TURNAROUND TIME OPTIMIZATION IN HEMATOLOGY LABORATORIES: EVALUATING THE IMPACT OF ERROR-FREE TESTING INTERVENTIONS THROUGH SIX SIGMA METHODOLOGY

Abstract

Introduction: Laboratory Turnaround Time (TAT) serves as a critical performance indicator in clinical laboratories and varies depending on the nature of the test (stat versus routine), analyte type, and institutional protocols. TAT is broadly defined as the duration from the initiation of a laboratory test order to the final reporting of results. The comprehensive TAT encompasses the entire “brain-to-brain” cycle starting from the clinician’s test request to the interpretation and application of the result in patient management. Six Sigma focuses on quantifying process defects as Defects Per Million Opportunities (DPMO), with an aspirational target of 3.4 defects per million, signifying near-zero error.

Materials and Methods: This analytical study was conducted at the hematology departments of multiple tertiary care hospitals in Lahore, Pakistan. Complete blood count (CBC) samples were collected systematically over a one-month period. All samples were analyzed using a fully automated five-part differential hematological analyzer (Sysmex XN-9000) ensuring standardized processing and reporting protocols. The routine TAT for CBC in these laboratories was set at 4 hours. The Sigma metric for CBC parameters was calculated using the formula: Sigma (ơ) = [TEa - bias)/CV]. Where TEₐ represents Total Allowable Error, Bias is the systematic deviation from the true value, and CV denotes the Coefficient of Variation.

Findings: Defects were identified based on delayed reporting exceeding the standard TAT, and Six Sigma values were derived by calculating the DPMO. An initial assessment of TAT and Sigma metrics was performed before any intervention. Subsequently, laboratory personnel underwent targeted training focused on optimizing analytical processes, emphasizing sample handling, analyzer operation, and result validation. After the one-month intervention period, the TAT and Sigma metrics were reassessed to evaluate the impact of training on process efficiency and error reduction.

Conclusion: This study provides an evidence-based framework for applying Six Sigma methodology to optimize laboratory TAT in tertiary care settings. By identifying key process inefficiencies and implementing targeted corrective actions, significant improvements in TAT and analytical quality can be achieved, ultimately enhancing patient care delivery.