Supplementary file 1_The development and validation of Coffee Use Disorder and Coffee Addiction Scale (CUDCAS) and its correlation with insomnia and anxiety symptoms.docx

BackgroundCoffee is a globally consumed beverage. However, the impairments associated with its excessive use remain under-recognized. There is currently no standardized measurement for coffee use disorder based on DSM-5 application. This study describes the development and psychometric properties of the Coffee Use Disorder and Coffee Addiction Scale (CUDCAS)—a self-report tool developed specifically for this purpose.
MethodsA cross-sectional survey was designed and delivered to 523 participants. Items from CUDCAS (11 items with reference cluster) indicate substance use disorder criteria taken from the DSM-5 and were rated on a three point Likert scale and used descriptive statistics; internal consistency (Cronbach's α and McDonald's ω); exploratory/confirmatory factor analysis (EFA, CFA); item response theory (IRT), and correlations with caffeine consumption, insomnia (AIS) and anxiety symptoms (GAD-7) were also examined.
ResultsCUDCAS was found to be a very reliable (α and ω = 0.86) measure of coffee use disorder symptoms. CFA results supported the unidimensional factor structure of the CUDCAS and the overall model fit was good (CFI = 0.92, TLI = 0.90, RMSEA = 0.07, SRMR = 0.04). The IRT analyses further demonstrated an appropriate distribution of item difficulties, measurement of item precision and subsequently, CUDCAS as an overall measurement of coffee use disorder that is responsive to coffee consumption. CUDCAS also demonstrated significant correlations with caffeine consumption (r = 0.54), insomnia (r = 0.37), and anxiety (r = 0.32), respectively, for construct validity.
ConclusionsThe findings suggest that the CUDCAS is a reliable and valid tool to assess the symptoms of coffee use disorder, and the current results provide support for its use in research and clinical settings.

背景
咖啡是全球范围内广受消费的饮品。然而，过量饮用咖啡所引发的损害仍未得到充分重视与认知。目前尚无基于《精神障碍诊断与统计手册第五版》（DSM-5）应用框架的标准化咖啡使用障碍测评工具。本研究介绍了咖啡使用障碍与咖啡成瘾量表（Coffee Use Disorder and Coffee Addiction Scale, CUDCAS）的开发过程及其心理测量学属性，该量表是专为该测评场景研发的自评式工具。

方法
本研究设计了横断面调查方案，共招募523名参与者。咖啡使用障碍与咖啡成瘾量表（CUDCAS）包含11个条目及参照聚类组，其条目均源自DSM-5中的物质使用障碍诊断标准，采用三点李克特（Likert）量表进行评分。研究采用的分析方法包括描述性统计、内部一致性检验（克朗巴赫α系数与麦克唐纳ω系数）、探索性因子分析（Exploratory Factor Analysis, EFA）与验证性因子分析（Confirmatory Factor Analysis, CFA）、项目反应理论（Item Response Theory, IRT），同时检验了该量表与咖啡因摄入量、失眠症状（阿森斯失眠量表, AIS）及焦虑症状（广泛性焦虑障碍7条目量表, GAD-7）的相关性。

结果
研究结果显示，CUDCAS用于测评咖啡使用障碍症状时具有极佳的可靠性（α与ω系数均为0.86）。验证性因子分析结果支持CUDCAS的单维因子结构，整体模型拟合效果良好（CFI=0.92, TLI=0.90, RMSEA=0.07, SRMR=0.04）。项目反应理论分析进一步证实，条目难度分布合理、条目测量精度达标，整体而言CUDCAS可作为咖啡使用障碍的有效测评工具，且对咖啡摄入量变化具有敏感性。此外，CUDCAS与咖啡因摄入量（r=0.54）、失眠症状（r=0.37）及焦虑症状（r=0.32）均存在显著相关性，符合结构效度的检验要求。

结论
本研究结果表明，CUDCAS是一款可靠且有效的咖啡使用障碍症状测评工具，现有研究结果为其在科研与临床场景中的应用提供了充分的支持依据。