广义可加模型在H1N1疫苗效果评估中的应用

目的探讨广义可加模型在处理非线性数据方面的优势。方法以H1N1疫苗临床试验数据为实例,分别用广义可加模型与一般线性模型对已知不成线性的影响因素进行模型拟合,分析影响H1N1疫苗抗体滴度的相关因素。分别用偏差统计量及误差均方对模型拟合效果进行评价。结果与一般线性模型相比,广义可加模型的拟合效果更好,具有较小的偏差统计量和误差均方。结论广义可加模型在处理非线性数据时,拟合效果优于一般线性模型,在自变量与因变量不成线性关系时,应首选广义可加模型。     

交叉设计多中心临床试验的混合效应模型

目的 :探讨交叉设计多中心临床试验资料的分析方法。方法 :采用混合效应的一般线性模型和混合效应的广义线性模型。结果 :将个体作为随机效应来估计时 ,可以增加误差自由度 ,提高估计精度 ,同时可以考虑中心效应、患者的年龄、性别、基线等协变量的影响 ,并且对于缺失数据在不丢失信息的情况下照样能进行分析。结论 :在交叉设计多中心临床试验资料的分析中 ,混合效应的一般线性模型适用于连续性结果变量的分析 ,混合效应的广义线性模型适用于分类结果变量的分析。     

负二项回归模型用于肝炎患者复发次数的SAS程序实现

目的结合肝炎复发次数实例,选取负二项回归模型拟合数据,为计数资料的正确分析提供理论依据。方法对山西省太原市传染病医院2007年6月至12月乙型肝炎、丙型肝炎患者复发情况的随访调查资料,通过SAS软件GENMOD(广义线性模型)过程拟合负二项回归模型,对肝炎复发的影响因素进行分析。结果年龄越大、受感染时间越长、治疗信心越缺乏、认为收入对治疗的影响越明显的肝炎患者复发次数越多。结论SAS/GENMOD过程拟合负二项回归模型,程序简便,结果输出规范,可提供常用的连接函数和概率分布,结果可更准确地解释肝炎复发次数的情况。     

城市地区房颤脑卒中患者住院费用分析

目的:对房颤脑卒中患者的住院费用及其影响因素进行分析,以便进一步估算房颤所致脑卒中的经济负担,为房颤脑卒中的预防提供证据。方法:采用分层随机抽样方法,从2010年全国城镇基本医疗保险参保住院患者数据库中抽取158例房颤伴脑卒中住院患者资料,对所抽取患者的住院费用进行描述性分析,并通过单因素分析和多元线性回归分析影响患者住院费用的因素。结果:患者平均年龄为(73.6±9.1)岁,其中50.00%为男性;患者平均住院时间为17.5d;平均住院费用为17480.27元(中位数:11975.32元,四分位间距:7863.30～19941.85元),其中药品费用占总费用的比例为50.6%,医疗保险负担了总住院费用的49.4%。多元线性回归显示,患者医疗保险类型对房颤伴脑卒中患者的住院费用有显著性影响(P<0.001),城镇职工的住院费用比城镇居民高54%。结论:房颤脑卒中患者的住院费用很高,提示对房颤患者进行脑卒中预防可节省医疗费用。     

带有对称误差的群体药代动力学参数的贝叶斯估计

目的:研究对称分布用于药代动力学中参数的估计是否合理。方法:在广义线性模型框架下,以贝叶斯方法推导出模型中各回归参数的后验,再用MCMC算法结合模拟得出参数的具体值。结果:对5 000次模拟的结果进行统计分析,得到各参数的点估计值和置信域及相应图表,符合模拟的预设值。对称分布与广义线性模型结合,得到了较好的参数估计值。结论:群体药物代谢动力学中可以考虑使用对称分布进行参数的估计。     

线性回归预测模型有效超前期的确定方法

线性回归预测模型是应用线性回归技术,根据历史数据建立回归方程．用此回归方程进行超前预测。然而,建立了一个线性回归模型能否用其做无限期的超前预测呢？显然,一个预测模型的预测精度随着超前期的增加而逐渐降低,即预测误差越来越大。当外推至某一期时,预测误差之大,使该模型继续作外报预测几乎不再有什么实际意义。此时的预测超前期的长度我们称之为有效超前期。下面讨论线性回归预测模型有效超前期的一种确定方法。且确定方法对于一元线性回归预测模型此模型参数的最小二乘估计为：未来视察值如果将来在第k＋1期时,实际观察值超…     

基于改进曲线回归模型的人全血中环孢素A谷浓度预测

目的：建立基于改进曲线回归的人全血中环孢素A（CsA）谷浓度预测模型,为临床个体化用药提供依据。方法：回顾收集天津医科大学总医院37名使用CsA治疗免疫相关性全血细胞减少症（IRP）的患者生理生化检测指标相关信息,采用主成分分析法（PCA）-多元线性回归模型和PCA-多项式曲线回归模型利用上述指标对患者全血中CsA谷浓度进行预测。结果：利用PCA将33个生理生化指标降维简化,确定10个主成分。PCA-多元线性回归模型的拟合优度为0.254 6,均方误差为175.8;PCA-多项式曲线回归模型的拟合优度为1.000,均方误差为3e^-15。结论：PCA-多项式曲线回归模型拟合程度高,均方误差较小,优于PCA-多元线性回归模型。PCA-多项式曲线回归模型更适合用于IRP患者CsA谷浓度的预测。     

如何进行因变量为二值变量的多logistic回归分析－怎样在药物应用与监测研究中正确运用统计学（十二）

通常的多重线性回归模型中,因变量常为一个连续性变量,而在临床医学、药学实验中因变量有时为分类变量,此时需要采用logistic回归模型进行分析。Logistic回归属于概率型回归,即因变量是某事件（代表自变量取某特定值所对应的事件,如患者被治愈）发生的概率。因变量的性质通常可以有以下3种情形：1）二值变量,如成功或失败、生存或死亡;     

线性回阳预测模型有效超前期的确定方法

线性回归预测模型是应用线性回归技术,根据历史数据建立回归方程,用此回归方程进行超前预测.然而,建立了一个线性回归模型能否用其做无限期的超前预测呢?显然,一个预测模型的预测精度随着超前期的增加而逐渐降低,即预测误差越来越大.当外推至某一期时,预测误差之大,使该模型继续作外推预测几乎不再有什么实际意义,此时的预测超前期的长度我们称之为有效超前期.下面讨论线性回归预测模型有效超前期的一种确定方法.     

线性回归结合灰色模型在门诊量预测中的应用

应用线性回归技术和 GM( 1,1)灰色模型对某院 1990～ 1999年门诊量进行了分析预测。结果表明 ,两种方法的加权组合预测误差较小 ,能为医院科学决策提供依据 ,是一种较好的预测方法。     

沧州市急性阑尾炎“医保”患者药品费用分析

目的:了解沧州市"医保"患者药品使用情况及药品费用控制政策的实施效果。方法:以算术平均数和构成比等指标描述急性阑尾炎患者的药品费用水平,利用秩和检验与多元线性回归模型等方法比较"医保"患者和自费患者的药品费用。结果:"医保"患者药品费用占住院总费用的30%~35%,《沧州市城镇职工基本医疗保险药品目录》以外药品费用占全部药费的9%以下,"医保"患者的药费高于自费患者。结论:沧州市"医保"患者药品费用控制效果较好,但药品费用仍有降低的空间。     

3种医疗付费方式对门诊呼吸科患者用药的影响

目的比较公费、自费、地方医保3种医疗付费方式对医院门诊呼吸科患者用药情况的影响。方法选取2007年7月至12月门诊呼吸科处方,每周随机抽取1天进行统计和分析。结果门诊呼吸科医保患者人均药费最高;3种付费方式的联合用药和抗菌药物使用均呈递增趋势。结论3种医疗付费方式,在联合用药和抗菌药物使用频率等方面对门诊呼吸科就诊患者存在一定影响。     

Appreciation of medical treatments through confidence intervals

The typical way of judging about either the efficacy of a new treatment or, on the contrary, the damage of a pollutant agent is through a test of hypothesis having its ineffectiveness as null hypothesis. This is the typical operational field of Kolmogorov's statistical framework where wastes of data (for instance non significant deaths in a polluted region) represent the main drawback. Instead, confidence intervals about treatment/pollution effectiveness are a way of exploiting all data, whatever their number is. We recently proposed a new statistical framework, called Algorithmic Inference, for overcoming crucial difficulties usually met when computing these intervals and abandoning general simplifying hypotheses such as errors' Gaussian distribution. When effectiveness is expressed in terms of regression curves between observed data we come to a learning problem that we solve by identifying a region where the whole curve lies with a given confidence. The approach to inference we propose is very suitable for identifying these regions with great accuracy, even in the case of nonlinear regression models and/or a limited size of the observed sample, provided that a normally powered computing station is available. In the paper we discuss this new way of extracting functions from the experimental data and drawing conclusions about the treatments originating them. From an operational perspective, we give the general layout of the procedure for computing confidence regions as well as some applications on real data.     

医保新农合政策下我院药品费用拒付情况分析和对策

摘 要 目的：了解我院参加医保新农合的患者病历中药品费用被拒付的情况,分析拒付原因,寻找策略。方法: 收集2014年10月～2015年10月我院参加医保新农合的患者病历中药品费用被拒付的数据,分析不同拒付原因,并提出减少医保新农合政策下药品费用拒付的应对策略。结果: 我院药品费用被拒付最常见的原因是违反医保新农合政策中的限制用药,其次为中成药、抗菌药不合理使用。医院应根据药品费用被拒付原因寻找对策,促进医保新农合政策落实,加强临床合理用药管理和医保新农合政策下的规范用药。结论: 我院参加医保新农合患者的药品费用被拒付的主要原因是我院医保新农合政策执行不彻底,存在违反医保政策用药的现象。药学部应在监管合理用药的同时,着重宣传医保新农合用药政策,实施站位前移,参与用药方案制定,促进规范用药。     

Non-steady state kinetic analysis of the regulation of adenylate cyclase by GTP-binding proteins

The time course of cAMP production by S49 cell membranes in the presence of forskolin and a nonhydrolyzable GTP analog can yield information about the regulation of adenylate cyclase by both the inhibitory and stimulatory GTP-binding proteins (Gi and Gs). The time courses are complex and interpretation in terms of the activities of G1 and Gs requires a quantitative hypothesis. We present a general quantitative hypothesis that defines adenylate cyclase as existing in a distribution of two states, active and inactive. Gi and Gs, in their active states, alter the equilibrium of this distribution. Two distinct models are derived based on this hypothesis to accommodate two different proposed mechanisms for the action of Gi to inhibit adenylate cyclase: 1) a direct interaction between Gi and the catalytic subunit of adenylate cyclase and 2) a direct interaction between Gi and Gs. Perturbations of the regulation of adenylate cyclase by pertussis toxin and phorbol ester are simulated and interpreted using the models. The effect of pertussis toxin is quantitatively reconciled by decreases in the guanine nucleotide-independent adenylate cyclase activity and in the apparent rate of activation of Gi from 2.0/min to 0.01/min. The effect of phorbol ester is best accommodated by the model as a change in the distribution of active and inactive adenylate cyclase from 36% initially active to 47% active after phorbol ester treatment, without postulating any effect of phorbol ester on Gi or Gs. Both of these interpretations are independent of the model used. The effect of forskolin is also examined within the context of the two models. The results of this examination suggest an experimental approach for testing the models. These examples illustrate the usefulness of quantitative analysis of time course data using a model for the regulation of adenylate cyclase. We propose that, with this combined experimental and theoretical approach, one can address the relevance of hypotheses generated from experimental studies with isolated components to the molecular mechanisms of adenylate cyclase regulation in cellular membranes.     

Impact of Subject Attrition on Sample Size Determinations for Longitudinal Cluster Randomized Clinical Trials

Subject attrition is a ubiquitous problem in any type of clinical trial and, thus, needs to be taken into consideration at the design stage particularly to secure adequate statistical power. Here, we focus on longitudinal cluster randomized clinical trials (cluster-RCT) that aim to test the hypothesis that an intervention has an effect on the rate of change in the outcome over time. In this setting, the cluster-RCT assumes a three-level hierarchical data structure in which subjects are nested within a higher level unit such as clinics and are evaluated for outcome repeatedly over the study period. Furthermore, the subject-specific slopes can be modeled in terms of fixed or random coefficients in a mixed-effects linear model. Closed-form sample size formulas for testing the preceding hypothesis have been developed under an assumption of no attrition. In this article, we propose closed-form approximate samples size determinations with anticipated attrition rates by modifying those existing sample size formulas. With extensive simulations, we examine performances of the modified formulas under three attrition mechanisms: attrition completely at random, attrition at random, and attrition not at random. In conclusion, the proposed modification is very effective under fixed-slope models but yields biased, perhaps substantially so, statistical power under random slope models.     

General treatment of linear pharmacokinetics

A general treatment of linear pharmacokinetics that enables equations to be obtained simply for all linear compartmental models, with input in one or more compartments, is presented. Two approaches are described: one based on a full Laplace transformation and one that avoids transformation of the input functions and the use of convolution integrals. The latter approach is of particular interest when dealing with complex input functions not having a simple Laplace transform. The concept of acceptor and donor subsystems is introduced. It is demonstrated that disposition in certain models may be simplified and analyzed in terms of disposition in subsystems of simpler composition. The treatment presented is illustrated with several examples.     

慢行乙型病毒性肝炎治疗药物的经济学评价

目的：慢性HBV的抗病毒药物治疗已经取得突破性进展,但我国相关的医疗保险政策和治疗药物品种遴选严重滞后。本文用药物经济学评价慢性HBV治疗中基本医疗保险政策和药品目录遴选,以期为合理的基本医疗保险费用、药物治疗品种选择等提供依据。方法：针对慢性HBV治疗现状,分析我国基本医疗保险制度存在的问题,用药物经济学方法评价和遴选基本医疗保险用药品种,制定医院临床用药目录和治疗方案,评价单病种治疗药物和方案,指导公众选择药物。结果：开展慢行乙型病毒性肝炎治疗药物的经济学研究和评价,有利于为患者选择合理的药物治疗方案,有助于有限的医疗保险基金发挥最大效益。结论：药物经济学是研究和解决合理的基本医疗保险费用、药物治疗品种选择、临床合理用药等问题的重要工具,是解决基本医疗保险费用和药物治疗品种选择的重要手段。