<prompt> Which one of the following statements regarding pre-post clinical trials is most appropriate -They can not be randomizedThey are useful in studies involving moalityThey use the patient as his or her own controlThey are usually easier to interpret than the comparable parallel clinical trial  <response>: They use the patient as his or her own control. Pre-post clinical trial does not have a true control group. Each patient has a pre test score followed by a post test. Reference: Handbook of drug abuse prevention by Slobada Bukoski; pg no.534-35. 