van Dijk D, Aufdemkampe G, van Langeveld S
Center Hospital Apeldoorn, The Netherlands.
Spinal Cord. 1999 Feb;37(2):123-8. doi: 10.1038/sj.sc.3100800.
The main purpose of this study was to determine the accuracy and reliability of the Queen Alexandra Pressure Measurement System (QA PMS). Furthermore, we examined whether there were significant differences in measured pressures of the buttock area during sitting between normal subjects and spinal cord injured (SCI) patients.
Accuracy (calibration) and reliability (test-retest) study.
The spinal cord unit of Tertiary Care Centre 'De Hoogstraat' in Utrecht, The Netherlands.
A convenience sample of 16 SCI patients and 15 normal subjects.
The accuracy was determined by using the Standard Error of the Mean (SEM, in mmHg). The Technical Error of Measurement (TEM, in mmHg) was calculated as measure for differences between two paired measurements. The reliability was determined by using an Intraclass Correlation Coefficient (ICC). Significant differences in measured pressures between both groups (P<0.05) were determined by using an unpaired (two sample) t-test.
Accuracy (calibration): mean SEM=0.30 (+/-0.1) mmHg, indicating a high level of accuracy. Differences between two paired measurements: mean TEM calibration= 1.87 (+/-0.76) mmHg; mean TEM normal subjects=4.76 (+/-1.78) mmHg; mean TEM SCI patients=6.34 (+/-2.19) mmHg. Reliability: mean ICC(3,1) calibration=0.85 (95% CI=0.74 0.95); mean ICC(2.1) normal subjects=0.92 (95% CI=0.90 0.94); mean ICC(2.1) SCI patients=0.90 (95% CI=0.88 0.92). The normal subjects had significantly higher mean pressures (P=0.028) than the SCI patients (mean pressures 31.0 vs 28.5 mmHg), whilst the SCI patients had significantly higher peak-pressures (P=0.0000) than the normal subjects (mean peak-pressures: 134.1 vs 75.7 mmHg).
The QA Pressure Measurement System has sufficient accuracy and good reliability as a measurement procedure. There are significant differences between the measured pressures of both groups: the significantly higher peak pressures of the SCI patients seem to be the most important.
本研究的主要目的是确定亚历山德拉女王压力测量系统（QA PMS）的准确性和可靠性。此外，我们还研究了正常受试者和脊髓损伤（SCI）患者在坐姿时臀部区域测量压力是否存在显著差异。
准确性（校准）和可靠性（重测）研究。
荷兰乌得勒支三级护理中心“De Hoogstraat”的脊髓科。
16例SCI患者和15名正常受试者的便利样本。
准确性通过使用平均标准误差（SEM，单位为mmHg）来确定。测量技术误差（TEM，单位为mmHg）作为两次配对测量之间差异的指标进行计算。可靠性通过使用组内相关系数（ICC）来确定。两组之间测量压力的显著差异（P<0.05）通过使用非配对（两样本）t检验来确定。
准确性（校准）：平均SEM = 0.30（±0.1）mmHg，表明准确性较高。两次配对测量之间的差异：平均TEM校准 = 1.87（±0.76）mmHg；正常受试者平均TEM = 4.76（±1.78）mmHg；SCI患者平均TEM = 6.34（±2.19）mmHg。可靠性：平均ICC(3,1)校准 = 0.85（95%CI = 0.74至0.95）；正常受试者平均ICC(2.1) = 0.92（95%CI = 0.90至0.94）；SCI患者平均ICC(2.1) = 0.90（95%CI = 0.88至0.92）。正常受试者的平均压力（P = 0.028）显著高于SCI患者（平均压力分别为31.0和28.5 mmHg），而SCI患者的峰值压力（P = 0.0000）显著高于正常受试者（平均峰值压力：134.1和75.7 mmHg）。
QA压力测量系统作为一种测量方法具有足够的准确性和良好的可靠性。两组测量压力之间存在显著差异：SCI患者显著更高的峰值压力似乎最为重要。
