What type of analysis should be employed when there are protocol deviations and attrition in a clinical trial?

In the context of clinical trials, when there are protocol deviations and attrition, the intention-to-treat analysis is the preferred method because it helps ensure that the results remain unbiased and reflective of real-world outcomes. This approach includes all participants who were originally assigned to each treatment group, regardless of whether they completed the trial as per the protocol or adhered to the assigned treatment.

By analyzing data in this manner, the intention-to-treat method preserves the initial randomization of participants, which is crucial for mitigating biases that could arise from noncompliance or dropouts. This leads to more reliable estimates of the treatment effect since it takes into account all participants and their original group assignments, which more accurately mirrors clinical practice where not all patients may adhere strictly to treatment protocols.

In contrast, other methods like per-protocol analysis analyze only those participants who completed the study according to the protocol, potentially leading to biased results. Exclusion analysis focuses on removing specific data points based on predefined criteria, and subgroup analysis may only look at effects within specific subsets of participants, both of which can further complicate the interpretation of overall trial findings. Therefore, the intention-to-treat approach is the most robust choice for preserving the validity of the study outcomes in the presence of deviations