STEPP Study — Proximal Intercessory Prayer and Sensory Improvement in Mozambique (2010)

The STEPP study (Study of the Therapeutic Effects of Proximal Intercessory Prayer) was conducted in rural Mozambique by Candy Gunther Brown (Indiana University Department of Religious Studies) and colleagues. Published in the Southern Medical Journal in September 2010, it evaluated 24 Mozambican subjects reporting impaired hearing (14) or vision (11) before and after receiving proximal intercessory prayer from local Christian ministers.

Using an Earscan 3 audiometer and standard "Illiterate E" vision charts, researchers measured statistically significant improvements in both sensory domains (hearing: p<0.003; vision: p<0.02). Authors noted that effect sizes exceeded what has been documented in prior hypnosis and suggestion research.

Methodological Concerns

The study attracted sustained criticism from clinicians and methodologists. The primary concerns are: (1) no randomized control group; (2) assessors were not blinded to treatment condition; (3) subjects knew they were receiving prayer, creating a demand effect; (4) baseline medical diagnosis of impairment was not independently verified by audiologists or ophthalmologists; (5) no follow-up measurement was conducted. The sample size of 24 is too small to control for regression to the mean.

No replication study has been published. The study remains the most-cited empirical data point in the prayer-and-healing literature because it appeared in a peer-reviewed venue. That classification should not be mistaken for methodological rigor sufficient to establish causation.