dropout

辍学
  • 文章类型: Journal Article
    机器学习算法通常用于快速有效地从人群中计算人。用于人群计数的测试时间自适应方法调整模型参数并采用额外的数据增强来使模型更好地适应测试期间遇到的特定条件。当前的大多数研究集中在无监督领域适应上。这些方法通常执行数百次训练迭代,除了源域的注释数据之外,需要每个新目标域的大量未注释数据。与这些方法不同,我们提出了一种元测试时间自适应人群计数方法,称为CrowdTTA,它将测试时间适应的概念集成到元学习框架中,使计数模型更容易适应未知的测试分布。为了促进像素级的可靠监控信号,我们通过将dropout层插入计数模型来引入不确定性。然后使用不确定性来生成有价值的伪标签,作为调整模型的有效监督信号。在元学习的背景下,一个图像可以被视为一个任务的人群计数。在每次迭代中,我们的方法是双层优化过程。在内部更新中,我们采用自监督一致性损失函数来优化模型,以模拟测试阶段发生的参数更新过程。在外部更新中,我们根据具有地面实况的图像真实地更新参数,提高模型的性能,并使伪标签在下一次迭代中更准确。在测试时间,输入图像用于在测试图像之前调整模型。与各种监督学习和域适应方法相比,我们通过在不同数据集上的广泛实验得到的结果展示了我们方法在不同人群密度和规模的数据集上的一般适应能力。
    Machine learning algorithms are commonly used for quickly and efficiently counting people from a crowd. Test-time adaptation methods for crowd counting adjust model parameters and employ additional data augmentation to better adapt the model to the specific conditions encountered during testing. The majority of current studies concentrate on unsupervised domain adaptation. These approaches commonly perform hundreds of epochs of training iterations, requiring a sizable number of unannotated data of every new target domain apart from annotated data of the source domain. Unlike these methods, we propose a meta-test-time adaptive crowd counting approach called CrowdTTA, which integrates the concept of test-time adaptation into the meta-learning framework and makes it easier for the counting model to adapt to the unknown test distributions. To facilitate the reliable supervision signal at the pixel level, we introduce uncertainty by inserting the dropout layer into the counting model. The uncertainty is then used to generate valuable pseudo labels, serving as effective supervisory signals for adapting the model. In the context of meta-learning, one image can be regarded as one task for crowd counting. In each iteration, our approach is a dual-level optimization process. In the inner update, we employ a self-supervised consistency loss function to optimize the model so as to simulate the parameters update process that occurs during the test phase. In the outer update, we authentically update the parameters based on the image with ground truth, improving the model\'s performance and making the pseudo labels more accurate in the next iteration. At test time, the input image is used for adapting the model before testing the image. In comparison to various supervised learning and domain adaptation methods, our results via extensive experiments on diverse datasets showcase the general adaptive capability of our approach across datasets with varying crowd densities and scales.
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  • 文章类型: Journal Article
    根据国际主要准则,对于不能接受手术治疗的肥胖和精神/心理障碍患者,建议采取营养方法和心理治疗.共有94名患者(T0)完成了一系列自我报告措施:症状清单-90-修订版(SCL-90-R),Barratt冲动性量表-11(BIS-11),暴饮暴食量表(BES),肥胖相关幸福感问卷-97(ORWELL-97),和明尼苏达州多相人格量表-2(MMPI-2)。然后,进行了12次简短的心理动力学心理治疗,随后参与者完成随访评估(T1).确定了两组患者:第1组(n=65),谁在T0和T1完全完成了评估;和第2组辍学(n=29),仅在T0而不是T1完成评估。实施机器学习模型以调查哪些变量与治疗失败最相关。通过考虑两个变量:MMPI-2校正(K)量表和SCL-90-R恐惧症(PHOB)量表,分类树模型识别出退出治疗的患者,准确率约为80%。鉴于关于这一主题的研究数量有限,本研究结果突出了考虑患者适应水平和社会背景的重要性,将他们纳入治疗计划。警告说明,含义,并讨论了未来的方向。
    According to the main international guidelines, patients with obesity and psychiatric/psychological disorders who cannot be addressed to surgery are recommended to follow a nutritional approach and a psychological treatment. A total of 94 patients (T0) completed a battery of self-report measures: Symptom Checklist-90-Revised (SCL-90-R), Barratt Impulsiveness Scale-11 (BIS-11), Binge-Eating Scale (BES), Obesity-Related Well-Being Questionnaire-97 (ORWELL-97), and Minnesota Multiphasic Personality Inventory-2 (MMPI-2). Then, twelve sessions of a brief psychodynamic psychotherapy were delivered, which was followed by the participants completing the follow-up evaluation (T1). Two groups of patients were identified: Group 1 (n = 65), who fully completed the assessment in both T0 and T1; and Group 2-dropout (n = 29), who fulfilled the assessment only at T0 and not at T1. Machine learning models were implemented to investigate which variables were most associated with treatment failure. The classification tree model identified patients who were dropping out of treatment with an accuracy of about 80% by considering two variables: the MMPI-2 Correction (K) scale and the SCL-90-R Phobic Anxiety (PHOB) scale. Given the limited number of studies on this topic, the present results highlight the importance of considering the patient\'s level of adaptation and the social context in which they are integrated in treatment planning. Cautionary notes, implications, and future directions are discussed.
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  • 文章类型: Journal Article
    背景:保留治疗对于针对酒精使用障碍(AUD)的干预措施的成功至关重要。影响全球超过1亿人。以前的大多数研究都使用经典的统计技术来预测治疗退出,他们的结果仍然没有定论。这项研究旨在使用新颖的机器学习工具来识别更精确地预测辍学的模型。能够为风险较高的人制定更好的保留策略。方法:在全州公共治疗网络中,对39,030名(17.3%为女性)参与者进行了一项回顾性观察性研究,这些参与者接受了门诊酒精使用障碍的治疗。参与者在2015年1月1日至2019年12月31日期间招募。我们应用了不同的机器学习算法来创建模型,使人们能够预测治疗的过早停止(退出)。为了以最佳精度提高这些模型的可解释性,被认为是黑盒模型,还应用了可解释性技术分析。结果:将使用所谓的黑盒模型(支持向量分类器(SVC))之一获得的模型视为最佳模型,最佳模型的结果,从可解释性的角度来看,表明,对治疗退出具有更大解释能力的变量是以前的药物使用以及精神病合并症。在这些变量中,那些曾接受过阿片类药物替代治疗并在精神卫生服务机构中接受过协调精神护理的患者显示出最大的预测辍学能力.结论:通过使用新的机器学习技术对大量有代表性的酒精使用障碍治疗患者样本,我们已经确定了几种机器学习模型,这些模型有助于预测更高的治疗退出风险。先前对其他物质使用障碍(SUDs)的治疗和并发精神病合并症是最佳的退出预测因子,表现出这些特征的患者可能需要更强化或补充的干预措施才能从治疗中获益.
    Background: Retention in treatment is crucial for the success of interventions targeting alcohol use disorder (AUD), which affects over 100 million people globally. Most previous studies have used classical statistical techniques to predict treatment dropout, and their results remain inconclusive. This study aimed to use novel machine learning tools to identify models that predict dropout with greater precision, enabling the development of better retention strategies for those at higher risk. Methods: A retrospective observational study of 39,030 (17.3% female) participants enrolled in outpatient-based treatment for alcohol use disorder in a state-wide public treatment network has been used. Participants were recruited between 1 January 2015 and 31 December 2019. We applied different machine learning algorithms to create models that allow one to predict the premature cessation of treatment (dropout). With the objective of increasing the explainability of those models with the best precision, considered as black-box models, explainability technique analyses were also applied. Results: Considering as the best models those obtained with one of the so-called black-box models (support vector classifier (SVC)), the results from the best model, from the explainability perspective, showed that the variables that showed greater explanatory capacity for treatment dropout are previous drug use as well as psychiatric comorbidity. Among these variables, those of having undergone previous opioid substitution treatment and receiving coordinated psychiatric care in mental health services showed the greatest capacity for predicting dropout. Conclusions: By using novel machine learning techniques on a large representative sample of patients enrolled in alcohol use disorder treatment, we have identified several machine learning models that help in predicting a higher risk of treatment dropout. Previous treatment for other substance use disorders (SUDs) and concurrent psychiatric comorbidity were the best predictors of dropout, and patients showing these characteristics may need more intensive or complementary interventions to benefit from treatment.
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  • 文章类型: Journal Article
    这项研究调查了大学背景下社会资本在留住在职学生方面的作用。它专门考察了大学社会资本因素的影响,如师生关系,对等网络,和支持服务——关于在职学生的辍学意向,强调就业能力信任的中介作用。使用来自EurostudentVII调查的1902名在职学生的样本,这项研究采用因子分析技术和结构方程模型来得出其发现。结果表明,大学社会资本显着降低了在职学生的辍学意愿。牢固的师生关系,对支持服务的满意度,健壮的对等网络,高就业能力信任对这一社会资本产生积极影响。师生关系之间存在统计上显著的负相关,对等网络,就业能力信任,和辍学的意图。此外,调查结果表明,如果不提高学生的就业信任度,支助服务的效力可能有限。这些发现不仅有助于有关学生保留和大学社会资本发展的论述,而且还为旨在支持在职学生的高等教育策略提供了实用见解。
    This study investigates the role of social capital within the university context in retaining working students. It specifically examines the effects of university social capital factors-such as teacher-student relationships, peer networks, and support services-on the dropout intentions of working students, emphasizing the mediating role of employability trust. Using a sample of 1902 working students from the Eurostudent VII survey, this study employed factor analysis techniques and structural equation modeling to derive its findings. The results indicated that university social capital significantly reduces dropout intentions among working students. Strong teacher-student relationships, satisfaction with support services, robust peer networks, and high employability trust positively influence this social capital. There is a statistically significant negative association between teacher-student relationships, peer networks, employability trust, and dropout intentions. Furthermore, the findings reveal that without enhancing students\' employability trust, the effectiveness of support services might be limited. These findings not only contribute to the discourse on student retention and the development of university social capital but also provide practical insights for higher education strategies aimed at supporting working students.
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  • 文章类型: Journal Article
    目的:炎症性肠病(IBD)的多学科方法最近对儿科患者产生了积极影响,降低辍学率,促进向成人护理过渡。我们的研究旨在评估这种方法如何影响疾病活动,辍学率,和过渡。
    方法:我们进行了一项纵向观察研究,包括所有在儿童-青少年时期诊断为IBD的患者,至少随访12个月。对于每个病人来说,终点包括治疗方法,需要手术和过渡功能。
    结果:我们纳入了19例患者:13例溃疡性结肠炎(UC)和6例克罗恩病(CD)。大多数患者需要多种治疗方案,两组都有超过50%的人接受生物药物治疗。合规性很好,在每组中单个退出(10,5%)。与UC组相比,CD组的手术需求明显更高(16%vs.7.7%,p<0.01)。与CD组相比,UC组的过渡平均年龄显着高于CD组(19.2±0.7岁SD与18.3±0.6年SD,p<0.05)。
    结论:根据我们的经验,在过渡年龄患者中对IBD的多学科方法似乎有效地实现了临床缓解,提供减少治疗性辍学的潜力。
    OBJECTIVE: A multidisciplinary approach to Inflammatory Bowel Disease (IBD) has recently demonstrated a positive impact in pediatric patients, reducing dropout rates and facilitating the transition to adult care. Our study aims to evaluate how this approach influences disease activity, dropout rates, and transition.
    METHODS: We conducted a longitudinal observational study including all patients diagnosed with IBD during pediatric-adolescent age, with a minimum follow-up period of 12 months. For each patient, endpoints included therapeutic approach, need for surgery and transition features.
    RESULTS: We included 19 patients: 13 with Ulcerative Colitis (UC) and 6 with Crohn\'s disease (CD). Most patients required multiple lines of therapy, with over 50% in both groups receiving biological drugs. Compliance was good, with a single dropout in each group (10, 5%). The need for surgery was significantly higher in the CD group compared to the UC group (16% vs. 7.7%, p < 0.01). Mean age at transition was significantly higher in the UC group compared to the CD group (19.2 ± 0.7 years SD vs. 18.3 ± 0.6 years SD, p < 0.05).
    CONCLUSIONS: In our experience, the multidisciplinary approach to IBD in transition-age patients appears effective in achieving clinical remission, offering the potential to reduce therapeutic dropouts.
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  • 文章类型: Journal Article
    背景:饮食行为显著影响不同人群的健康结果。不健康的饮食与严重的疾病和巨大的经济负担有关,每年导致约1100万人死亡和重大的残疾调整生命年。数字饮食干预为改善饮食行为提供了可访问的解决方案。然而,自然减员,定义为参与者在干预完成前退出,是一个重大挑战,率高达75%-99%。高减员损害了干预的有效性和可靠性,并加剧了健康差异,强调需要理解和解决其原因。
    目的:本研究系统回顾了数字饮食干预中减员的文献,以确定根本原因,提出潜在的解决方案,并将这些发现与行为理论概念相结合,形成一个全面的理论框架。该框架旨在阐明减员背后的行为机制,并指导更有效的数字饮食干预措施的设计和实施。最终降低流失率,减轻健康不平等。
    方法:我们进行了系统评价,荟萃分析,和专题综合。跨7个电子数据库的全面搜索(PubMed,MEDLINE,Embase,中部,WebofScience,CINAHLPlus,和学术搜索完成)是针对2013年至2023年之间发表的研究进行的。资格标准包括探索数字饮食干预中的减员的原始研究。数据提取侧重于研究特征,示例人口统计,流失率,减员的原因,和潜在的解决方案。我们遵循了ENTREQ(增强定性研究综合报告的透明度)和PRISMA(系统评论和荟萃分析的首选报告项目)指南,并使用RStudio(Posit)进行荟萃分析和NVivo进行主题综合。
    结果:在442项确定的研究中,21符合纳入标准。荟萃分析显示,对照组的平均流失率为35%,38%为干预组,40%用于观察性研究,具有高度异质性(I²=94%-99%),表明影响因素不同。主题综合确定了15个相互关联的主题,这些主题与行为理论概念保持一致。基于这些主题,力-资源模型的开发是为了探索流失的根本原因,并从行为理论的角度指导未来干预措施的设计和实施。
    结论:高流失率是数字饮食干预的一个重要问题。开发的框架通过驱动力系统和支持资源系统之间的相互作用概念化了减员,提供对参与者流失的细微差别的理解,概括为动力不足、资源不足或匹配不良。它强调了数字饮食干预的关键必要性,以动态地平衡动机成分与可用资源。主要建议包括用户友好的设计,行为因素激活,识字训练,力量-资源匹配,社会支持,个性化适应,和动态跟进。将这些策略扩展到人口水平可以增强数字健康公平性。有必要对该框架进行进一步的实证验证,同时制定了行为理论指导的数字饮食干预指南。
    背景:PROSPEROCRD42024512902;https://tinyurl.com/3rjt2df9。
    BACKGROUND: Dietary behaviors significantly influence health outcomes across populations. Unhealthy diets are linked to serious diseases and substantial economic burdens, contributing to approximately 11 million deaths and significant disability-adjusted life years annually. Digital dietary interventions offer accessible solutions to improve dietary behaviors. However, attrition, defined as participant dropout before intervention completion, is a major challenge, with rates as high as 75%-99%. High attrition compromises intervention validity and reliability and exacerbates health disparities, highlighting the need to understand and address its causes.
    OBJECTIVE: This study systematically reviews the literature on attrition in digital dietary interventions to identify the underlying causes, propose potential solutions, and integrate these findings with behavior theory concepts to develop a comprehensive theoretical framework. This framework aims to elucidate the behavioral mechanisms behind attrition and guide the design and implementation of more effective digital dietary interventions, ultimately reducing attrition rates and mitigating health inequalities.
    METHODS: We conducted a systematic review, meta-analysis, and thematic synthesis. A comprehensive search across 7 electronic databases (PubMed, MEDLINE, Embase, CENTRAL, Web of Science, CINAHL Plus, and Academic Search Complete) was performed for studies published between 2013 and 2023. Eligibility criteria included original research exploring attrition in digital dietary interventions. Data extraction focused on study characteristics, sample demographics, attrition rates, reasons for attrition, and potential solutions. We followed ENTREQ (Enhancing the Transparency in Reporting the Synthesis of Qualitative Research) and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and used RStudio (Posit) for meta-analysis and NVivo for thematic synthesis.
    RESULTS: Out of the 442 identified studies, 21 met the inclusion criteria. The meta-analysis showed mean attrition rates of 35% for control groups, 38% for intervention groups, and 40% for observational studies, with high heterogeneity (I²=94%-99%) indicating diverse influencing factors. Thematic synthesis identified 15 interconnected themes that align with behavior theory concepts. Based on these themes, the force-resource model was developed to explore the underlying causes of attrition and guide the design and implementation of future interventions from a behavior theory perspective.
    CONCLUSIONS: High attrition rates are a significant issue in digital dietary interventions. The developed framework conceptualizes attrition through the interaction between the driving force system and the supporting resource system, providing a nuanced understanding of participant attrition, summarized as insufficient motivation and inadequate or poorly matched resources. It underscores the critical necessity for digital dietary interventions to balance motivational components with available resources dynamically. Key recommendations include user-friendly design, behavior-factor activation, literacy training, force-resource matching, social support, personalized adaptation, and dynamic follow-up. Expanding these strategies to a population level can enhance digital health equity. Further empirical validation of the framework is necessary, alongside the development of behavior theory-guided guidelines for digital dietary interventions.
    BACKGROUND: PROSPERO CRD42024512902; https://tinyurl.com/3rjt2df9.
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  • 文章类型: Journal Article
    多囊卵巢综合症(PCOS)是一种导致育龄妇女荷尔蒙失调的疾病。荷尔蒙失衡导致月经周期延迟甚至不存在。患有PCOS的女性主要患有极端的体重增加,面部毛发生长,痤疮,脱发,皮肤变黑,和不规则的时期,在极少数情况下导致不孕。医生通常检查超声图像并得出受影响的卵巢,但无法确定是否为正常囊肿,PCOS,或癌囊肿手动。
    为了获得高风险的关键PCOS并检测病情和旨在减轻子宫内膜增生/癌症等健康危害的治疗,不孕症,妊娠并发症,以及与PCOS相关的慢性疾病如心脏代谢紊乱的长期负担。
    提出的自定义卷积神经网络方法(SD_CNN)用于提取特征和机器学习模型,例如SVM,随机森林,采用Logistic回归对PCOS图像进行分类。参数调整是用较少的参数完成的,以便克服过拟合问题。自定义模型根据分析的特征预测囊肿的发生,并有效地对类别标签进行分类。
    在支持向量机(SVM)和Logistic回归(LR)中,随机森林分类器被发现是最可靠和最准确的。准确率为96.43%。
    与各种其他方法相比,所提出的模型建立了更好的权衡,并有效地用于PCOS预测。
    UNASSIGNED: Polycystic Ovary Syndrome (PCOS) is a medical condition that causes hormonal disorders in women in their childbearing years. The hormonal imbalance leads to a delayed or even absent menstrual cycle. Women with PCOS mainly suffer from extreme weight gain, facial hair growth, acne, hair loss, skin darkening, and irregular periods, leading to infertility in rare cases. Doctors usually examine ultrasound images and conclude the affected ovary but are incapable of deciding whether it is a normal cyst, PCOS, or cancer cyst manually.
    UNASSIGNED: To have access to the high-risk crucial PCOS and to detect the condition and the treatment aimed at mitigating health hazards such as endometrial hyperplasia/cancer, infertility, pregnancy complications, and the long-term burden of chronic diseases such as cardiometabolic disorders linked with PCOS.
    UNASSIGNED: The proposed Self-Defined Convolution Neural Network method (SD_CNN) is used to extract the features and machine learning models such as SVM, Random Forest, and Logistic Regression are used to classify PCOS images. The parameter tuning is done with lesser parameters in order to overcome over-fitting issues. The self-defined model predicts the occurrence of the cyst based on the analyzed features and classifies the class labels effectively.
    UNASSIGNED: The Random Forest Classifier was found to be the most reliable and accurate among Support Vector Machine (SVM) and Logistic Regression (LR), with accuracy being 96.43%.
    UNASSIGNED: The proposed model establishes better trade-off compared to various other approaches and works effectually for PCOS prediction.
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  • 文章类型: Journal Article
    心理治疗失败涉及情境,关系,和个人因素。辍学是指患者在没有治疗师的知识或批准的情况下单方面终止治疗。当在实现初始问题的充分减少之前停止治疗时,发生过早终止。
    这项研究探讨了治疗师的情绪反应(反移情)的作用,性别,心理治疗取向,和心理治疗失败的背景下的患者诊断。
    使用了混合方法。五十九名意大利心理治疗师,大多是私下练习,至少有5年的经验,是通过意大利专业互联网网站招募的。对每位心理治疗师进行了治疗师反应问卷和僵局访谈。每个治疗师都被要求反思他们最后一个辍学的病人。用SPSS和T-LAB进行定量(MANOVA)和定性分析(文本内容分析),分别。
    定量分析表明,最常见的反移情反应是无助/不足,女性治疗师比男性治疗师更频繁地经历这种情况。定性分析确定了解释反移情反应中大部分差异的两个主要因素:父母/保护与敌对/愤怒,积极/满意与无助/不足,无助/不足的中央。此外,治疗中断方法的定性分析揭示了两个因素解释了超过50%的方差。缺乏沟通与负面主题有关,而介导和直接沟通与积极的术语相关。直接通信被认为是有用的,而调解沟通与辍学和依恋数字有关。
    在压力下,心理治疗师的焦虑水平增加,经常矛盾地或不可避免地管理。这些结果表明,对心理治疗师情绪反应的认识对于限制心理治疗失败很重要。这些发现为临床实践提供了有价值的见解。
    UNASSIGNED: Psychotherapeutic failures involve situational, relational, and personal factors. Dropout refers to a patient\'s unilateral termination of treatment without the therapist\'s knowledge or approval. Premature termination occurs when therapy is discontinued before achieving a sufficient reduction in initial problems.
    UNASSIGNED: This study explores the role of therapist\'s emotional response (countertransference), gender, psychotherapeutic orientation, and patient diagnosis in the context of psychotherapeutic failures.
    UNASSIGNED: A mixed-method approach was used. Fifty-nine Italian psychotherapists, practicing mostly privately with at least 5 years of experience, were recruited through Italian professional internet websites. The Therapist Response Questionnaire and the Impasse Interview were administered to each psychotherapist. Each therapist was asked to reflect on their last dropout patient. Quantitative (MANOVA) and qualitative analyses (textual content analysis) were conducted with SPSS and T-LAB, respectively.
    UNASSIGNED: The quantitative analyses revealed that the most frequent countertransference response was Helpless/Inadequate, with female therapists experiencing this more frequently than male therapists. The qualitative analyses identified two main factors explaining most of the variance in countertransference responses: Parental/Protective versus Hostile/Angry, and Positive/Satisfying versus Helpless/Inadequate, with Helpless/Inadequate central. Additionally, the qualitative analysis of treatment interruption methods revealed two factors explaining over 50% of the variance. Lack of communication was linked to negative themes, while mediated and direct communication were associated with positive terms. Direct communication was characterized as useful, while mediated communication was linked to dropout and attachment figures.
    UNASSIGNED: Under pressure, psychotherapists\' anxiety levels increase, often managed ambivalently or avoidantly. These results suggest that awareness of psychotherapist emotional responses is important to limit psychotherapeutic failures. These findings offer valuable insights for clinical practice.
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  • 文章类型: Journal Article
    视觉预测检查(VPC)通常用于评估药物计量学模型。然而,如果结果较差的患者提前退出,他们的表现可能会受到阻碍,就像临床试验中经常发生的那样,尤其是肿瘤学.虽然辍学的方法已经出现在文献中,它们的假设各不相同,灵活性,和性能,它们之间的区别并没有被广泛理解。本手稿旨在阐明哪些方法可以用于处理具有dropout的VPC,以及何时,以及使用置信区间的更多信息VPC方法。此外,我们建议基于观测数据而不是模拟数据来构建置信区间。开发了将dropout纳入VPC的理论框架,并将其应用于提出两种方法:完全和有条件。完整的方法是使用参数时间到事件模型来实现的,而条件方法是使用参数和Cox比例风险(CPH)模型实现的。这些方法的实际性能通过对来自纳武单抗和多西他赛的两项癌症临床试验的数据进行肿瘤生长动力学(TGD)建模来说明。随访患者直至疾病进展。该数据集包括来自855名受试者的3504个肿瘤大小测量值,由TGD模型描述。通过Weibull或CPH模型描述受试者的退出。模拟数据集还用于进一步说明VPC方法的属性。结果表明,与不调整辍学的幼稚方法相比,更熟悉的完整方法可能无法为TGD模型评估提供有意义的改进,并且可以通过使用Weibull模型或Cox比例风险模型的条件方法胜过。总的来说,在VPC中包括置信区间应该会改善解释,当发生辍学时,有条件的方法被证明更普遍地适用,非参数方法可以提供额外的鲁棒性。
    Visual predictive checks (VPC) are commonly used to evaluate pharmacometrics models. However their performance may be hampered if patients with worse outcomes drop out earlier, as often occurs in clinical trials, especially in oncology. While methods accounting for dropouts have appeared in literature, they vary in assumptions, flexibility, and performance, and the differences between them are not widely understood. This manuscript aims to elucidate which methods can be used to handle VPC with dropout and when, along with a more informative VPC approach using confidence intervals. Additionally, we propose constructing the confidence interval based on the observed data instead of the simulated data. The theoretical framework for incorporating dropout in VPCs is developed and applied to propose two approaches: full and conditional. The full approach is implemented using a parametric time-to-event model, while the conditional approach is implemented using both parametric and Cox proportional-hazard (CPH) models. The practical performances of these approaches are illustrated with an application to the tumor growth dynamics (TGD) modeling of data from two cancer clinical trials of nivolumab and docetaxel, where patients were followed until disease progression. The dataset consisted of 3504 tumor size measurements from 855 subjects, which were described by a TGD model. The dropout of subjects was described by a Weibull or CPH model. Simulated datasets were also used to further illustrate the properties of the VPC methods. The results showed that the more familiar full approach might not provide meaningful improvement for TGD model evaluation over the naive approach of not adjusting for dropout, and could be outperformed by the conditional approach using either the Weibull model or the Cox proportional hazard model. Overall, including confidence intervals in VPC should improve interpretation, the conditional approach was shown to be more generally applicable when dropout occurs, and the nonparametric approach could provide additional robustness.
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  • 文章类型: Journal Article
    背景:我国医学生流失率较高。本研究利用列线图技术,基于19个个体和工作相关特征,建立了中国医学本科生辍学意愿的预测模型。
    方法:进行了重复的横断面研究,通过滚雪球抽样,在T1(2020年8月至2021年4月)和T2(2022年10月)的969名参与者中招收3536名医学本科生。人口统计(年龄,性别,研究阶段,收入,关系状态,精神病史)和心理健康因素(包括抑郁症,焦虑,压力,倦怠,酒精使用障碍,困倦,生活质量,疲劳,自杀企图史(SA),和躯体症状),以及与工作相关的变量(职业选择遗憾和原因,工作场所暴力经历,以及对中国医疗保健环境的总体满意度),是通过问卷收集的。来自T1的数据分为训练队列和内部验证队列,而T2数据作为外部验证队列。对列线图的性能进行了区分评估,校准,临床适用性,并使用接收器工作特性曲线(ROC)进行泛化,曲线下面积(AUC),校正曲线,和决策曲线分析(DCA)。
    结果:从19个个人和工作相关因素来看,五个被确定为构建列线图的重要预测因子:SA的历史,职业选择遗憾,工作场所暴力的经验,抑郁症状,和倦怠。训练的AUC值,内部验证,和外部验证队列分别为0.762,0.761和0.817.列线图证明了可靠的预测和区分,在训练和验证队列中进行充分的校准和概括。
    结论:此列线图在预测中国医学本科生的辍学意向方面具有合理的准确性。它可以指导大学,医院,和政策制定者确定学生处于危险之中,从而告知有针对性的干预措施。解决潜在因素,如抑郁症状,倦怠,职业选择遗憾,工作场所暴力可能有助于减少医学本科生的流失。
    背景:这是一项观察性研究。没有与此手稿相关的临床试验编号。
    BACKGROUND: The attrition rate of Chinese medical students is high. This study utilizes a nomogram technique to develop a predictive model for dropout intention among Chinese medical undergraduates based on 19 individual and work-related characteristics.
    METHODS: A repeated cross-sectional study was conducted, enrolling 3536 medical undergraduates in T1 (August 2020-April 2021) and 969 participants in T2 (October 2022) through snowball sampling. Demographics (age, sex, study phase, income, relationship status, history of mental illness) and mental health factors (including depression, anxiety, stress, burnout, alcohol use disorder, sleepiness, quality of life, fatigue, history of suicidal attempts (SA), and somatic symptoms), as well as work-related variables (career choice regret and reasons, workplace violence experience, and overall satisfaction with the Chinese healthcare environment), were gathered via questionnaires. Data from T1 was split into a training cohort and an internal validation cohort, while T2 data served as an external validation cohort. The nomogram\'s performance was evaluated for discrimination, calibration, clinical applicability, and generalization using receiver operating characteristic curves (ROC), area under the curve (AUC), calibration curves, and decision curve analysis (DCA).
    RESULTS: From 19 individual and work-related factors, five were identified as significant predictors for the construction of the nomogram: history of SA, career choice regret, experience of workplace violence, depressive symptoms, and burnout. The AUC values for the training, internal validation, and external validation cohorts were 0.762, 0.761, and 0.817, respectively. The nomogram demonstrated reliable prediction and discrimination, with adequate calibration and generalization across both the training and validation cohorts.
    CONCLUSIONS: This nomogram exhibits reasonable accuracy in foreseeing dropout intentions among Chinese medical undergraduates. It could guide colleges, hospitals, and policymakers in pinpointing students at risk, thus informing targeted interventions. Addressing underlying factors such as depressive symptoms, burnout, career choice regret, and workplace violence may help reduce the attrition of medical undergraduates.
    BACKGROUND: This is an observational study. There is no Clinical Trial Number associated with this manuscript.
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