Schünemann Holger J, Griffith Lauren, Jaeschke Roman, Goldstein Roger, Stubbing David, Guyatt Gordon H
Department of Medicine, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, 462 Grider Street, Buffalo, NY 14215, USA.
J Clin Epidemiol. 2003 Dec;56(12):1170-6. doi: 10.1016/s0895-4356(03)00115-x.
BACKGROUND/OBJECTIVES: The chronic respiratory questionnaire (CRQ), the St. Georges Respiratory Questionnaire (SGRQ), and the feeling thermometer (FT) evaluate change in health-related quality of life (HRQL) in patients with chronic airflow limitation (CAL). Although the interpretability, and in particular the minimal important difference (MID) in score changes, is well established for the CRQ, this is not the case for the SGRQ and FT. The objective of our study is to explore the interpretation of the SGRQ and FT.
We analyzed data from 84 patients who completed the CRQ, SGRQ, and FT before beginning pulmonary rehabilitation and 3 months later. We calculated correlations between the four CRQ domains (dyspnea, fatigue, emotional function, and mastery) and the three SGRQ domains (symptoms, activities, and impact), the SGRQ total score, and the FT. When Pearson's correlations were >/=0.5, we constructed regression equations and used the slope to calculate the change in SGRQ and FT score that corresponded to a change in CRQ score of 0.5 (the MID). Having established MID for SGRQ we than used a similar approach to examine the relation between the SGRQ and FT results.
Comparison with the CRQ dyspnea domain suggested the MID in SGRQ total score is approximately 3.05 with a 95% confidence interval (95% CI) ranging from 0.39 to 5.71 and a change of 5.67 (95% CI 3.43-7.92) represents a moderate change (1.0 on the CRQ dyspnea domain). The MID for the FT based on the CRQ fatigue domain was 6.1 (95% CI 1.87-10.28). The FT MID based on the SGRQ activities domain, impacts domain, and total score were, respectively, 7.4 (95% CI 3.44-11.35), 5.6 (95% CI 1.6-9.64), and 5.9 (95% CI 1.97-9.78).
An MID for the SGRQ approximates the previously suggested estimate of 4 on a scale of 0 to 100. The MID for the FT in patients with CAL is approximately 5 to 8 units on the 0 to 100 scale. These MID estimates should facilitate interpretation of clinical trials in which outcome measures include the SGRQ or FT.
背景/目的：慢性呼吸问卷（CRQ）、圣乔治呼吸问卷（SGRQ）和感觉温度计（FT）用于评估慢性气流受限（CAL）患者健康相关生活质量（HRQL）的变化。虽然CRQ的可解释性，尤其是分数变化的最小重要差异（MID）已得到充分确立，但SGRQ和FT并非如此。我们研究的目的是探讨SGRQ和FT的解释。
我们分析了84例患者的数据，这些患者在开始肺康复前及3个月后完成了CRQ、SGRQ和FT。我们计算了CRQ的四个领域（呼吸困难、疲劳、情绪功能和掌控感）与SGRQ的三个领域（症状、活动和影响）、SGRQ总分以及FT之间的相关性。当Pearson相关性≥0.5时，我们构建回归方程并使用斜率来计算与CRQ分数变化0.5（MID）相对应的SGRQ和FT分数变化。在确定了SGRQ的MID后，我们采用类似方法研究SGRQ与FT结果之间的关系。
与CRQ呼吸困难领域相比，SGRQ总分的MID约为3.05，95%置信区间（95%CI）为0.39至5.71，变化5.67（95%CI 3.43 - 7.92）代表中度变化（CRQ呼吸困难领域为1.0）。基于CRQ疲劳领域的FT的MID为6.1（95%CI 1.87 - 10.28）。基于SGRQ活动领域、影响领域和总分的FT的MID分别为7.4（95%CI 3.44 - 11.35）、5.6（95%CI 1.6 - 9.64）和5.9（95%CI 1.97 - 9.78）。
SGRQ的MID在0至100的量表上接近先前建议的4的估计值。CAL患者中FT的MID在0至100的量表上约为5至8个单位。这些MID估计值应有助于解释以SGRQ或FT作为结局指标的临床试验。
