Developing and Validating an Islamic Spiritual Health Questionnaire Among Iranian Adults: A PLS‑SEM Approach

Despite the significance of spiritual health in health psychology literature, existing instruments are mostly grounded in Western frameworks and cannot assess dimensions of Islamic spirituality. The present study sought to develop and validate an Islamic Spiritual Health Questionnaire, grounded in authoritative Quranic and narrative sources, to provide an indigenous, valid instrument for evaluating spiritual aspects rooted in a monotheistic worldview. The study employed a sequential exploratory mixed-methods design. In the qualitative phase, 27 components of spiritual health were extracted from Islamic texts (the Holy Quran, Nahj al-Balāghah, al-Ṣaḥīfah al-Sajjādiyyah, al-Kāfī, and several other hadith collections) through inductive content analysis, yielding 54 items. The content validity of 27 items was then confirmed via CVR and CVI indices based on the opinions of 10 experts in theology and psychology. In the quantitative phase, the 27-item questionnaire was first piloted with 63 participants, yielding an overall Cronbach's alpha of 0.946; two items were removed based on participant feedback and expert judgment. In the final stage, the 25-item version was administered to 438 individuals selected via stratified random sampling from the general population, and exploratory and confirmatory factor analyses were conducted using PLS-SEM in SmartPLS 3 software. Exploratory factor analysis identified four main factors: theocentrism, public relations, control of carnal desires, and social responsibility. Confirmatory factor analysis indicated that all item loadings exceeded 0.4, and all paths were significant at the 0.05 level (t > 1.96). The indices of convergent validity (AVE > 0.5), discriminant validity, and composite reliability (CR > 0.7) were acceptable for all dimensions. R² values were moderate-to-strong for all dependent variables in the model, and Q² values were strong for all endogenous constructs. The overall goodness-of-fit index (GOF = 0.818) reflected a strong model fit. This instrument's total reliability was supported by a Cronbach's alpha of 0.973, split-half coefficients ranging from 0.823 to 0.963, and a test-retest correlation of 0.67 over a 2-week interval. The criterion validity of the questionnaire was also confirmed through significant positive correlations with the "Spiritual Health Scale Based on Islamic Sources (r = 0.719, p < 0.001) and the "Paloutzian and Ellison Spiritual Well-Being" scale (r = 0.553, p < 0.001). The Islamic Spiritual Health Questionnaire demonstrates established content, construct, and criterion validity, along with high reliability, and can be employed as a robust and precise instrument for assessing spiritual health based on Islamic teachings in research, educational interventions, and clinical settings.