Table 1

Characteristics of included studies

Study	Quality^1-150	Type	No enrolled/ completed	Treatment	Dose/day	Duration (weeks)
Ekstrom19	A7	Crossover	50/48	Ranitidine	300 mg	4
Ford20	A6	Crossover	11/10	Omeprazole	20 mg	4
Goodall21	A6	Crossover	20/18	Cimetidine	1000 mg	6
Gustafsson22	A7	Crossover	40/37	Ranitidine	150 or 300 mg	4
Kjellen23	C4	Parallel	NA/62	Conservative		8
Larrain24	A7	Parallel	90/81	Cimetidine or surgery	1200 mg	26
Meier25	A7	Crossover	15/15	Omeprazole	40 mg	6
Nagel26	B6	Crossover	15/14	Ranitidine	450 mg	1
Teichtahl27	B6	Crossover	25 / 20	Omeprazole	40 mg	4
Boeree28	B7	Parallel	36/30	Omeprazole	80 mg	12
Levin29	B7	Crossover	11/9	Omeprazole	80 mg	8
Kiljander30	B7	Crossover	57/52	Omeprazole	80 mg	8

↵1-150 Letters indicate whether the method of allocation to treatment groups was: A=adequate; B=unclear; C=inadequate. Numbers are Jadad scores from 1 to 7 where higher numbers indicate less opportunity for bias.
NA = not available.