Quality assurance using patient split samples: recommendations for primary healthcare laboratories.

Abstract

Objectives: The increasing adoption of point-of-care testing (POCT) in primary healthcare highlights the need for robust quality assurance (QA) procedures to ensure result reliability. The patient split sample approach, i.e. comparing POCT and central laboratory results from the same patient, can be a valuable QA tool, though practical guidance for its implementation remains scarce. This study aimed to develop clear, user-friendly recommendations for non-laboratory personnel in primary healthcare laboratories on when and how to perform such comparisons and to recommend acceptable limits for the compared results.

Methods: In 2023, an expert group was established, composed of medical specialists in laboratory medicine, researchers, and laboratory advisors. The recommendations were formulated based on relevant literature, the professional experience of the group members, and Noklus' educational framework for primary care laboratories. Pragmatic acceptability limits were established taking several approaches into account. The draft recommendations were audited among more than 120 Noklus employees and final consensus was reached in 2024.

Results: Comparing POCT results with central laboratory results is recommended when: (A) no suitable EQA program exists for a given POCT; (B) appropriate internal quality control materials are lacking or inadequate; or (C) POCT results contradict clinical expectations. Acceptable limits for the compared results were set at 15 or 20 %, depending on the measurand. Results outside these limits should be reviewed using a structured checklist.

Conclusions: These are the first published recommendations for using patient split samples in primary healthcare that are designed to be simple and user-friendly for non-laboratory personnel, facilitating widespread adoption.