Cramarossa Gemma, Chen Emily, Khan Luluel, Zhang Liying, Nguyen Janet, Tsao May, Danjoux Cyril, Barnes Elizabeth, Sahgal Arjun, Holden Lori, Jon Flo, Dennis Kristopher, Chow Edward
Rapid Response Radiotherapy Program, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Canada.
World J Oncol. 2011 Dec;2(6):281-288. doi: 10.4021/wjon386w. Epub 2011 Dec 19.
To identify symptom clusters in a subgroup of patients reporting exclusively non-zero Edmonton Symptom Assessment System (ESAS) scores at baseline, and to compare clusters with those identified in the total patient population. Secondary objective was to determine whether symptom clusters in patients with bone metastases vary when extracted using different statistical methods.
An existing dataset compiled from bone metastases patients was used to identify a "non-zero" subgroup of patients reporting severity scores > 0 for all nine ESAS symptoms at baseline. Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA) and Exploratory Factor Analysis (EFA) were performed on the non-zero subgroup to derive symptom clusters at baseline and 1, 2, 4, 8 and 12 weeks following radiation treatment. Symptom clusters in the total patient sample at baseline were also derived using the three statistical methods.
At baseline, different symptom clusters were identified in the non-zero subgroup compared with the total patient population regardless of the statistical method utilized. When comparing clusters derived using different statistical methods, symptom cluster results varied depending on the method employed, with a few exceptions where analogous clusters were derived using two different statistical methods at a specific time point. A complete consensus between all three methods was never observed. Only two ESAS symptoms, anxiety and depression, consistently occurred in the same cluster across different methods and over time.
Compiling data from all eligible consenting patients may not provide an accurate overview of clustering among all the symptoms included in the assessment tool. The quantity and composition of symptom clusters identified varied based on whether patients with zero symptom severity scores were included at baseline and which statistical method was utilized.
在一组基线时埃德蒙顿症状评估系统（ESAS）分数均不为零的患者中识别症状群，并将这些症状群与在全体患者人群中识别出的症状群进行比较。次要目标是确定使用不同统计方法提取骨转移患者的症状群时，症状群是否会有所不同。
使用从骨转移患者中汇编的现有数据集，确定一个“非零”亚组患者，这些患者在基线时所有9项ESAS症状的严重程度评分均>0。对该非零亚组进行主成分分析（PCA）、层次聚类分析（HCA）和探索性因子分析（EFA），以得出基线时以及放射治疗后1、2、4、8和12周的症状群。还使用这三种统计方法得出了基线时全体患者样本中的症状群。
在基线时，无论采用何种统计方法，非零亚组中识别出的症状群与全体患者人群中的症状群均不同。在比较使用不同统计方法得出的症状群时，症状群结果因所采用的方法而异，只有少数例外情况，即在特定时间点使用两种不同统计方法得出了类似的症状群。从未观察到所有三种方法之间完全一致的情况。在不同方法和不同时间，只有两项ESAS症状，即焦虑和抑郁，始终出现在同一症状群中。
汇总所有符合条件且同意参与的患者的数据，可能无法准确概述评估工具中所包含的所有症状之间的聚类情况。根据基线时是否纳入症状严重程度评分为零的患者以及所采用的统计方法，所识别出的症状群的数量和组成会有所不同。
