The effect of religious and spiritual interventions on the biological, psychological, and spiritual outcomes of oncology patients: A meta-analytic review

In addition to biomedical forms of treatment, many cancer patients have elected to use complementary and alternative medicine (CAM) of a spiritual or religious nature. However, the effectiveness of such spiritual and religious interventions is uncertain. Using a meta-analytic approach, the present study synthesized available treatment-outcome studies on spiritual and religious interventions for cancer patients to determine the efficacy of such interventions. Effect sizes were calculated for three types of outcome measures: biological, psychological, and spiritual. The authors found that nondrug spiritual and religious interventions produced small to moderate effect sizes for treatment versus control comparisons and small effect sizes for pre- versus posttreatment comparisons. Studies that used psychedelic drugs to promote spiritual experiences produced large effect sizes for both treatment versus control and pre- versus posttreatment comparisons. Finally, they found that, overall, treatment versus control comparisons produced larger effect sizes than did pre- versus posttreatment comparisons. Limitations of the studies discussed in the present meta-analysis included the lack of control groups, randomization, and a large number of participants. The results suggest that there is a shortage of sufficiently detailed, high-quality treatment outcome studies examining the efficacy of spiritual and religious interventions for oncology patients. (C) 2004 by The Haworth Press, Inc. All rights reserved.