Adequate sample size for developing prediction models is not simply related to events per variable

ObjectivesThe choice of an adequate sample size for a Cox regression analysis is generally based on the rule of thumb derived from simulation studies of a minimum of 10 events per variable (EPV). One simulation study suggested scenarios in which the 10 EPV rule can be relaxed. The effect of a range of binary predictors with varying prevalence, reflecting clinical practice, has not yet been fully investigated.Study Design and SettingWe conducted an extended resampling study using a large general-practice data set, comprising over 2 million anonymized patient records, to examine the EPV requirements for prediction models with low-prevalence binary predictors developed using Cox regression. The performance of the models was then evaluated using an independent external validation data set. We investigated both fully specified models and models derived using variable selection.ResultsOur results indicated that an EPV rule of thumb should be data driven and that EPV ≥ 20 ​ generally eliminates bias in regression coefficients when many low-prevalence predictors are included in a Cox model.ConclusionHigher EPV is needed when low-prevalence predictors are present in a model to eliminate bias in regression coefficients and improve predictive accuracy.     

利用数据挖掘对某医院零加成后慢病门诊费用分析

目的： 通过分析该院药品零加成后慢病门诊费用变化，为后续医保费用管控及合理用药提供参考意见。方法： 使用数据挖掘方法，分别利用费用消耗占比、月度次均费用变化情况以及皮尔逊相关系数（Pearson Correlation Coefficient）分析各类费用变化情况及药品费用对其他费用的影响。结果： 次均总费用、次均西成药费用、次均中草药费用整体呈现下降的趋势，次均检查费用、次均检验费用、次均挂号费用、次均手术费用、次均麻醉费用、次均治疗费用呈现上升趋势。结论： 次均总费用下降主要是由于次均西成药费的下降所产生的，但是次均西成药费下降与次均麻醉费用、次均检验费用、次均检查费用上升是呈现相关性的，这也揭示了次均总费用下降速度慢于次均西成药费下降速度的原因。     

某院重点监控中成药的管理实践

目的：探索对中成药重点监控药品合理使用的有效药事管理措施。方法：基于药品销售金额、DDDs，和DUI为评价指标，通过四步筛选法确定中成药重点监控目录，结合用药合理性评价结果进行药事管控。通过对比监管前后某院医疗指标变化情况，对管理效果进行参考性评价。结果：在疗效相同的前提下，重点监控中成药的金额占比持续下降，中成药的药占比由24.4%下降至15.8%；中成药的人均药费由1 492.5元降至878.3元；而病种类数、收治人数、治愈率均无显著性差异。中成药的用药不合理使用率也大幅度下降。结论：通过建立重点监控中成药的管理措施，规范医疗机构药物使用并取得一定成效。为中成药的管理提供新的思路。     

Can physical prehabilitation prevent complications after colorectal cancer surgery in frail older patients?

IntroductionFrail patients with colorectal cancer (CRC) are at increased risk of complications after surgery. Prehabilitation seems promising to improve this outcome and therefore we evaluated the effect of physical prehabilitation on postoperative complications in a retrospective cohort of frail CRC patients.MethodsThe study consisted of all consecutive non-metastatic CRC patients ≥70 years who had elective surgery from 2014 to 2019 in a teaching hospital in the Netherlands, where a physical prehabilitation program was implemented from 2014 on. We performed both an intention-to-treat and per protocol analysis to evaluate postoperative complications in the physical prehabilitation (PhP) and non-prehabilitation (NP) group.ResultsEventually, 334 elective patients were included. The 124 (37.1%) patients in the PhP-group presented with higher age, higher comorbidity scores and walking-aid use compared to the NP-group. Medical complications occurred in 26.6% of the PhP-group and in 20.5% of the NP-group (p = 0.20) and surgical complications in 19.4% and 14.3% (p = 0.22) respectively. In all frailty subgroups, the medical complications were lower in the PhP-group compared to the NP-group (35.9% vs. 45.5% for patients with ≥2 comorbidities, 36.2% vs. 39.1% for ASA score ≥ III, 29.2% vs. 45.8% for walking-aid use). Differences were not significant.ConclusionsIn this study, patients selected for physical prehabilitation had a worse frailty profile and therefore a higher a priori risk of postoperative complications. However, the postoperative complication rate was not increased compared to patients who were less frail at baseline and without prehabilitation. Hence, physical prehabilitation may prevent postoperative complications in frail CRC patients ≥70 years.     

Is ivabradine suitable to control undesirable tachycardia induced by dobutamine in cardiogenic shock treatment?

Inotropic treatment remains the cornerstone for cardiogenic shock, an emergency that requires immediate resuscitative therapy before shock irreversibly damages vital organs. Although the sympathomimetic drug dobutamine is the most widely-used inotropic drug worldwide, it has several side effects including sinus tachycardia. Dobutamine partly restores systolic heart failure (HF); however, it increases the heart rate (HR) which counterbalances the beneficial effects. Ivabradine, a new selective I_f inhibitor, provides specific HR reduction and is indicated in stable coronary artery disease and in stable chronic HF with left ventricular dysfunction. Despite scarce data indicating beneficial effects of ivabradine in sinus tachycardia in various clinical settings, this drug remains contraindicated in acute HF. We propose that ivabradine could help to prevent the dobutamine-induced side effects, and that their combination in clinical practice could lead to pure inotropic effects, useful for the management of cardiogenic shock.