Investigation of the Impact of Some Pre-Analytical Variables on Hematology Sample Rejection Rates at Masvingo Provincial Laboratory, Zimbabwe (2024)

Abstract

The investigation aimed to assess the impact of pre-analytical variables on hematology sample rejection rates at Masvingo Provincial Laboratory in Zimbabwe. High rejection rates can compromise patient care and laboratory efficiency, necessitating a thorough understanding of contributing factors. A retrospective cross-sectional study design was employed, analysing data from all haematology samples submitted over a one-year period in 2024. The study included both accepted and rejected samples, leveraging historical records to identify patterns. Key informant interviews with laboratory personnel and healthcare providers supplemented the quantitative data. A standardized data extraction form, validated through expert consultations and pretesting, captured information on specimen collection, handling, and transportation conditions. Ethical approval was secured prior to the study. Monthly rejection rates fluctuated between 0.2% and 3.0%, with the highest rates observed in June, July, and October. Clotted samples emerged as the primary cause of rejection (28%), followed by incorrect tube usage (18%) and lip emic samples (14%). Analysis revealed that the majority of rejections originated from the paediatric ward, highlighting specific areas for improvement. The findings underscore the critical role of pre-analytical factors in sample rejection rates. Recommendations include enhancing training for staff on specimen handling and collection techniques, particularly in high-rejection wards. Implementing systematic reviews of procedures may further reduce rejection rates, ultimately improving patient outcomes and laboratory efficiency.