Abstract Background: Laboratory test results are crucial for clinical decisions, but errors at any stage can compromise patient safety. Despite technological advances and quality systems, laboratory processes remain vulnerable, necessitating structured risk assessment. Limited research exists on integrating Failure Mode and Effects Analysis (FMEA) with Sigma metrics. This study addresses these gaps through a comprehensive risk assessment in a NABL-accredited tertiary care hospital laboratory. Methods: A retrospective observational study was conducted over 2.5 years. FMEA was used to identify errors across all phases of the total testing process. Quarterly error rates were calculated, converted to defects per million (DPM), and expressed as Sigma metrics. Risk Priority Numbers (RPN = severity × detectability × frequency) were scored quarterly to prioritize failures. The effect of corrective actions was evaluated by comparing pre- and post-intervention Sigma values. Results: Across ten quarters (five pre- and five post-intervention), 23 error types were identified. The highest RPNs (>20) were observed for haemolysed samples, clotted samples, and non-intimation of critical values. Haemolysed samples declined from 0.97% to 0.49% (ARR 0.48%; RR 0.51; 95% CI 0.47–0.55; p < 0.0001). Clotted samples reduced from 0.24% to 0.06% (ARR 0.18%; RR 0.24; 95% CI 0.20–0.29; p < 0.0001). Non-intimation of critical values decreased from 2.63% to 2.18% (RR 0.83; 95% CI 0.70–0.99; p = 0.065). Conclusion: Integrating FMEA with Sigma metrics provides a robust framework for identifying, prioritizing, and reducing laboratory errors. Continuous monitoring and corrective action are essential to sustain improvements in laboratory quality and patient safety.
Ramachandra et al. (Mon,) studied this question.