학술논문
Day to day changes in free and total PSA: significance of biological variation.
Document Type
Article
Author
Source
Subject
*PROSTATE cancer
*PROSTATE hypertrophy
*PROSTATE-specific antigen
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Language
ISSN
1365-7852
Abstract
In this study we evaluated the physiological variation of free and total prostate-specific antigen (PSA) levels to determine how the percent free/total PSA was affected. Twenty four patients had blood drawn for ten consecutive weekdays. The percent coefficient of variation (%CV) of biological variation was calculated. The results were log-normally distributed with geometric means of 12.0% CV, 7.3% CV, and 8.8% CV for free, total, and percent free/total PSA, respectively. When applied, the percent free/total, PSA would need to fluctuate by 31% to indicate that a significant change (critical difference, P<0.05) between two measurements had occurred. Biological variation of PSA measurements is substantial. [ABSTRACT FROM AUTHOR]