Sampling Patients Within and Across Health Care Providers: Multi-Stage Non-Nested Samples in Health Services Research

In order to better inform study design decisions when sampling patients within and across health care providers we develop a simulation-based approach for designing complex multi-stage samples. The approach explores the tradeoff between competing design goals such as precision of estimates, coverage of the target population and cost.We elicit a number of sensible candidate designs, evaluate these designs with respect to multiple sampling goals, investigate their tradeoffs, and identify the design that is the best compromise among all goals. This approach recognizes that, in the practice of sampling, precision of the estimates is not the only important goal, and that there are tradeoffs with coverage and cost that should be explicitly considered. One can easily add other goals. We construct a sample frame with all phase III clinical cancer treatment trials that are conducted by cooperative oncology groups of the National Cancer Institute from October 1, 1998 through December 31, 1999. Simulation results for our study suggest sampling a different number of trials and institutions than initially considered.Simulations of different study designs can uncover efficiency gains both in terms of improved precision of the estimates and in terms of improved coverage of the target population. Simulations enable us to explore the tradeoffs between competing sampling goals and to quantify these efficiency gains. This is true even for complex designs where the stages are not strictly nested in one another.     

ROOT ZX根管长度测量仪临床应用评价

目的 评价森田ROOT ZX根管长度测量仪临床应用价值.方法 用根管长度测量仪对108例根管进行根管测量,以此长度进行根管预备后,按测量长度插入牙胶尖摄X线牙片,计算出实际根管长度,求得测量准确率.结果 ROOT ZX测量准确率为92.6%.结论 ROOT ZX根管长度测量仪应用安全可靠、准确率高.     

Appendizitissonographie durch chirurgen — Erfahrungssache? Eine prospektive studie

A number of studies have shown that ultrasound has an advantage over physical examination in the diagnosis of acute appendicitis. Most of these studies were conducted by experts in the field of ultrasonography. In this study the influence of experience on the results of the sonography of actue appendicitis were evaluated. All 203 patients admitted to our unit between December 1990 and December 1992 were examined physically and sonographically by a team of surgeons consisting of one experienced sonographer and six inexperienced surgical trainees. Laparotomy was performed in 136 patients (46%). Appendicitis was demonstrated histologically in 119 cases (39.4%). Initial clinical findings were positive in 87 (28.8%). Sonography was positive in 119 patients (39.4%). The 163 patients not operated on demonstrated other pathology on ultrasound in 60 cases (19.9%). The rate of negative laparotomies amounted to 7.2% in our study. Sensitivity and specificity for the sonographic diagnosis were 92% and 95%, respectively. They were only 81% and 80% for physical examination. Overall accuracy was 92% for sonography. Sensitivity and specificity for the inexperienced surgeons were 87% and 93%, respectively, while the experienced surgeon reached values of 97% and 98%, respectively. The results of both groups are comparable with values in the literature, suggesting that ultrasound evaluation of appendicitis is not a diagnostic tool limited to a few experienced sonographers.     

The history of thought concerning the hypothalamus and its functions

Many initial studies related to identification of the boundaries and structural components, nuclei, tracts and interconnections of the hypothalamus, this continues. Early interest also focused on hypothalamic control of somatic activities and autonomie nervous system functions. During the present century chiefly, interest has developed in the hypothalamus and control of water balance, thirst, water retention and loss (diabetes insipidus and polydipsia). Its role in control of metabolism, body weight (obesity), and the regulation of body temperature has attracted the attention of physiologists for many years. Others have studied hypothalamic regulation of sex and reproductive phenomena. The hypothalamus is now attracting much attention because of its production of neuroendocrine secretions and role in control of the endocrine system. Physiologists realized very early that the hypothalamus is involved in emotional expression, in reaction to stress and adaptive adjustments. Its involvement in disease states and resistance thereto and in determining the nature of behavior has now been recognized as a matter of great importance. The origins of all these interests are reviewed.     

精神发育迟滞儿童特殊教育三年随访

采用Ｈ－ＮＴＬＡ量表及婴儿～初中学生社会生活能力量表对太原市一个培智学校４４例精神发育迟滞患儿从１９８９～１９９２年连续４次测查智力，２次测查适应行为。结果显示３年间ＩＱ值变化无显著统计学意义，但视觉联想、概念关系、注意力及视觉识知能力有明显提高。患儿适应行为明显提高。经多元逐步回归分析显示，精神发育迟滞儿童智商的提高和母亲文化程度较高、患儿智力低下程度较轻、母亲职业为科技或行政管理人员、患儿初始教育年龄早呈正相关。     

多层螺旋CT与选择性冠状动脉造影对照研究及其临床应用

目的 评价冠状动脉多层螺旋CT血管造影(MSCTA)的临床应用价值。方法 25例患者均行冠状动脉MSCTA与选择性冠状动脉造影(SCA)，分析右冠状动脉、左冠状动脉主干、前降支和回旋支的通畅性，狭窄发生的部位和严重程度。将MSCTA与SCA结果对照，初步评价MSCTA的临床应用价值。结果 71支MSCTA显示无狭窄的冠状动脉支中，68支与SCA一致；29支显示狭窄的动脉支中，19支与SCA一致。其阴性预测值和阳性预测值分别为95．8％和65．5％；敏感度、特异度和准确度分别为86．4％、87．2％、87，0％。结论 MSCTA作为微创性检查，是评价冠状动脉病变和变异的重要的筛选手段。     

Association and linkage with quantitative traits

This paper examines two approaches for the analysis of quantitative traits: (1) association studies and (2) linkage studies. The trait studied was Q1 from simulated Problem 2 data set in Genetic Analysis Workshop 9. Our purpose was to evaluate associations present in the data, to identify nongenetic and genetic predictors of the trait, and to explore the simulated genome for linkage. Through the association study, we found evidence for the primary major gene associated with this trait. The linkage study found evidence of residual genetic effect acting through other traits. Adjustments of Q1 for Q2 and Q3 led to a failure to find significant effects of MG2 and MG3. This supports the suggestion that adjustment for genetically influenced traits for effects of other genetic traits can reduce the power to detect major gene effects. In summary, we detected the major gene directly associated with the trait of interest through association studies. Linkage analysis detected evidence for two other genes associated to a lesser degree with the trait. © 1995 Wiley-Liss, Inc.     

强迫症的自尊和自我和谐研究

目的:对门诊强迫症患者的自尊和自我和谐状况进行研究.方法:对52例符合CCMD-3诊断标准的门诊强迫症患者进行一般资料,MAUDSLEY强迫问卷(MOCI),耶鲁布郎强迫量表(Y-BOCS),社会功能缺陷筛选量表(SDSS),主观幸福感阶梯量表(Subjective well-being,SWB),自尊量表(Self-esteem),自我和谐量表(Self consistency and congruence scale,SCCS)评定,并与正常人作对照.结果:(1)强迫症患者的不和谐性(51.40±9.02)、自尊水平(23.67±4.81)高于对照组(35.64±6.91,18.12±5.88)(t=10.008及5.728,P<0.01).(2)主观幸福感与自尊,不和谐性与自尊相关(r=0.580,0.387,P<0.01).结论:强迫症患者的自我和谐性差、自尊水平高可能是疾病的病理基础.     

4409名学生心理健康状况及家庭环境与吸烟行为分析

目的:探讨中学生心理行为特征和心理健康状况及家庭心理环境与中学生吸烟行为的关系.方法:以苏州市4409名初中、高中、职业中学的学生为对象,采用SCL-90、家庭环境量表和自编问题进行问卷调查.结果:反叛性、冒险性强,倾向早熟、毅力差、顺从敏感性高是吸烟的危险因素,而情感调节性和认同敏感性与吸烟无关;吸烟组与对照组SCL-90在总分、阳性项目数、躯体化、强迫症状、人际关系敏感、抑郁、焦虑、敌对、恐怖、偏执、精神病性方面的评分均高于对照组,且有统计学意义(P＜0.01);吸烟组在FES-CV中的亲密度、情感表达、知识性、道德宗教观、组织性平均分明显低于对照组(P＜0.01),而在FES-CV的矛盾性的平均分则明显高于对照组(P＜0.01).结论:中学生行为的反叛性、冒险性、早熟性、毅力性和不良心理健康水平是中学生吸烟的危险因素;同时不良家庭关系也是中学生吸烟的危险因素,一个亲密、融洽的家庭环境可能会减少中学生吸烟,而一个矛盾的家庭则可能会增加中学生吸烟.     

Mammographic screening: case-control studies.

BACKGROUND: The case-control design can be used to evaluate the benefit of cancer screening programmes. MATERIALS AND METHODS: This paper outlines the main methodological features of the case-control design in this context, and indicates some potential biases. It also reviews the existing case-control literature on mammographic screening. RESULTS: Case-control studies consistently indicate a reduction of approximately 50% in breast cancer mortality associated with mammography. This result indicates greater benefit than shown in randomised trials; however, one should recognise that trials indicate effectiveness whereas case-control studies indicate efficacy. The two types of evidence are broadly compatible when one allows for screening non-compliance and contamination in the randomised trials. CONCLUSIONS: The case-control evidence supports and is consistent with the findings of randomised trials of mammography. Effectiveness estimates from trials indicate the benefit of screening to the population as a whole, and are pertinent to the public policy debate as to the value of offering screening. In contrast, case-control studies indicate benefit to actual screening participants. As such, case-control estimates of efficacy are appropriate for individual decision-making by women about their use of mammography when it is potentially available to them.