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571.
BURKE V; BEILIN LJ; GERMAN R; GROSSKOPF S; RITCHIE J; PUDDEY IB; ROGERS P 《QJM : monthly journal of the Association of Physicians》1992,84(1):583-591
In a study of 843 independent-living men and women aged between60 and 87 in Perth, Western Australia, stepwise multiple regression,after correction for initial levels of systolic blood pressure,showed that postural fall in systolic blood pressure was positivelyrelated to alcohol intake of more than 20 ml/day, the use ofsleeping tablets and higher levels of anxiety on the Spielbergerstate-trait scale, and negatively related to body mass index.Postural fall in blood pressure was not significantly relatedto treatment for hypertension, age, sex, patterns of usual physicalactivity, tea or coffee drinking, or the diagnosis of diabetesmellitus. This analysis is the first to examine the relationshipbetween lifestyle factors and the magnitude of the fall in systolicblood pressure on standing after adjustment for the associationbetween the change in a variable and its initial level. Ouranalysis suggests the need for further study of the possiblerole of lifestyle factors such as the use of sleeping tabletsand alcohol in postural hypotension in the elderly. 相似文献
572.
J Vanagaite Vingen LJ Stovner 《Cephalalgia : an international journal of headache》1998,18(6):313-318
Light and sound-induced discomfort and pain thresholds were measured in 26 patients with cervicogenic headache, in 40 patients with tension-type headache, and in 100 headache-free controls. Neither headache group was significantly different as to photophobia and phonophobia, but both were significantly more sensitive to light and sound than controls ( p <0.0001), even when patients were tested in the headache-tree period ( p <0.05). Episodic and chronic tension-type headache had similar photo- and phonophobia thresholds ( p ≥0.7). Tension-type headache patients were more photo- and phonophobic during headache than outside attack ( p <0.05), but this was not true for cervicogenic headache ( p ≥0.56). In cervicogenic headache patients, photophobia ( p <0.05) but not phonophohia ( p =0.28) was greater on the symptomatic side than on the non-symptomatic side. 相似文献
573.
For a two-group comparative study, a stratified inference procedure is routinely used to estimate an overall group contrast to increase the precision of the simple two-sample estimator. Unfortunately, most commonly used methods including the Cochran-Mantel-Haenszel statistic for a binary outcome and the stratified Cox procedure for the event time endpoint do not serve this purpose well. In fact, these procedures may be worse than their two-sample counterparts even when the observed treatment allocations are imbalanced across strata. Various procedures beyond the conventional stratified methods have been proposed to increase the precision of estimation when the naive estimator is consistent. In this paper, we are interested in the case when the treatment allocation proportions vary markedly across strata. We study the stochastic properties of the two-sample naive estimator conditional on the ancillary statistics, the observed treatment allocation proportions and/or the stratum sizes, and present a biased-adjusted estimator. This adjusted estimator is asymptotically equivalent to the augmentation estimators proposed under the unconditional setting. Moreover, this consistent estimation procedure is also equivalent to a rather simple procedure, which estimates the mean response of each treatment group first via a stratum-size weighted average and then constructs the group contrast estimate. This simple procedure is flexible and readily applicable to any target patient population by choosing appropriate stratum weights. All the proposals are illustrated with the data from a cardiovascular clinical trial, whose treatment allocations are imbalanced. 相似文献
574.
575.
不同产地和品种淫羊藿中淫羊藿苷的HPLC分析 总被引:17,自引:0,他引:17
目的 :对中药淫羊藿中淫羊藿苷的含量分析进行方法学研究 ,并测定淫羊藿的不同产地、不同品种、不同药用部位的淫羊藿苷的含量。方法 :采用RP HPLC技术对 7个品种 2 3个样品进行测定。以PERKIN EIMER SH/5C18柱为分析柱 ,流动相为乙腈 水 36%乙酸 ( 2 5∶73.5∶1 .5)流速 1 .0ml/min。UV检测波长 2 70nm。结果 :本方法测定淫羊藿苷含量在 0 .0 2 1 2~ 0 .1 2 7μg ,0 .53~ 1 .696μg范围内呈良好的线性关系。不同产地、不同品种、不同药用部位的淫羊藿其淫羊藿苷的含量为 0 .0 0 30 7%~ 1 .55%。同一植株不同部位中淫羊藿苷的含量分布叶 >叶茎 >茎 >根。结论 :淫羊藿由于产地不同、品种不同其淫羊藿苷的含量相差悬殊。本测定方法为筛选优良品种和扩大药源提供了简便易行的方法 相似文献
576.