Why is blinding or coding used in GLP studies and when might it apply?

• A. To speed up data entry
• B. To prevent bias in data collection and interpretation; used when the study design calls for it
• C. To protect sensitive data from unauthorized access
• D. To ensure uniform sample labeling

Answer: (B)

Blinding or coding is used to prevent bias in data collection and interpretation by keeping the people who record or judge results unaware of which treatment or group a sample belongs to. This helps ensure observations and measurements reflect true effects rather than expectations or personal influence. It applies when the study design includes subjective assessments or endpoints that could be swayed by knowing the treatment—so researchers, technicians, or analysts remain unbiased. In GLP studies, blinding can be implemented as single- or double-blind, and coding is used to conceal group identity so samples or data are analyzed without that knowledge. For example, a pathologist assessing tissue samples or a laboratory analyst measuring outcomes should not know which treatment a sample came from to avoid influencing their judgment. Blinding isn’t about speeding data entry, protecting sensitive data, or labeling; it specifically targets reducing bias in how data are collected and interpreted, and is used when the design calls for it to protect data integrity.