Table 1.

GRADE evaluation of interventions for heartburn in pregnancy

Important outcomes	Symptom severity, adverse effects
Number of studies (participants)	Outcome	Comparison	Type of evidence	Quality	Consistency	Directness	Effect size	GRADE	Comment
What are the effects of interventions to prevent or treat heartburn in pregnancy?
2 (206)	Symptom severity	Antacids v placebo	4	–2	0	0	0	Low	Quality points deducted for unclear method of randomisation and no between group statistical analysis in one RCT
1 (30)	Symptom severity	Antacid v antacid plus acid-suppressing drug	4	–2	0	0	0	Low	Quality points deducted for sparse data and for unclear method of randomisation

Type of evidence: 4 = RCT; 2 = Observational; 1 = Non-analytical/expert opinion. Consistency: similarity of results across studies Directness: generalisability of population or outcomes Effect size: based on relative risk or odds ratio