I do not think having a clinical background is overly necessary to perform clinical research. Like any job, you end up getting trained to do things the specific way your employer wants you to do them anyway. The biggest plus to having a clinical background (i.e. RN), however, would be if the patient in the study has an adverse effect to what is being tested. Having a clinical background in that sense would be safer for the patient due to the researcher having experience in acute care.