Laboratory tests have an important place in the diagnosis and treatment of patients. This requires test results to be accurate, repeatable, and timely. The pre-analytical phase is the phase where laboratory errors are most common and includes the largest portion of the total testing process. Another feature of the pre-analytical phase is that not only laboratory personnel are involved in the process, but also other healthcare personnel and patients working in clinics1. Therefore, it is very important that the quality of the pre-analytical process is also assured.
One of the most common pre-analytical errors is patient and sample identification. These errors are known to have very serious medical consequences. Conventional or two-dimensional barcodes are used to reduce pre-analytical errors, particularly patient and sample matching errors2. Alternative solutions available thanks to the developments in information technology (IT) are radio frequency identification (RFID) tags, infrared (IR) based patient tracking, wireless networks, patient smart cards and biometric technologies3. Innovative approaches for univocal patient identification are also emerging, such as human hand dorsum skin tissue detection4, probabilistic matching5 or near-field communication (NFC). Interestingly, Hawker et al6 recently developed an automated device based on four cameras that photographs the outside of a sample tube and then, via optical character recognition (OCR), recognizes discrepancies between patient ID in the LIS and patient ID on the blood tube label.
The reference procedure published by the CLSI for the collection of diagnostic blood samples by venipuncture includes instruction that blood tubes should be labeled after filling, not before. This is in clear contradiction with the recommendations of the World Health Organization (WHO) and the Italian Society for Clinical Biochemistry and Laboratory Medicine (SIBioC) () both mandating that blood tubes be labeled before and after filling. In particular, EFLM's WG-PRE also recommends that patient and specimen identity always be checked near the patient, but concludes that labeling of tubes before or after blood collection should be based on local risk analysis of phlebotomy.
As can be seen, there is no consensus on whether barcoding should be done before or after phlebotomy. Some investigators recommend using pre-barcoded tubes to reduce patient and sample matching errors, but some investigators report that, contrary to expectations, this can be life-threatening due to the lack of real-time sampling time. By using pre-barcoded tubes; It is expected that the workload and waiting time before blood collection will decrease, the label paper quality will be better and the inconveniences caused by manual sticking errors will be eliminated. Does this time gain make a significant difference on the total TAT? However, the most critical time period that creates a bottleneck in practice is the time spent during phlebotomy; because in classical applications the barcoding of the tubes is done by other laboratory staff before sampling, but in modern applications, the labeling process is done with automatic barcoding robots next to the patient. Therefore, while the expectation that pre-labeled tubes will reduce the workload and save time is true for the use of manual labeling, it is not true when using modern phlebotomy flow systems. In addition, life-threatening patient sample matching errors are experienced in inpatient services, especially in emergency services, due to the use of previously barcoded tubes. In case of using only specially numbered tubes on which there is no name etc information, the error rate may increase even more.
When using previously barcoded tubes, this expectation of time savings, which can be achieved in blood collection units with higher sample counts, is taken into account; however, problems with traceability of the sample in the process after it reaches the laboratory are not taken into account. Moreover, in daily laboratory practice, laboratory workers often need data such as the name on the barcode of the sample, the service it came from and the time of blood collection for the separation, pre-treatment, analysis and storage of the sample; they can do this visually by quickly looking at the label. Since it is not possible to visually access this information in previously individually barcoded tubes, laboratory workers will often want to access this information by entering the barcode information of the sample into the LIMS system; however, this is a serious waste of time and tedious and error-prone process.
... the most critical time to bottleneck in practice is during phlebotomy; because in classical applications the barcoding of the tubes is done by other laboratory staff before sampling, but in modern applications, the labeling process is done with automatic barcoding robots next to the patient. Therefore, while the expectation that pre-labeled tubes will reduce the workload and save time is true for the use of manual labeling, it is not true when using modern phlebotomy flow systems.
Ali Rıza Şişman, Prof. Dr.
In addition, the fact that all tube manufacturers do not have single barcoded tubes beforehand causes difficulty in supply. In addition, the global applicability of the use of previously single barcoded tubes will also require tight coordination and standardization among the relevant companies. Because if the barcode numbers used by the tube manufacturers overlap, the contradictions that may arise will narrow the options of the institutions and may cause errors. It is known that HBYS/LIMS systems in use do not have single-label usage modes before. These systems will need to be modified to accommodate the use of previously single labeled tubes, and historical data will need to be updated to accommodate this change.
As a result, when the available data are evaluated together, the available information and the proposed evidence on how pre-coded tubes accelerate the pre-analytical process and contribute to patient sample barcode matching in wards are not sufficient. On the contrary, the fact that the phlebotomy time is open to the risk of life-threatening dangers such as the lack of real time and the absence of visually traceable information in the barcodes may create sample tracking problems within the clinic and laboratory. In other words, it is obvious that there is a need for scientific studies that reveal the advantages and disadvantages of the use of these tubes.
1 Ross JW, Boone DJ. Assessing the effect of mistakes in the total testing process on the quality of patient care [Abstract]. In: 1989 Institute on Critical Issues in Health Laboratory Practice: improving the quality of health management through clinician and laboratorian teamwork. Minneapolis: Institute on Critical Issues in Health Laboratory Practice, 1991.
2 Lippi G, Blanckaert N, Bonini P, Green S, Kitchen S, Palicka V, Vassault AJ, Mattiuzzi C, Plebani M. Causes, consequences, detection, and prevention of identification errors in laboratory diagnostics. Clin Chem Lab Med. 2009; 47(2):143-53.
3 Lippi G, Chiozza L, Mattiuzzi C, Plebani M. Patient and Sample Identification. Out of the Maze?. J Med Biochem. 2017;36(2):107-112. Published 2017 Apr 22. doi:10.1515/jomb-2017-0003
4 A study of hand back skin texture patterns for personal identification and gender classification. Xie J, Zhang L, You J, Zhang D, Qu X Sensors (Basel). 2012; 12(7):8691-709.
5 An empirical comparison of record linkage procedures. Gomatam S, Carter R, Ariet M, Mitchell G Stat Med. 2002 May 30; 21(10):1485-96.
6 Hawker CD, McCarthy W, Cleveland D, Messinger BL.Invention and validation of an automated camera system that uses optical character recognition to identify patient name mislabeled samples. Clin Chem. 2014 Mar; 60(3):463-70.
A project done at SBU Tepecik EAH, based on Phlerobo system, has been selected amongst the best practices list of Ministry of Health.