Preanalytical errors are those occurring at any point before a specimen is analyzed—during collection, labeling, transportation to a laboratory, processing of specimens within a laboratory and/or when placing specimens into storage.1 Mishandling and mislabeling errors during sample collection and subsequent patient misidentification can lead to specimen loss, misdiagnosis and, in some instances, serious adverse events such as blood product mismatching or administration of inappropriate medical treatment.2,3 Mislabeling or mishandling of specimens in an etiology study such as Aetiology of Neonatal Infection in South Asia (ANISA) could very likely result in errors in pathogen-specific incidence, risk factor analysis, treatment success and other analyses and could impact the validity of the conclusions drawn. Preanalytical error rates vary greatly across countries and facilities, owing mainly to different available resources, standards and oversight of procedures.2,4 They account for the majority of errors in the modern laboratory, whereas analytical laboratory errors have seen a 10-fold decrease over the past 5 decades through introduction of higher standardization, technology and automation. During this time, the proportion of preanalytical errors has grown from 70% to 93% of all diagnostic errors.5–9 The threat these errors pose to scientific validity underscores the need for significant efforts to keep preanalytical errors to a minimum.
Barcode-based labeling systems have been used to improve accuracy in a variety of tasks and ensure staff follow processes.10 The development and introduction of barcode systems designed to work alongside a specific work flow have been shown to dramatically reduce laboratory specimen misidentifications while simultaneously increasing protocol adherence and diagnostic efficiency in both hospital-based laboratory settings11 and community-based research in developing countries.12
The ANISA study is taking place at community-level sites in Bangladesh, India and Pakistan. The field teams collect data and biological specimens from both community-acquired cases of possible serious bacterial infection and healthy controls in a variety of urban and rural settings in these countries. We assumed that the risk of preanalytical errors would be potentially high in the ANISA study because each site had different clinical and field settings, health practitioners and pre-existing laboratory procedures, whereby specimens would be transported to various laboratories both inside and outside the respective countries. The validity of the ANISA study findings depends on accurately detecting pathogens present in biological specimens and reliably linking these laboratory results to the correct study participant data. Thus, we developed a centrally designed barcode-based specimen labeling and tracking system and complementary customized software to identify and track specimens and store data in a central database. This article describes the design and implementation of that system.
The key elements of the barcoded labeling system were designed by the project coordination team located in Dhaka, Bangladesh. Careful customization was needed to match the project field and laboratory protocols for streamlining, integration and adoption of the new system by project staff. Furthermore, this system had to be designed to operate as a fully integrated part of the larger custom-designed ANISA data management system, which was devised and supported by the ANISA Data Coordination Center.13
ANISA site teams capture data on community-acquired neonatal infection cases and healthy controls from 0 to 59 days of life, using an active and passive surveillance system, and specimens are drawn upon physician diagnosis without delay.14 Specimen collection takes place at various locations ranging from formal hospital settings to rural community health clinics to mobile teams in households. Therefore, the specimen labeling and tracking procedures have to be versatile and straight forward enough to be used in a variety of field conditions.
The study physician and a trained phlebotomist are responsible for collection of a maximum of 3 specimen types upon diagnosis: (i) blood; (ii) pooled nasopharyngeal and oropharyngeal (NP-OP) swabs and (iii) cerebrospinal fluid (CSF). Collection of all 3 specimen types does not always occur and is not always performed at the same time, in the same place or in some cases by the same practitioner. CSF samples are collected rarely, only in cases where young infants are hospitalized for suspected meningitis. Each of these biological specimens can be collected in up to 4 separate receptacles, requiring different processing, storage and specific shipment temperatures during transport to the laboratory. Different specimens from a single young infant follow a variety of processing paths (Fig. 1). Follow-up specimens are requested if the blood specimen yields bacteria upon culture and the child’s condition has not improved or has deteriorated after 72 hours.
Once specimens are received at the laboratory, each receptacle is directed to different diagnostic testing pathways and the sample separated accordingly into multiple aliquots. Thus, each particular specimen type, episode and individual receptacle requires an identifier unique to that specific event, specimen and receptacle, and all specimens have to be reliably and inextricably linked to the individual from whom they are drawn.
Taking these conditions into account, the tracking system was designed to be reliable and accurate while following the path of each specimen and aliquot through collection, transfer to alternate receptacles during each laboratory processing step and during shipment between laboratories and to a biorepository. The system was intended to be as simple as possible for the end user to increase efficiency and accuracy and be easily adopted by partner laboratories.
The initial step in design of the labeling system was consultation with the staff at the central laboratory in Dhaka. The staff determined the required areas in the protocol where labels would be useful and agreed upon a list of features that would be helpful to incorporate into the specimen tracking system. First, the labeling system had to be easily understandable, accurate and include an open field for writing additional information, such as study identification number (ID), date and bacterial isolate description. Second, the labels would ideally include a color-coded band to identify specimen source type throughout the processing chain for easy visual identification by phlebotomists, porters and laboratory technicians (red for blood, green for NP-OP and gray for CSF). Labels had to be easily readable for staff and compatible with locally available generic barcode scanners. The label dimensions had to fit the smallest specimen collection vessels, vials and sample tubes used in the laboratory. Labels had to be durable and easy to use and affix onto containers and laboratory paperwork. All materials used in the labels also had to be highly resistant to both the tropical heat and the extreme cold of liquid nitrogen (as high as 40°C and as low as −190°C), including the ink and adhesives, which had to remain unaffected by moisture and frost from conventional and ultra-low freezers. The system also needed to include extra labels in case midstream modification of the laboratory protocol was required. Finally, the system would preferably be low cost.
Various iterations of the specimen labeling and tracking system were reviewed and modified to ensure that laboratory staff were comfortable with plans for daily use of the end product and felt a degree of ownership in the design. During successive consultations with staff and project data programmers, a detailed standard operating procedure and explanatory animated PowerPoint presentation was produced and refined to clarify both the laboratory protocol for using the labeling system and the integrated data entry steps. Feedback was obtained in the early stages to ensure smooth integration of the specimen labeling and tracking system into ANISA laboratory procedures.
Label Creation and Testing
We contracted Symbology Inc. (Maple Grove, MN; www.symbology.com) for label production and guidance in selecting appropriate materials and in other aspects of printing custom labels and barcodes. The organization provided a written guarantee that each label sheet would have a unique specimen ID with no duplications. To ensure that labels would stand up to study requirements, samples were sent to the central laboratory at Dhaka and tested by simulating field and laboratory conditions. The printed barcodes were tested using locally purchased scanners in the central laboratory before the finalization of the label orders.
All specimen labels came in sets, which were preprinted on rolls of bleached glassine backing containing 100 specimen collection sets per roll, with perforations between each sheet. Each sheet contained 12 individual labels made of white polypropylene backed with an emulsion acrylic adhesive. Labels had a temperature tolerance range of −196°C to 90°C and identical dimensions (25.4 mm × 25.0 mm). Every label sheet (Fig. 2) included a header portion for writing the study ID once the sheet was assigned to a child’s specimen collection and for stapling the label set onto the specimen collection form.
Based on extensive consultation with both laboratory and Symbology staff, the label design was finalized, and a single custom aluminum die cast was developed to cut out the team’s specimen label sheets. The same die cast was used for each of the 3 specimen types with customized label suffix patterns for the blood, NP-OP and CSF specimens. Label rolls of 100 were printed in separate specimen-specific batches to aid in inventory control at the sites. The custom die cast had a considerable upfront cost (~US$1000), but once the die was finalized the label spools could be produced at high speed and with guaranteed accuracy to any number, reducing the cost of a single label sheet to under US$0.40. Site print ranges were ordered, programmed, printed, boxed and shipped to each study site directly (Fig. 2).
Defining Label Ranges
All labels required for a complete battery of tests had a predefined specimen ID taken from the range assigned for each site. Selected ranges allow for each label set and individual label throughout the project to have a unique barcode ID. Each barcoded label contains encoded information identifying the specimen type, study site and specimen number (Table 1). For example, B10001-B19999 is the specimen ID range available for blood (B) samples from site 1 (Sylhet). Furthermore, each label in a set also had a label-specific suffix from 1 to 4 characters in length. These suffixes corresponded to the specific use for the particular label of that particular specimen type (Fig. 2). The suffixes were as simple as possible; for example, each label set has one label with the suffix “FORM,” indicating that it is to be used for the specimen collection form. Similarly, the “EDTA” label is always affixed to the EDTA blood collection tube. This simple strategy clarifies for laboratory staff which label is to be used for each process for that particular specimen. Each label’s contents were both encoded into the barcode, as well as printed on the label in 7 pt Arial font. This composition ensured that every specimen, obtained anywhere in the study, had a unique specimen number and suffix to indicate the specific processing step (Table 2).
In practice, study staff can simply take a sheet of specimen labels from a color-coded roll and staple it onto the correct specimen collection form. Specimen IDs are independently assigned so that they are neither linked to a particular ANISA child nor to any other specimens beforehand. In short, the critical linkage in the ANISA database between a child’s different specimen types is only created in the data set using the ANISA study ID upon arrival at the laboratory.
Specimen Collection and Labeling Process
Standard specimen collection procedures were established, and performance results were centrally monitored to ensure quality and consistency.15 Project staff used collection forms stapled together with the barcode label sheets during specimen collection. The label set is first affixed to the appropriate collection form, and the young infant’s ANISA ID is written on the top portion of the specimen form and label sheet. Then the FORM barcode label is placed into the designated space on the collection form so that the specimen barcode ID and the ANISA study ID are on both documents, ensuring rematching in case of detachment. Each receptacle is then labeled before the specimen collection attempt. The specimens are then drawn following standard procedures. Evidence shows that checklists improve both adherence to protocol and quality control in other critical medical and nonmedical areas.16 Therefore, the NP-OP swabbing and phlebotomy are performed using centrally developed ANISA guidelines, which include the labeling step to standardize procedures and limit contamination before specimen arrival at site laboratories.17
All labeled specimens and paired forms are transported together promptly to the designated laboratories. The inoculated blood culture bottles and CSF specimens are kept at room temperature (between 20°C and 37°C), avoiding extremes, whereas the NP-OP swabs and EDTA blood tubes are kept between 4°C and 8°C during transport. In cases where immediate transport is not available, the specimens are placed in temporary incubators or refrigerators, as appropriate, until transport can be arranged. Transfer of specimens between laboratories is recorded using the ANISA specimen collection form, which records relevant information regarding collection and transport conditions.
Upon arrival at the laboratory, the specimen collection FORM barcode is scanned into the computer system to record specimen receipt. The system, customized for this purpose and linked to the ANISA database, recognizes the barcode label that contains the specimen type, and the appropriate data entry screen for that specimen type is prompted automatically. To record and detect problems during specimen transportation, the receiving microbiologist then enters data directly into the computer from the collection form, including the arrival temperature, sample volume and sample container integrity. An automated time stamp of specimen arrival at the laboratory is also recorded and compared with the specimen collection time so that transport time can be calculated. The specimen ID is then paired with the ANISA ID. This first pairing event links the ANISA study participant with each of their specimens. This linkage is used in all subsequent tracking and analysis steps. Cross-confirmation using 2 or more linked numbers has been shown to substantially reduce critical errors in matching patients before blood transfusions.18 The ANISA ID is later reconfirmed with the specimen ID recorded on the physician assessment form to further ensure accuracy. Synchronization of the ANISA study ID with the specimen ID in the ANISA data management system is required for results of laboratory tests to then be matched with all of the information previously collected on the demographic, risk factors and medical history of the mother-child pair. Once all laboratory tests are completed, laboratory data are routinely uploaded to the ANISA central database.13
Once specimens are successfully received and entered, the specimen tracking system is able to follow them through each step of the laboratory protocol, including the processing of each specimen, its location, volume, distribution into multiple aliquots and so on. Finally, the system links each of the subsequent results of conventional and molecular diagnostic methods. The use of barcode labels in the laboratory is made easier by the presence of barcode scanners connected directly to the molecular machinery, including the MagNA Pure Compact System (Roche Diagnostics, Indianapolis, IN) and the ViiA 7 Real-Time PCR System (Thermo Fisher Scientific Inc., Waltham, MA). Barcode scanners are used along with customized tracking forms and facilitate accurate recording of ANISA laboratory activities, including documentation of any deviation from the standard operating procedure. Together these systems ensure that preanalytical errors are minimized, that ANISA’s molecular steps are performed within the parameters of the protocol and that all results are reliably linked to the full results of the TaqMan array card (Thermo Fisher Scientific Inc.) runs in the ANISA central database.
The location of all of the stored specimens is recorded for all sites in the custom-built ANISA data system and in the integrated biorepository software system, which relies on the barcode labels to store the various specimen aliquots. The system retains information on the count, volume, freeze-thaw events and exact locations and ages of all stored specimens across all ANISA site laboratories. This system is also color-matched with the barcode labels to ensure simplicity and error reduction during long-term storage in the −80°C freezers (Fig. 3). Full tracking records of specimen processing and any anomalies at various steps are recorded and will be available to inform the final interpretation of the end results of the project.
The custom ANISA specimen labeling and tracking system along with the ANISA data capture system ensures harmonized multinational specimen collection, testing and archiving for biological specimens. This system streamlines work processes in the laboratories and reduces complexity and time for laboratory staff, minimizing opportunities for preanalytical errors, and thus directly protecting valuable specimens and data.
The inherent time lag between physical collection and entry of data forms from the field creates a gap as young infants become ill very early in life; specimen receipt is often the first time that the data system captures the existence/birth of a sick (or control) neonate via the collection of specimens. This computerized system provides reliable real-time information on the project’s performance and important input for the data-based monitoring activities,19 allowing the coordination team to quickly and accurately track study progress and performance in the laboratories and clinics.
By including rigid rules for input of laboratory data into the data capture system relying heavily on the barcode labels, the system reinforces logical sequences of processing steps to be followed by staff, improving protocol adherence and maintaining a linear specimen processing protocol via integrated real-time computer entry by staff.
The extent of automation within the laboratory, especially in the molecular methodology, which employs a highly automated total nucleic acid extraction platform and TaqMan array card processes, is facilitated by the barcode-based specimen labeling system. Integration into these automated procedures reduces or prevents preanalytical labeling errors, which can waste time, considerable resources and even misattribute specimen findings. Because specimen labels are matched with ANISA IDs and the history of the ANISA child, the results of the molecular tests are directly synchronized with each ANISA child’s and mother’s data, avoiding human transcription errors.
In summary, the system standardizes laboratory protocols, assists in project monitoring and safeguards specimens and data against human errors, greatly limiting the chances for preanalytical errors, improving consistency and protecting the validity of study findings.
In the future, full digitization of forms in the field by using personal digital assistants and direct electronic entry may mean that barcode-labeled specimens have even greater potential to reliably link community-based research with laboratory-based investigations. The use of machine-readable specimen labels can and should be expanded to field management and can systematically protect high-value specimens from human error and loss. Local production of resilient labels and guaranteed label printing runs would further cut the costs of implementing this type of system. Traditional 2-dimensional barcodes may also be improved with more advanced compound barcodes and even more versatile Radio Frequency Identification (known as RFID) labeling in the near future as prices are reduced.20 Regardless of the underlying technology, centralized design efforts must incorporate input from the staff who will be using the labeling system to improve adoption, understanding and confidence in these types of systems.
The authors gratefully acknowledge the technical assistance and team work of Mr. Mahmudur Rahman, Ms. Mahfuza Marzan, Mr. Iftekhar Rafiquillah and Mr. Md. Hasanuzzaman. They also acknowledge our numerous other talented and supportive colleagues at the Child Health Research Foundation, the icddr,b and the Centers for Disease Control and Prevention, Atlanta.
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Keywords:Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.
specimen tracking; barcode; preanalytical error; ANISA; biorepository