TABLE 3.

Meta‐analysis results of placebo response when improvement was the primary endpoint and placebo effect in studies where stability vs deterioration was the primary endpoint; heterogeneity was assessed based on the significance of the between‐study heterogeneity, and on the size of the I² value

Primary endpoint	Number of studies included	Total number of subjects included	Heterogeneity		Percent of placebo subjects meeting primary endpoint (95% CI)
			P‐value	I2
Improvement (placebo response)	9	180	<.01	51%	11 (4, 21)
Stability vs deterioration (placebo effect)	5	176	.50	0%	43 (35, 50)

Abbreviation: CI, confidence interval.