混合Poisson分布及其应用：疾病的统计分布（五）

本文讨论了混合Ｐｏｉｓｓｏｎ分布的性质、应用条件、参数的估计及混合Ｐｏｉｓｓｏｎ分布阶数的确定，指出混合Ｐｏｉｓｓｏｎ分布可用于混合样本的判别归类，并用Ｂａｙｅｓ的思想导出其判别归类方法。模拟试验结果表明：当混合Ｐｏｉｓｓｏｎ分布中各部分的比例相差不大，而各部分的均值相差较大时，抽样效果和拟合效果越好，所得到的估计值越接近理论值；反之效果越差。     

铁路系统医院136篇口腔修复、正畸学论文的统计分析

通过对铁路系统医院１３６篇口腔修复、正畸学论文的统计分析，来评价医院口腔修复、正畸的科研水平，同时也揭示了科研工作中存在的问题。指出只有加强科研协作、扩大学术交流、增加科研投入，提高科研水平，使科研成果更趋完善。     

Intelligent dialogue based on statistical models of clinical decision-making

The independence Bayesian model has been used widely in computer programs designed to support clinical decision-making. A reasoning strategy has been developed to enable these programs to conduct clinically pertinent dialogue and explain their reasoning. It has been implemented in a program for the diagnosis of acute abdominal pain based on the Bayesian model of de Dombal et al. Several features of the dialogue design have been adopted from artificial intelligence research, including shared initiative and critiquing. The program adopts a flexible goal-driven strategy, attempting to confirm the clinician's diagnosis or rule out the likeliest alternative. Symptoms and signs are selected in order of their expected weights of evidence in favour of the hypothesized disease.     

Laboratory screening method for selection of healthy volunteers

The aim of laboratory screening in Phase I is to exclude subjects with subclinical illness, who might be at increased risk in the study, and who might also adversely influence interpretation of the results. A new method for laboratory screening, based on Bayesian probability theory, is proposed, which consists of: 1. Drawing up a list of diseases to be excluded. 2. Defining for each disease, the maximum acceptable risk that an included subject could be affected by it. 3. Identifying one test for each disease. 4. Using a contingency table to calculate the specificity of the test and integrating the estimated prevalence of the disease from epidemiological data. 5. Applying the percentage obtained by the calculation of specificity to the previously determined distribution of values in the volunteer population to identify the threshold value for inclusion. Use of this deductive method in screening volunteers for Phase I trials affords increased security of selection, while reducing the number of non-pertinent exclusions because of laboratory findings.     

Real-time refinement of subthalamic nucleus targeting using Bayesian decision-making on the root mean square measure.

The subthalamic nucleus (STN) is a major target for treatment of advanced Parkinson's disease patients undergoing deep brain stimulation surgery. Microelectrode recording (MER) is used in many cases to identify the target nucleus. A real-time procedure for identifying the entry and exit points of the STN would improve the outcome of this targeting procedure. We used the normalized root mean square (NRMS) of a short (5 seconds) MER sampled signal and the estimated anatomical distance to target (EDT) as the basis for this procedure. Electrode tip location was defined intraoperatively by an expert neurophysiologist to be before, within, or after the STN. Data from 46 trajectories of 27 patients were used to calculate the Bayesian posterior probability of being in each of these locations, given RMS-EDT pair values. We tested our predictions on each trajectory using a bootstrapping technique, with the rest of the trajectories serving as a training set and found the error in predicting the STN entry to be (mean +/- SD) 0.18 +/- 0.84, and 0.50 +/- 0.59 mm for STN exit point, which yields a 0.30 +/- 0.28 mm deviation from the expert's target center. The simplicity and computational ease of RMS calculation, its spike sorting-independent nature and tolerance to electrode parameters of this Bayesian predictor, can lead directly to the development of a fully automated intraoperative physiological procedure for the refinement of imaging estimates of STN borders.     

Novel ROC-type method for testing the efficiency of multivariate statistical methods in fMRI.

The receiver operating characteristic (ROC) method is a useful and popular tool for testing the efficiency of various diagnostic tests applicable to functional MRI (fMRI) data. Typically, the diagnostic tests are applied on simulated and pseudo-human fMRI data, and the area under the ROC curve is used as a measure of the efficiency of the diagnostic test. The effectiveness of such a method depends on how well the simulated data approximate the real data. For multivariate statistical methods, however, this technique is usually inadequate, as the spatial dependence among voxels is ignored for simulated data. In this work a modified ROC method using real fMRI data with a broader scope is proposed. This method can be applied to most fMRI postprocessing techniques, including multivariate analyses such as canonical correlation analysis (CCA). Also, the relationship of the modified ROC method with the conventional ROC method is discussed in detail.     

眼外伤临床统计规范探讨

眼外伤是我国眼科住院三大主要疾病之一，占眼科住院病人总数的１６￣３２％。每年发表临床统计文章百余篇，但由于统计资料不全面，标准不统一，降低了这部分劳动的价值。本文就眼外伤临床统计规范及某些问题进行讨论，强调规范化的重要意义。     

Cerebrovascular deaths before and after the appearance of oral contraceptives

The mortality of cerebrovascular diseases in Denmark was analysed for men and women 15-44 years of age, in a 14-year period before and after the appearance of oral contraceptives (OC) in 1966. 1,670 deaths were registered over 28 years, during which the female incidence of cerebrovascular deaths increased by 19% (P less than 0.025), while the male mortality was unchanged. Women showed a percentage increase in deaths from cerebral thromboembolic attacks (CTA) of 33%, men a fall of 14%. The increase of female CTA deaths was most pronounced in the young fertile group, the age group with a high OC use. A relative risk of CTA of 3.3-4.5 for OC users compared with non-users could explain the CTA trend difference between women and men. No other single risk factor responsible for the observed trends could be identified. Both women and men had a significant increase in the mortality of subarachnoidal hemorrhages, and a significant fall in the mortality of intracerebral hemorrhages.     

测胎儿器官重量探讨其生长发育规律

根据1022例新鲜胎尸的不同受精龄与体重，十项重要器官（心、肝、脾、左右肺、左右肾、左右肾上腺、胸腺等）的重量进行测量，将所测得的原始数据输入到IBM-PC/XT微型计算机内进行数据处理。探讨胎儿生长发育的基本规律。结果：（1）建立了胎儿体重与胎龄之间的推算式；（2）建立了胎儿各重要器官重量与胎龄之间的推算式；（3）建立了胎儿体重每月平均增长量与胎龄之间的推算式；（4）按胎儿体重每月平均增长量，用有序聚类分析方法，将胎儿生长发育过程划分为三个阶段。     

青岛市居民就诊单位选择影响因素的多项式Logistic回归分析

①目的研究影响青岛市城乡居民选择就诊单位的因素。②方法采用多项式Logistic回归分析法，分析影响青岛市城乡居民选择就诊单位的主要因素。③结果影响市区病人选择就诊单位的主要因素是医疗保健制度和居民健康状况．农村病人的主要影响因素是家庭收入、健康状况和受教育程度。④结论居民就诊单位选择受多种因素的影响，建议加快医疗保健制度的改革．完善医疗保健制度。