Implementing randomized assignment in a nursing clinical randomized control trial.

During the design phase of any research, an investigator addresses internal and external threats to validity and develops mechanisms to minimize these threats. Controlling for threats to study validity enhances the meaningfulness and generalizability of study outcomes. Representativeness of the study sample is one key design feature undertaken to ensure study validity; however, during clinical trials the investigator must stay attuned to ongoing situations that can alter sample representativeness. In the context of an ongoing nursing-led randomized control trial, threats to sample representativeness are discussed. These threats can occur in any study and may require modification of the study design to maintain validity of research outcomes. This article provides insight regarding threats to study validity encountered by one research team and the modifications undertaken to address them.