Cooke J, Carew S, O'Connor M, Costelloe A, Sheehy T, Lyons D
Clinical Age Assessment Unit, Mid-Western Regional Hospital, Dooradoyle, Limerick, Ireland.
QJM. 2009 May;102(5):335-9. doi: 10.1093/qjmed/hcp020. Epub 2009 Mar 9.
Orthostatic hypotension (OH) is associated with troublesome symptoms and increased mortality. It is treatable and deserving of accurate diagnosis. This can be time consuming. The current reference standard for its diagnosis is head-up tilt (HUT) testing with continuous beat-to-beat plethysmography. Our objective was to assess the accuracy of sit-stand testing with semi-automatic sphygmomanometry for the diagnosis of OH.
Retrospective test of diagnostic accuracy.
This was a retrospective study performed using a database maintained by a busy syncope unit. HUT testing was performed using an automated tilt table with Finometer monitoring. A 3 min 70 degrees HUT was performed following 5 min supine. Sitting blood pressure (BP) was measured following 3 min rest. Standing BP was measured within 30 s of assuming the upright posture. The results of sit-stand testing were compared with HUT testing as a reference standard. Both tests happened within 5 min of each other and patients underwent no intervention between tests.
From a total of 1452 consecutive HUTs, we identified 730 with pre-test measures of sitting and standing BP. The mean age of this group was 70.57 years (SD = 15.1), 62% were female. The sensitivity of sit-stand testing was calculated as 15.5%, specificity as 89.9%, positive predictive value as 61.7%, negative predictive value as 50.2% and the likelihood ratio as 1.6. The area under the Receiver Operator Curve was 0.564.
We have demonstrated that sit-stand testing for OH has very low diagnostic accuracy. We recommend that the more time-consuming reference standard method of diagnosis be used if the condition is suspected.
直立性低血压（OH）与令人困扰的症状及死亡率增加相关。它是可治疗的，值得进行准确诊断。这可能会很耗时。目前其诊断的参考标准是采用连续逐搏体积描记法的头高位倾斜（HUT）试验。我们的目的是评估使用半自动血压计进行坐立试验对OH诊断的准确性。
诊断准确性的回顾性试验。
这是一项利用繁忙晕厥单元维护的数据库进行的回顾性研究。使用配备Finometer监测的自动倾斜台进行HUT试验。仰卧5分钟后进行3分钟70度的HUT试验。休息3分钟后测量坐位血压（BP）。在采取直立姿势后30秒内测量站立位BP。将坐立试验结果与作为参考标准的HUT试验结果进行比较。两项试验在彼此5分钟内进行，且患者在两次试验之间未接受任何干预。
在总共1452次连续的HUT试验中，我们确定了730例有坐位和站立位BP预测试量值的患者。该组患者的平均年龄为70.57岁（标准差=15.1），62%为女性。坐立试验的敏感性计算为15.5%，特异性为89.9%，阳性预测值为61.7%，阴性预测值为50.2%，似然比为1.6。受试者操作特征曲线下面积为0.564。
我们已证明坐立试验对OH的诊断准确性非常低。我们建议，如果怀疑患有该疾病，应采用耗时更长的参考标准诊断方法。
