Table 2.

Comparison of the effects of MBIs and sham (control) interventions in the acute pain studies, focusing on the main pain outcomes.

References	Main mechanisms	Type of sham intervention	Pain outcomes
			Intensity/ threshold	Tolerance	Unpleasantness	Catastrophizing
Case et al. (2021)	Opioid-mediated modulation of expectations	- Active (Book Listening) or Passive control - Saline infusion	MBI>Controls	N/A	N/A	N/A
Davies et al. (2021)	Placebo effects of MBIs	Specific Sham mindfulness	MBI=Control	MBI=Control	MBI>Control	N/A
Davies et al. (2022)	Role of expectations in placebo effects of MBIs	Specific Sham mindfulness	MBI=Control	MBI=Control	MBI=Control	N/A
Esch et al. (2017)	Opioid modulation	- Passive control - Saline infusion	N/A	MBI=Control	N/A	N/A
May et al. (2018)	Opioid modulation	Saline infusion	MBI>Control	N/A	MBI>Control	N/A
Namjoo et al. (2019)	Opioid modulation	Saline infusion	MBI>Control	N/A	N/A	N/A
Sharon et al. (2016)	Opioid modulation	Saline infusion	MBI=Control	N/A	MBI=Control	N/A
Wells et al. (2020)	Opioid modulation	- Slow-paced Breathing or Sham Mindfulness Meditation - Saline infusion	MBI>Control	N/A	MBI=Control	N/A
Zeidan et al. (2015)	MBI vs. placebo analgesia	- Placebo conditioning - General Sham Mindfulness (GSM) - Active control (Book listening)	MBI>active controls (GSM)>Book listening	N/A	MBI>active controls (GSM)>Book listening	N/A
Zeidan et al. (2016)	Opioid modulation	- Active (book listening) - Saline infusion	MBI>Control	N/A	MBI>Control	N/A

MBI>Control means that the effect of MBI was significantly higher than the sham intervention.