Clinical Diagnostics: Accurate measurements are essential for correct diagnosis and treatment of diseases.
Pharmacokinetics: Accurate data is vital for understanding drug absorption, distribution, metabolism, and excretion.
Regulatory Compliance: Regulatory bodies such as the
FDA require validated methods that ensure accuracy to approve new drugs.
How is Accuracy Measured?
Accuracy is typically assessed by comparing the test results to a known reference value. This can be done using:
Standard Reference Materials (SRMs) Spiked Samples – where known quantities of analytes are added to the sample matrix
Inter-laboratory Comparisons – comparing results from different laboratories using the same method
Types of Accuracy
There are generally two types of accuracy considered in bioanalytical methods: Trueness: The closeness of the mean test results obtained by the method to the true value. It is usually expressed in terms of bias.
Precision: The degree to which repeated measurements under unchanged conditions show the same results. Precision is often used interchangeably with accuracy, but it is actually a component of it.
Factors Affecting Accuracy
Several factors can affect the accuracy of bioanalytical methods: Analytical Techniques – The choice of technique (e.g.,
HPLC,
Mass Spectrometry) can impact accuracy.
Sample Preparation: Incorrect sample preparation can introduce errors.
Instrument Calibration: Poor calibration can lead to inaccurate results.
Matrix Effects: Interferences from other substances in the sample can affect accuracy.
Improving Accuracy
To improve accuracy, various strategies can be employed: Method Validation: Ensuring that the method is validated for its intended use.
Quality Control: Implementing rigorous QC procedures, including the use of control samples and proficiency testing.
Regular Calibration: Regularly calibrating instruments and using reference standards.
Training: Ensuring that personnel are well-trained in using the methods and instruments.
Regulatory Guidelines on Accuracy
Regulatory agencies like the
FDA, the
EMA, and others have published guidelines that outline the requirements for accuracy in bioanalytical methods. These guidelines typically require that:
Accuracy should be assessed across the entire range of the analytical method.
Results should be within acceptable limits, usually defined as a percentage deviation from the true value.
Conclusion
Accuracy is a cornerstone of
Bioanalytical Sciences, influencing the reliability of results in clinical diagnostics, drug development, and regulatory compliance. By understanding and controlling the factors that affect accuracy, and by adhering to stringent validation and quality control measures, bioanalytical scientists can ensure that their methods yield reliable and reproducible results.
