Preanalytical Variables
Patient and collection factors that can influence hormone test results before laboratory analysis, including fasting status, timing, and sample handling.
Full Definition
Preanalytical variables encompass all factors that can affect hormone test results before the sample reaches the analytical instrument, including patient preparation, collection timing, sample handling, and storage conditions. Critical preanalytical considerations in hormone testing include fasting requirements for insulin and glucose-related hormones, timing relative to circadian rhythms for cortisol and growth hormone, menstrual cycle phase for reproductive hormones, and medication effects on binding proteins. Proper sample collection techniques, appropriate tube types, processing delays, and storage temperatures also significantly impact results. Many spurious hormone results can be traced to preanalytical issues, making proper patient preparation and specimen handling protocols essential for accurate hormone testing.
Usage
Usage note: Always consider preanalytical factors when hormone results are unexpected or discordant with clinical findings.
In Context
- "The elevated cortisol result was attributed to preanalytical variables including stress during blood draw." — Result investigation report
- "Proper control of preanalytical variables is essential for reliable hormone testing outcomes." — Laboratory quality manual