A clinical researcher wants to compare patient outcomes from a new practice guideline vs existing… Patients will be blindly assigned… Which research method should be used?

This method assesses outcomes before and after an intervention within the same group, making it more susceptible to confounding variables and biases. Since the researcher wants to compare two distinct groups (new vs. existing guidelines), a pretest-posttest design would not effectively isolate the effects of the respective interventions.

A cross-sectional study examines data at a single point in time, providing a snapshot rather than a causal relationship. This approach is unsuitable for evaluating the effectiveness of different guidelines over time, as it does not involve intervention or random assignment, which are crucial for determining patient outcomes linked directly to the guidelines.

Time-series research involves repeated observations over time, which might measure trends but does not provide a controlled comparison between two distinct interventions. This method lacks the random assignment needed to draw causal conclusions about the effectiveness of the new versus existing practice guidelines.