What is Laboratory Quality Control?
Laboratory quality control is all the measures put in place to eliminate the risk of non-conforming outcomes. It involves systems that safeguard the accuracy, reliability, and timeliness of lab results by ensuring the early detection of results or measurement errors and the procedures to rectify them. It should be performed regularly and quality control materials should be treated the same as samples, from the beginning to the end of the run.
Laboratory quality control (QC) ensures that the lab processes and operations run efficiently and guarantees the production of accurate and reproducible results. In addition, the QC measures developed in a lab are the building blocks for the process of certification and accreditation.
Failure to integrate quality control in a laboratory can lead to several negative consequences, including the following:
- Time wastage, as experiments and tests are repeated.
- Budget implications, as more reagents are needed to carry out repeat tests and experiments.
- Unreliable results, which will impact the integrity of the lab and consequently any funding options and certification/accreditation process.
- Loss of customer loyalty and satisfaction.
- Safety concerns due to non-compliance in the absence of quality control mechanisms.
- Delayed diagnosis or unnecessary treatments for patients.
The process of setting up laboratory quality management begins with identifying all the lab processes and practices that are susceptible to inefficiencies, errors, and safety concerns, in order to build systems that secure them as discussed below.
Detecting and Minimizing Laboratory Errors
Errors in the laboratory can occur in three experimental or test stages.
- Post analytical
In the pre-analytical stage, the error occurs when test samples or materials are mishandled prior to analysis. This may include errors like sample mix-up, mislabeling, improper storage or transportation and unsuitable sample collection methods.
To minimize pre-analytical errors, ensure that:
- Proper sample collection methods are followed by adhering to the standard operating procedure.
- Samples and test materials are clearly labeled using name or lab codes, date of collection, source, test to be done.
- Test materials are transported to the lab in proper containers and at the recommended temperature. For any potentially infectious or toxic sample, triple packaging rules outlined by the International Air Transport Association (IATA) regulations should be followed and proper warning labels attached.
Samples and test material are properly stored to avoid negative impacts on the quality of results. Samples that might undergo degradation could lead to false results.
- It is advisable to always carry out sub-sampling. Storing aliquots of test material provides back-up in cases of errors in downstream processes.
In the analytical stage, errors arise during the process of testing or experimentation. This could be due to the use of the wrong test reagents, the use of defective and non-calibrated equipment, the use of the wrong proportions of reagents, and general non-adherence to standard operating procedures (SOPs).
These errors can be minimized by ensuring that:
- All laboratory equipment are well maintained and calibrated.
- A proper inventory is in place, outlining all reagents and their validity to ensure no expired reagents are in use.
- All standard operating procedures are documented and accessible.
- Actions are taken on staff that is continually non-compliant with the SOPs use.
Errors can be introduced in the post-analytical stage through incorrect calculations, recording, and interpretation of results.
To minimize these types of errors:
- Avoid manual calculations.
- Ensure that only well-trained personnel interpret and record results.
Establishing a Laboratory Quality Management System
A laboratory quality management system (QMS) streamlines and coordinates all the processes and operations within the lab, ensuring that each step is well planned, controlled, and correctly performed. It encompasses both the managerial and technical aspects of the lab procedures. The goal of a laboratory QMS is to ensure that results are accurate, reliable, and obtained under a traceable process that can easily detect errors.
To establish a proper quality management system, several widely used systems essential have been developed and are discussed separately below;
The laboratory should have an outlined hierarchical chart showing how management, supervisory roles, and authority flows. In addition, there should be documentation showing the functions and duties of every lab member, their competencies, experience, training attended and training required.
The appointment of individuals to integral positions like lab manager (for operational supervision), safety officer, and quality control officer is necessary.
The effective management of laboratory staff is crucial because they are the most important lab resource. Capacity building by ensuring they undergo regular training and motivation, as well as proper handling of staff concern ensures optimal performance. There should be regular meetings between the management and all staff to disseminate information and discuss issues of concern.
To ensure conformity to SOPs, performance appraisal and proficiency tests should be part of quality assessment.
All laboratory equipment should be documented with an inventory on maintenance and occurrences. After its installation, members should be properly trained on the use of the new equipment. Equipment manuals should be easily accessible in the laboratory area for easy reference.
Purchasing and Inventory
The buying of reagents, media, and supplies should be centralized, with one individual tasked with that responsibility. The procedures should be written and implemented to ensure that all supplies are correctly selected.
The process control refers to the management of all the activities employed in the handling of samples. This involves all the pre-analytical, analytical, and post-analytical stages. Due to the wide range of processes and individuals involved, including processes/persons that are outside of the laboratory premises like sample collection and transportation, adherence to standard best practices should be enforced for all handlers of the sample or test material. Documentation should be availed for all parties and a coordination person or team in place to ensure a smooth workflow.
Documents and Records
The laboratory documentation and records include SOPs, good laboratory practices (GLPs), equipment maintenance logs, occurrence books, etc. The documents provide information about the laboratory’s policies, processes, and testing procedures and should be stored in the laboratory quality manual for each laboratory. An SOP should be written for all procedures in the laboratory, including specimen collection, transport, storage, and waste disposal.
Occurrence management ensures quality control by identification of errors or non-conformance, recording them and putting in place corrective measures such as retraining programs, equipment servicing, or replacements. The laboratory must have provision for documentation of such errors and occurrences that may interfere with proper laboratory operations.
This involves investigations to verify process compliance and reliability of results. It can be either internal or external assessment and audit. The internal assessment is done by members of the lab and makes use of test controls like standards to validate the testing process and equipment.
The external assessment and audit involve the use of persons or agencies outside of the lab premises. This is done through lab visits by the assessors to observe processes, validating tests by sending aliquots of test materials to the external assessment agency or having the assessing agency send in unknown material for testing in the lab.
This process follows assessment and auditing. It involves all the corrective efforts made after the identification of points of errors and non-compliance. All actions should be documented, SOPs and QMS should be updated, and the changes in process and procedures should be communicated to the lab members.
It is important for laboratories offering services to maintain open communication channels with clients. Ensure that the customer is able to freely give feedback through interviews, questionnaires or meetings and have access to a complaints medium. All customer feedback should be documented, analyzed, and used for process improvement.
Facilities and Safety
A laboratory contains potentially harmful chemicals and infective material and therefore several safety protocols should be in place to protect the staff, environment, and the community. The laboratory management should ensure that all lab members are well-trained in safety requirements, SOPs, emergency response, and waste management. Different guidelines exist depending on the risk level of the lab.
Emergency response aids such as showers, fire blankets and extinguishers, first aid kits, should be easily accessible within the lab and the members effectively trained on their use. Detailed information on laboratory safety can be found here.
International Laboratory Standard
There are many international standards for laboratories that regulate specific laboratory aspects or programs. These standards are developed by international bodies such as the World Health Organization (WHO), the International Organization for Standardization (ISO), and field-specific international institutions. The standards developing body may recognize an institution through three different processes.
- Certification: Where the body gives a written assurance that the product or services of the institution meet specific requirements.
- Accreditation: Where the body provides a formal acknowledgment that an institution is competent in providing a service or producing a product.
- Licensure: Given by a government organization in recognition of skills, knowledge, and training, allowing the institution to operate.
The WHO standards are developed for disease-specific laboratories like Polio, where the organization conducts proficiency testing on the accredited labs regularly.
The ISO is the world’s largest developer and publisher of international standards, which are applicable to many kinds of organizations, including laboratories, providing a technical base for health, safety, and conformity assessment. Various standards are provided under different categories, i.e. general quality management systems like the ISO 9001 certification that a lab can use to prove its proficiency. Other standards like the ISO/IEC:17025 is more specific to testing and calibration laboratories. Third-party audits are done to evaluate the laboratory with the goal of attaining accreditation.
For a laboratory, achieving ISO accreditation shows that its processes and technical competence are of high quality and meet the confidence framework of international standards.
The benefits of ISO certification or accreditation for a laboratory are:
- Expands the laboratories’ market share because of the gain in customer’s confidence in lab processes.
- It is subject to continual assessment, thus, giving the laboratory a continuous mechanism for quality improvement.
- It is an avenue for improvement of staff competencies due to the period evaluations.
- International accreditation and certification may be a requirement for certain funding agencies.
- It improves the credibility of results obtained from the lab.
- In some countries, government registration of laboratories is dependent on international accreditation or certification.
- It enhances customer satisfaction and loyalty.
Laboratory quality management increases overall performance and greater confidence in the reliability of results obtained in the lab. When developing quality practices, ensure that all the lab’s processes and procedures are outlined so as to create a proper workflow with clear responsibilities. The lab management should make certain that the staff is actively involved in the development and implementation of the quality system to enhance compliance. The many benefits of a proper laboratory quality management system far outweigh the laborious design, set-up, and monitoring process and it is important for any analytical, diagnostic, or research lab to have one in place.
- NCCLS. Application of a quality management system model for laboratory services; Approved Guideline: Third Edition. NCCLS document GP26-A3. NCCLS. Wayne, Pennsylvania. 2004.
- ISO 15189:2007. Medical laboratories: requirements for quality and competence. Geneva, Switzerland: International Organization for Standardization; 2007
- Verónica Valdivieso-Gómez and Rocío Aguilar-Quesada (August 22nd 2018). Quality Management Systems for Laboratories and External Quality Assurance Programs, Quality Control in Laboratory, Gaffar Sarwar Zaman, IntechOpen, DOI: 10.5772/intechopen.73052
- Guide to Quality in Analytical Chemistry An Aid to Accreditation. 2002 CITAC and Eurachem publishing.
- Roberta B. Carey, Sanjib Bhattacharyya, Sue C. Kehl, Larissa M. Matukas, Michael A. Pentella, Max Salfinger and Audrey N. Schuetzg. Implementing a Quality Management System in the Medical Microbiology Laboratory. Clinical microbiology reviews. 2018 doi 10.1128/CMR.00062-17