Psychometric properties of the Spiritual Attitude and Involvement List Short Form (SAIL-SF) and its moderating role between threatening experiences and posttraumatic growth in Spanish people with chronic pain

The short form of the Spiritual Attitude and Involvement List (SAIL-SF) was recently developed as a brief measure of connectedness with oneself, the environment, and the transcendent, conceptualized as a universal human experience. This study extends prior research by examining the reliability and construct validity of the SAIL-SF in people from Spain with chronic pain. Furthermore, it examined whether spirituality moderated the association between threatening experiences and posttraumatic growth. The study sample (n = 259) was comprised mostly of women (88%), aged 22 to 89 years. Participants completed a sociodemographic questionnaire, the SAIL-SF, and measures of pain, mindfulness, self-compassion, distress, threatening experiences, and posttraumatic growth. The SAIL-SF was administered twice, four weeks apart. Model fit indices supported a single-factor structure (CFI > 0.95, TLI > 0.92, RMSEA < 0.09, SRMR < 0.09 at both time points), consistent with the general spirituality theoretical model. SAIL-SF scores showed good internal consistency (Cronbach’s α and McDonald’s ω >0.75 at both time points) and adequate test–retest reliability (ICC = 0.79). The autoregressive structural equation model indicated substantial temporal stability, with strong lagged associations for both the general factor and the seven items. Convergent and discriminant validity were also supported. Threatening life experiences were significantly associated with posttraumatic growth, but only at higher levels of spirituality, suggesting a moderation effect. Overall, the SAIL-SF demonstrated robust psychometric properties in a Spanish chronic pain population. These findings support the inclusion of spirituality within the biopsychosocial model of pain as a relevant factor in understanding adjustment to chronic pain.