S1 Data -

Background and objectives
Cognitive impairment is common in haemodialysis patients and associated with adverse health outcomes. This may be due to cognitive impairments interfering with daily functioning and self-care, but evidence is limited. This cross-sectional study aims to explore the interrelationships between cognition and functional outcomes in haemodialysis patients.
Methods
Haemodialysis patients completed measures of objective cognitive function (Montreal Cognitive Assessment), everyday problem-solving skills (scenario-based task), and subjective cognitive complaints (self-report). Participants also self-reported sociodemographic information, functional interference, treatment nonadherence, and mood and fatigue symptoms. Patients’ clinical data including comorbidities and lab results were extracted from medical record. Structural equation modelling was performed.
Results
A total of 268 haemodialysis patients (mean age = 59.87 years; 42.5% female) participated. The final model showed satisfactory fit: CFI = 0.916, TLI = 0.905, RMSEA = 0.033 (90% confidence interval 0.024 to 0.041), SRMR = 0.066, χ2(493) = 618.573 (p < .001). There was a negative association between objective cognitive function and subjective cognitive complaints. Cognitive complaints were positively associated with both functional interference and treatment nonadherence, whereas objective performance was not. Everyday problem-solving skills emerged as a distinct aspect of cognition not associated with objective performance or subjective complaints, but had additive utility in predicting functional interference.
Conclusions
Subjective cognitive complaints and everyday problem-solving skills appear to be stronger predictors of functional variables compared to objective performance based on traditional tests. Routine screening of everyday cognitive difficulties may allow for early identification of dialysis patients at risk of cognitive impairment, functional interference, treatment nonadherence, and poor clinical outcomes.

研究背景与研究目的
认知功能障碍在血液透析患者中较为常见，且与不良健康结局相关。该现象可能源于认知损害干扰日常功能与自我照护，但相关研究证据仍较为有限。本横断面研究旨在探讨血液透析患者的认知功能与功能转归指标之间的内在关联。

研究方法
血液透析患者完成了三项测评：客观认知功能（蒙特利尔认知评估量表（Montreal Cognitive Assessment））、日常问题解决能力（基于情景的任务范式）以及主观认知主诉自评。参与者还需自行报告社会人口学信息、功能干扰情况、治疗不依从状况，以及情绪与疲劳症状。患者的合并症与实验室检查结果等临床数据均从病历中提取。本研究采用结构方程模型（Structural Equation Modelling）进行数据分析。

研究结果
本研究共纳入268名血液透析患者，平均年龄为59.87岁，女性占比42.5%。最终构建的模型拟合效果良好：CFI=0.916，TLI=0.905，RMSEA=0.033（90%置信区间为0.024至0.041），SRMR=0.066，χ²(493)=618.573（p<0.001）。客观认知功能与主观认知主诉呈负相关。认知主诉与功能干扰、治疗不依从均呈正相关，而客观认知表现则无此关联。日常问题解决能力作为认知功能的独立维度，与客观认知表现及主观认知主诉均无关联，但在预测功能干扰方面具有附加效用。

研究结论
相较于基于传统测试的客观认知表现，主观认知主诉与日常问题解决能力似乎是功能相关指标更强的预测因子。常规筛查日常认知困难，有助于早期识别存在认知障碍、功能干扰、治疗不依从及不良临床结局风险的血液透析患者。