Biostatistics & Research · single question
Bias that specifically arises from the systematic way participants are both CHOSEN and LOST from a study is best called:
Show answer and explanation
Correct answer: D. Attrition bias
Attrition bias (follow-up bias) occurs when participants drop out in a non-random manner, affecting who completes the study and thus the validity of results.
- A. Reporting bias refers to selective reporting of outcomes/results, not participant selection or retention.
- B. Sampling bias refers to errors in how the sample was chosen from the population — not specifically about loss of participants during the study.
- C. Selection bias refers to systematic errors in who is recruited at baseline, not who is retained.
- D. CORRECT. Attrition bias = systematic differences between those who complete the study and those who drop out. When combined with how participants were initially selected, this compromises both internal and external validity.
Practice Biostatistics & Research questions Biostatistics & Research study notes