Psychometric Properties and Scale Invariance of Positive Thinking Skills Scale (PTSS) in Medical Students

Background Positive thinking skills are fundamentally important in various fields, including mental health, education, and medicine. Within the context of medical education, where stress and pressure are prevalent, positive thinking can be a transformative force in enhancing resilience and empathy. However, careful validation of measurement tools is required to ensure their applicability in different cultural contexts. Objective The aim of this study was to adapt and validate the Positive Thinking Skills Scale (PTSS) among Peruvian medical students. Methods An instrumental study was conducted. A total of 408 Peruvian medical students aged between 18 to 35 years (M = 19, SD = 2.55) participated. The Positive Thinking Skills Scale (PTSS), academic self-efficacy, and burnout were used. A confirmatory factor analysis (CFA) was performed to assess the factorial structure of the PTSS. Additionally, a sequence of hierarchical variance models was used to evaluate measurement invariance by gender. For the reliability assessment, Cronbach's alpha (α) and omega (ω) coefficients were used. Results The CFA supported the unifactorial structure of 8 items with adequate goodness-of-fit indices: χ2 (20) = 69.860, CFI = 0.95, TLI = 0.93, RMSEA = 0.08 (90% CI: 0.06–0.09), SRMR = 0.04. Reliability using Cronbach's Alpha (α = 91) and McDonald's Omega (ω = 91) was excellent. Likewise, convergent and discriminant validity between the PTSS and measures of academic self-efficacy and burnout was demonstrated. Conclusions The Peruvian version of the PTSS is effective in measuring positive thinking skills. The PTSS represents a valid, reliable, and invariant tool for assessing and promoting positive thinking, which has profound implications on the mental health and overall well-being of future doctors.