Bendroflumethiazide (versus unexposed)

Study	Type of data	Exposure measurement	Outcome assessment	Adjustment
Leather, 1968	randomized controlled trial	On entry to the trial patients were allocated at random to control or treatment groups.	The clinical management in control and treated groups was the same. The patients were cared for by the obstetricians and given bed-rest and sedation as required. The decision to terminate pregnancy was taken by the obstetricians.	No adjustment. Randomisation. Exclusion of twin pregnancies.