鼻咽癌病因学的病例—对照研究

本文以病例—对照的方法探讨了在黑龙江省与鼻咽癌发生有关的危险因素。调查鼻咽癌病例及对照共127对。在单因素与条件Logistic回归分析中均表明幼儿期食咸鱼(OR=5.5, χ²=4.92, P<0.05)及长期生活在烧煤的环境中(OR=1.894, χ²=4.655, P<0.05)可能与鼻咽癌的发生有关。此外,条件Logistic回归分析还发现,鼻窦炎病史也可能与鼻咽癌的发生有联系(B=1.385, exp(B)=3,995, P<0.1)。在对病例及对照的一级亲属患恶性肿瘤情况的调查中发现,鼻咽癌病例组有肿瘤家族史者多于对照组,其差异有统计学意义(χ²=10.32, P<0.01)。     

Evaluating risk factors associated with severe hypoglycaemia in epidemiology studies—what method should we use?

AIMS: To determine the most appropriate regression models to use when assessing risk factors for severe hypoglycaemia and to investigate the impact of model misspecification and its clinical implications. METHODS: A total of 1229 children with Type 1 diabetes (mean age 11.7 years sd 4.1), of which 605 (49.2%) were males, were studied. Prospective assessment of severe hypoglycaemia (an event leading to loss of consciousness or seizure) was made over the 9-year period, 1992-2001. Patients were seen every 3 months and episodes of hypoglycaemia along with clinical data were recorded. Over 70% of children never experienced a severe hypoglycaemic event. Data were analysed using the Poisson regression, negative binomial, zero-inflated Poisson (ZIP) and zero-inflated negative binomial (ZINB) models. The over-dispersion and likelihood ratio statistics were calculated and the analytical methods compared. RESULTS: The Poisson regression model did not fit the data well. The negative binomial and the zero inflated Poisson and negative binomial models fitted the data better than Poisson. CONCLUSIONS: The commonly used Poisson regression models to analyse hypoglycaemia epidemiology may lead to biased parameter estimates and incorrect determination of risk factors for hypoglycaemia. We recommend the use of the negative binomial or zero inflated models to examine any risk factors associated with severe hypoglycaemia. Careful consideration must be given to the interpretation of hypoglycaemia surveys and their analysis.     

增龄过程中心脏径限的变化及其影响因素

为探讨年龄增长及伴随的一些生理性变化对心脏径限的影响,对300余例20—81岁(平均46±16岁)的正常成人进行了超声心动图研究。多元逐步回归及协方差分析表明,左室壁厚度随年龄俱增,而左室舒张未期内径变化不大;室间隔/左室后壁厚度比值亦渐有增长,反映了室间隔的随龄增长稍快于左室后壁,故在增龄过程中,左室流出道稍有缩小;左房、主动脉根部和右室内径均有随年龄而增长的变化。二尖瓣舒张期 EF 斜率随年龄增长渐有下降,可能反映了左室顺应性的降低及二尖瓣弹性的减退。此外,一些心脏测值有性别差异,不少径限尚与体格大小或血压水平有相关关系。对于不同年龄组间心脏径限差异的原因,以及心脏径限彼此间的关系进行了分析和讨论,认为在临床上评价心脏径限正常与否和异常程度时,应考虑年龄、性别、体格大小、血压等因素的影响。     

武汉市人口死亡率季节变动规律的分析

本文运用百分率趋势检验和逐步回归等统计方法,测定和分析了武汉市江岸区居民死亡的季节变动规律。结果表明:月死亡、心血管病和呼吸系病死亡都有明显的冬季高峰,意外死亡多半在夏季;婴幼儿和老年人死亡的季节波动性较大;心脏病、呼吸系病在寒冷月份上升成为第二、第四位死因;逐步回归分析的结果表明:温度是对死亡影响较大的气象因素,肿瘤死亡与季节变化的关系不大。     

Moorfields回归分析及多变量区别分析诊断开角型青光眼

目的研究Moorfields回归分析(MRA)及多变量区别分析(MDA)的2个指标FSM和RB诊断开角型青光眼的能力,及MRA在视盘整体和视盘分区间的差异。方法对23例正常人(26眼)、26例可疑开角型青光眼患者(32眼)和21例开角型青光眼患者(21眼)进行HRT-Ⅱ和OCTOPUS视野计G2-TOP程序两项检查。结果视盘整体MRA、FSM、RB与视野缺损指数间相关系数分别为0.537、-0.565、-0.716(P<0.01),且3个组间差异均有统计学意义(P<0.01),随着视盘面积增大,MRA、FSM和RB特异性均下降。可疑组中视盘分区MRA与视野检查一致率均高于整体,一致率最高分区为颞下(78.13%)。各分区中MRA敏感性、特异性最高的分区为颞上和颞下。结论MRA和MDA检测开角型青光眼能力较强,且与视野检查间存在较好的相关性,但应用于大视盘分析时须谨慎下结论。     

急性重症肝炎患者发生肝性脑病危险因素多元Logistic回归研究

目的探索急性重症肝炎患者发生肝性脑病的危险因素，以便进行早期干预。方法收集血浆凝血酶原时间（PT）延长，活动度〈40％的急性重症肝炎患者69例，对69例患者的年龄、性别和基础疾病等临床背景资料和总胆红素、直接胆红素、谷草转氨酶（AST）、谷丙转氨酶（ALT）、血浆白蛋白、胆碱脂酶、血浆凝血酶原时间（PT）、白细胞计数（WBC）、血小板计数（Plt）等实验室检查数据进行单因素分析和多元Logistic回归分析。结果单因素分析和多元Logistic回归分析均提示年龄、血胆红素水平和血浆凝血酶原时间在肝性脑病组和非肝性脑病组之间有统计学差异。结论约30％的急性重症肝炎患者发展成为肝性脑病。高龄、血浆凝血酶原时间延长、活动度下降、高血浆总胆红素等是急性重症肝炎患者发展成为肝性脑病的潜在危险因素。     

艺术嗓音歌声客观评价初探

目的探讨客观评价艺术嗓音歌声的方法。方法对48名声乐专业青年大学生录制专业训练歌声信号,提取歌声平均能量、频率误差、音域误差作为评价参数,使用神经网络方法和多元线性回归方法客观评价歌声质量,并与资深专业教师的主观评价进行比较。结果客观评价歌声质量的方法中,神经网络方法误差在4%之内,而线性回归方法误差在6%之内,前者较优。结论神经网络方法利用评价参数能正确客观评价歌声质量,有助于科学地指导选拔和训练艺术嗓音人才。     

多分类有序反应变量logistic回归应用条件的检验

目的 对多分类有序反应变量logistic回归的应用条件寻求科学合理的检验方法。方法 使用卡方分布的理论，SAS软件及抽样调查方法。结果 设计出多分类有序反应变量logistic回归应用条件的卡方检验方法，推导出反应变量取各水平的概率计算公式及卡方检验中理论值、自由度的计算公式，并在作者主持的国家医师资格临床实践技能考试研究中取得了成功效果。结论 多分类有序反应变量logistic回归得到完善和补充，具有较大的理论和实际意义。     

A simplified statistical method for local INR using linear regression

A simplified method of International Normalized Ratio (INR) derivation using linear regression of certified INR plotted against local prothrombin time (PT) results has been compared with INR from conventional orthogonal regression. Linear regression assumes error only with the local PT results whereas orthogonal regression assumes error with both reference and local results. The reliability of local INR derivation using lyophilized plasmas has been assessed in a collaborative study. INR from conventional fresh plasma International Sensitivity Index (ISI) calibrations have been compared with INR from calibrations with two types of lyophilized plasma, artificially depleted and coumarin.
Although calibration slopes differed with the two types of analysis and the different lyophilized plasmas, both gave reasonable approximations to fresh plasma ISI calibrations. With orthogonal regression the overall percentage INR deviation was 5.25% with the artificially depleted plasmas and 6.85% for the results with lyophilized coumarins. With the linear regression, deviation was 8.40% for the artificially depleted plasmas and 5.05% for coumarin-treated patients' lyophilized plasmas. The simpler regression method appears to be worthy of further study as the present report has demonstrated that if the calibrant plasmas are accurately certified with the thromboplastin International Reference Plasma (IRP) results approximate to the conventionally determined INR using the manual PT technique. Coagulometers require further assessment.     

农村地区高血压危险因素的病例对照研究

对四川省农村地区218例原发性高血压(其中包括109例临界高血压)进行配对(1:2)病例对照研究。资料分析采用了条件Logistic回归分析方法。研究结果提示心率、高血压家族史、环境噪声、体重指数(QI)等综合因素与临界高血压和确诊高血压均有显著的联系。心率、体重指数(QI)以及高血压家族史是原发性高血压较稳定的影响因素,心率可作为研究血压的必测指标。环境因素对原发性高血压的影响不可忽视。原发性高血压是遗传因素、环境因素等综合作用的结果。