Table 1.

The role of the statistician in developing the statistical plan

Clarify the research questions or hypothesis. Are the primary hypotheses clearly stated, adequate and realistic? Identify the outcome variables related to the research questions. Are the primary or secondary endpoints clearly defined? Does the study design appropriately and adequately address the proposed hypothesis? Are the issues of the bias, blinding or stratification properly handled in the study? Are the assumptions used for sample size estimation clearly elaborated and supported by proper preliminary data and/or references? Is there a clearly specified, appropriate data analysis plan? Is there an appropriate data and safety monitoring plan, interim analysis plan, or pre-established early stopping rule?