Failure of randomisation by "sealed" envelope.
Peto
R
R
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D002216:Captopril / Q000627:therapeutic use*; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000401:mortality; D012107:Research Design
D000806:Angiotensin-Converting Enzyme Inhibitors; D002216:Captopril