Medical research is the systematic, rigorous investigation of health-related problems in order to generate new knowledge or confirm existing knowledge, with the potential benefit of evidence-based medical practice and policy guidance. The validity of the findings from medical research requires a thorough process from design, to data collection and data analysis.1 However, the methods that researchers use during analyses are often unsuitable for the designs used during study conduct. Researchers are supposed to choose the study designs at the time of protocol development, before any investigation is carried out. Different study designs have different strengths and weaknesses.2 The selected design should be the most appropriate design to answer the objectives of a study. This decision is crucial, as study design reflects directly on the hypothesis of interest. Sample size and other design aspects of the study are aimed at achieving valid conclusions of a trial or study. It is therefore important to strive for compatibility between study design and analysis plan.</p
