부산대학교 도서관

Introduction The Profile of Mood States is one of the most widely used instruments to assess mood states. It is a rapid and economic method of assessing transient affective states (McNair et al. 2003) and it has been translated and validated to several languages including Portuguese. In our country we have several versions, with different factorial structures and number of items. The scale presents a list of feelings and emotions (adjectives) that people commonly experience. With university students, we have used a version composed of 36 items that evaluates three factors, with good validity and reliability: Depression, Anxiety/Hostility and Positive Affect (Amaral et al. 2013). However, to be included in digital apps that in addition to ecological momentary assessment parameters require a weekly or even daily assessment of mood states, this version has little usability. Objectives To develop a shorter version of the POMS-36 based on Exploratory Factor Analysis and to analyse its construct validity using Confirmatory Factor Analysis in a sample of Portuguese college students. Methods 765 students (69.2% females; mean age=22.09±2.433; range: 17-26) fill in the POMS-36 and the Perceived Stress Scale (Amaral et al. 2014). The total sample was randomly divided in two sub-samples. Sample A (N=380) was used to EFA and sample B (N=385) was used to CFA. Results Through EFA (with varimax rotation and extracting three factors), the four items with the highest loadings in their respective factor were selected. Then, the CFA, carried out with the AMOS, revealed that this three-factor model, with two pairs of correlated errors, indicated a good fit (X2/df= 4.6010; CFI =.9561; GFI =.9406; TLI=.9559; RMSEA=.0687, p[rmsea=0.04]. The internal consistency analysis resulted in α (Cronbach alphas)