Noncomparative study

Unblinded (open) study without control group; although lack of controls will most often lead to the problem of confounding by the indication, comparative studies are not always necessary/ethically justified to evaluate drug efficacy esp. in the following examples:

(1) drug effect is very dramatic (e.g. prompt awakening of a patient who is comatose from an overdose of methadone when naloxone is administered),

(2) predictable, invariable, progressive disease without therapy (e.g. scurvy, if vitamin C is not administered),

(3) disease without spontaneous cure (e.g. gonorrhea, treatment with suitable antibiotic);