AIMS: Religion and spirituality can be resources for internal strength and resilience, and may assist with managing life's challenges. Prior studies have been undertaken primarily in countries with high proportions of religious/spiritual people. We investigated (i) whether being religious/spiritual is an independent predictor of patient-reported outcomes (PROs) in a large international sample of adults with congenital heart disease, (ii) whether the individual level of importance of religion/spirituality is an independent predictor for PROs, and (iii) if these relationships are moderated by the degree to which the respective countries are religious or secular.

METHODS AND RESULTS: APPROACH-IS was a cross-sectional study, in which 4028 patients from 15 countries were enrolled. Patients completed questionnaires to measure perceived health status; psychological functioning; health behaviors; and quality of life. Religion/spirituality was measured using three questions: Do you consider yourself religious or spiritual?; How important is religion, spirituality, or faith in your life?; and If religious, to what religion do you belong?. The country level of religiosity/secularity was appraised using data from the Gallup Poll 2005-2009. General linear mixed models, adjusting for patient characteristics and country differences were applied. Overall, 49.2% of patients considered themselves to be religious/spiritual. Being religious/spiritual and considering religion/spirituality as important in one's life was positively associated with quality of life, satisfaction with life and health behaviors. However, among patients living in more secular countries, religion/spirituality was negatively associated with physical and mental health.

CONCLUSION: Religiosity/spirituality is an independent predictor for some PROs, but has differential impact across countries.