Turnaround Time of Laboratory Investigations and Factors Responsible for Delays in a Tertiary Care Teaching Hospital in Eastern India: A Cross-Sectional Study

Background The timely delivery of laboratory reports is crucial for guiding medical decisions and ensuring optimal patient care. The efficiency of clinical laboratory services, measured by turnaround time (TAT), directly impacts patient outcomes. This study aimed to evaluate the TAT for biochemical and haematological investigations at AIIMS Patna, to identify areas for improvement. Methods A descriptive cross-sectional study using Hospital Information System (HIS) data from January to March 2022 was undertaken. Only samples with same-day requisition and collection were included to avoid patient-related delays. A total of 201,552 analysable samples - 178,596 biochemistry (88.6%) and 22,956 haematology (11.4%) - were extracted. Time stamps for requisition, sample acceptance, result entry, and result validation were retrieved. TAT was quantified as pre-analytical (requisition to sample acceptance), analytical (acceptance to result entry), post-analytical (entry to validation), and total TAT. Median values, with 10th to 90th percentiles, were calculated. Additionally, awareness of TAT was assessed among 46 laboratory staff using a structured questionnaire. Results Of 521,822 laboratory records retrieved from the HIS, 201,552 samples (38.6%) with complete and valid time-stamp data were available for analysis, after exclusion of records with implausible or negative time intervals. The overall median total TAT was 278 minutes (4 hours 38 minutes), with comparable median values for biochemistry (279 minutes) and haematology (273 minutes). Phase-wise analysis showed that the pre-analytical phase contributed approximately 56%, and the post-analytical phase 18%, of the total TAT, indicating that non-analytical processes accounted for nearly three-quarters of the overall delay. When analytical benchmarks were applied, 136,741 biochemistry samples (76.5%) met the