Definition/Introduction

Clinical laboratories are healthcare facilities providing a wide range of laboratory procedures that aid clinicians in diagnosing, treating, and managing patients.[1] These laboratories are manned by scientists trained to perform and analyze tests on samples of biological specimens collected from patients. 

In addition, clinical laboratories may employ pathologists, clinical biochemists, laboratory assistants, laboratory managers, biomedical scientists, medical laboratory technicians, medical laboratory assistants, phlebotomists, and histology technicians.[2] Most clinical laboratories are situated within or near hospital facilities to provide access to clinicians and their patients.[1]

Classifications of clinical laboratories indicated below reveal that these facilities provide quality laboratory tests that are significant for addressing medical and public health needs.

The list below is non-exhaustive as new laboratory models are emerging:

• Ownership
  • Government (usually part of hospitals and medical centers under the Department of Pathology or Laboratory Medicine)
  • Private (part of a medical or healthcare institution)
• Function
  • General clinical laboratories provide standard diagnostic laboratory tests
  • Specialty laboratories provide less commonly used diagnostic and confirmatory tests
• Test specialization 
  • Clinical chemistry
  • Clinical Microbiology
  • Hematology
  • Blood banking and serology (ie, Immunohematology, Transfusion medicine)
  • Histopathology and cytopathology
  • Molecular biology
  • Public health: providing tests such as water analysis and testing for environmental toxins
• Laboratory network: facilities operated, managed, and supervised by authorities at different levels
  • Peripheral laboratories provide routine screening, diagnostic (eg, conventional and rapid diagnostic tests), and follow-up tests for patients, usually within the local community[3]
  • Intermediate-level laboratories at the district, provincial, and regional-level facilities
    • May conduct additional tests than those provided in peripheral laboratories and can serve as referral laboratories for special cases. 
    • Aside from performing tests, they perform management and supervisory tasks under specific areas of jurisdiction.[4]
  • National reference laboratories, also known as the central level, oversee the overall management of the laboratory network and provide a range of routine and specialized laboratory testing, introducing and phasing new diagnostic tests.[1] They also perform the following functions:
    • Policy and program implementation
    • Training and development
    • Monitoring, evaluation, and research[1]

In the past, the value of clinical laboratories as an integral part of the healthcare system was unrecognized.[5] Over time, more clinicians have recognized the need for laboratory tests to confirm their diagnoses and support monitoring patient response to therapy.[6] Aside from value to individual patients, clinical laboratories were also used for screening and surveillance of diseases. On a larger scale, program managers used some relevant tests as surrogate indicators to assess the progress of public, international, and global health programs.[7]

Laboratory networks were developed across countries and states to foster coordination and collaboration within the specified geographic areas.[8] Quality management systems within these laboratories have recently become significant issues, including standardization of laboratory services, strengthening laboratory systems, and developing new and rapid diagnostic tools. These issues are continually addressed by local and international health authorities and technical experts employing a patient-centered approach.

Clinical laboratories perform testing logically and strictly. Generally, there are 3 phases of the laboratory testing process that each facility should follow. Standard operating procedure manuals and job aids are written for guidance for each phase step: pre-analytical, analytical, and post-analytical.[9] The pre-analytical phase is critical, with over 60% to 70% of laboratory errors occurring in this phase.[10] 

Clinical laboratory professionals have embraced technology over the years to derive answers to clinical questions. Modern clinical laboratories use technologies, including spectrophotometry, atomic absorption spectroscopy, cytometry, flame emission photometry, nephelometry, electrochemical, optical sensors, electrophoresis, and chromatography.

• Spectrophotometry is a technique used to measure the absorbance of colored compounds in solution, helping to identify and quantify various substances in blood and body fluids.[11]
• Atomic absorption spectroscopy (AAS): a vital tool in clinical analysis, enabling the measurement of metallic element concentrations within biological fluids and tissues like whole blood, plasma, urine, saliva, brain tissue, liver, hair, and muscle tissue.[12]
• Cytometry is a technique to measure the properties of individual cells, such as size, shape, and DNA content, which can help diagnose and monitor conditions like cancer or genetic disorders.[13]
• Flame emission photometry: a technique to measure the emission of light from a sample excited by a flame, helping to identify and quantify compounds in blood and body fluids.[14]
• Nephelometry is a technique to measure the turbidity of a solution, which helps diagnose and monitor conditions like liver disease or kidney failure.[15]
• Electrochemical technologies are used to measure the electrical properties of a solution, such as pH, conductivity, and redox potential, which help diagnose and monitor conditions like acid-base disorders or electrolyte imbalances.[16]
• Optical sensor technologies: use sensors that detect and measure various properties of a sample using light, such as refractive index or fluorescence, which helps identify and quantify various substances in biological fluids.[17]
• Electrophoresis is a technique to separate and analyze proteins in a sample, which helps diagnose and monitor conditions like multiple myeloma or amyotrophic lateral sclerosis.[18]
• Chromatography is a technique that helps identify and quantify different components in blood and bodily fluids by separating and analyzing compounds in a sample according to their molecular properties, such as size, charge, or shape.[19]

The landscape of clinical laboratory operations has transformed due to the integration of automation, impacting both the analytical and non-analytical aspects. This transition towards automation commenced over 5 decades ago, focusing on automating laboratory test procedures.[20] However, the true leap occurred in the 1990s when non-analytical automation gained momentum, featuring conveyor systems, interfaced analyzers, and automated specimen processing and storage. Automation in the clinical laboratory is classified into 3 categories: manual, stand-alone automation (modular), and total lab automation (TLA).[21]

Automation has a wide-ranging impact, improving laboratory ordering, testing, and reporting processes while eliminating tedious and time-consuming chores.[22] It has ushered in a new era of heightened productivity by streamlining the use of reagents and materials, standardizing operations, and reducing the occurrence of outliers. The efficiency increases production rates and improves accuracy and precision in test results. Automation is a cornerstone in modern clinical laboratories, revolutionizing operations and elevating the overall quality of laboratory testing.[23]

Clinical laboratory specialists perform an array of tasks, including developing and validating new laboratory tests, assessing and defining the analytical and clinical performance, conveying laboratory results to clinicians, offering valuable education and guidance to the clinical team, evaluating the cost-effectiveness and intrinsic value, ensuring strict compliance with regulatory standards, engaging in quality assurance measures, and participating in both basic and clinical research endeavors.[24] 

The laboratory professional must maintain the confidentiality of medical information, use resources appropriately, abide by codes of conduct, follow ethical publishing rules, and manage and disclose conflicts of interest.[25]

Issues of Concern

Providing high-quality diagnostic testing is the goal of all clinical laboratories. Improving laboratory capacity is crucial to address various issues and problems. Managing resources, training, supervision, planning, budgeting, quality assurance, logistics and supply, and biosafety and equipment management are necessary to optimize laboratory services provided to patients.[25]

In 2018, the World Health Organization developed and released the Essential Diagnostics List (EDL). This list was expected to align the health community to the accessibility and availability of high-quality testing of clinical laboratories, especially in resource-limited settings.[26] Using the EDL with essential medicines list (EML), authorities can now focus their efforts so that people receive the necessary laboratory services.[27]

Accreditation for clinical laboratories was recently relevant due to the emergence of international laboratory standards. Several guidelines for laboratories have been developed to regulate laboratory test procedures and maintain their quality.[28] An example of laboratory accreditation is the ISO 15189 provided by the International Organization for Standardization (ISO), which focuses on meeting the requirements for the quality and competence of medical laboratories.[29] Another example is biosafety guidelines around microbiological agents such as bacteria, viruses, parasites, and microbiological products.[30]

The need for risk management in clinical laboratories was highlighted to maintain the accuracy and reliability of laboratory tests. The Clinical Laboratory Standards Institute (CLSI) developed a guideline to introduce risk management principles specifically in the clinical laboratory.[31] From risk assessment to risk analysis, evaluation, and control to continuous quality improvement, the clinical laboratory should be able to minimize errors along its path of the workflow (ie, preanalytic, analytic, and postanalytic phases). Significant risks such as specimen collection, processing, and disposal of laboratory wastes should be considered.[32]

A laboratory information system (LIS) is valuable in managing results and other pertinent information regarding patients and their samples.[33] The development of a laboratory information system started in the 1960s, concentrating on data reduction, analog-digital conversion, and radioimmunoassay analysis. Recently, the focus has evolved into digital histopathology and genomics, issues about patient access to data, and more.[34] In a rapidly changing environment for the modalities of patient record systems, there is a need for collaboration between clinical systems developers and laboratory-based informaticians to modify and improve the existing technology to meet patient needs.

Clinical Significance

As the challenges faced by clinical laboratories rise, clinicians should be aware of the impact on their patients. While patients and people in the community are not well aware, the function and mandate of clinical laboratories remain the same: the provision of high-quality laboratory diagnostic tests.

Improving existing laboratory services should not be overlooked when developing newer diagnostic tests.[35] Health authorities at the global level and stakeholders, including clinicians, experts, and other healthcare professionals at the local level, must recognize that clinical laboratories affect the most important clients of healthcare: patients.[36] 

Nursing, Allied Health, and Interprofessional Team Interventions

In the clinical laboratory setting, the collaborative efforts of various healthcare professionals, including physicians, advanced practitioners, nurses, pharmacists, and allied health experts, are instrumental in patient-centered care and outcomes. Nurses play a pivotal role by utilizing their skills in patient advocacy, attention to detail, and specimen collection. They contribute significantly to ethical considerations, ensuring patient confidentiality and dignity in all laboratory procedures. Alongside nurses, allied health professionals and pharmacists exhibit expertise in managing and interpreting laboratory results, informing diagnosis and treatment.

Interprofessional communication is a cornerstone, facilitating seamless critical information exchanges among team members, leading to enhanced care coordination and patient safety. This collaborative approach ensures the timely delivery of laboratory results to clinicians, empowering informed clinical decisions. As a result, the clinical laboratory becomes an integral part of the healthcare ecosystem, promoting patient-centered care, fostering improved team performance, and ultimately elevating patient outcomes.