Impact of social support on psychosocial symptoms and quality of life in cancer patients: results of a multilevel model approach from a longitudinal multicenter study

<b>Background:</b> This prospective multicenter study aimed to investigate the courses of positive support (PS) and detrimental interaction (DI), two different aspects of social support, and the relation between social support and psychosocial distress and/or health-related quality of life (HRQOL) in a large sample of patients with different cancers. <b>Methods:</b> For this observational study, we enrolled adult patients with cancer from 13 comprehensive cancer centers (CCCs) in Germany. We included a total of 1087 patients in our analysis. We assessed the outcomes via standardized self-report questionnaires at three measurement points: at admission for acute care (T1), 6 (T2) and 12 months (T3) thereafter. Our outcome variables included PS and DI, depression and anxiety symptoms, distress, mental quality of life (MQoL) and physical QoL (PQoL). Data were analyzed using three-level hierarchical linear modeling (HLM) and group-based trajectory modeling. <b>Results:</b> During the first year after the cancer diagnosis, both PS and DI decreased in our sample. Baseline depression symptom severity was a significant predictor of PS and DI. Further analyses revealed significant associations between PS, DI and the course of depression and anxiety symptoms, and MQoL. PS buffered the negative effects of DI with regards to these variables. Low DI was associated with better PQoL, whereas PS was not. In general, the impact of social support on psychosocial outcomes was weak to moderate. <b>Conclusions:</b> Our findings provide evidence for the influence of PS and DI on psychosocial symptoms and HRQOL, and emphasize the importance of psycho-oncological interventions that strengthen PS and prevent or reduce DI for patients with cancer and their relatives.

**背景：** 本项前瞻性多中心研究旨在探讨社会支持的两个不同维度——积极支持（Positive Support, PS）与不良互动（Detrimental Interaction, DI）的变化轨迹，以及大型不同癌症患者样本中，社会支持与心理社会困扰及/或健康相关生活质量（Health-related Quality of Life, HRQOL）之间的关联。
**方法：** 本项观察性研究纳入了来自德国13家综合癌症中心（Comprehensive Cancer Centers, CCCs）的成年癌症患者，最终分析样本量为1087例。研究在三个时间点采用标准化自报告问卷评估结局指标：急性治疗入院时（T1）、治疗后6个月（T2）及12个月（T3）。本次研究的结局指标涵盖积极支持、不良互动、抑郁与焦虑症状、心理困扰、心理生活质量（Mental Quality of Life, MQoL）以及躯体生活质量（Physical QoL, PQoL）。数据分析采用三水平分层线性模型（Hierarchical Linear Modeling, HLM）与基于群体的轨迹建模。
**结果：** 在癌症确诊后的首年内，本研究样本的积极支持与不良互动水平均呈下降趋势。基线抑郁症状严重程度是积极支持与不良互动的显著预测因子。进一步分析显示，积极支持、不良互动与抑郁、焦虑症状及心理生活质量的变化轨迹存在显著关联。积极支持可缓冲不良互动对上述变量的负面影响。较低的不良互动水平与更佳的躯体生活质量相关，而积极支持则无此关联。总体而言，社会支持对心理社会结局的影响程度为弱至中等。
**结论：** 本研究结果证实了积极支持与不良互动对癌症患者心理社会症状及健康相关生活质量的影响，并强调了强化积极支持、预防或减轻不良互动的心理肿瘤学（psycho-oncological）干预措施，对于癌症患者及其家属的重要意义。