Internal validation

内部验证
  • 文章类型: Journal Article
    目的:心脏瓣膜反流患者正在增加;早期筛查潜在的心力衰竭(HF)患者是至关重要的。
    方法:选取2019年11月1日至2023年10月31日在广州中医药大学第一附属医院心血管病科住院的509例心脏瓣膜反流患者。选择了三百五十六个案例作为建模的训练集,并选取153个案例作为模型内部验证的验证集。
    结果:建立了具有以下9个危险因素的心力衰竭预测模型:房颤(AF),肺部感染(PI),冠状动脉疾病(CAD),肌酐(CREA),低密度脂蛋白胆固醇(LDL-C),d-二聚体(DDi),左心室舒张末期内径(LVEDd),二尖瓣反流(MR)和主动脉瓣反流(AR)。通过C指数[训练集:曲线下面积(AUC)0.937,95%置信区间(CI)0.911-0.963;验证集:AUC0.928,95%CI0.890-0.967]评估模型。Hosmer-Lemeshow检验(训练集:χ210.908,P=0.207;验证集:χ24.896,P=0.769)显示训练集和验证集在模型区分和校准方面均表现良好。决策曲线分析表明,训练集和验证集均具有较高的净收益,表明该模型具有良好的实用性。十倍交叉验证表明,训练集与验证集具有很高的相似性,说明该模型具有良好的稳定性。
    结论:瓣膜反流患者心力衰竭的发生与房颤有显著的相关性,PI,CAD,CREA,LDL-C,DDi,LVEDD,MR和AR基于这些风险因素,开发并验证了心力衰竭的预测模型,表现出良好的差异化和实用性,精度高、稳定性好,提供了一种预测心力衰竭的方法。
    OBJECTIVE: Patients with heart valvular regurgitation is increasing; early screening of potential patients developing heart failure (HF) is crucial.
    METHODS: From 1 November 2019 to 31 October 2023, a total of 509 patients with heart valvular regurgitation hospitalized in the Department of Cardiovascular Disease of the First Affiliated Hospital of Guangzhou University of Traditional Medicine were enrolled. Three hundred fifty-six cases were selected as the training set for modelling, and 153 cases were selected as the validation set for the internal validation of the model.
    RESULTS: A predictive model of heart failure with the following nine risk factors was developed: atrial fibrillation (AF), pulmonary infection (PI), coronary artery disease (CAD), creatinine (CREA), low-density lipoprotein cholesterol (LDL-C), d-dimer (DDi), left ventricular end-diastolic diameter (LVEDd), mitral regurgitation (MR) and aortic regurgitation (AR). The model was evaluated by the C-index [the training set: area under curve (AUC) 0.937, 95% confidence interval (CI) 0.911-0.963; the validation set: AUC 0.928, 95% CI 0.890-0.967]. Hosmer-Lemeshow test (the training set: χ2 10.908, P = 0.207; the validation set: χ2 4.896, P = 0.769) revealed that both the training and validation sets performed well in terms of model differentiation and calibration. Decision curve analysis showed that both the training and validation sets have higher net benefits, indicating that the model has good utility. Ten-fold cross-validation showed that the training set has high similarities with the validation set, which means that the model has good stability.
    CONCLUSIONS: The occurrence of heart failure in patients with valvular regurgitation has a significant correlation with AF, PI, CAD, CREA, LDL-C, DDi, LVEDd, MR and AR. Based on these risk factors, a prediction model for heart failure was developed and validated, which showed good differentiation and utility, high accuracy and stability, providing a method for predicting heart failure.
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  • 文章类型: Journal Article
    临床预测模型提供了健康结果的风险,可以告知患者并支持医疗决策。然而,大多数模型在实践中从未真正实现。这种缺乏实现的一个普遍听到的原因是预测模型通常没有经过外部验证。虽然我们通常鼓励外部验证,我们认为,外部验证通常既不充分,也不需要作为实施前的必要步骤。因此,任何可用的外部验证都不应被视为模型实现的许可证。我们通过讨论关于外部验证的三个常见误解来澄清这一论点。我们认为没有一种类型的推荐验证设计,并不总是需要外部验证,有时需要多个外部验证。本文的见解可以帮助读者思考,设计,解释,并欣赏外部验证研究。
    Clinical prediction models provide risks of health outcomes that can inform patients and support medical decisions. However, most models never make it to actual implementation in practice. A commonly heard reason for this lack of implementation is that prediction models are often not externally validated. While we generally encourage external validation, we argue that an external validation is often neither sufficient nor required as an essential step before implementation. As such, any available external validation should not be perceived as a license for model implementation. We clarify this argument by discussing 3 common misconceptions about external validation. We argue that there is not one type of recommended validation design, not always a necessity for external validation, and sometimes a need for multiple external validations. The insights from this paper can help readers to consider, design, interpret, and appreciate external validation studies.
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  • 文章类型: Journal Article
    背景:与普通人群相比,阿片类药物使用障碍患者的标准化死亡率要高得多;然而,缺乏明确的个体预后信息对药物治疗服务中的优先考虑或目标干预措施提出了挑战.以前的预后模型已经开发出来,以估计在常规处方阿片类药物的人中发生阿片类药物使用障碍和阿片类药物相关过量的风险,但是,根据我们的知识,目前还没有一项研究用于评估阿片类药物使用障碍患者接受药物服务的死亡风险.鉴于同期常规收集预后指标,并作为适当的服务优先级和有针对性的干预措施的决策点,初次向药物服务提供是评估死亡风险的务实时机。这项研究旨在开发和内部验证一个模型,以根据英格兰药物服务最初评估时记录的预后指标来估计阿片类药物使用障碍患者6个月的死亡风险。
    方法:英国国家数据集,其中包含2013年4月1日至2023年4月1日期间向药物服务机构提供服务的个人的记录(n>800,000)(国家药物治疗监测系统(NDTMS))与他们的终生住院和死亡记录(医院事件统计-国家统计局(HES-ONS))。根据与阿片类药物使用障碍患者死亡率增加相关的人口统计学和临床特征的文献综述,确定了12个候选预后指标变量。变量将在初次提交给药物服务时提取,死亡率在6个月时测量。将开发两个多变量Cox回归模型,一个用于6个月的全因死亡率,一个用于6个月的药物相关死亡率,一个用于连续变量的分数多项式方法的反向消除。内部验证将使用自举方法进行。两种模型的区分将使用Harrel的c和d统计量进行报告。将呈现校准曲线和斜率,比较预期和观察到的事件率。
    结论:本研究中开发和内部验证的模型旨在改善在英格兰向药物服务机构就诊的阿片类药物使用障碍患者的死亡风险的临床评估。将需要在不同人群中进行外部验证,以将模型开发为工具,以协助未来的临床决策。
    BACKGROUND: People with opioid use disorder have substantially higher standardised mortality rates compared to the general population; however, lack of clear individual prognostic information presents challenges to prioritise or target interventions within drug treatment services. Previous prognostic models have been developed to estimate the risk of developing opioid use disorder and opioid-related overdose in people routinely prescribed opioids but, to our knowledge, none have been developed to estimate mortality risk in people accessing drug services with opioid use disorder. Initial presentation to drug services is a pragmatic time to evaluate mortality risk given the contemporaneous routine collection of prognostic indicators and as a decision point for appropriate service prioritisation and targeted intervention delivery. This study aims to develop and internally validate a model to estimate 6-month mortality risk for people with opioid use disorder from prognostic indicators recorded at initial assessment in drug services in England.
    METHODS: An English national dataset containing records from individuals presenting to drug services between 1 April 2013 and 1 April 2023 (n > 800,000) (the National Drug Treatment Monitoring System (NDTMS)) linked to their lifetime hospitalisation and death records (Hospital Episode Statistics-Office of National Statistics (HES-ONS)). Twelve candidate prognostic indicator variables were identified based on literature review of demographic and clinical features associated with increased mortality for people in treatment for opioid use disorder. Variables will be extracted at initial presentation to drug services with mortality measured at 6 months. Two multivariable Cox regression models will be developed one for 6-month all-cause mortality and one for 6-month drug-related mortality using backward elimination with a fractional polynomial approach for continuous variables. Internal validation will be undertaken using bootstrapping methods. Discrimination of both models will be reported using Harrel\'s c and d-statistics. Calibration curves and slopes will be presented comparing expected and observed event rates.
    CONCLUSIONS: The models developed and internally validated in this study aim to improve clinical assessment of mortality risk for people with opioid use disorder presenting to drug services in England. External validation in different populations will be required to develop the model into a tool to assist future clinical decision-making.
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  • 文章类型: Journal Article
    背景:2019年冠状病毒病(COVID-19)大流行发现全世界都没有为正确的管理做好准备。意大利是2020年2月底第一个经历SARS-CoV-2病毒传播的欧洲国家。由于医院人满为患,所提供的护理质量并不总是最佳的.大量非ICU病房的患者本可以在家中接受治疗。有一个分数会非常有用,根据个人和临床特征以及简单的血液检查,可以足够可靠地预测患者患有或未患有可能导致其死亡的疾病的可能性。这项研究旨在开发一种评分系统,以确定哪些COVID-19患者在入院时具有高死亡风险,加快和加强临床决策。方法:回顾性分析建立多变量预后预测模型。结果:从两个意大利大学医院数据库获得派生和外部验证队列,包括388例(10.31%死亡)和1357例(7.68%死亡)确诊COVID-19患者。多变量逻辑模型用于选择与住院死亡相关的七个变量(年龄,基线氧饱和度,血红蛋白值,白细胞计数,中性粒细胞的百分比,血小板计数,和肌酐值)。校准和鉴别结果令人满意,在推导队列中预测死亡率的累积AUC为0.924(95%CI:0.893-0.944),在外部验证队列中预测死亡率为0.808(95%CI:0.886-0.828)。将获得的风险评分与ISARIC4C死亡率评分进行比较,到目前为止,考虑到所有其他最重要的分数,评估COVID-19患者的死亡风险。在评估死亡的可预测性方面,它的表现优于上述所有得分。它的灵敏度,特异性,和AUC高于其他COVID-19评分系统,当后者是在我们的衍生队列中对388例患者进行计算时。结论:总之,CZ-COVID-19评分可以帮助所有医生识别那些需要更多关注以提供更好的治疗方案的COVID-19患者,或者,相反,通过确定那些不需要住院治疗的患者,因此可以在不过度拥挤的医疗设施的情况下被送回家。我们开发并验证了基于7个变量的新的COVID-19患者入院风险评分。计算非常简单,并且比所有其他类似分数都更好地评估死亡的可预测性。
    Background: The coronavirus disease 2019 (COVID-19) pandemic has found the whole world unprepared for its correct management. Italy was the first European country to experience the spread of the SARS-CoV-2 virus at the end of February 2020. As a result of hospital overcrowding, the quality of care delivered was not always optimal. A substantial number of patients admitted to non-ICU units could have been treated at home. It would have been extremely useful to have a score that, based on personal and clinical characteristics and simple blood tests, could have predicted with sufficient reliability the probability that a patient had or did not have a disease that could have led to their death. This study aims to develop a scoring system to identify which patients with COVID-19 are at high mortality risk upon hospital admission, to expedite and enhance clinical decision making. Methods: A retrospective analysis was performed to develop a multivariable prognostic prediction model. Results: Derivation and external validation cohorts were obtained from two Italian University Hospital databases, including 388 (10.31% deceased) and 1357 (7.68% deceased) patients with confirmed COVID-19, respectively. A multivariable logistic model was used to select seven variables associated with in-hospital death (age, baseline oxygen saturation, hemoglobin value, white blood cell count, percentage of neutrophils, platelet count, and creatinine value). Calibration and discrimination were satisfactory with a cumulative AUC for prediction mortality of 0.924 (95% CI: 0.893-0.944) in derivation cohorts and 0.808 (95% CI: 0.886-0.828) in external validation cohorts. The risk score obtained was compared with the ISARIC 4C Mortality Score, and with all the other most important scores considered so far, to evaluate the risk of death of patients with COVID-19. It performed better than all the above scores to evaluate the predictability of dying. Its sensitivity, specificity, and AUC were higher than the other COVID-19 scoring systems when the latter were calculated for the 388 patients in our derivation cohort. Conclusions: In conclusion, the CZ-COVID-19 Score may help all physicians by identifying those COVID-19 patients who require more attention to provide better therapeutic regimens or, on the contrary, by identifying those patients for whom hospitalization is not necessary and who could therefore be sent home without overcrowding healthcare facilities. We developed and validated a new risk score based on seven variables for upon-hospital admission of COVID-19 patients. It is very simple to calculate and performs better than all the other similar scores to evaluate the predictability of dying.
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  • 文章类型: Journal Article
    背景:大多数导管相关性血流感染(CRBSI)和中线相关性血流感染(CLABSI)的监测系统都是基于人工图表审查。我们的目标是验证重症监护病房(ICU)中CRBSI和CLABSI监测的全自动算法。
    方法:我们开发了一种全自动算法来检测CRBSI,瑞士三级医院ICU患者的CLABSI和ICU发作血流感染(ICU-BSI)。算法中包含的参数基于最近进行的系统评价。关于人口统计的结构化数据,行政数据,该算法处理了从医院数据仓库获得的中心血管导管和微生物结果(血培养和其他临床培养物)。CRBSI的验证是通过将结果与6年期间的前瞻性手动BSI监测数据进行比较来进行的。CLABSI进行了为期2年的回顾性评估。
    结果:从2016年1月至2021年12月,在346名ICU患者中发现854名血培养阳性。中位年龄为61.7岁[IQR50-70];从女性患者中收集了205个(24%)阳性样本。该算法检测到5个CRBSI,109CLABSI和280ICU-BSI。通过自动监测确定的2016年至2021年期间的CRBSI和CLABSI总体发生率为0.18/1000导管天(95%CI0.06-0.41)和3.86/1000导管天(95%CI:3.17-4.65)。敏感性,特异性,CRBSI算法的阳性预测值和阴性预测值,为83%(95%CI43.7-96.9),100%(95%CI99.5-100),100%(95%CI56.5-100),和99.9%(95%CI99.2-100),分别。通过算法将一个CRBSI错误分类为ICU-BSI,因为在血液培养物和下呼吸道样本中鉴定了相同的细菌。从2020年1月到2021年12月对CLABSI的手动审查(n=51)未发现算法中的任何错误。
    结论:仅使用结构化数据对危重患者进行CRBSI和CLABSI检测的全自动算法提供了有效的结果。下一步将是评估在具有不同电子健康记录系统的几家医院中实施该计划的可行性和外部有效性。
    BACKGROUND: Most surveillance systems for catheter-related bloodstream infections (CRBSI) and central line-associated bloodstream infections (CLABSI) are based on manual chart review. Our objective was to validate a fully automated algorithm for CRBSI and CLABSI surveillance in intensive care units (ICU).
    METHODS: We developed a fully automated algorithm to detect CRBSI, CLABSI and ICU-onset bloodstream infections (ICU-BSI) in patients admitted to the ICU of a tertiary care hospital in Switzerland. The parameters included in the algorithm were based on a recently performed systematic review. Structured data on demographics, administrative data, central vascular catheter and microbiological results (blood cultures and other clinical cultures) obtained from the hospital\'s data warehouse were processed by the algorithm. Validation for CRBSI was performed by comparing results with prospective manual BSI surveillance data over a 6-year period. CLABSI were retrospectively assessed over a 2-year period.
    RESULTS: From January 2016 to December 2021, 854 positive blood cultures were identified in 346 ICU patients. The median age was 61.7 years [IQR 50-70]; 205 (24%) positive samples were collected from female patients. The algorithm detected 5 CRBSI, 109 CLABSI and 280 ICU-BSI. The overall CRBSI and CLABSI incidence rates determined by automated surveillance for the period 2016 to 2021 were 0.18/1000 catheter-days (95% CI 0.06-0.41) and 3.86/1000 catheter days (95% CI: 3.17-4.65). The sensitivity, specificity, positive predictive and negative predictive values of the algorithm for CRBSI, were 83% (95% CI 43.7-96.9), 100% (95% CI 99.5-100), 100% (95% CI 56.5-100), and 99.9% (95% CI 99.2-100), respectively. One CRBSI was misclassified as an ICU-BSI by the algorithm because the same bacterium was identified in the blood culture and in a lower respiratory tract specimen. Manual review of CLABSI from January 2020 to December 2021 (n = 51) did not identify any errors in the algorithm.
    CONCLUSIONS: A fully automated algorithm for CRBSI and CLABSI detection in critically-ill patients using only structured data provided valid results. The next step will be to assess the feasibility and external validity of implementing it in several hospitals with different electronic health record systems.
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  • 文章类型: Journal Article
    在临床实践中使用TDM来监测危重病人使用抗生素的血浆水平是一种完善的方法,可以优化患者对药物治疗的反应。考虑到药物的特点,患者的临床和生理状态以及引起临床表现的病原体的任何特殊情况。在我们的实验室里,我们已经开发了一种单一的LC-MS/MS分析,用于给药由八种抗菌剂和两种选择性抑制剂组成的抗菌小组的血清浓度。提出的方法使用了一家商业公司提供的认证材料,并使用EMA指南进行了内部验证。结果表明灵敏度高,精度,和准确性,较低的基体效应与简单的样品制备和节省时间的程序相结合。我们通过测试没有病理指标的血清样本和从溶血,黄疸,或血脂样本。该测定显示了94%至101%的回收率范围。
    The use of TDM in clinical practice to monitor the plasma levels of antibiotics administered to critically ill patients is a well-established approach that allows for optimization of the patient\'s response to drug therapy, considering the characteristics of the drug, the clinical and physiological status of the patient and any peculiar of the pathogen that caused the clinical picture. In our laboratory, we have developed a single LC-MS/MS analysis for dosing the serum concentration of an antibacterial panel composed of eight antibacterial and two selective inhibitors. The method presented used a certified material furnished by a commercial company and was internally validated using the EMA guidelines. The results have shown high sensitivity, precision, and accuracy, a lower matrix effect combined with simple sample preparation and a time-saving procedure. We have evaluated the recovery rate and matrix effect by testing serum samples without pathological index and serum pools obtained from haemolysed, icteric, or lipemic samples. The assay has shown a recovery range between 94% and 101%.
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  • 文章类型: Journal Article
    调查高血糖妊娠中与先兆子痫相关的危险因素,并建立基于常规妊娠护理的预测模型。
    回顾性收集951例高血糖孕妇的临床资料,包括诊断为妊娠期糖尿病(DIP)和妊娠期糖尿病(GDM)的患者,2017年1月至2019年12月在安徽医科大学附属妇幼保健院妊娠34周后分娩。观察指标包括妊娠24-29+6周的肝肾功能因子检测,产妇年龄,和基础血压。对指标进行了单因素筛选,应用R语言的“rms”软件包,通过逐步回归法探讨HIP妊娠与PE相关的因素。采用多变量logistic回归分析建立预测模型。基于以上结果,构建列线图以预测HIP孕妇发生PE的风险.然后,该模型从三个方面进行了评估:歧视,校准,和临床效用。使用引导程序执行内部验证。
    多因素logistic回归分析显示胱抑素C,尿酸,谷氨酰氨基转移酶,血尿素氮,和基础收缩压作为妊娠合并HIP的PE的预测因子。预测模型得出的曲线下面积(AUC)值为0.8031(95%CI:0.7383-0.8679),最佳阈值为0.0805,此时敏感性为0.8307,特异性为0.6604.Hosmer-Lemeshow试验值P=0.3736,Brier评分值为0.0461。经过1000次Bootstrap重新采样进行内部验证后,AUC为0.7886,Brier评分为0.0478,校准曲线的预测概率与实际概率相似.基于上述构造列线图以使模型可视化。
    这项研究开发了一种预测HIP孕妇PE的模型,通过常规妊娠护理的信息实现PE风险的高预测性能。
    UNASSIGNED: To investigate the risk factors associated with preeclampsia in hyperglycemic pregnancies and develop a predictive model based on routine pregnancy care.
    UNASSIGNED: The retrospective collection of clinical data was performed on 951 pregnant women with hyperglycemia, including those diagnosed with diabetes in pregnancy (DIP) and gestational diabetes mellitus (GDM), who delivered after 34 weeks of gestation at the Maternal and Child Health Hospital Affiliated to Anhui Medical University between January 2017 and December 2019. Observation indicators included liver and kidney function factors testing at 24-29+6 weeks gestation, maternal age, and basal blood pressure. The indicators were screened univariately, and the \"rms\" package in R language was applied to explore the factors associated with PE in HIP pregnancy by stepwise regression. Multivariable logistic regression analysis was used to develop the prediction model. Based on the above results, a nomogram was constructed to predict the risk of PE occurrence in pregnant women with HIP. Then, the model was evaluated from three aspects: discrimination, calibration, and clinical utility. The internal validation was performed using the bootstrap procedure.
    UNASSIGNED: Multivariate logistic regression analysis showed that cystatin C, uric acid, glutamyl aminotransferase, blood urea nitrogen, and basal systolic blood pressure as predictors of PE in pregnancy with HIP. The predictive model yielded an area under curve (AUC) value of 0.8031 (95% CI: 0.7383-0.8679), with an optimal threshold of 0.0805, at which point the sensitivity was 0.8307 and specificity of 0.6604. Hosmer-Lemeshow test values were P = 0.3736, Brier score value was 0.0461. After 1000 Bootstrap re-samplings for internal validation, the AUC was 0.7886, the Brier score was 0.0478 and the predicted probability of the calibration curve was similar to the actual probability. A nomogram was constructed based on the above to visualize the model.
    UNASSIGNED: This study developed a model for predicting PE in pregnant women with HIP, achieving high predictive performance of PE risk through the information of routine pregnancy care.
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  • 文章类型: Journal Article
    背景:随着越来越多的基于网络的计算器旨在提供个人在腰椎手术后获得改善的概率,有必要确定这些模型的准确性。
    目的:对基于Web的降低质量结果数据库(QOD-Calc)进行内部和外部验证研究。
    方法:观察性纵向队列。
    方法:患者在质量结果数据库(QOD)中纳入了整个研究范围,在单一机构中纳入了DaneSpine的患者进行了选择性腰椎手术,并提供了基线数据以完成QOD-Calc和12个月的术后数据。
    方法:Oswestry残疾指数(ODI),背部和腿部疼痛的数字等级量表(NRS),EuroQOL-5D(EQ-5D)。
    方法:将基线数据元素输入到QOD-Calc中,以确定每位患者NRS腿部疼痛有任何改善和30%改善的概率,背痛,EQ-5D和ODI。将这些概率与每个QOD和DaneSpine病例的实际12个月术后数据进行比较。进行了接收器操作特性分析,并创建了校准图以评估模型性能。
    结果:分析包括24,755例QOD和8,105例DaneSpine腰椎病例。QOD-Calc具有可接受的至突出的能力(AUC:0.694-0.874)来预测QOD队列中的任何改善,并且具有中等至可接受的能力(AUC:0.658-0.747)来预测30%改善。在DaneSpine队列中,QOD-Calc具有预测任何改善的可接受至例外能力(AUC:0.669-0.734)和预测30%改善的中度至例外能力(AUC:0.619-0.862)。DaneSpine队列的AUC始终低于QOD验证队列的AUC。
    结论:QOD-Calc在预测与用于开发QOD-Calc的患者相似的患者群体中的结局方面表现良好。虽然仍然可以接受,模型性能在不同的人群中稍差,尽管样本更均匀。模型性能也可能归因于低辨别阈值,接近90%的病例报告结果有任何改善。可能需要开发高度特定于人口特征的预测模型。
    BACKGROUND: With an increasing number of web-based calculators designed to provide the probabilities of an individual achieving improvement after lumbar spine surgery, there is a need to determine the accuracy of these models.
    OBJECTIVE: To perform an internal and external validation study of the reduced Quality Outcomes Database web-based Calculator (QOD-Calc).
    METHODS: Observational longitudinal cohort.
    METHODS: Patients enrolled study-wide in Quality Outcomes Database (QOD) and patients enrolled in DaneSpine at a single institution who had elective lumbar spine surgery with baseline data to complete QOD-Calc and 12-month postoperative data.
    METHODS: Oswestry Disability Index (ODI), Numeric Rating Scales (NRS) for back and leg pain, EuroQOL-5D (EQ-5D).
    METHODS: Baseline data elements were entered into QOD-Calc to determine the probability for each patient having Any Improvement and 30% Improvement in NRS leg pain, back pain, EQ-5D and ODI. These probabilities were compared with the actual 12-month postop data for each of the QOD and DaneSpine cases. Receiver-operating characteristics analyses were performed and calibration plots created to assess model performance.
    RESULTS: 24,755 QOD cases and 8,105 DaneSpine lumbar cases were included in the analysis. QOD-Calc had acceptable to outstanding ability (AUC: 0.694-0.874) to predict Any Improvement in the QOD cohort and moderate to acceptable ability (AUC: 0.658-0.747) to predict 30% Improvement. QOD-Calc had acceptable to exceptional ability (AUC: 0.669-0.734) to predict Any improvement and moderate to exceptional ability (AUC: 0.619-0.862) to predict 30% Improvement in the DaneSpine cohort. AUCs for the DaneSpine cohort was consistently lower that the AUCs for the QOD validation cohort.
    CONCLUSIONS: QOD-Calc performs well in predicting outcomes in a patient population that is similar to the patients that was used to develop it. Although still acceptable, model performance was slightly worse in a distinct population, despite the fact that the sample was more homogenous. Model performance may also be attributed to the low discrimination threshold, with close to 90% of cases reporting Any Improvement in outcome. Prediction models may need to be developed that are highly specific to the characteristics of the population.
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  • 文章类型: Journal Article
    会阴创伤是分娩的常见并发症,可对长期健康产生严重影响。很少有研究检查了多种风险因素的综合影响。我们开发并内部验证了风险预测模型,以使用来自一般产科人群的数据预测三度和四度会阴撕裂。
    使用科克大学妇产医院(CUMH)所有单胎阴道分娩数据的风险预测模型,爱尔兰在2019年和2020年。产科医生或助产士在出生时诊断出三度/四度眼泪,并将其定义为延伸到肛门括约肌复合体或累及肛门括约肌复合体和肛门直肠粘膜的眼泪。我们使用单变量和多变量逻辑回归和向后逐步选择来开发模型。候选预测因素包括婴儿性别,产妇年龄,产妇体重指数,奇偶校验,交货方式,出生体重,期后交货,引产和公共/私人产前护理。我们使用接受者工作特性(ROC)曲线C-统计量来评估判别,和自举技术用于评估内部验证。
    在8,403例单胎阴道分娩中,8,367(99.54%)有关于模型开发预测因子的完整数据。共有128名女性(1.53%)患有三度/四度撕裂。最终模型中保留了三个变量:无效,分娩方式(特别是镊子分娩或腹腔分娩)和增加出生体重(每100克增加)(C统计量:0.75,95%CI:0.71,0.79)。我们使用这些预测因子开发了一个列线图来计算第三/第四度眼泪的个性化风险。自举表明良好的内部性能。
    使用我们的列线图可以提供三度/四度眼泪的个性化风险评估,并可能为女性提供潜在风险咨询。
    UNASSIGNED: Perineal trauma is a common complication of childbirth and can have serious impacts on long-term health. Few studies have examined the combined effect of multiple risk factors. We developed and internally validated a risk prediction model to predict third and fourth degree perineal tears using data from a general obstetric population.
    UNASSIGNED: Risk prediction model using data from all singleton vaginal deliveries at Cork University Maternity Hospital (CUMH), Ireland during 2019 and 2020. Third/fourth degree tears were diagnosed by an obstetrician or midwife at time of birth and defined as tears that extended into the anal sphincter complex or involved both the anal sphincter complex and anorectal mucosa. We used univariable and multivariable logistic regression with backward stepwise selection to develop the models. Candidate predictors included infant sex, maternal age, maternal body mass index, parity, mode of delivery, birthweight, post-term delivery, induction of labour and public/private antenatal care. We used the receiver operating characteristic (ROC) curve C-statistic to assess discrimination, and bootstrapping techniques were used to assess internal validation.
    UNASSIGNED: Of 8,403 singleton vaginal deliveries, 8,367 (99.54%) had complete data on predictors for model development. A total of 128 women (1.53%) had a third/fourth degree tear. Three variables remained in the final model: nulliparity, mode of delivery (specifically forceps delivery or ventouse delivery) and increasing birthweight (per 100 gram increase) (C-statistic: 0.75, 95% CI: 0.71, 0.79). We developed a nomogram to calculate individualised risk of third/fourth degree tears using these predictors. Bootstrapping indicated good internal performance.
    UNASSIGNED: Use of our nomogram can provide an individualised risk assessment of third/fourth degree tears and potentially aid counselling of women on their potential risk.
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  • 文章类型: Journal Article
    GA118-24B遗传分析仪(以下简称,\"GA118-24B\")是自主研发的毛细管电泳仪。在目前的研究中,我们设计了一系列验证实验,以测试其在检测DNA片段方面的性能,与应用生物系统3500基因分析仪(以下,\"3500\")。在该验证中使用三种市售的常染色体短串联重复序列多重试剂盒。结果表明,GA118-24B对三种试剂盒具有可接受的光谱校准。准确性和一致性研究的结果也令人满意。GA118-24B显示出优异的精度,标准偏差小于0.1bp。敏感性和混合物研究表明,GA118-24B可以检测低模板DNA和复杂混合物,以及在平行实验中3500产生的结果。根据实验结果,我们设置了具体的分析阈值和随机阈值。此外,在分辨率研究中,GA118-24B在某些尺寸范围内显示出比3500更高的优势。而不是传统的商业多重套件,GA118-24B在自行开发的八种染料多重系统上性能稳定,这不是在3500遗传分析仪上进行的。我们将我们的验证结果与以前的研究结果进行了比较,发现我们的结果令人信服。总的来说,我们得出结论,GA118-24B是用于法医DNA鉴定的稳定可靠的遗传分析仪。
    The GA118-24B Genetic Analyzer (hereafter, \"GA118-24B\") is an independently developed capillary electrophoresis instrument. In the present research, we designed a series of validation experiments to test its performance at detecting DNA fragments compared to the Applied Biosystems 3500 Genetic Analyzer (hereafter, \"3500\"). Three commercially available autosomal short tandem repeat multiplex kits were used in this validation. The results showed that GA118-24B had acceptable spectral calibration for three kits. The results of accuracy and concordance studies were also satisfactory. GA118-24B showed excellent precision, with a standard deviation of less than 0.1 bp. Sensitivity and mixture studies indicated that GA118-24B could detect low-template DNA and complex mixtures as well as the results generated by 3500 in parallel experiments. Based on the experimental results, we set specific analytical and stochastic thresholds. Besides, GA118-24B showed superiority than 3500 within certain size ranges in the resolution study. Instead of conventional commercial multiplex kits, GA118-24B performed stably on a self-developed eight-dye multiplex system, which were not performed on 3500 Genetic Analyzer. We compared our validation results with those of previous research and found our results to be convincing. Overall, we conclude that GA118-24B is a stable and reliable genetic analyzer for forensic DNA identification.
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