Summary of findings 12. Transcranial direct current stimulation compared to sham stimulation for the management of abdominal pain in Crohn's disease and inflammatory bowel disease.

Transcranial direct current stimulation compared to sham stimulation for the management of abdominal pain in Crohn's disease and inflammatory bowel disease
Patient or population: people with inflammatory bowel disease Setting: single centre, Medical Department I (Gastroenterology, Infectious Diseases, Rheumatology) of the Charite‐Campus Benjamin Franklin, Germany Intervention: transcranial direct current stimulation Comparison: sham stimulation
Outcomes	Anticipated absolute effects* (95% CI)		Relative effect (95% CI)	№ of participants (studies)	Certainty of the evidence (GRADE)
	Risk with sham stimulation	Risk with transcranial direct current stimulation
Treatment success as defined by the authors	‐	‐	‐	‐	Not measured
Abdominal pain frequency or change in frequency	‐	‐	‐	‐	Not measured
Pain intensity (0‐10cm visual analogue scale)	‐	MD 1.65 lower (3.29 lower to 0.01 lower)	‐	20 (1 study)	⊕⊕⊝⊝ low a
Withdrawal due to adverse events	0 per 1000	0 per 1000 (0 to 0)	Not estimable	20 (1 study)	⊕⊕⊝⊝ low a
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: confidence interval; MD: mean difference; PPT: Pressure Pain Threshold
GRADE Working Group grades of evidence High certainty: We are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: We are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: Our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect. Very low certainty: We have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect.

^aDowngraded two levels due to imprecision from very sparse data.