Nicholas J J, Taylor F H, Buckingham R B, Ottonello D
Ann Rheum Dis. 1976 Jun;35(3):282-4. doi: 10.1136/ard.35.3.282.
The circumference of the knees and thighs at three locations was measured in 10 patients on two consecutive occasions by three observers. Analysis of the results for interobserver, intraobserver and among-patient variation established that a change in circumference noted by different observers on two different days is significant if it exceeds 1-5 cm at the midpatella, 2-7 cm at 7 cm above, and 3-5 cm at 15 cm above the patella. If a single observer performs both measurements, the change need exceed only 1-0, 2-0, and 2-7 cm, respectively, to be significant.
三名观察者在两个连续的时间点对10名患者的膝盖和大腿三个部位的周长进行了测量。对观察者间、观察者内和患者间变异的结果分析表明，如果不同观察者在两个不同日期记录的周长变化在髌骨中部超过1.5厘米、髌骨上方7厘米处超过2.7厘米、髌骨上方15厘米处超过3.5厘米，则该变化具有显著性。如果由一名观察者进行两次测量，那么变化分别只需超过1.0厘米、2.0厘米和2.7厘米就具有显著性。
