Clinical Laboratory Specimen Rejection--association with the Site of Patient Care and Patients' Characteristics: Findings from a Single Health Care Organization

Context: Programs to track laboratory quality have reported aggregated specimen rejection rates ranging from 0.30% to 0.83%. Because the performance of the laboratory, rather than errors, has been the focus, reasons for specimen rejection or demographic characteristics of individuals at risk for specimens of poor quality may not be fully understood.

Objective: To calculate the proportions of rejected specimens stratified by point of collections and demographic information of patients.

Design: Retrospective cross-sectional study. Data were retrieved from the intrainstitutional electronic databases.

Results: The proportions of specimens that were rejected in the emergency department and inpatient services were 2-fold and more than 5-fold higher, respectively, than for the outpatient services. Assessment of data by patients' ethnic heritages yielded no significant differences among African Americans (0.38%), Caucasians (0.38%), or "Others" (0.35%) in the outpatient services (P = .07). In the emergency department, the proportions of rejected specimens for African Americans (2.24%) were almost twice that of Caucasians (1.39%) and 30% higher than for Others (1.70%). A similar finding was observed for the inpatient services.

Conclusions: The effect of ethnicity on the proportions of rejected specimens was significant for samples that were collected in the emergency department and inpatient services, even after adjusting for the total number of specimens. A constellation of factors, that is, disease severity and seriousness, practice of blood sample collection, and lesser proficiency of the nursing staff in phlebotomy may be reasons for this observation. However, the likelihood of differential care, although unlikely, cannot be refuted by the present data.