system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Please refer to the summary above to answer this question
The APPLE study investigators are currently preparing for a 30-year follow-up evaluation. They are curious about the number of participants who will partake in follow-up interviews. The investigators noted that of the 83 participants who participated in APPLE study's 20-year follow-up, 62 were in the treatment group and 21 were in the control group. This finding raises concerns for which of the following?"
assistant
Attrition bias