Determining the optimal study period involves balancing several considerations: - Preliminary Research: Review existing literature to understand typical study periods for similar research. - Pilot Studies: Conduct pilot studies to assess the feasibility of data collection and to identify any potential temporal biases. - Statistical Power: Ensure that the chosen period provides sufficient data points to achieve adequate statistical power for detecting meaningful associations. - Consultation with Experts: Engage with epidemiologists and statisticians to refine the study period selection.