Valid assessment of spiritual quality of life with the WHOQOL-SRPB BREF across religious, spiritual, and secular persons: A psychometric study.

Spiritual well-being is increasingly recognized as a distinctive, important, and cross-cultural concept in quality of life assessment. The Spiritual Quality of Life-9 subscale (SQOL-9) of the World Health Organization’s Quality of Life Spirituality, Religiousness, and Personal Beliefs brief instrument (WHOQOL-SRPB BREF) was designed to facilitate cross-cultural assessment of SQOL among people who are neither religious nor spiritual (NRS), spiritual but not religious (SNR), and religious and spiritual (RS). The present study (N = 2,003 adults) sought to examine the SQOL-9 factor structure, measurement equivalence/invariance, degree of redundancy with positive religious coping, and relationship with well-being (e.g., meaning in life, satisfaction with life, physical health, and mental health) across these 3 groups. Results suggested that the SQOL-9 is defined by 2 factors. The first factor (“spiritual coping QOL”) lacked metric invariance between the NRS and RS, suggesting that the meaning of this factor differs for these 2 groups. It also showed evidence of empirical redundancy with positive religious coping among the RS. This factor was either inversely related, or unrelated, to well-being within each group, suggesting it may function as a proxy for stress when the second factor (“existential QOL”) is accounted for. However, the existential QOL factor was robustly associated with well-being for all groups. Invariance results indicated this factor had a similar conceptual meaning across the three groups, but the observed mean scores are not always directly comparable. In summary, the SQOL-9 demonstrated important strengths and limitations for the assessment of SQOL across diverse worldviews.