Department of Psychology, Uppsala University, Uppsala, Sweden.
Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, & Stockholm Health Care Services, Region Stockholm, Solna, Sweden.
BMC Psychiatry. 2023 Sep 22;23(1):690. doi: 10.1186/s12888-023-05162-4.
Stress reflects physical and psychological reactions to imposing demands and is often measured using self-reports. A widely-used instrument is the Perceived Stress Scale (PSS), intended to capture more general aspects of stress. A Swedish translation of the PSS is available but has not previously been examined using modern test theory approaches. The aim of the current study is to apply Rasch analysis to further the understanding of the PSS' measurement properties, and, in turn, improve its utility in different settings.
Data from 793 university students was used to investigate the dimensionality of different version of the PSS (14, 10, and 4 items) as well as potential response patterns among the participants.
The current study demonstrates that the PSS-14 has two separate factors, divided between negatively worded items (perceived stress) and positively worded items (perceived [lack of] control), although with only the negative subscale exhibiting good reliability. Response patterns were analyzed using Differential Item Functioning, which did not find an influence of gender on any of the items, but for age regarding the positive subscale (items 6 and 9). The PSS-10 also demonstrated adequate reliability for the negative subscale, but the PSS-4 was not deemed suitable as a unidimensional scale.
Based on the results, none of the versions of the PSS should be used by sum-scoring all of the items. Only the negative items from the PSS-14 or PSS-10 can be used as unidimensional scales to measure general aspects of stress. As for different response patterns, gender may nevertheless be important to consider, as prior research has found differences on several items. Meanwhile, content validity is discussed, questioning the relevance of anger and being upset when measuring more general aspects of stress. Finally, a table to convert the PSS-7 (i.e., negative items) ordinal sum scores to interval level scores is provided.
压力反映了对强加要求的身心反应，通常通过自我报告来衡量。一种广泛使用的工具是感知压力量表（PSS），旨在捕捉压力的更一般方面。PSS 有瑞典语翻译版本，但以前没有使用现代测试理论方法进行检查。本研究的目的是应用 Rasch 分析来进一步了解 PSS 的测量特性，并提高其在不同环境中的实用性。
使用来自 793 名大学生的数据，研究了不同版本的 PSS（14、10 和 4 项）的维度以及参与者之间潜在的反应模式。
本研究表明，PSS-14 有两个独立的因素，分为负面项目（感知压力）和正面项目（感知[缺乏]控制），尽管只有负面子量表具有良好的可靠性。使用差异项目功能分析对反应模式进行了分析，没有发现性别对任何项目有影响，但对正子量表（项目 6 和 9）的年龄有影响。PSS-10 也表现出对负子量表的足够可靠性，但 PSS-4 不适合作为单一维度量表。
基于结果，不应使用所有项目的总和得分来使用 PSS 的任何版本。只有 PSS-14 或 PSS-10 的负项才能作为衡量压力一般方面的单一维度量表使用。至于不同的反应模式，性别可能仍然是一个重要的考虑因素，因为之前的研究发现了几个项目的差异。同时，讨论了内容效度，质疑在衡量压力的更一般方面时测量愤怒和不安的相关性。最后，提供了一个将 PSS-7（即负项）的顺序总和得分转换为区间水平得分的表格。
