A-182 Analysis of Sample Recollections in an Outpatient Laboratory: A 5-Year Big Data Study

Abstract Background Laboratory testing requires continuous improvement to ensure accurate results. Standardizing processes and quality indicators is essential for the efficient management of laboratory services and analyses. The pre-analytical phase is particularly vulnerable to variables that may compromise sample integrity and lead to laboratory errors. Inadequate pre-analytical conditions can affect test results, leading to sample recollection, which delays diagnosis and causes patient discomfort. Additionally, recollection results in wasted supplies, time, and human resources. This study aims to identify the main causes of recollection and the most affected tests to improve protocols and enhance the quality of clinical analyses. Methods The present study is a descriptive, cross-sectional, and retrospective analysis of recollection cases in a Brazilian laboratory from 2020 to 2024, utilizing big data. The analysis focused on identifying the causes of recollection and the most affected tests among 23,016,266 tests performed during this period. Results This study critically analyzed the LIS database of a laboratory in Brazil, identifying 9,880 recollection cases over the 5 years. The proportion of recollections among all laboratory tests performed was 0.04% in 2020 (n=1618/3,646,518); 0.05% in 2021 (n = 2,160/4,515,699), 0.05% in 2022 (n=2,222/4,760,254), 0.04% in 2023 (n = 2,042/4,901,612), and 0.04% in 2024 (n = 1,838/5,192,183). Among the most frequent reasons for recollection, result confirmation accounted for 37.8% (3,737/9,880) of cases, followed by insufficient sample volume in 16.2% (1,605/9,880). Samples collected in the wrong tube were the third most common cause, representing 8.7% (868/9,880), while samples outside stability conditions accounted for 5.6% (557/9,880), and hemolysis for 4.3% (429/9880). When grouping the reasons for recollection, issues related to sample collection were the most prevalent 37,5% (3705/9880), followed by problems in sample storage 10,8% (1071/9880) and transportation 4,7% (467/9880). Regarding the most affected tests, recollections for zinc measurement accounted for 13.64% (1,348/9,880) of cases, followed by complete blood count (CBC) at 5.45% (538/9,880), copper at 5.02% (496/9,880), aluminum at 4.19% (414/9,880), and potassium at 2.97% (293/9,880). Grouping tests by section, mineral assays represented the highest proportion of recollections, 25.23% (2,493/9,880), followed by CBC in 5.45% (538/9,880), vitamin assays in 4.96% (490/9,880), and ion analysis at 4.74% (468/9,880). Also, coagulation tests accounted for 2.54% (251/9,880) of recollections. Conclusion This five-year analysis of sample recollections has highlighted key areas for improvement in the pre-analytical phase. The study reveals that factors such as result confirmation, insufficient sample volume, and improper sample collection are the primary causes. Tests related to zinc, complete blood count (CBC), and mineral assays were the most frequently affected, underlining the need for enhanced protocols in these areas. Addressing issues related to sample collection, storage, and transportation is crucial for reducing recollection rates, minimizing waste, and ensuring faster, more accurate diagnoses. Standardizing procedures, improving staff training, and leveraging data analytics for real-time monitoring can significantly improve the quality of laboratory services and patient care.