Psychoactive medication use, sensori-motor function and falls in older women.

1. A 1 year prospective study was undertaken to identify possible mediating physiological mechanisms for the association between psychoactive medication use and falls in 414 women aged 65 to 99 years (mean age 73.7 years, s.d. = 6.3) who were randomly selected from the community. 2. Women taking certain psychoactive medications showed impaired performance in a number of sensori-motor measures, including tactile sensitivity, lower limb muscle strength, reaction time and balance control compared with women not taking these medications. Those using psychoactive medications were also comparatively inactive--taking part in only 1.1 h of planned exercise per week compared with 2.6 h for non-users (F = 12.44, df = 1,412, P < 0.01). 3. Multiple logistic regression analysis revealed that use of long-acting benzodiazepines (OR = 7.03, 95% CI = 2.12-23.28) and antidepressants (OR = 2.84, 95% CI = 1.00-8.02) was significantly associated with multiple falls, whilst adjusting for age, other drug category use, frequency of alcohol use, and number of medical conditions. Use of any two psychoactive medications was also significantly associated with falling frequency (Chi-square = 13.91, df = 1, P < 0.01). 4. Path analysis revealed a significant direct association (P < 0.001) between psychoactive medication use and falls, and a significant indirect association mediated via reduced physiological functioning (P < 0.001). Postural hypotension was not significantly associated with falls (RR = 1.37, 95% CI = 0.84-2.22). 5. The findings suggest that psychoactive medication use may predispose older people to falling by impairing important sensori-motor systems that contribute to postural stability.     

QUADAS评价:一种用于诊断性研究的质量评价工具(修订版)

背景 QUADAS是一种新近发展起来的诊断性研究的质量评价工具。虽然已有系统评价采用了QUADAS,但尚未得以正式确证。本研究的目的是评价QUADAS的有效性和实用性。方法3位评价者采用QUADAS独立评价30项研究的质量。比较每位评价者的评分与最终结论之间的意见一致度。这主要是通过比较所有QUADAS条目的总分和每个单项的得分来实现的。20位曾在其系统评价中使用过QUADAS的评价者就其使用经验完成一份简短的问卷。结果就所有条目而言,每位评价者的评分与最终结论之间的意见一致度分别达到了91%、90%和85%。就单项QUADAS条目而言,一致度在50%至100%之间,中位值是90%。与难以解释的试验结果和退出病例相关的条目,评分结果差异最大。有关QUADAS内容的反馈意见普遍较好,仅少数评价者提出了有关QUADAS涵盖面、使用便利性、评分说明的清晰度及有效性方面的问题。结论QUADAS内容本身无需作大的修改。评价过程的主要困难出现在难以解释的试验结果和退出病例这2个条目的评分上。对这些条目的评分指南提出了修改意见。评价者必需根据其系统评价制定相应的评分指南,并确保所有评价者都清楚如何评分。评价者还应考虑是否所有的QUADAS条目都与其系统评价相关,以及其他质量条目是否应作为其系统评价的评价部分。     

Iron, ascorbate and copper status of Sowetan Blacks with calcific chronic pancreatitis

Vitamin C can be used to overcome oxidative stress and ease pain in chronic pancreatitis. But its use is deprecated in conditions of tissue iron overload, because its bioactive form, ascorbate, can accelerate free-radical reactions that are driven by transition metals. We measured iron, ascorbate and copper in Sowetan Blacks (RSA) with chronic pancreatitis, obtaining serum/plasma from 14 consecutive patients and 15 controls. Compared with data from corresponding groups in Manchester, African samples had less ascorbate (p < 0.0001), but more caeruloplasmin (p < 0.0001). African and British controls had comparable iron and iron-binding capacity. Plasma from African patients had less ascorbate than that from African controls (p < 0.005) and in six samples, ferritin exceeded 300 micrograms/l (677 pmol/l). Low- molecular-mass iron or copper, capable of participating in free radical reactions, was not detected. British patients, had similar caeruloplasmin levels to African patients but higher ascorbate levels. There is no evidence of iron overload in our African samples. Outwardly healthy controls from Soweto have elevated levels of caeruloplasmin, possibly to compensate for dietary deficiency of ascorbate. Persistent oxidative stress is a unifying feature of chronic pancreatitis, but its degree is higher in African than British patients. Supplements of vitamin C should be safe in Blacks of southern Africa.