions, and viral infection status in ME/CFS patients with an aim of identifying biomarkers for characterization and/or treatment of the disease. METHODS: In 2021, one-hundred and sixty-six (166) patients diagnosed with ME/CFS and 83 healthy controls in the US participated in this study via a social media-based application (app). The patients and heathy volunteers consented to the study and provided self-collected finger-stick blood and first morning void urine samples from home. RNA from the fingerstick blood was tested using DxTerity's 51-gene autoimmune RNA expression panel (AIP). In addition, DNA from the same fingerstick blood sample was extracted to detect viral load of 4 known ME/CFS associated viruses (HHV6, HHV7, CMV and EBV) using a real-time PCR method. RESULTS: Among the 166 ME/CFS participants in the study, approximately half (49%) of the ME/CFS patients reported being house-bound or bedridden due to severe symptoms of the disease. From the AIP testing, ME/CFS patients with severe, bedridden conditions displayed significant increases in gene expression of IKZF2, IKZF3, HSPA8, BACH2, ABCE1 and CD3D, as compared to patients with mild to moderate disease conditions. These six aforementioned genes were further upregulated in the 22 bedridden participants who suffer not only from ME/CFS but also from other autoimmune diseases. These genes are involved in T cell, B cell and autoimmunity functions. Furthermore, IKZF3 (Aiolos) and IKZF2 (Helios), and BACH2 have been implicated in other autoimmune diseases such as systemic lupus erythematosus (SLE) and Rheumatoid Arthritis (RA). Among the 240 participants tested with the viral assays, 9 samples showed positive results (including 1 EBV positive and 8 HHV6 positives). CONCLUSIONS: Our study indicates that gene expression biomarkers may be used in identifying or differentiating subsets of ME/CFS patients having different levels of disease severity. These gene targets may also represent opportunities for new therapeutic modalities for the treatment of ME/CFS. The use of social media engaged patient recruitment and at-home sample collection represents a novel approach for conducting clinical research which saves cost, time and eliminates travel for office visits.

MLL::AF9 degradation induces rapid changes in transcriptional elongation and subsequent loss of an active chromatin landscape.

MLL rearrangements produce fusion oncoproteins that drive leukemia development, but the direct effects of MLL-fusion inactivation remain poorly defined. We designed models with degradable MLL::AF9 where treatment with small molecules induces rapid degradation. We leveraged the kinetics of this system to identify a core subset of MLL::AF9 target genes where MLL::AF9 degradation induces changes in transcriptional elongation within 15 minutes. MLL::AF9 degradation subsequently causes loss of a transcriptionally active chromatin landscape. We used this insight to assess the effectiveness of small molecules that target members of the MLL::AF9 multiprotein complex, specifically DOT1L and MENIN. Combined DOT1L/MENIN inhibition resembles MLL::AF9 degradation, whereas single-agent treatment has more modest effects on MLL::AF9 occupancy and gene expression. Our data show that MLL::AF9 degradation leads to decreases in transcriptional elongation prior to changes in chromatin landscape at select loci and that combined inhibition of chromatin complexes releases the MLL::AF9 oncoprotein from chromatin globally.

Patching of the Inferior Vena Cava Following Lateral Venorrhaphy in Penetrating Traumatic Injury.

Penetrating injury to the inferior vena cava (IVC) is associated with high morbidity and mortality. Luminal narrowing can occur following lateral venorrhaphy and can lead to future morbidity. This case report discusses the success of patch repair following lateral venorrhaphy in two trauma patients. We describe the use of patch repair to eliminate stenosis of the IVC resulting from primary repair in the setting of traumatic injury. Furthermore, trauma patients are known to be at high risk for venous thromboembolism, and we describe the use of low molecular weight heparin as chemical prophylaxis for prevention of this complication following patch repair.

Telehealth in Pediatric Surgical Subspecialties: Rapid Adoption in the Setting of COVID-19.

Background/Purpose: Telehealth has evolved over the past several decades to address varying medical needs. Most recently, it has been widely utilized as a result of the COVID-19 pandemic. Most previous studies have not performed in-depth analyses of patient satisfaction with telehealth technologies. This project investigated patient satisfaction with the abrupt implementation of telemedicine within pediatric surgical subspecialties during the COVID-19 pandemic. Materials and Methods: We conducted a single-center review to determine patients' satisfaction with telemedicine during the early stages of the pandemic. Surveys were distributed to patients who completed a telemedicine video visit within a pediatric surgical subspecialty at Connecticut Children's Medical Center between March 16 and May 16, 2020. Results: A total of 1,608 patients were contacted, with 457 surveys completed (28.4%). Of all respondents, 95.6% were "very satisfied" or "satisfied" with their overall telemedicine appointment. Seventy-three percent reported no difficulty with completing their visit. Eighty-seven percent would consider another telemedicine visit again in the future. No significant difference was found between the payor mix for telemedicine and in-person appointments. Conclusions: The implementation of telemedicine at Connecticut Children's Medical Center during the COVID-19 pandemic was successful despite numerous barriers to use. Families not only showed high rates of satisfaction with the overall visit and provider interaction, but also an overwhelming openness to future use of telehealth.

Best Buy in Public Health or Luxury Expense?: The Cost-effectiveness of a Pediatric Operating Room in Uganda From the Societal Perspective.

OBJECTIVE: To determine the cost-effectiveness of building and maintaining a dedicated pediatric operating room (OR) in Uganda from the societal perspective. BACKGROUND: Despite the heavy burden of pediatric surgical disease in low-income countries, definitive treatment is limited as surgical infrastructure is inadequate to meet the need, leading to preventable morbidity and mortality in children. METHODS: In this economic model, we used a decision tree template to compare the intervention of a dedicated pediatric OR in Uganda for a year versus the absence of a pediatric OR. Costs were included from the government, charity, and patient perspectives. OR and ward case-log informed epidemiological and patient outcomes data, and measured cost per disability adjusted life year averted and cost per life saved. The incremental cost-effectiveness ratio (ICER) was calculated between the intervention and counterfactual scenario. Costs are reported in 2015 US$ and inflated by 5.5%. FINDINGS: In Uganda, the implementation of a dedicated pediatric OR has an ICER of $37.25 per disability adjusted life year averted or $3321 per life saved, compared with no existing operating room. The ICER is well below multiple cost-effectiveness thresholds including one times the country's gross domestic product per capita ($694). The ICER remained robust under 1-way and probabilistic sensitivity analyses. CONCLUSION: Our model ICER suggests that the construction and maintenance of a dedicated pediatric operating room in sub-Saharan Africa is very-cost effective if hospital space and personnel pre-exist to staff the facility. This supports infrastructure implementation for surgery in sub-Saharan Africa as a worthwhile investment.

Exploring the Small Mass Ratio Binary Black Hole Merger via Zeno's Dichotomy Approach.

We perform a sequence of binary black hole simulations with increasingly small mass ratios, reaching to a 128:1 binary that displays 13 orbits before merger. Based on a detailed convergence study of the q=m_{1}/m_{2}=1/15 nonspinning case, we apply additional mesh refinement levels around the smaller hole horizon [30] to reach successively the q=1/32, q=1/64, and q=1/128 cases. Roughly a linear computational resources scaling with 1/q is observed on eight-nodes simulations. We compute the remnant properties of the merger: final mass, spin, and recoil velocity, finding precise consistency between horizon and radiation measures. We also compute the gravitational waveforms: their peak frequency, amplitude, and luminosity. We compare those values with predictions of the corresponding phenomenological formulas, reproducing the particle limit within 2%, and we then use the new results to improve their fitting coefficients.

A Critical Appraisal of the July Effect: Evaluating Complications Following Pancreaticoduodenectomy.

BACKGROUND: Reports of higher rates of medical errors in the month of July have generated concern regarding major surgery at academic institutions early in the yearly promotion cycle. This study was designed to evaluate perioperative outcomes in patients undergoing pancreaticoduodenectomy (PD) at different times of the year. MATERIALS AND METHODS: Outcomes were retrospectively evaluated for patients treated in July versus the rest of the year and in the first quarter (July-September) versus the remaining quarters. The primary outcome was operative morbidity as measured by Clavien-Dindo grade, a classification system of surgical complications. Secondary outcomes included mortality, operative blood loss, pancreatic fistula formation, delayed gastric emptying, intraabdominal abscess, anastomotic leak, reoperation, and other variables of interest. RESULTS: From January 2003 to September 2015, 472 patients underwent PD by a single academic surgeon. Overall, 77.1% of PDs were performed for malignancy. The number of patients did not significantly vary by month or by quarter. The incidence of major morbidity (Clavien-Dindo grade ≥ III) in patients who had a PD was 12.2% in July and 17.5% in all other months (P = 0.79). The rate of pancreatic fistula, intraabdominal abscess, reoperation, readmission, and mortality did not differ significantly by month or by quarter (P > 0.05 for all). CONCLUSIONS: The current study does not find any correlation between time of year and operative morbidity or mortality, suggesting that PD can be safely performed irrespective of timing.

Pediatric intussusception in Uganda: differences in management and outcomes with high-income countries.

PURPOSE: In high-income countries the presentation and treatment of intussusception is relatively rapid, and most cases are correctable with radiographically-guided reduction. In low-income countries, many delays affect outcomes and surgical intervention is required. This study characterizes the burden and outcome of pediatric intussusception in Uganda. METHODS: Prospective case series of intussusception cases from May 2015 to July 2016 at a tertiary referral hospital in Uganda. RESULTS: Forty patients were included in the study. Male to female ratio was 3:2. Average duration of symptoms before presentation was 4.5 days. Median duration of symptoms in referred patients was 4 days and 2 days in non-referred patients (P value 0.0009). All 40 patients underwent surgical treatment: 25% had resection and enterostomy, 15% had resection and primary anastomosis, 2.5% had resection, primary anastomosis and enterostomy and 57.5% underwent manual reduction. Mortality was 32% and febrile patients on admission were 20 times more likely to die (P value 0.040). CONCLUSION: Intussusception carries a high operative and mortality rate in Uganda. Referred patients presented later than non-referred patients to health facilities. Fever on examination at admission was positively associated with mortality. This disease remains a target for quality metrics in global pediatric surgery. TYPE OF STUDY: Diagnostic study. LEVEL OF EVIDENCE: III.

Whole-Exome Sequencing of Syndromic Adrenocortical Carcinoma Reveals Distinct Mutational Profile From Sporadic ACC.

Next-generation sequencing has provided genetic profiles of a large number of sporadic adrenocortical carcinomas (ACCs), but the applicability of these results to ACC cases associated with tumor predisposition syndromes is unclear. Although the germline features of these syndromes have been well described, the somatic mutational landscape of the tumors they give rise to is less clear. Our group obtained germline and tumor tissue from a pediatric patient who developed ACC during her first year of life, which was treated successfully. She was subsequently diagnosed with additional tumors later in childhood. Whole exome sequencing analysis was performed followed by in silico protein function prediction, revealing a probably deleterious germline TP53 L265P mutation. The somatic mutational burden was comparable between the index case and a previously published cohort of 40 sporadic cases, but the mutational spectrum was distinct in terms of raw base-change frequency as well as in a trinucleotide context-specific analysis. No canonical somatic genetic drivers of ACC were identified in the reported case, suggesting that syndromic adrenocortical tumors may represent a genetically distinct entity from sporadic tumors.

Effect of curcumin supplementation on serum expression of select cytokines and chemokines in a female rat model of nonalcoholic steatohepatitis.

OBJECTIVE: We recently reported that curcumin supplementation in a metabolically (i.e., Western diet [WD]) and chemically (i.e., CCl4) induced female rat model of non-alcoholic steatohepatitis (NASH) was associated with lower liver pathology scores and molecular markers of inflammation. This occurred when curcumin was given during induction of disease (preventative arm; 8-week WD with or without curcumin [8WD + C vs. 8WD]) as well as when given after disease development (treatment arm; 12-week WD with or without curcumin during weeks 9-12 [12WD + C vs. 12WD]). Herein, we sought to extend our findings from that study by determining the effects of curcumin supplementation on cytokine/chemokine expression in serum collected from these same rats. RESULTS: 24 cytokines/chemokines were assayed. IL-2 (+ 80%) and IL-13 (+ 83%) were greater with curcumin supplementation in the prevention arm. IL-2 (+ 192%), IL-13 (+ 87%), IL-17A (+ 81%) and fractalkine (+ 121%) were higher while RANTES was lower (- 22%) with curcumin supplementation in the treatment arm (p < 0.05 for all). RANTES concentrations also correlated significantly with hepatic pathology scores of inflammation (r = 0.417, p = 0.008). Select serum cytokines/chemokines were affected with curcumin supplementation in this female rat model of NASH. Moreover, curcumin's effect(s) on RANTES and its association with liver disease pathogenesis and progression may warrant further investigation.

Prediction of Postoperative Surgical Risk: A Needs Assessment for a Medical Student Curriculum.

OBJECTIVE: Medical students' abilities to predict postoperative complications and death are unknown. We hypothesize that medical students will lack confidence in determining surgical risk and will significantly overestimate surgical risk for post-operative morbidities and mortality. DESIGN: Participants were invited to participate in an electronic, anonymous survey to assess their ability to predict surgical risk. The survey presented 7 complex clinical scenarios representative of a diverse general surgery practice. Participants were asked to assess the likelihood of different morbidities and mortality on a 0-100% scale, and predictions were compared to the ACS NSQIP risk calculator. SETTING: Yale School of Medicine, New Haven, Connecticut; Tertiary medical center PARTICIPANTS: Third year medical students on their surgery clerkship as well as general surgery residents were invited to participate. RESULTS: Most students were not confident about predicting postoperative complications (83.3%) or mortality (70.8%). Most students did not feel that the surgery clerkship adequately prepared them to assess surgical risk (69.6%). When compared to surgical residents for most presented cases (57% of cases), students and residents similarly overestimated postoperative morbidities and mortality. Estimates varied significantly, with wide 95% confidence intervals. Only 17% of NSQIP predicted estimates fell within the 95% confidence intervals. CONCLUSIONS: Medical students overestimate morbidity and mortality following surgery in complex patients. Additionally, they lack confidence in their ability to predict surgical complications. A formal curriculum for risk prediction is needed for medical students.