Evaluation of Non Conformances in the Total Testing Process of a NABL-accredited Clinical Biochemistry Laboratory: An Observational Study

Introduction: Maintaining quality within clinical laboratories is fundamental to patient safety and reliable diagnosis. Every stage of the Total Testing Process (TTP) from sample collection to result reporting, is prone to errors that can affect both clinical decisions and operational efficiency. Systematic identification and analysis of Non Conformances (NCs) form an integral part of accreditation and continual quality improvement. Aim: To analyse the nature, frequency, and underlying causes of NCs in a National Accreditation Board for Testing and Calibration Laboratories (NABL)-accredited, clinical biochemistry laboratory attached to a medical college. Materials and Methods: An observational study was conducted in the Clinical Biochemistry Laboratory of a tertiary care teaching hospital located in rural Gujarat, India, over a 12- month period, from March 2023 to February 2024. All recorded NCs were reviewed and categorised according to seven domains, including type, recurrence, severity, root cause, and impact. Root Cause Analysis (RCA) was undertaken using the “5 Whys” and Fishbone (Ishikawa) diagram approaches. Data were analysed descriptively and expressed as frequencies and percentages. Results: A total of 439 NCs were documented. Pre-analytical errors were most frequent (53.30%), followed by analytical (43.51%) and post-analytical (3.19%) errors. Human error (62.18%) and technical factors (36.90%) were the main root causes. Most NCs were isolated (76.77%) and minor (70.16%), chiefly affecting resource utilisation (59.91%) and turnaround time (29.16%). Conclusion: Pre-analytical weaknesses and human-related factors remain the key contributors to laboratory NCs. Regular monitoring, structured RCA, and continuous staff training are essential to sustain accuracy, efficiency, and quality within clinical biochemistry laboratories.