Introduction
Al-Rahba hospital pays great attention to the accuracy of test results. Among the procedures dedicated to the attainment of this goal are correlation and validation of results. All Al-Rahba laboratories take care of tests’ consistency and deal with inconsistent outcomes in accordance with the policies.
Definition of Correlation and Validation
Correlations of results present the most crucial part of laboratory practice. Correlation is the process of comparing the outcomes of two or more laboratory tests with the aim of checking their accuracy. With the help of correlation, laboratory specialists are able to find any inconsistencies or errors (1). Therefore, this process is of utmost importance since any error may be detrimental to patients. Inaccuracy in lab results is unacceptable in Al-Rahba where all measures are taken to provide the highest quality of treatment. Correlation is synonymous with the association: both of these concepts presuppose a measure of comparing two or more variables.
Carrying out the correlation of results and investigations is the requirement of the Joint Commission Accreditation Process and is considered a constituent of high-quality laboratory practice (2). Correlation has to be performed between any lab instruments that run the same analysis in the same laboratory. Also, the requirement concerns the assays performed in primary and backup laboratories within the same healthcare facility. It is crucial for lab technologists and assistants to confirm that all results obtained within their laboratory are identical. In another case, there is a threat to the health of the patients using the services of such institutions.
The procedure of correlation presupposes calibration and validation of all instruments. Validation is the process of affirming that allows ensuring that the assay system will appropriately “recover the concentration or activity” of the measured substance (2). Validation provides objective evidence by means of a process definition that the test’s performance is kept within the requirements. Validation incorporates the following aspects concerning the critical evaluation of evidence:
- systematic errors as an outcome of information bias, selection bias, or confounding;
- clinical significance of results;
- quantitative features of treatment and diagnosis;
- external generalizability or validity;
- the effect size and specific features concerning its precision;
- application of the obtained outcomes in practice (3).
The protocols, algorithms, and recommendations for the selection of procedures that are to be validated are grounded on clinical studies and hospital policies. Recommendations should be adjusted in each particular case, and the responsibility for validation is on lab technicians and physicians.
The Procedure of Validation of New Tests and Batches of Reagents Required for Diagnosis
Prior to performing any new tests, laboratory technologists need to validate them, as well as batches of reagents. There are three types of validation: analytic validation, clinical validation, and clinical utility (4). Analytic validation presupposes the evaluation of the assay and its performance aspects. Also, this validation type helps to establish the ideal conditions for generating accurate and reliable analyses. Clinical validation is the property of a test to identify or predict a threat of a specific health condition. Clinical utility is the establishment of the net balance between health-related benefits and risks related to the use of the test in practice (4).
The procedure of validation of new tests and batches of reagents needed for diagnosis incorporates the following steps:
- verification of analytic precision and accuracy;
- verification and documentation of any indications of analytic sensitivity;
- verification and documentation of analytic interferences;
- verification of the reportable range;
- verification and establishment of reference intervals;
- assessment of the reference intervals’ appropriateness;
- taking corrective measures is needed (4).
The significance of validation is of utmost importance since neglecting it may lead to serious adverse outcomes. If a new test or reagent batch does not correspond to the standards, it will not produce positive outcomes for patients. Moreover, it may present a threat to their lives. However, with appropriate validation, laboratory technologists can use method comparison data and institute the reference range for new methods and tests.
To prevent plausible errors, lab specialists should limit transference to a single change of methods. The “observed total error” may not be larger than the “recommended total error” (4). The laboratory should establish the appropriate analytical measurable range and clinically reportable range.
Potential Errors and Policies and Procedures Used to Avoid Them
Inaccurately performed or neglected correlation and validation procedures may lead to serious issues. If a test is not validated or if the correlation between various methods has not been performed, there is no reliability of such tests. Unreliable measures undermine the laboratory’s and hospital’s successful operation. Moreover, there is a major negative outcome for the patients. If tests are not reliable, treatment methods will not be helpful or even may be injurious.
The policies used to avoid the potential errors are established in the Calibration and Standards section of the Chemistry and Toxicology CAP Accreditation Checklist (4). According to these standards, laboratories are required to perform a correlation a minimum of once in six months. Another policy is the Clinical Laboratory Improvement Act that regulates correlation testing.
Conclusion
The procedures of correlation and validation belong to the most important elements of productive laboratory performance. Without regular correlation and validation of tests, a laboratory cannot ensure the highest quality of results. In Al-Rahba labs, particular attention is paid to these procedures. Every laboratory arranges the validation of tests and correlation of analyses on a regular basis to provide the most beneficial outcomes for the patients.
References
- College of American Pathologists. All common checklist: CAP accreditation program. Northfield: College of American Pathologists; 2015.
- College of American Pathologists. Commission on laboratory accreditation, laboratory accreditation program; chemistry and toxicology checklist. Northfield: College of American Pathologists; 2012.
- Radman I, Vodanović M, Radman I. Clinical-laboratory correlations and communication diagnostic process. Informatol. 2013., 46(1): 17-25.
- Sarewitz S J. CAP accreditation requirements for validation of laboratory tests. Northfield: College of American Pathologists; 2013.