Abstract：
BACKGROUND: The existing research data are still not able to provide an answer to the issue of the correlation between dyspnea and inflammation in stable chronic obstructive pulmonary disease (COPD). The purpose of this study was to assess the possible relationship between a noninvasive medium called the exhaled breath condensate (EBC) and dyspnea in stable COPD patients.
METHODS: A group of ten patients (five with and five without COPD) participated. The exhaled breath condensate was analyzed for the first time with a high-resolution device, the Accusizer 780SIS. The particle concentration of the EBC was measured and correlated with tools used for dyspnea assessment and clinical picture (modified Research Council dyspnea scale, mMRC scale; modified Borg dyspnea scale; and COPD Assessment Test, CAT scale). Because of the very small sample size (Ν = 10), bootstrapping method (applying 5000 bootstrap resamples with 95% confidence intervals) was used to derive robust estimates of standard errors and confidence intervals for estimates of means and correlation coefficients. Bootstrap works well in small sample sizes by ensuring the correctness of tests.
RESULTS: The bootstrap means of EBC, mMRC, Borg, and CAT scales were 223863.43 (95% CI, 151308.58-297603.04), 1.30 (95% CI, 0.70-1.90), 1.55 (95% CI, 0.55-2.80), and 6.70 (95% CI, 4.80-8.60), respectively. The bootstrap Pearson\'s correlation coefficient (r) of EBC, mMRC, Borg, and CAT scales were 0.889 (95% CI, 0.716-0.979), 0.641 (95% CI, -0.542-0.887), and 0.569 (95% CI, -0.184-0.912), respectively.
CONCLUSIONS: The effect size of the correlations is significantly high at the 0.01 level (two-tailed) between the EBC and the mMRC scale, less high at the 0.05 level (two-tailed) between the EBC and the Borg dyspnea scale and marginally with the CAT scale, respectively. Studies with larger samples will be needed to obtain more reliable results.
METHODS: A group of ten patients (five with and five without COPD) participated. The exhaled breath condensate was analyzed for the first time with a high-resolution device, the Accusizer 780SIS. The particle concentration of the EBC was measured and correlated with tools used for dyspnea assessment and clinical picture (modified Research Council dyspnea scale, mMRC scale; modified Borg dyspnea scale; and COPD Assessment Test, CAT scale). Because of the very small sample size (Ν = 10), bootstrapping method (applying 5000 bootstrap resamples with 95% confidence intervals) was used to derive robust estimates of standard errors and confidence intervals for estimates of means and correlation coefficients. Bootstrap works well in small sample sizes by ensuring the correctness of tests.
RESULTS: The bootstrap means of EBC, mMRC, Borg, and CAT scales were 223863.43 (95% CI, 151308.58-297603.04), 1.30 (95% CI, 0.70-1.90), 1.55 (95% CI, 0.55-2.80), and 6.70 (95% CI, 4.80-8.60), respectively. The bootstrap Pearson\'s correlation coefficient (r) of EBC, mMRC, Borg, and CAT scales were 0.889 (95% CI, 0.716-0.979), 0.641 (95% CI, -0.542-0.887), and 0.569 (95% CI, -0.184-0.912), respectively.
CONCLUSIONS: The effect size of the correlations is significantly high at the 0.01 level (two-tailed) between the EBC and the mMRC scale, less high at the 0.05 level (two-tailed) between the EBC and the Borg dyspnea scale and marginally with the CAT scale, respectively. Studies with larger samples will be needed to obtain more reliable results.
摘要：
背景：现有的研究数据仍然无法为稳定期慢性阻塞性肺疾病（COPD）中呼吸困难与炎症之间的相关性问题提供答案。这项研究的目的是评估一种称为呼出气冷凝液（EBC）的无创介质与稳定期COPD患者呼吸困难之间的可能关系。
方法：一组10例患者（5例有COPD，5例无COPD）参加。首次用高分辨率装置分析了呼出的气体冷凝液,Accusizer780SIS.测量EBC的颗粒浓度，并与用于呼吸困难评估和临床表现的工具相关（修改的ResearchCouncil呼吸困难量表，mMRC量表;改良Borg呼吸困难量表;COPD评估测试,CAT量表)。由于样本量非常小(N=10)，使用自举方法(应用5,000次自举再采样,置信区间为95%)得出均值和相关系数估计值的标准误差和置信区间的稳健估计值.通过确保测试的正确性，Bootstrap在小样本量下运行良好。
结果：EBC的引导手段，mMRC,博格,CAT量表为223863.43(95%CI，151308.58-297603.04)，1.30（95%CI，0.70-1.90），1.55（95%CI，0.55-2.80），和6.70（95%CI，4.80-8.60），分别。EBC的自举皮尔森相关系数(r)，mMRC,博格,CAT量表为0.889（95%CI，0.716-0.979），0.641（95%CI，-0.542-0.887），和0.569（95%CI，-0.184-0.912），分别。
结论：在EBC和mMRC量表之间的0.01水平（双尾），相关性的效应大小显着高，在EBC和Borg呼吸困难量表之间的0.05水平（双尾）较低，而在CAT量表中的水平较低，分别。需要进行更大样本的研究才能获得更可靠的结果。
方法：一组10例患者（5例有COPD，5例无COPD）参加。首次用高分辨率装置分析了呼出的气体冷凝液,Accusizer780SIS.测量EBC的颗粒浓度，并与用于呼吸困难评估和临床表现的工具相关（修改的ResearchCouncil呼吸困难量表，mMRC量表;改良Borg呼吸困难量表;COPD评估测试,CAT量表)。由于样本量非常小(N=10)，使用自举方法(应用5,000次自举再采样,置信区间为95%)得出均值和相关系数估计值的标准误差和置信区间的稳健估计值.通过确保测试的正确性，Bootstrap在小样本量下运行良好。
结果：EBC的引导手段，mMRC,博格,CAT量表为223863.43(95%CI，151308.58-297603.04)，1.30（95%CI，0.70-1.90），1.55（95%CI，0.55-2.80），和6.70（95%CI，4.80-8.60），分别。EBC的自举皮尔森相关系数(r)，mMRC,博格,CAT量表为0.889（95%CI，0.716-0.979），0.641（95%CI，-0.542-0.887），和0.569（95%CI，-0.184-0.912），分别。
结论：在EBC和mMRC量表之间的0.01水平（双尾），相关性的效应大小显着高，在EBC和Borg呼吸困难量表之间的0.05水平（双尾）较低，而在CAT量表中的水平较低，分别。需要进行更大样本的研究才能获得更可靠的结果。
