What does attrition refer to in a study?

Attrition in a study specifically refers to the loss of participants over time, whether due to withdrawal from the study or being lost to follow-up. This loss can occur for various reasons, such as participants dropping out for personal reasons, lack of interest, or inability to continue participating. Understanding attrition is crucial because it can impact the validity and reliability of the research findings. High attrition rates may lead to biases if the characteristics of those who leave the study differ from those who remain, potentially skewing results and limiting the generalizability of the findings. Recognizing and addressing attrition is an essential aspect of study design and data interpretation in evidence-informed practice.