Vascularized fascial flap for reconstruction of combined oral mucosa-mandibular defects: The multi-modal biological assessment.

OBJECTIVE: The reconstruction of composite defects in the oral and maxillofacial region using vascularized fascial flaps, such as the fibular, iliac, and temporal fascial flaps, has gained increasing attention among surgeons. However, there remains uncertainty regarding the suitability of fascial flaps as transplants, as well as their healing processes and outcomes, due to their non-mucosal nature. This study aims to comprehensively assess the biological aspects of vascularized fascial flaps at clinical, histological, and genetic levels, with the goal of providing essential biological references for their clinical application. STUDY DESIGN: This study enrolled three patients who underwent reconstruction of combined oral mucosa-mandibular defects using fibular vascularized fascial flaps between 2020 and 2023. Data regarding changes in the appearance of the fascial flaps, bulk-RNA sequencing, and histological slices of initial fascia, initial gingiva, and transformed fascia were collected and analyzed. RESULTS: Within three months, the fascial flaps exhibited rapid epithelial coverage and displayed distinct characteristics resembling mucosa. High-throughput RNA sequencing analyses and histological slices revealed that the transformed fascia exhibited tissue structures similar to mucosa and demonstrated unique advantages in promoting blood vessel formation and reducing scarring through the high-level expression of relevant genes. CONCLUSION: These findings emphasize the potential and feasibility of utilizing vascularized fascial flaps for oral mucosa reconstruction, establishing their unique advantage as transplant materials, and providing significant biological information and references for their selection and clinical application.

An economical single-shot pulse picker without nonlinear effect and dispersion.

An economical and stable single-shot pulse picker design without dispersion, nonlinear effect, and limitation on wavelength is proposed. This design is composed of a periodic pulse blocker (PPB), a control unit, and a mechanical shutter. It has successfully been applied to the commercial high-fluence femtosecond laser with 11-mm beam diameter, 2-mJ pulse energy, and 1-kHz repetition rate. Significantly, by incorporating commercial optical choppers equipped with custom-designed chopper blades in the PPB, this design can accommodate lasers with fluences reaching 610 mJ/cm2 and the standard 1 kHz repetition rate typical of high-fluence lasers. Furthermore, the proposed design provides a cost-effective substitute compared to using electro-optic modulators or acousto-optic modulators.

Health risk assessment of drinking groundwater in rural areas of Ru village and surrounding areas in Wutai County, China.

Nitrate pollution in groundwater is a global environmental problem that poses risks to human health. We investigate the health risks of nitrate in rural drinking groundwater in Rucun Township and surrounding areas of Wutai County, and provide a basis for healthy drinking water. By using statistical analysis software (SPSS19) and hydrogeochemical analysis software (AqQA), a qualitative and quantitative evaluation of nitrate health risks was conducted among populations of different ages and genders through water sample collection, chemical analysis, and construction of a human health risk model (HHRA). Through research, it was found that the average concentration of nitrate in the study area is 43.99 mg/L. Groundwater is severely polluted by NO3-, and nitrate pollution areas are mainly concentrated in the main human activity areas, especially in the main agricultural production areas. The Quaternary loess layer, as a permeable layer, cannot prevent groundwater from being polluted by NO3-. Through evaluation, it is believed that there is a health risk of nitrate pollution in rural drinking groundwater in Rucun Township and surrounding areas. Health risk level: infants>children>adult females>adult males. The discovery and evaluation results can provide a basis for the prevention and control of nitrate pollution in groundwater.

Health risk assessment of nitrate pollution of drinking groundwater in rural areas of Suihua, China.

In order to investigate the health risks of NO3- in rural drinking groundwater in Suihua, China and provide a basis for healthy drinking water, 40 sets of groundwater samples were collected in the Suihua area, and the average concentration of nitrate in the study area was 71.66 mg/L, statistical analysis software (SPSS19), Hydrogeochemical Analysis Software (AqQA) and groundwater pollution analysis software were used. Through water sample collection, chemical analysis and construction of human health risk model (HHRA), a qualitative and quantitative assessment of NO3- health risk was carried out for people of different ages and sexes, and it was concluded that there was NO3- pollution health risk in rural drinking groundwater in Suihua. Health risk level: infants > children > adult females > adult males. The evaluation provides a scientific basis for the prevention and control of NO3- pollution in groundwater and new ideas for preventing human health risks.

A Metal-Polyphenol-Based Oxygen Economizer and Fenton Reaction Amplifier for Self-Enhanced Synergistic Photothermal/Chemodynamic/Chemotherapy.

To overcome the limitations of doxorubicin (DOX) chemotherapy, nanomedicines that integrate additional photothermal therapy (PTT) and chemodynamic therapy (CDT) strategies are highlighted as promising alternatives for the treatment of malignant tumors. However, time-consuming preparation processes, biosafety concerns, and the bottlenecks of individual therapeutic modalities often limit the practical applications of this strategy. To address these issues, this work designs an oxygen economizer that additionally serves as a Fenton reaction amplifier through the simple assembly of epigallocatechin gallate (EGCG), pluronic F-127 (PF127), iron (III) ions, and doxorubicin (DOX) for the enhancement of synergistic PTT/CDT/chemotherapy. The resulting nanoformulation, EFPD, can target mitochondria and inhibit cell respiration to reduce O2 consumption, thus boosting DOX-mediated H2 O2 generation for enhanced CDT and simultaneously improving hypoxia-limited DOX chemotherapy efficacy. Moreover, the coordination between EGCG and Fe3+ provides EFPD with excellent photothermal conversion efficiencies (η = 34.7%) for PTT and photothermal-accelerated drug release. Experimental results indicate that EFPD-mediated synergistic enhancement of PTT/CDT/chemotherapy can achieve excellent therapeutic outcomes, including enhanced ablation of solid tumors, reduced metastasis and cardiotoxicity, and extended life spans.

The Chinese version of the skin tear knowledge assessment instrument (OASES): Cultural adaptation and validation.

BACKGROUND: Skin tear knowledge is an important predictor of the decreased incidence and management of skin tears, and the knowledge level among Chinese nurses is unknown so far. A validated instrument for measuring skin tear knowledge is urgent. OBJECTIVE: To culturally adapt the skin tear knowledge assessment instrument (OASES) into Chinese and verify its validity and reliability in the Chinese context. METHODS: The cultural adaptation process for OASES into Chinese was established on Beaton's translation model. Content validity was determined by the 8-expert group in wound care. A nationwide psychometric validation study was performed on a convenience sample of 3333 nurses from 113 tertiary hospitals, of whom 98 nurses finished the test-retest procedure for reliability analysis. Item validity (item difficulty and discriminating index) and construct validity (known-groups technique) were tested. RESULTS: The content validity index was 0.88-1.00. The item validity was as follows: Item difficulty ranged from 0.16 to 0.86, with an average value of 0.52; the discriminating index varied between 0.05 and 0.61. The known-group technique demonstrated excellent construct validity with a significant difference between predefined groups with theoretically expected higher knowledge scores and theoretically expected lower knowledge scores (P < 0.001). For the test-retest reliability, the Intraclass correction coefficient (ICC) during a 14-day interval for the overall tool was 0.79 (95% CI = 0.71-0.86), and Cohen's kappa value for each item varied from 0.17 to 0.62. CONCLUSIONS: The Chinese version of OASES was validated to be suitable for skin tear knowledge assessment with acceptable psychometric properties, through which the knowledge and training priorities of skin tear among Chinese nurses can be quantified.

Evaluation of the Clinical Utility of the Bone Metastases Ensemble Trees for Survival Decision Support Platform (BMETS-DSP): A Case-Based Pilot Assessment.

PURPOSE: The Bone Metastases Ensemble Trees for Survival Decision Support Platform (BMETS-DSP) provides patient-specific survival predictions and evidence-based recommendations to guide multidisciplinary management for symptomatic bone metastases. We assessed the clinical utility of the BMETS-DSP through a pilot prepost design in a simulated clinical environment. METHODS: Ten Radiation Oncology physicians reviewed 55 patient cases at two time points: without and then with the use of BMETS-DSP. Assessment included 12-month survival estimate, confidence in and likelihood of sharing estimates with patients, and recommendations for open surgery, systemic therapy, hospice referral, and radiotherapy (RT) regimen. Paired statistics compared pre- versus post-DSP outcomes. Reported statistical significance is P < .05. RESULTS: Pre- versus post-DSP, overestimation of true minus estimated survival time was significantly reduced (mean difference -2.1 [standard deviation 4.1] v -1 month [standard deviation 3.5]). Prediction accuracy was significantly improved at cut points of < 3 (72 v 79%), ≤ 6 (64 v 71%), and ≥ 12 months (70 v 81%). Median ratings of confidence in and likelihood of sharing prognosis significantly increased. Significantly greater concordance was seen in matching use of 1-fraction RT with the true survival < 3 months (70 v 76%) and < 10-fraction RT with the true survival < 12 months (55 v 62%) and appropriate use of open surgery (47% v 53%), without significant changes in selection of hospice referral or systemic therapy. CONCLUSION: This pilot study demonstrates that BMETS-DSP significantly improved physician survival estimation accuracy, prognostic confidence, likelihood of sharing prognosis, and use of prognosis-appropriate RT regimens in the care of symptomatic bone metastases, supporting future multi-institutional validation of the platform.

Cost-effectiveness of prophylactic cranial irradiation in stage III non-small cell lung cancer.

INTRODUCTION: In stage III non-small cell lung cancer (NSCLC), prophylactic cranial irradiation (PCI) reduces the brain metastases incidence and prolongs the progression-free survival without improving overall survival. PCI increases the risk of toxicity and is currently not adopted in routine care. Our objective was to assess the cost-effectiveness of PCI compared with no PCI in stage III NSCLC from a Dutch societal perspective. METHODS: A cohort partitioned survival model was developed based on individual patient data from three randomized phase III trials (N = 670). Quality-adjusted life years (QALYs) and costs were estimated over a lifetime time horizon. A willingness-to-pay (WTP) threshold of €80,000 per QALY was adopted. Sensitivity and scenario analyses were performed to address parameter uncertainty and to explore what parameters had the greatest impact on the cost-effectiveness results. RESULTS: PCI was more effective and costly (0.443 QALYs, €10,123) than no PCI, resulting in an incremental cost-effectiveness ratio (ICER) of €22,843 per QALY gained. The probability of PCI being cost-effective at a WTP threshold of €80,000 per QALY was 93%. The probability of PCI gaining three and six additional months of life were 76% and 56%. The scenario analysis adding durvalumab increased the ICER to €35,159 per QALY gained. Using alternative survival distributions had little impact on the ICER. Assuming fewer PCI fractions and excluding indirect costs decreased the ICER to €18,263 and €5554 per QALY gained. CONCLUSION: PCI is cost-effective compared to no PCI in stage III NSCLC, and could therefore, from a cost-effectiveness perspective, be considered in routine care.

Longitudinal Trends of Financial Toxicity in Patients With Lung Cancer: A Prospective Cohort Study.

BACKGROUND: Cancer therapy is associated with severe financial burden. However, the magnitude and longitudinal patient relationship with financial toxicity (FT) in the initial course of therapy is unclear. METHODS: Patients with stage II-IV lung cancer were recruited in a prospective longitudinal study between July 2018 and March 2020. FT was measured via the validated COmprehensive Score for financial Toxicity (COST) at the time of cancer diagnosis and at 6-month follow-up (6MFU). 6MFU data were compared with corresponding baseline data. A lower COST score indicates increased financial hardship. RESULTS: At the time of analysis, 215 agreed to participate. Subsequently, 112 patients completed 6MFU. On average, slightly more FT was observed at diagnosis compared with 6MFU (median COSTbase 25 v COST6M 27; P < .001); however, individual patients experienced large changes in FT. At 6MFU, 27.7% of patients had made financial sacrifices to pay for treatment but only 4.5% refused medical care based on cost. Median reported out-of-pocket (OOP) costs for the initial 6 months of cancer treatment was $2,496 (range, $0-25,900). Risk factors for FT at diagnosis were unique from risk factors at 6MFU. Actual OOP expenses were not correlated with FT; however, inability to predict upcoming treatment expenses resulted in higher FT at 6MFU. DISCUSSION: FT is a pervasive challenge during the initiation of lung cancer treatment. Few patients are willing to sacrifice medical care regardless of the cost. Risk factors for FT evolve, resulting in unique interventional targets throughout therapy.

Order matters: How covert value updating during sequential option sampling shapes economic preference.

Standard neuroeconomic decision theory assumes that choice is based on a value comparison process, independent from how information about alternative options is collected. Here, we investigate the opposite intuition that preferences are dynamically shaped as options are sampled, through iterative covert pairwise comparisons. Our model builds on two lines of research, one suggesting that a natural frame of comparison for the brain is between default and alternative options, the other suggesting that comparisons spread preferences between options. We therefore assumed that during sequential option sampling, people would 1) covertly compare every new alternative to the current best and 2) update their values such that the winning (losing) option receives a positive (negative) bonus. We confronted this "covert pairwise comparison" model to models derived from standard decision theory and from known memory effects. Our model provided the best account of human choice behavior in a novel task where participants (n = 92 in total) had to browse through a sequence of items (food, music or movie) of variable length and ultimately select their favorite option. Consistently, the order of option presentation, which was manipulated by design, had a significant influence on the eventual choice: the best option was more likely to be chosen when it came earlier in the sequence, because it won more covert comparisons (hence a greater total bonus). Our study provides a mechanistic understanding of how the option sampling process shapes economic preference, which should be integrated into decision theory.

Failure mode and effects analysis for proactive healthcare risk evaluation: A systematic literature review.

RATIONALE, AIMS, AND OBJECTIVES: Failure mode and effects analysis (FMEA) is a valuable reliability management tool that can preemptively identify the potential failures of a system and assess their causes and effects, thereby preventing them from occurring. The use of FMEA in the healthcare setting has become increasingly popular over the last decade, being applied to a multitude of different areas. The objective of this study is to review comprehensively the literature regarding the application of FMEA for healthcare risk analysis. METHODS: An extensive search was carried out in the scholarly databases of Scopus and PubMed, and we only chose the academic articles which used the FMEA technique to solve healthcare risk analysis problems. Furthermore, a bibliometric analysis was performed based on the number of citations, publication year, appeared journals, authors, and country of origin. RESULTS: A total of 158 journal papers published over the period of 1998 to 2018 were extracted and reviewed. These publications were classified into four categories (ie, healthcare process, hospital management, hospital informatization, and medical equipment and production) according to the healthcare issues to be solved, and analyzed regarding the application fields and the utilized FMEA methods. CONCLUSION: FMEA has high practicality for healthcare quality improvement and error reduction and has been prevalently employed to improve healthcare processes in hospitals. This research supports academics and practitioners in effectively adopting the FMEA tool to proactively reduce healthcare risks and increase patient safety, and provides an insight into its state-of-the-art.

Occupational Health and Safety Risk Assessment based on Combination Weighting and Uncertain Linguistic Information: Method Development and Application to a Construction Project.

OCCUPATIONAL APPLICATIONSOccupational hazards and work-related accidents are a substantial problem in countries around the world. Therefore, it is of great importance to develop appropriate techniques to assess and reduce the risk of occupational hazards. In many situations, however, exact data are inadequate to model real-life scenarios, because of the complexity of occupational health and safety (OHS) risk assessment problems. We present a new OHS risk assessment model to assess and rank the risk of occupational hazards based on combination weighting and uncertain linguistic information. Moreover, a practical example of a shopping mall construction project is given to illustrate the effectiveness of the proposed model. The new model was found to provide a useful, practical, and flexible way for risk evaluation in OHS. In particular, it offered a new method for capturing domain expert opinions and prioritizing potential occupational hazards to improve the health and safety of workers.

TECHNICAL ABSTRACTBackground OHS is an important issue, since it has great impact on the cost, productivity, and social reputation of a company. Occupational hazards have attracted considerable attention from both researchers and practitioners, because they can cause financial and personal loss as well as intangible damage within organizations and enterprises worldwide.Purpose Our aim was to develop a new model to assess and rank the risk of occupational hazards and identify high-risk ones for the promotion of occupational health.Methods The q-rung orthopair uncertain linguistic sets (q-ROULSs) are utilized to deal with uncertain risk assessment information provided by experts. An extended evaluation based on distance from average solution (EDAS) method is introduced to determine the risk priorities of occupational hazards. Moreover, a combination weighting method is adopted to derive the relative weights of risk criteria. A case study, involving a shopping mall construction project, was used to illustrate the applicability and validity of the proposed model.Results Ten occupational hazards were identified and, according to the proposed model, their risk priority scores were determined. From these scores, three hazards were determined as the most serious (i.e., collision with immobile objects or being struck by moving objects; fall of a person from height; and trapping, being crushed-inside or between objects). Conclusions: The proposed model was found to be a reliable and practical tool for the risk assessment of occupational hazards in OHS. It can depict the uncertain risk assessments of experts in a more prominent manner, and produce a reliable risk ranking of occupational hazards for corrective actions.

Sour grapes and sweet victories: How actions shape preferences.

Classical decision theory postulates that choices proceed from subjective values assigned to the probable outcomes of alternative actions. Some authors have argued that opposite causality should also be envisaged, with choices influencing subsequent values expressed in desirability ratings. The idea is that agents may increase their ratings of items that they have chosen in the first place, which has been typically explained by the need to reduce cognitive dissonance. However, evidence in favor of this reverse causality has been the topic of intense debates that have not reached consensus so far. Here, we take a novel approach using Bayesian techniques to compare models in which choices arise from stable (but noisy) underlying values (one-way causality) versus models in which values are in turn influenced by choices (two-way causality). Moreover, we examined whether in addition to choices, other components of previous actions, such as the effort invested and the eventual action outcome (success or failure), could also impact subsequent values. Finally, we assessed whether the putative changes in values were only expressed in explicit ratings, or whether they would also affect other value-related behaviors such as subsequent choices. Behavioral data were obtained from healthy participants in a rating-choice-rating-choice-rating paradigm, where the choice task involves deciding whether or not to exert a given physical effort to obtain a particular food item. Bayesian selection favored two-way causality models, where changes in value due to previous actions affected subsequent ratings, choices and action outcomes. Altogether, these findings may help explain how values and actions drift when several decisions are made successively, hence highlighting some shortcomings of classical decision theory.

Mediating factors explaining the associations between polycyclic aromatic hydrocarbons exposure, low socioeconomic status and diabetes: A structural equation modeling approach.

Exposure to polycyclic aromatic hydrocarbons (PAHs) is linked with increased risk of diabetes, whereas socioeconomic status (SES) may contribute to the development of diabetes. However, the mechanisms underlying the relationships between them are unclear. We used structural equation modeling (SEM) to identify mediating factors in the associations of PAHs exposure, low SES with diabetes risk. Data were collected from 2751 Wuhan participants at baseline from the Wuhan-Zhuhai Cohort Study (n = 3053). They answered the questionnaires regarding socio-demographic, participated physical examinations and provided urine samples for measurements of urinary monohydroxy-polycyclic aromatic hydrocarbons (OH-PAHs) levels. SEM was used to identify the mediating factors (such as hypertension, body mass index (BMI), triglycerides (TG) and total cholesterol (TCHO)) in the associations of low SES or PAHs exposure with diabetes risk. We observed that partial effect of PAHs exposure (ß = 0.281, p = 0.034), BMI (ß = 0.182, p = 0.000), TG (ß = 0.358, p = 0.000), TCHO (ß = 0.203, p = 0.009) or hypertension (ß = 0.385, p = 0.000) on diabetes was directive. Moreover, low SES also exhibited a directive effect on PAHs exposure (ß = -0.084, p = 0.000), BMI (ß = 0.301, p = 0.000), hypertension (ß = 0.134, p = 0.003) and TG (ß = 0.087, p = 0.001). PAHs exposure directly affected TCHO levels (ß = 0.080, p = 0.002) and TG (ß = 0.076, p = 0.017). The proportion of the effect of PAHs exposure on diabetes mediated by TG and TCHO was 15.6%. The proportion of the effect of low SES on diabetes mediated by BMI, hypertension and TG was 89.1%. The results suggested that low SES increased diabetes risk, which may be partially explained by BMI, hypertension and triglycerides, and exposure to high levels of PAHs may have indirect contribution to increased risk for diabetes with dyslipidemia.

Differences in Physician Compensation Between Men and Women at United States Public Academic Radiation Oncology Departments.

PURPOSE: A pay gap between men and women has been identified in many medical specialties. However, radiation oncology has been excluded from most analyses. This study sought to determine whether such a disparity exists among physicians in US public academic radiation oncology departments. MATERIALS AND METHODS: Radiation oncology physician faculty at US public academic medical schools were identified in states that report public university radiation oncology faculty salary. Information pertaining to sex, academic rank, experience, clinical volume, and academic productivity were collected. Simple (1 predictor) and multiple (more than 1 predictor) generalized linear mixed-effect models for compensation were used to simultaneously assess the impact of physician-level and institutional-level variables, while accounting for potential correlations within institutions. To minimize the impact of faculty members working less than a full-time equivalent, a Monte Carlo simulation-based sensitivity analysis was conducted, and faculty with reported salaries under $175,000 were excluded. RESULTS: A total of 247 eligible faculty (81 women, 166 men) with public salary data were identified at 22 US public academic radiation oncology departments in 14 states. Unadjusted mean salary was 12.6% ($48,974) lower for women ($341,173; 95% confidence interval [CI], $304,581-$382,162) than it was for men ($390,147; 95% CI, $353,693-$430,358; P < .01). A $26,458 gap (6.4%) in mean salary between men ($411,829; 95% CI, $367,282-$461,780) and women ($385,371; 95% CI, $342,388-$433,749) persisted on multivariable analysis after accounting for other factors (P < .01). The salary gap remained statistically significant on sensitivity analysis. CONCLUSIONS: Mean salary for women at US public academic radiation oncology departments was lower than mean salary for men, after adjusting for confounders. Our analysis was limited to public data and could not account for relevant private personal choices and departmental factors. The salary gap may differ in other practice environments. Further research is warranted to determine the cause of this disparity, whether it exists in other practice environments, and how to successfully address it.

Impact of race, ethnicity, and socioeconomic factors on receipt of radiation after breast conservation surgery: analysis of the national cancer database.

INTRODUCTION: Many eligible women with invasive breast cancer do not receive recommended adjuvant radiation (RT), despite its role in local control and overall survival. We examined trends in RT use over 10 years, and the impact of sociodemographic factors on the receipt of standard-of-care RT, using the National Cancer Database (NCDB). MATERIALS/METHODS: Women under age 70 with invasive breast cancer who underwent BCS from 2004 to 2014 were analyzed. Receipt of RT was evaluated in the whole cohort and by time period to identify temporal trends. Multiple logistic regression models were used to assess associations between factors such as race, insurance status, ethnicity, and receipt of RT. RESULTS: A total of 501,733 patients met eligibility criteria. The percentage of patients undergoing adjuvant RT increased from 86.7% in 2004 to 92.4% in 2012, and then decreased in 2013 and 2014 to 88.9%. On univariate analysis, patients of white race were significantly more likely to receive RT compared with patients of black race (90.4% vs 86.9%, p < 0.0001), as were non-Hispanic women compared to Hispanic patients (90.2% vs. 85.3%, p < 0.0001). On multivariate analysis, race, ethnicity, insurance status, education level, and age remained significantly associated with receipt of RT. On temporal analysis, gaps remained stable, with no significant improvements over time. CONCLUSIONS: This analysis suggests a recent decline in guideline-concordant receipt of RT in women under 70, and persistent disparities in the use of RT after BCS by race, ethnicity, and socioeconomic factors. These findings raise concern for a recent detrimental change in patterns of care delivery.

Covariate adjustment using propensity scores for dependent censoring problems in the accelerated failure time model.

In many medical studies, estimation of the association between treatment and outcome of interest is often of primary scientific interest. Standard methods for its evaluation in survival analysis typically require the assumption of independent censoring. This assumption might be invalid in many medical studies, where the presence of dependent censoring leads to difficulties in analyzing covariate effects on disease outcomes. This data structure is called "semicompeting risks data," for which many authors have proposed an artificial censoring technique. However, confounders with large variability may lead to excessive artificial censoring, which subsequently results in numerically unstable estimation. In this paper, we propose a strategy for weighted estimation of the associations in the accelerated failure time model. Weights are based on propensity score modeling of the treatment conditional on confounder variables. This novel application of propensity scores avoids excess artificial censoring caused by the confounders and simplifies computation. Monte Carlo simulation studies and application to AIDS and cancer research are used to illustrate the methodology.

Personalized Risk Prediction in Clinical Oncology Research: Applications and Practical Issues Using Survival Trees and Random Forests.

A crucial component of making individualized treatment decisions is to accurately predict each patient's disease risk. In clinical oncology, disease risks are often measured through time-to-event data, such as overall survival and progression/recurrence-free survival, and are often subject to censoring. Risk prediction models based on recursive partitioning methods are becoming increasingly popular largely due to their ability to handle nonlinear relationships, higher-order interactions, and/or high-dimensional covariates. The most popular recursive partitioning methods are versions of the Classification and Regression Tree (CART) algorithm, which builds a simple interpretable tree structured model. With the aim of increasing prediction accuracy, the random forest algorithm averages multiple CART trees, creating a flexible risk prediction model. Risk prediction models used in clinical oncology commonly use both traditional demographic and tumor pathological factors as well as high-dimensional genetic markers and treatment parameters from multimodality treatments. In this article, we describe the most commonly used extensions of the CART and random forest algorithms to right-censored outcomes. We focus on how they differ from the methods for noncensored outcomes, and how the different splitting rules and methods for cost-complexity pruning impact these algorithms. We demonstrate these algorithms by analyzing a randomized Phase III clinical trial of breast cancer. We also conduct Monte Carlo simulations to compare the prediction accuracy of survival forests with more commonly used regression models under various scenarios. These simulation studies aim to evaluate how sensitive the prediction accuracy is to the underlying model specifications, the choice of tuning parameters, and the degrees of missing covariates.

Association of a Simulated Institutional Gender Equity Initiative With Gender-Based Disparities in Medical School Faculty Salaries and Promotions.

Importance: Despite progress in narrowing gender-based salary gaps, notable disparities persist in the scientific community. The significance of pay difference may be underestimated, with little data evaluating its effect on lifetime wealth after accounting for factors like time to promotion and savings. Objectives: To characterize gender disparities in salary and assess the outcomes associated with a gender equity initiative (GEI). Design, Setting, and Participants: Quality improvement study with simulations of salary and additional accumulated wealth (AAW) using retrospectively reviewed Johns Hopkins University School of Medicine annual salary and promotion data. All academic faculty were included in the faculty salary analysis from 2005 (n = 1481) and 2016 (n = 1885). Main Outcomes and Measures: Salary and longitudinal promotion data from 2005 to 2016 were used to estimate gender-based differences in salary and time to promotion. The effect of these differences on total salary and AAW, including retirement and salary-based investments, was simulated for a representative male and female faculty member over a 30-year career in 3 scenarios: (1) pre-GEI, (2) post-GEI, and (3) in real time for GEI, beginning with and progressing through these initiatives. Results: Analyses of salaries of 1481 faculty (432 women) in 2005 and 1885 faculty (742 women) in 2016 revealed that a decade after GEI implementation, the overall mean (SE) salary gap by gender decreased from -2.6% (1.2%) (95% CI, -5.6% to -0.3%) to -1.9% (1.1%) (95% CI, -4.1% to 0.3%). Simulation of pre-GEI disparities correlated with male faculty collecting an average lifetime AAW of $501 416 more than the equivalent woman, with disparities persisting past retirement. The AAW gap decreased to $210 829 in the real-time GEI simulation and to $66 104 using post-GEI conditions, reflecting success of GEI efforts. Conclusions and Relevance: Even small gender-based salary gaps are associated with substantial differences in lifetime wealth, but an institutional commitment to achieving equitable promotion and compensation for women can appreciably reduce these disparities. The findings of this study support broad implementation of similar initiatives without delay, as results may take more than a decade to emerge. A modifiable version of the simulation is provided so that external users may assess the potential disparities present within their own institutions.