Lord P W, Brooks A G, Edwards J M
Thorax. 1977 Feb;32(1):67-70. doi: 10.1136/thx.32.1.67.
Variations in the estimation of airway resistance (Raw) and thoracic gas volume (Vtg) made by different observers using body plethysmography have been investigated. Five observers determined Raw and Vtg in normal subjects using prerecorded signals so that intrasubject variations were eliminated. The slopes of the oscillography tracings required to make the determinations were assessed using a cursor and a scale fitted to the oscilloscope. Significant and consistent differences in Raw determined by different observers were found,with a mean range of 37%. Great care should therefore be taken when comparing results obtained by different observers. The variation between observers measuring Vtg was significant and consistent but of much smaller magnitude than was the case for Raw, having a mean range of 12%.
研究了不同观察者使用体容积描记法对气道阻力（Raw）和肺总量（Vtg）进行估计时的差异。五名观察者使用预先录制的信号测定正常受试者的Raw和Vtg，从而消除个体内部差异。使用光标和示波器上的刻度来评估进行测定所需的示波图描记的斜率。发现不同观察者测定的Raw存在显著且一致的差异，平均差异范围为37%。因此，在比较不同观察者获得的结果时应格外小心。测量Vtg的观察者之间的差异显著且一致，但幅度比Raw的情况小得多，平均差异范围为12%。
