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Performance evaluation and user experience of BT-50 transportation unit with automated and scheduled quality control measurements

  • Minori Tabata , Rie Nakai , Kyoko Kajihara , Hiromi Nakagawa , Shinichi Yamasaki , Fumiaki Hayashi and Sho Mokuda ORCID logo EMAIL logo
Published/Copyright: May 17, 2024
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Clinical Chemistry and Laboratory Medicine (CCLM)
From the journal Clinical Chemistry and Laboratory Medicine (CCLM) Volume 62 Issue 12

Abstract

Objectives

Even in the current era of hematology analyzer automation and peripheral equipment, quality control sample measurement remains a manual task, leading to variability in quality control data and increased workload. In this study, we evaluated the performance of quality control measurement using the BT-50 Transportation Unit (BT-50, Sysmex, Kobe, Japan), equipped with a scheduled automatic quality control function, to ensure measurement accuracy and streamline the workflow of hematology testing.

Methods

We evaluated the automatic measurement performance of quality control samples using the BT-50 for six representative blood test parameters: WBC (white blood cell), RBC (red blood cell), HGB (hemoglobin), HCT (hematocrit), PLT (platelet), and RET% (reticulocyte percent). We evaluated the equivalence and compared measurement accuracy between the BT-50 and the manual method. We then compared the variability to other laboratories and confirmed the stability of quality control samples. We also evaluated changes in workflow and staff resources before and after the introduction of the BT-50.

Results

The quality control measurement results for the BT-50 and the manual method were found to be equivalent for all six parameters. The variability measured by the BT-50 was lower for some parameters compared to the manual method. Furthermore, the workflow was streamlined by reducing manual processes, resulting in increased efficiency.

Conclusions

We confirmed the performance of quality control measurements using the schedule function of the BT-50. Introducing the BT-50 reduced the operator’s workload, improved operational efficiency, and promoted the standardization of quality control measurements.

Keywords: BT-50; hematology analyzer; quality control; standardization; workflow; XR-Series

Introduction

In recent years, diagnostic device manufacturers have automated transportation and clinical testing at an accelerated pace. Various tasks have been mechanized in hematology, general chemistry, immunoassay and microbiology [1]. In addition, many analyzers performing different types of tests are physically integrated as modular systems [2]. With hematology analyzers, not only the measurement of samples, but also pre- and post-measurement processes such as sample arrival confirmation, sorting, and storage, have been automated. However, there are still necessary manual tasks performed by operators which involve measurement of quality control samples [3]. It involves retrieving quality control samples stored in a refrigerator, allowing them to stand at room temperature and then performing the prescribed mixing. The measurement results of quality control samples can be affected by interoperator techniques such as time and mixing procedures. To prevent from those, the operators must follow the multi-step pre-test procedure described in the package insert and measure the sample. However, they might be complicated in laboratory work, and it is difficult to completely avoid interoperator variability.

The recently released BT-50 Transportation Unit (BT-50, Sysmex, Kobe, Japan) aims to reduce those manual work and variation among operators for quality control measurement. The BT-50 is connected to the pre-measurement process of the XR-Series Automated Hematology Analyzer XR-9000 (XR-9000, Sysmex, Kobe, Japan). To assist with known challenges, it has a cooling function for quality control samples and a scheduled automatic measurement function. In this study, we evaluated the cooling function and automatic measurement performance of the quality control samples using the BT-50. We also conducted a workflow efficiency evaluation of the BT-50.

Materials and methods

Samples

We used quality control blood samples XN CHECK Levels 1, 2, 3 (Sysmex, Kobe, Japan) for the XR-Series. Level 1 targets low, Level 2 normal, and Level 3 high concentrations. The package insert for XN CHECK specifies that it should be stored at 2–8 °C, and the expiration period after opening is 7 days.

Automated method

The BT-50 is connected to the pre-measurement process of the XR-Series Automated Hematology Analyzer XR-9000 (XR-9000, Sysmex, Kobe, Japan) [4]. The BT-50 has a cooling unit capable of storing up to nine vials of quality control samples. The BT-50 automatically moves the quality control samples from the cooling unit to an incubation unit at 23 °C or more for 15 min, and then delivers them to the measurement rack. Before the initial measurement, the samples are mixed using a special method suitable for quality control. After completing the measurements on all analyzers, the samples are automatically transported back to the BT-50 and are then returned to the cooling unit.

The quality control samples were measured using the analyzers in the XR-9000. The parameters evaluated were the representative complete blood count tests: WBC (white blood cell), RBC (red blood cell), HGB (hemoglobin), HCT (hematocrit), PLT (platelet), and RET% (reticulocyte percent).

Manual method

XN CHECK was taken out of the refrigerator and left to stand at room temperature for 15 min. As described in the package insert, the vial was held with both hands and rolled for 15 s. Then the vial was held with fingers, the wrists were turned upside down while quickly shaking the sample 20 times to ensure no clumps adhered to the bottom. After that, the sampler measurement was performed using the rack on the analyzer. In the sampler measurement, automatic mixing in the same manner as regular sample measurements is performed inside the analyzer for each measurement. After the measurement is completed, the vials are immediately returned to the refrigerator. The manual method was performed by four laboratory technicians randomly during the evaluation period.

Comparison of accuracy and precision

To compare the equivalence and precision of the quality control samples measured by the BT-50 and manual method for the target parameters, the following evaluation was conducted. XN CHECK Levels 1, 2, 3 were automatically set in the cooling unit of the BT-50, and quality control measurements were performed after automatic mixing twice a day (morning and afternoon) for 10 days on four analyzers in the XR-9000. As a reference method, XN CHECK Levels 1, 2, 3 stored in the refrigerator were manually mixed and measured using the same analyzers. When the vial was depleted, a new vial from the same lot was used. The obtained results were statistically analyzed to evaluate the equivalence and precision between automated mixing method using BT-50 and manual method.

Inter-laboratory comparison of variability

Our laboratory participates in the external survey program Caresphere XQC (Sysmex, Kobe, Japan). The program is ISO/IEC17043 accredited, and it conducts inter-laboratory comparisons required by ISO15189. This system uses daily internal quality control data for real-time external accuracy managements and equipment monitoring. The monthly reports issued by Caresphere XQC allow us to evaluate the Precision Index (PI), which indicates how the variation of our own analyzer compares to the average variation of the entire population (Eq. (1)).

(1) PI=(SD of own analyzer)/(mean of SDs of other analyzers in the population)

In this study, we checked the PI values on the four analyzers using the BT-50 for automatic quality control measurements from February to April 2023. Average PI values were calculated for the 3-month period and compared to the variability from other laboratories. If the PI value exceeded 2.0, the variation of our own analyzer is considered large. It should be noted that XN CHECK Level 3 is not available for sale in Japan, so Levels 1 and 2 were evaluated. The population consisted of XR-Series analyzers without the BT-50 (as of April 2023 – 190 using Level 1 and 274 using Level 2).

Stability

To confirm the function of the cooling unit in the BT-50, we evaluated the stability of XN CHECK after opening the vials. XN CHECK Levels 1, 2, 3 (one vial each) were set in the cooling unit. Measurements were monitored continuously for 8 days (twice a day, morning and afternoon) using one analyzer starting Day 0 though Day 7 after the control vial was opened. We confirmed that each measurement result was within the acceptable range calculated from the weighted average CV% of quality control samples from three different past lots, relative to the average of the six measurement results from Day 0 to Day 2.

Workflow

Before the introduction of the XR-9000, our laboratory used two automated hematology analyzer XE-5000 by HS transportation system (Sysmex, Kobe, Japan). In this study, we compared the changes in workflow related to quality control measurements before and after the introduction of the XR-9000. We categorized each work process as “manual” or “automated” and compared the number of processes for each category. We also compared changes in the daily schedule.

Statistics

To confirm equivalence, the Two One-Sided Tests (TOST) was used [5]. The equivalence bound was defined as the weighted average 3SD value measured using three past lots of the quality control samples. If the result of the test was p<0.05, the two groups were considered equivalent. For comparing precision, the Levene’s test, which is a test for equal variances, was used [6]. If the result of the test was p<0.05, it was determined that the variances were not equal, and the method with the smaller coefficient of variation (CV%) was judged to have significantly lower variability. JMP software version 15.2.0 (Cary, NC: SAS Institute Inc.) was used for statistical analysis.

Results

Comparison of accuracy and precision

Table 1 shows the results of the TOST for the six target parameters. The quality control measurements of XN CHECK Levels 1, 2, 3 were performed by the BT-50 and manual method. The average values for each parameter over a period of 10 days and the p-values from the TOST were calculated. For all analyzers, concentration levels and parameters, p<0.05 indicated the equivalence between the two methods.

Table 1:

Equivalence between the BT-50 and manual method.

Equivalence bound Analyzer A Analyzer B Analyzer C Analyzer D
BT-50 Manual p-Value BT-50 Manual p-Value BT-50 Manual p-Value BT-50 Manual p-Value
A. XN CHECK Level 1
WBC, 10⁹/L 0.188 3.113 3.059 <0.0001 3.148 3.120 <0.0001 3.139 3.106 <0.0001 3.060 3.072 <0.0001
RBC, 1012/L 0.059 2.366 2.351 <0.0001 2.313 2.302 <0.0001 2.364 2.356 <0.0001 2.365 2.371 <0.0001
HGB, g/dL 0.16 5.97 5.93 <0.0001 5.89 5.88 <0.0001 5.99 5.97 <0.0001 5.92 5.94 <0.0001
HCT, % 0.59 17.81 17.68 <0.0001 17.57 17.41 <0.0001 17.93 17.84 <0.0001 17.79 17.73 <0.0001
PLT, 10⁹/L 9.1 97.8 94.4 <0.0001 96.5 94.0 <0.0001 102.6 98.6 0.0002 100.3 98.5 <0.0001
RET%, % 0.407 5.580 5.591 <0.0001 5.530 5.533 <0.0001 5.359 5.389 <0.0001 5.593 5.562 <0.0001
B. XN CHECK Level 2
WBC, 10⁹/L 0.318 7.171 7.138 <0.0001 7.276 7.268 <0.0001 7.220 7.208 <0.0001 7.159 7.198 <0.0001
RBC, 1012/L 0.107 4.371 4.361 <0.0001 4.355 4.331 <0.0001 4.374 4.361 <0.0001 4.463 4.421 <0.0001
HGB, g/dL 0.24 11.91 11.87 <0.0001 11.98 11.89 <0.0001 11.98 11.97 <0.0001 11.96 11.92 <0.0001
HCT, % 1.35 35.12 34.95 <0.0001 35.08 34.75 <0.0001 35.42 35.23 <0.0001 35.51 35.11 <0.0001
PLT, 10⁹/L 15.7 263.3 262.3 <0.0001 263.4 265.3 <0.0001 271.4 269.9 0.0002 268.3 264.2 <0.0001
RET%, % 0.302 2.442 2.463 <0.0001 2.453 2.431 <0.0001 2.428 2.401 <0.0001 2.533 2.503 <0.0001
C. XN CHECK Level 3
WBC, 10⁹/L 0.460 17.060 16.901 <0.0001 17.181 17.181 <0.0001 17.125 17.096 <0.0001 17.000 16.960 <0.0001
RBC, 1012/L 0.120 5.089 5.072 <0.0001 5.107 5.092 <0.0001 5.107 5.100 <0.0001 5.192 5.178 <0.0001
HGB, g/dL 0.30 15.93 15.84 <0.0001 15.95 15.95 <0.0001 15.94 15.91 <0.0001 15.95 15.91 <0.0001
HCT, % 1.56 45.56 45.33 <0.0001 45.92 45.66 <0.0001 46.11 46.00 <0.0001 46.18 45.84 <0.0001
PLT, 10⁹/L 26.8 583.3 577.7 <0.0001 587.3 585.7 <0.0001 604.1 599.4 <0.0001 598.5 597.3 <0.0001
RET%, % 0.160 1.089 1.095 <0.0001 1.088 1.085 <0.0001 1.096 1.083 <0.0001 1.142 1.117 <0.0001

  1. It shows the average value from the automatic quality control measurement using the BT-50 and manual method for 10 days on the four analyzers. The p-value is the result of the equivalence test TOST (Two One-Sided Tests) of both methods using the equivalence bound. (A) XN CHECK Level 1, (B) XN CHECK Level 2, (C) XN CHECK Level 3. WBC; white blood cell, RBC; red blood cell, HGB; hemoglobin, HCT; hematocrit, PLT; platelet, RET%; reticulocyte percent.

Table 2 presents the results of the CV% and the p-values from the Levene’s test for the variability of automatic quality control measurements using the BT-50, as well as the manual method, for the target parameters over a period of 10 days. On some analyzers, the HGB, PLT, and RET% values at Level 1, and PLT values at Level 3, showed p<0.05, indicating significant variance differences. For the parameters with a significant difference, the results of automatic quality control measurements using the BT-50 showed lower variability compared to the manual method (Figure 1). For the other parameters, no significant difference in variability was observed between the two methods.

Table 2:

Equality of variances between the BT-50 and manual method.

Analyzer A Analyzer B Analyzer C Analyzer D
BT-50 CV, % Manual CV, % p-Value BT-50 CV, % Manual CV, % p-Value BT-50 CV, % Manual CV, % p-Value BT-50 CV, % Manual CV, % p-Value
A. XN CHECK Level 1
WBC 1.52 % 2.07 % 1.74 % 1.33 % 1.37 % 1.81 % 2.13 % 1.91 %
RBC 0.78 % 0.75 % 0.87 % 1.01 % 0.83 % 0.96 % 0.99 % 0.97 %
HGB 0.96 % 0.75 % 1.22 % 0.76 % 1.07 % 0.79 % 0.62 % 0.82 %b
HCT 1.50 % 1.56 % 1.18 % 1.45 % 1.19 % 1.41 % 1.33 % 1.45 %
PLT 2.60 % 5.37 %a 3.13 % 5.34 % 3.26 % 4.65 % 3.25 % 5.69 %a
RET% 3.17 % 3.31 % 1.86 % 3.65 %b 2.99 % 3.04 % 2.00 % 2.79 %
B. XN CHECK Level 2
WBC 1.18 % 1.26 % 0.99 % 1.12 % 1.68 % 1.26 % 1.09 % 1.00 %
RBC 0.70 % 0.78 % 0.88 % 1.05 % 0.91 % 0.65 % 0.80 % 0.91 %
HGB 0.94 % 0.40 % 0.64 % 0.66 % 0.76 % 0.49 % 0.74 % 0.64 %
HCT 1.20 % 1.25 % 1.27 % 1.67 % 1.36 % 1.08 % 1.01 % 1.38 %
PLT 1.93 % 2.88 % 2.27 % 2.98 % 1.89 % 3.17 % 2.38 % 2.41 %
RET% 3.38 % 3.59 % 3.15 % 2.65 % 3.86 % 3.69 % 3.38 % 2.72 %
C. XN CHECK Level 3
WBC 0.87 % 1.05 % 1.01 % 0.78 % 1.07 % 1.00 % 1.00 % 1.19 %
RBC 0.76 % 0.75 % 0.73 % 0.76 % 0.65 % 0.67 % 0.86 % 0.75 %
HGB 0.65 % 0.44 % 0.59 % 0.48 % 0.51 % 0.43 % 0.83 % 0.57 %
HCT 1.23 % 1.10 % 1.03 % 1.27 % 0.90 % 1.15 % 1.13 % 0.90 %
PLT 1.14 % 1.83 %a 1.81 % 1.68 % 1.32 % 1.52 % 1.82 % 1.70 %
RET% 5.04 % 3.27 % 3.72 % 3.69 % 5.00 % 4.13 % 5.32 % 4.32 %

  1. It shows the coefficient of variation (CV) measured by the automatic quality control measurement using the BT-50 and manual method for 10 days on the four analyzers. The p-value is the result of Levene’s test which is a test for equal variances of both variances. ap<0.05. bp<0.01. (A) XN CHECK Level 1, (B) XN CHECK Level 2, (C) XN CHECK Level 3. WBC; white blood cell, RBC; red blood cell, HGB; hemoglobin, HCT; hematocrit, PLT; platelet, RET%; reticulocyte percent.

Figure 1: Parameters with significant differences in variances. It shows box-and-whisker plot for parameters with significant variance differences measured by the automatic quality control measurement using the BT-50 and manual method for 10 days on the four analyzers. Boxes represent the 1st to 3rd quantiles, and the partition represents the median. Whiskers indicate minimum and maximum values, and dots indicate outliers. (A) Analyzer A, XN CHECK Level 1, PLT. (B) Analyzer A, XN CHECK Level 3, PLT. (C) Analyzer B, XN CHECK Level 1, RET%. (D) Analyzer D, XN CHECK Level 1, HGB. (E) Analyzer D, XN CHECK Level 1, PLT. PLT, platelet; RET%, reticulocyte percent; HGB, hemoglobin.
Figure 1:

Parameters with significant differences in variances. It shows box-and-whisker plot for parameters with significant variance differences measured by the automatic quality control measurement using the BT-50 and manual method for 10 days on the four analyzers. Boxes represent the 1st to 3rd quantiles, and the partition represents the median. Whiskers indicate minimum and maximum values, and dots indicate outliers. (A) Analyzer A, XN CHECK Level 1, PLT. (B) Analyzer A, XN CHECK Level 3, PLT. (C) Analyzer B, XN CHECK Level 1, RET%. (D) Analyzer D, XN CHECK Level 1, HGB. (E) Analyzer D, XN CHECK Level 1, PLT. PLT, platelet; RET%, reticulocyte percent; HGB, hemoglobin.

Inter-laboratory comparison of variability

The average PI values of the XN CHECK Level 1 and 2 for four analyzers were obtained from the Caresphere XQC monthly reports from February to April 2023. The PI values, which compare the variability of measurements from our laboratory with average variability of analyzers in other Japanese laboratories, did not exceed 2.0 for any analyzer and/or parameter. The maximum value was 1.05, and most values were below 1.0.

Stability

Figure 2 shows the results of automatic quality control measurements using the BT-50 for XN CHECK Levels 1, 2, and 3 for up to 7 days after opening vials. Each measurement result fell within the acceptable range calculated based on the weighted average CV% of three past lots of the quality control samples for each parameter, relative to the average of the six measurements from Day 0 to Day 2.

Figure 2: Stability after opening vials. The graphs show the results of automatic quality control measurements using the BT-50 for up to 7 days after opening vials. The Solid line shows average of six measurements from Day 0 to Day 2. Dotted line shows acceptable lower and upper range. (A) XN CHECK Level 1, (B) XN CHECK Level 2, (C) XN CHECK Level 3. WBC, white blood cell; RBC, red blood cell; HGB, hemoglobin; HCT, hematocrit; PLT, platelet; RET%, reticulocyte percent.
Figure 2:

Stability after opening vials. The graphs show the results of automatic quality control measurements using the BT-50 for up to 7 days after opening vials. The Solid line shows average of six measurements from Day 0 to Day 2. Dotted line shows acceptable lower and upper range. (A) XN CHECK Level 1, (B) XN CHECK Level 2, (C) XN CHECK Level 3. WBC, white blood cell; RBC, red blood cell; HGB, hemoglobin; HCT, hematocrit; PLT, platelet; RET%, reticulocyte percent.

Workflow

Figure 3 illustrates the detailed breakdown and comparison of the workflow related to quality control measurements before and after XR-9000 introduction in our laboratory. Before the introduction, there were 10 manual processes and 2 automatic processes. After the introduction, the number of manual processes decreased to 1, while the number of automatic processes increased to 9. Regarding the operator’s workflow, before the introduction, 6 steps were required to move samples to the analyzer or refrigerator. After the introduction, only 1 step was needed which significantly decreased the operator’s involvement in the process.

Figure 3: Process diagram of wake-up and quality control measurement comparisons (before and after the XR-9000 installation).
Figure 3:

Process diagram of wake-up and quality control measurement comparisons (before and after the XR-9000 installation).

Figure 4 shows a comparison of the daily schedule before and after the introduction of the XR-9000. Our laboratory operates 24 h a day, including overnight, and some analyzers are kept running without shutting down in the evening for emergency measurements. Operators responsible for the daytime shift start at 7:00 a.m. Before the introduction, operators performed manual tasks such as starting up and performing quality control measurements on analyzers that were shut down from 7:00 to 8:00 a.m. During this time, measurements of patient samples could not be performed. However, with the XR-9000 scheduling function along with the BT-50, the wakeup and quality control measurements were automatically completed by 7:00 a.m. This allowed the operators to measure inpatient samples immediately after arriving to the laboratory. In addition, the scheduling function enables automatic quality control measurements in the afternoon and continuous analyzer usage without interruption just before transitioning to the night shift.

Figure 4: Time schedule comparison (before and after the XR-9000 installation). QC, quality control measurement.
Figure 4:

Time schedule comparison (before and after the XR-9000 installation). QC, quality control measurement.

Discussion

The purpose of this evaluation was to confirm the basic performance and workflow efficiency of the BT-50, the world’s first hematology analyzer with an automated and scheduled quality control measurement function.

For the first evaluation of basic performance, a comparison was made with the manual method. It was found that comparable measurement values were obtained with the BT-50 and the manual method. The evaluation included placing samples in the incubation unit at room temperature and then completing the special mixing suitable for quality control samples on the analyzers. We found there to be significantly less variability with the automated quality control measurement using the BT-50 compared to the manual method specifically with Level 1 HGB, PLT, RET%, and Level 3 PLT in this study. Variability in the manual method is caused by the tendency of interoperator differences in the mixing method. In particular, Level 1 samples have low concentrations, making it difficult for the blood cell components to become homogeneous [7]. On the other hand, with the automated quality control measurement using the BT-50, the incubation time, temperature, mixing method, and number of mixings are standardized for each sequence. Based upon this evaluation, the reduced variability can be due to the standardized mixing method. Automated quality control measurements using the BT-50 have significant standardization advantages. ISO 15189-accredited laboratories are required to establish their own control limits based on statistics for proper monitoring of equipment conditions [8, 9]. They usually use the standard deviation and coefficient of variation calculated from the variability of quality control samples from multiple previous lots as acceptable limits. It is suggested that if the measurement value deviates by 2SD or 3SD, the possibility of error exists, and the patient sample measurement should be interrupted [10]. 3SD ensures that 99.7 % of the measurements fall within the control limits, but it also means that there is a 0.3 % probability of deviating from the acceptable limits. Hematology analyzers have many measurement parameters, so the frequency of variability of quality control results deviating from the acceptable limits is not necessarily low. If the control limits are exceeded, it requires retesting. In addition, various factors like the measurement sample, pre-measurement process, and analyzer itself can influence the results, making it difficult to identify the cause. If the pre-measurement process is automated and standardized, it becomes easier to consider the possibility of errors with the analyzer by eliminating the influence of the pre-measurement process in cause investigation. This can also reduce the frequency of deviations from the acceptable limits. It can result in fewer retests, less burden on operators, reduced analyzer down time and, improved turnaround time (TAT).

Next, as the second basic performance evaluation, the BT-50 cooling function was evaluated by checking the stability of XN CHECK after opening vials. Measurement results for all 6 parameters were obtained up to 7 days (the expiration period) after opening the vials and found to be within the acceptable range. This confirmed the vials were stable up until the expiration period and the function in the cooling unit of the BT-50 is problem-free. The cooling unit of the BT-50 is maintained at 2–8 °C and then automatically supplies samples to the measurement analyzer. The samples stand for 15 min in an incubation unit at room temperature maintained at 23 °C or more before measurement. Automation provides a significant advantage in ensuring quality through appropriate temperature management of the samples. With the manual method, there is a possibility of delaying the return of the samples to the refrigerator after measurement. By leaving samples at room temperature for a longer time, the quality is impacted. The decrease in quality may cause the measurement results to deviate from the acceptable limit, resulting in the need for retesting and mistakenly suspecting equipment errors during cause investigation. With automated quality control measurements, the samples are automatically stored in the cooling unit of the BT-50, minimizing quality control risks. Additionally, the BT-50 records the date each vial is opened, and the number of measurements completed, allowing for proper management of residual volume and expiration dates. Vials with expired expiration dates are not measured, ensuring the quality of quality control measurements.

We quantitatively evaluate the workflow changes related to the quality control measurement tasks before and after the introduction of the XR-9000. As shown in Figure 3, various manual tasks were automated following the introduction of the XR-9000 that included the following: analyzer wake-up, preparation of quality control samples, mixing of pre-measurement samples, and storage of samples in the post-measurement. The distance traveled by the operators, such as trips to remote refrigerators and steps to and from the equipment, is also reduced, contributing to better work efficiency and less hours required. Furthermore, as shown in Figure 4, before the introduction of the XR-9000, it took about 1 h for the preparation. It took 10 min for the PC to start up, 30 min for wake-up of the measurement unit, and 15 min for the quality control measurement. After the introduction of the XR-9000, by scheduling the automatic wake-up and quality control measurement, it is possible to complete almost 45 min of unmanned work. In our laboratory, by setting the schedule before the daytime laboratory working hours, the start time for patient sample measurements could be advanced without changing arrival time of operators. The operators only need to confirm the quality control measurement results and can start measuring patient samples immediately if there are no abnormalities. By reducing analyzer downtime, early morning sample measurements for wards and emergency departments can be completed immediately, reducing TAT for the morning outpatient samples. In other laboratories, if sample measurement start times are not changed, it may be possible to delay arrival time of the operators and improve staff satisfaction and work-life balance. Furthermore, standardized quality control measurements can be performed regardless of the operator skill level.

In conclusion, the automatic measurement of quality control samples using the scheduling function of the BT-50 is equivalent to the manual method, and the stability of quality control samples after opening vials was found to be good and the cooling function was sufficient in this study. Based on these results, we believe that the BT-50 significantly contributes to the efficiency of hematology testing workflow, reduces operator manual tasks, improves TAT, and standardizes quality control measurements.

Corresponding author: Sho Mokuda, MD, PhD, Division of Laboratory Medicine, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan, Phone: +81-82-257-1577; Fax: +81-82-257-1577, E-mail:

Acknowledgments

We would like to express my deepest gratitude to everyone for their guidance, support, and invaluable feedback throughout the entire process of this research.

  1. Research ethics: Not applicable.

  2. Informed consent: Not applicable.

  3. Author contributions: The authors have accepted responsibility for the entire content of this manuscript and approved its submission.

  4. Competing interests: Rie Nakai and Fumiaki Hayashi are employees of Sysmex Corporation. All other authors state no conflict of interest.

  5. Research funding: This study was supported by funding from JSPS KAKENHI (grant numbers 22K08599 to S. Mokuda).

  6. Data availability: The raw data can be obtained on request from the corresponding author.

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Received: 2024-02-15
Accepted: 2024-05-05
Published Online: 2024-05-17
Published in Print: 2024-11-26

© 2024 the author(s), published by De Gruyter, Berlin/Boston

This work is licensed under the Creative Commons Attribution 4.0 International License.

Abstract

Objectives

Even in the current era of hematology analyzer automation and peripheral equipment, quality control sample measurement remains a manual task, leading to variability in quality control data and increased workload. In this study, we evaluated the performance of quality control measurement using the BT-50 Transportation Unit (BT-50, Sysmex, Kobe, Japan), equipped with a scheduled automatic quality control function, to ensure measurement accuracy and streamline the workflow of hematology testing.

Methods

We evaluated the automatic measurement performance of quality control samples using the BT-50 for six representative blood test parameters: WBC (white blood cell), RBC (red blood cell), HGB (hemoglobin), HCT (hematocrit), PLT (platelet), and RET% (reticulocyte percent). We evaluated the equivalence and compared measurement accuracy between the BT-50 and the manual method. We then compared the variability to other laboratories and confirmed the stability of quality control samples. We also evaluated changes in workflow and staff resources before and after the introduction of the BT-50.

Results

The quality control measurement results for the BT-50 and the manual method were found to be equivalent for all six parameters. The variability measured by the BT-50 was lower for some parameters compared to the manual method. Furthermore, the workflow was streamlined by reducing manual processes, resulting in increased efficiency.

Conclusions

We confirmed the performance of quality control measurements using the schedule function of the BT-50. Introducing the BT-50 reduced the operator’s workload, improved operational efficiency, and promoted the standardization of quality control measurements.

Keywords: BT-50; hematology analyzer; quality control; standardization; workflow; XR-Series

Introduction

In recent years, diagnostic device manufacturers have automated transportation and clinical testing at an accelerated pace. Various tasks have been mechanized in hematology, general chemistry, immunoassay and microbiology [1]. In addition, many analyzers performing different types of tests are physically integrated as modular systems [2]. With hematology analyzers, not only the measurement of samples, but also pre- and post-measurement processes such as sample arrival confirmation, sorting, and storage, have been automated. However, there are still necessary manual tasks performed by operators which involve measurement of quality control samples [3]. It involves retrieving quality control samples stored in a refrigerator, allowing them to stand at room temperature and then performing the prescribed mixing. The measurement results of quality control samples can be affected by interoperator techniques such as time and mixing procedures. To prevent from those, the operators must follow the multi-step pre-test procedure described in the package insert and measure the sample. However, they might be complicated in laboratory work, and it is difficult to completely avoid interoperator variability.

The recently released BT-50 Transportation Unit (BT-50, Sysmex, Kobe, Japan) aims to reduce those manual work and variation among operators for quality control measurement. The BT-50 is connected to the pre-measurement process of the XR-Series Automated Hematology Analyzer XR-9000 (XR-9000, Sysmex, Kobe, Japan). To assist with known challenges, it has a cooling function for quality control samples and a scheduled automatic measurement function. In this study, we evaluated the cooling function and automatic measurement performance of the quality control samples using the BT-50. We also conducted a workflow efficiency evaluation of the BT-50.

Materials and methods

Samples

We used quality control blood samples XN CHECK Levels 1, 2, 3 (Sysmex, Kobe, Japan) for the XR-Series. Level 1 targets low, Level 2 normal, and Level 3 high concentrations. The package insert for XN CHECK specifies that it should be stored at 2–8 °C, and the expiration period after opening is 7 days.

Automated method

The BT-50 is connected to the pre-measurement process of the XR-Series Automated Hematology Analyzer XR-9000 (XR-9000, Sysmex, Kobe, Japan) [4]. The BT-50 has a cooling unit capable of storing up to nine vials of quality control samples. The BT-50 automatically moves the quality control samples from the cooling unit to an incubation unit at 23 °C or more for 15 min, and then delivers them to the measurement rack. Before the initial measurement, the samples are mixed using a special method suitable for quality control. After completing the measurements on all analyzers, the samples are automatically transported back to the BT-50 and are then returned to the cooling unit.

The quality control samples were measured using the analyzers in the XR-9000. The parameters evaluated were the representative complete blood count tests: WBC (white blood cell), RBC (red blood cell), HGB (hemoglobin), HCT (hematocrit), PLT (platelet), and RET% (reticulocyte percent).

Manual method

XN CHECK was taken out of the refrigerator and left to stand at room temperature for 15 min. As described in the package insert, the vial was held with both hands and rolled for 15 s. Then the vial was held with fingers, the wrists were turned upside down while quickly shaking the sample 20 times to ensure no clumps adhered to the bottom. After that, the sampler measurement was performed using the rack on the analyzer. In the sampler measurement, automatic mixing in the same manner as regular sample measurements is performed inside the analyzer for each measurement. After the measurement is completed, the vials are immediately returned to the refrigerator. The manual method was performed by four laboratory technicians randomly during the evaluation period.

Comparison of accuracy and precision

To compare the equivalence and precision of the quality control samples measured by the BT-50 and manual method for the target parameters, the following evaluation was conducted. XN CHECK Levels 1, 2, 3 were automatically set in the cooling unit of the BT-50, and quality control measurements were performed after automatic mixing twice a day (morning and afternoon) for 10 days on four analyzers in the XR-9000. As a reference method, XN CHECK Levels 1, 2, 3 stored in the refrigerator were manually mixed and measured using the same analyzers. When the vial was depleted, a new vial from the same lot was used. The obtained results were statistically analyzed to evaluate the equivalence and precision between automated mixing method using BT-50 and manual method.

Inter-laboratory comparison of variability

Our laboratory participates in the external survey program Caresphere XQC (Sysmex, Kobe, Japan). The program is ISO/IEC17043 accredited, and it conducts inter-laboratory comparisons required by ISO15189. This system uses daily internal quality control data for real-time external accuracy managements and equipment monitoring. The monthly reports issued by Caresphere XQC allow us to evaluate the Precision Index (PI), which indicates how the variation of our own analyzer compares to the average variation of the entire population (Eq. (1)).

(1) PI=(SD of own analyzer)/(mean of SDs of other analyzers in the population)

In this study, we checked the PI values on the four analyzers using the BT-50 for automatic quality control measurements from February to April 2023. Average PI values were calculated for the 3-month period and compared to the variability from other laboratories. If the PI value exceeded 2.0, the variation of our own analyzer is considered large. It should be noted that XN CHECK Level 3 is not available for sale in Japan, so Levels 1 and 2 were evaluated. The population consisted of XR-Series analyzers without the BT-50 (as of April 2023 – 190 using Level 1 and 274 using Level 2).

Stability

To confirm the function of the cooling unit in the BT-50, we evaluated the stability of XN CHECK after opening the vials. XN CHECK Levels 1, 2, 3 (one vial each) were set in the cooling unit. Measurements were monitored continuously for 8 days (twice a day, morning and afternoon) using one analyzer starting Day 0 though Day 7 after the control vial was opened. We confirmed that each measurement result was within the acceptable range calculated from the weighted average CV% of quality control samples from three different past lots, relative to the average of the six measurement results from Day 0 to Day 2.

Workflow

Before the introduction of the XR-9000, our laboratory used two automated hematology analyzer XE-5000 by HS transportation system (Sysmex, Kobe, Japan). In this study, we compared the changes in workflow related to quality control measurements before and after the introduction of the XR-9000. We categorized each work process as “manual” or “automated” and compared the number of processes for each category. We also compared changes in the daily schedule.

Statistics

To confirm equivalence, the Two One-Sided Tests (TOST) was used [5]. The equivalence bound was defined as the weighted average 3SD value measured using three past lots of the quality control samples. If the result of the test was p<0.05, the two groups were considered equivalent. For comparing precision, the Levene’s test, which is a test for equal variances, was used [6]. If the result of the test was p<0.05, it was determined that the variances were not equal, and the method with the smaller coefficient of variation (CV%) was judged to have significantly lower variability. JMP software version 15.2.0 (Cary, NC: SAS Institute Inc.) was used for statistical analysis.

Results

Comparison of accuracy and precision

Table 1 shows the results of the TOST for the six target parameters. The quality control measurements of XN CHECK Levels 1, 2, 3 were performed by the BT-50 and manual method. The average values for each parameter over a period of 10 days and the p-values from the TOST were calculated. For all analyzers, concentration levels and parameters, p<0.05 indicated the equivalence between the two methods.

Table 1:

Equivalence between the BT-50 and manual method.

Equivalence bound Analyzer A Analyzer B Analyzer C Analyzer D
BT-50 Manual p-Value BT-50 Manual p-Value BT-50 Manual p-Value BT-50 Manual p-Value
A. XN CHECK Level 1
WBC, 10⁹/L 0.188 3.113 3.059 <0.0001 3.148 3.120 <0.0001 3.139 3.106 <0.0001 3.060 3.072 <0.0001
RBC, 1012/L 0.059 2.366 2.351 <0.0001 2.313 2.302 <0.0001 2.364 2.356 <0.0001 2.365 2.371 <0.0001
HGB, g/dL 0.16 5.97 5.93 <0.0001 5.89 5.88 <0.0001 5.99 5.97 <0.0001 5.92 5.94 <0.0001
HCT, % 0.59 17.81 17.68 <0.0001 17.57 17.41 <0.0001 17.93 17.84 <0.0001 17.79 17.73 <0.0001
PLT, 10⁹/L 9.1 97.8 94.4 <0.0001 96.5 94.0 <0.0001 102.6 98.6 0.0002 100.3 98.5 <0.0001
RET%, % 0.407 5.580 5.591 <0.0001 5.530 5.533 <0.0001 5.359 5.389 <0.0001 5.593 5.562 <0.0001
B. XN CHECK Level 2
WBC, 10⁹/L 0.318 7.171 7.138 <0.0001 7.276 7.268 <0.0001 7.220 7.208 <0.0001 7.159 7.198 <0.0001
RBC, 1012/L 0.107 4.371 4.361 <0.0001 4.355 4.331 <0.0001 4.374 4.361 <0.0001 4.463 4.421 <0.0001
HGB, g/dL 0.24 11.91 11.87 <0.0001 11.98 11.89 <0.0001 11.98 11.97 <0.0001 11.96 11.92 <0.0001
HCT, % 1.35 35.12 34.95 <0.0001 35.08 34.75 <0.0001 35.42 35.23 <0.0001 35.51 35.11 <0.0001
PLT, 10⁹/L 15.7 263.3 262.3 <0.0001 263.4 265.3 <0.0001 271.4 269.9 0.0002 268.3 264.2 <0.0001
RET%, % 0.302 2.442 2.463 <0.0001 2.453 2.431 <0.0001 2.428 2.401 <0.0001 2.533 2.503 <0.0001
C. XN CHECK Level 3
WBC, 10⁹/L 0.460 17.060 16.901 <0.0001 17.181 17.181 <0.0001 17.125 17.096 <0.0001 17.000 16.960 <0.0001
RBC, 1012/L 0.120 5.089 5.072 <0.0001 5.107 5.092 <0.0001 5.107 5.100 <0.0001 5.192 5.178 <0.0001
HGB, g/dL 0.30 15.93 15.84 <0.0001 15.95 15.95 <0.0001 15.94 15.91 <0.0001 15.95 15.91 <0.0001
HCT, % 1.56 45.56 45.33 <0.0001 45.92 45.66 <0.0001 46.11 46.00 <0.0001 46.18 45.84 <0.0001
PLT, 10⁹/L 26.8 583.3 577.7 <0.0001 587.3 585.7 <0.0001 604.1 599.4 <0.0001 598.5 597.3 <0.0001
RET%, % 0.160 1.089 1.095 <0.0001 1.088 1.085 <0.0001 1.096 1.083 <0.0001 1.142 1.117 <0.0001

  1. It shows the average value from the automatic quality control measurement using the BT-50 and manual method for 10 days on the four analyzers. The p-value is the result of the equivalence test TOST (Two One-Sided Tests) of both methods using the equivalence bound. (A) XN CHECK Level 1, (B) XN CHECK Level 2, (C) XN CHECK Level 3. WBC; white blood cell, RBC; red blood cell, HGB; hemoglobin, HCT; hematocrit, PLT; platelet, RET%; reticulocyte percent.

Table 2 presents the results of the CV% and the p-values from the Levene’s test for the variability of automatic quality control measurements using the BT-50, as well as the manual method, for the target parameters over a period of 10 days. On some analyzers, the HGB, PLT, and RET% values at Level 1, and PLT values at Level 3, showed p<0.05, indicating significant variance differences. For the parameters with a significant difference, the results of automatic quality control measurements using the BT-50 showed lower variability compared to the manual method (Figure 1). For the other parameters, no significant difference in variability was observed between the two methods.

Table 2:

Equality of variances between the BT-50 and manual method.

Analyzer A Analyzer B Analyzer C Analyzer D
BT-50 CV, % Manual CV, % p-Value BT-50 CV, % Manual CV, % p-Value BT-50 CV, % Manual CV, % p-Value BT-50 CV, % Manual CV, % p-Value
A. XN CHECK Level 1
WBC 1.52 % 2.07 % 1.74 % 1.33 % 1.37 % 1.81 % 2.13 % 1.91 %
RBC 0.78 % 0.75 % 0.87 % 1.01 % 0.83 % 0.96 % 0.99 % 0.97 %
HGB 0.96 % 0.75 % 1.22 % 0.76 % 1.07 % 0.79 % 0.62 % 0.82 %b
HCT 1.50 % 1.56 % 1.18 % 1.45 % 1.19 % 1.41 % 1.33 % 1.45 %
PLT 2.60 % 5.37 %a 3.13 % 5.34 % 3.26 % 4.65 % 3.25 % 5.69 %a
RET% 3.17 % 3.31 % 1.86 % 3.65 %b 2.99 % 3.04 % 2.00 % 2.79 %
B. XN CHECK Level 2
WBC 1.18 % 1.26 % 0.99 % 1.12 % 1.68 % 1.26 % 1.09 % 1.00 %
RBC 0.70 % 0.78 % 0.88 % 1.05 % 0.91 % 0.65 % 0.80 % 0.91 %
HGB 0.94 % 0.40 % 0.64 % 0.66 % 0.76 % 0.49 % 0.74 % 0.64 %
HCT 1.20 % 1.25 % 1.27 % 1.67 % 1.36 % 1.08 % 1.01 % 1.38 %
PLT 1.93 % 2.88 % 2.27 % 2.98 % 1.89 % 3.17 % 2.38 % 2.41 %
RET% 3.38 % 3.59 % 3.15 % 2.65 % 3.86 % 3.69 % 3.38 % 2.72 %
C. XN CHECK Level 3
WBC 0.87 % 1.05 % 1.01 % 0.78 % 1.07 % 1.00 % 1.00 % 1.19 %
RBC 0.76 % 0.75 % 0.73 % 0.76 % 0.65 % 0.67 % 0.86 % 0.75 %
HGB 0.65 % 0.44 % 0.59 % 0.48 % 0.51 % 0.43 % 0.83 % 0.57 %
HCT 1.23 % 1.10 % 1.03 % 1.27 % 0.90 % 1.15 % 1.13 % 0.90 %
PLT 1.14 % 1.83 %a 1.81 % 1.68 % 1.32 % 1.52 % 1.82 % 1.70 %
RET% 5.04 % 3.27 % 3.72 % 3.69 % 5.00 % 4.13 % 5.32 % 4.32 %

  1. It shows the coefficient of variation (CV) measured by the automatic quality control measurement using the BT-50 and manual method for 10 days on the four analyzers. The p-value is the result of Levene’s test which is a test for equal variances of both variances. ap<0.05. bp<0.01. (A) XN CHECK Level 1, (B) XN CHECK Level 2, (C) XN CHECK Level 3. WBC; white blood cell, RBC; red blood cell, HGB; hemoglobin, HCT; hematocrit, PLT; platelet, RET%; reticulocyte percent.

Figure 1: Parameters with significant differences in variances. It shows box-and-whisker plot for parameters with significant variance differences measured by the automatic quality control measurement using the BT-50 and manual method for 10 days on the four analyzers. Boxes represent the 1st to 3rd quantiles, and the partition represents the median. Whiskers indicate minimum and maximum values, and dots indicate outliers. (A) Analyzer A, XN CHECK Level 1, PLT. (B) Analyzer A, XN CHECK Level 3, PLT. (C) Analyzer B, XN CHECK Level 1, RET%. (D) Analyzer D, XN CHECK Level 1, HGB. (E) Analyzer D, XN CHECK Level 1, PLT. PLT, platelet; RET%, reticulocyte percent; HGB, hemoglobin.
Figure 1:

Parameters with significant differences in variances. It shows box-and-whisker plot for parameters with significant variance differences measured by the automatic quality control measurement using the BT-50 and manual method for 10 days on the four analyzers. Boxes represent the 1st to 3rd quantiles, and the partition represents the median. Whiskers indicate minimum and maximum values, and dots indicate outliers. (A) Analyzer A, XN CHECK Level 1, PLT. (B) Analyzer A, XN CHECK Level 3, PLT. (C) Analyzer B, XN CHECK Level 1, RET%. (D) Analyzer D, XN CHECK Level 1, HGB. (E) Analyzer D, XN CHECK Level 1, PLT. PLT, platelet; RET%, reticulocyte percent; HGB, hemoglobin.

Inter-laboratory comparison of variability

The average PI values of the XN CHECK Level 1 and 2 for four analyzers were obtained from the Caresphere XQC monthly reports from February to April 2023. The PI values, which compare the variability of measurements from our laboratory with average variability of analyzers in other Japanese laboratories, did not exceed 2.0 for any analyzer and/or parameter. The maximum value was 1.05, and most values were below 1.0.

Stability

Figure 2 shows the results of automatic quality control measurements using the BT-50 for XN CHECK Levels 1, 2, and 3 for up to 7 days after opening vials. Each measurement result fell within the acceptable range calculated based on the weighted average CV% of three past lots of the quality control samples for each parameter, relative to the average of the six measurements from Day 0 to Day 2.

Figure 2: Stability after opening vials. The graphs show the results of automatic quality control measurements using the BT-50 for up to 7 days after opening vials. The Solid line shows average of six measurements from Day 0 to Day 2. Dotted line shows acceptable lower and upper range. (A) XN CHECK Level 1, (B) XN CHECK Level 2, (C) XN CHECK Level 3. WBC, white blood cell; RBC, red blood cell; HGB, hemoglobin; HCT, hematocrit; PLT, platelet; RET%, reticulocyte percent.
Figure 2:

Stability after opening vials. The graphs show the results of automatic quality control measurements using the BT-50 for up to 7 days after opening vials. The Solid line shows average of six measurements from Day 0 to Day 2. Dotted line shows acceptable lower and upper range. (A) XN CHECK Level 1, (B) XN CHECK Level 2, (C) XN CHECK Level 3. WBC, white blood cell; RBC, red blood cell; HGB, hemoglobin; HCT, hematocrit; PLT, platelet; RET%, reticulocyte percent.

Workflow

Figure 3 illustrates the detailed breakdown and comparison of the workflow related to quality control measurements before and after XR-9000 introduction in our laboratory. Before the introduction, there were 10 manual processes and 2 automatic processes. After the introduction, the number of manual processes decreased to 1, while the number of automatic processes increased to 9. Regarding the operator’s workflow, before the introduction, 6 steps were required to move samples to the analyzer or refrigerator. After the introduction, only 1 step was needed which significantly decreased the operator’s involvement in the process.

Figure 3: Process diagram of wake-up and quality control measurement comparisons (before and after the XR-9000 installation).
Figure 3:

Process diagram of wake-up and quality control measurement comparisons (before and after the XR-9000 installation).

Figure 4 shows a comparison of the daily schedule before and after the introduction of the XR-9000. Our laboratory operates 24 h a day, including overnight, and some analyzers are kept running without shutting down in the evening for emergency measurements. Operators responsible for the daytime shift start at 7:00 a.m. Before the introduction, operators performed manual tasks such as starting up and performing quality control measurements on analyzers that were shut down from 7:00 to 8:00 a.m. During this time, measurements of patient samples could not be performed. However, with the XR-9000 scheduling function along with the BT-50, the wakeup and quality control measurements were automatically completed by 7:00 a.m. This allowed the operators to measure inpatient samples immediately after arriving to the laboratory. In addition, the scheduling function enables automatic quality control measurements in the afternoon and continuous analyzer usage without interruption just before transitioning to the night shift.

Figure 4: Time schedule comparison (before and after the XR-9000 installation). QC, quality control measurement.
Figure 4:

Time schedule comparison (before and after the XR-9000 installation). QC, quality control measurement.

Discussion

The purpose of this evaluation was to confirm the basic performance and workflow efficiency of the BT-50, the world’s first hematology analyzer with an automated and scheduled quality control measurement function.

For the first evaluation of basic performance, a comparison was made with the manual method. It was found that comparable measurement values were obtained with the BT-50 and the manual method. The evaluation included placing samples in the incubation unit at room temperature and then completing the special mixing suitable for quality control samples on the analyzers. We found there to be significantly less variability with the automated quality control measurement using the BT-50 compared to the manual method specifically with Level 1 HGB, PLT, RET%, and Level 3 PLT in this study. Variability in the manual method is caused by the tendency of interoperator differences in the mixing method. In particular, Level 1 samples have low concentrations, making it difficult for the blood cell components to become homogeneous [7]. On the other hand, with the automated quality control measurement using the BT-50, the incubation time, temperature, mixing method, and number of mixings are standardized for each sequence. Based upon this evaluation, the reduced variability can be due to the standardized mixing method. Automated quality control measurements using the BT-50 have significant standardization advantages. ISO 15189-accredited laboratories are required to establish their own control limits based on statistics for proper monitoring of equipment conditions [8, 9]. They usually use the standard deviation and coefficient of variation calculated from the variability of quality control samples from multiple previous lots as acceptable limits. It is suggested that if the measurement value deviates by 2SD or 3SD, the possibility of error exists, and the patient sample measurement should be interrupted [10]. 3SD ensures that 99.7 % of the measurements fall within the control limits, but it also means that there is a 0.3 % probability of deviating from the acceptable limits. Hematology analyzers have many measurement parameters, so the frequency of variability of quality control results deviating from the acceptable limits is not necessarily low. If the control limits are exceeded, it requires retesting. In addition, various factors like the measurement sample, pre-measurement process, and analyzer itself can influence the results, making it difficult to identify the cause. If the pre-measurement process is automated and standardized, it becomes easier to consider the possibility of errors with the analyzer by eliminating the influence of the pre-measurement process in cause investigation. This can also reduce the frequency of deviations from the acceptable limits. It can result in fewer retests, less burden on operators, reduced analyzer down time and, improved turnaround time (TAT).

Next, as the second basic performance evaluation, the BT-50 cooling function was evaluated by checking the stability of XN CHECK after opening vials. Measurement results for all 6 parameters were obtained up to 7 days (the expiration period) after opening the vials and found to be within the acceptable range. This confirmed the vials were stable up until the expiration period and the function in the cooling unit of the BT-50 is problem-free. The cooling unit of the BT-50 is maintained at 2–8 °C and then automatically supplies samples to the measurement analyzer. The samples stand for 15 min in an incubation unit at room temperature maintained at 23 °C or more before measurement. Automation provides a significant advantage in ensuring quality through appropriate temperature management of the samples. With the manual method, there is a possibility of delaying the return of the samples to the refrigerator after measurement. By leaving samples at room temperature for a longer time, the quality is impacted. The decrease in quality may cause the measurement results to deviate from the acceptable limit, resulting in the need for retesting and mistakenly suspecting equipment errors during cause investigation. With automated quality control measurements, the samples are automatically stored in the cooling unit of the BT-50, minimizing quality control risks. Additionally, the BT-50 records the date each vial is opened, and the number of measurements completed, allowing for proper management of residual volume and expiration dates. Vials with expired expiration dates are not measured, ensuring the quality of quality control measurements.

We quantitatively evaluate the workflow changes related to the quality control measurement tasks before and after the introduction of the XR-9000. As shown in Figure 3, various manual tasks were automated following the introduction of the XR-9000 that included the following: analyzer wake-up, preparation of quality control samples, mixing of pre-measurement samples, and storage of samples in the post-measurement. The distance traveled by the operators, such as trips to remote refrigerators and steps to and from the equipment, is also reduced, contributing to better work efficiency and less hours required. Furthermore, as shown in Figure 4, before the introduction of the XR-9000, it took about 1 h for the preparation. It took 10 min for the PC to start up, 30 min for wake-up of the measurement unit, and 15 min for the quality control measurement. After the introduction of the XR-9000, by scheduling the automatic wake-up and quality control measurement, it is possible to complete almost 45 min of unmanned work. In our laboratory, by setting the schedule before the daytime laboratory working hours, the start time for patient sample measurements could be advanced without changing arrival time of operators. The operators only need to confirm the quality control measurement results and can start measuring patient samples immediately if there are no abnormalities. By reducing analyzer downtime, early morning sample measurements for wards and emergency departments can be completed immediately, reducing TAT for the morning outpatient samples. In other laboratories, if sample measurement start times are not changed, it may be possible to delay arrival time of the operators and improve staff satisfaction and work-life balance. Furthermore, standardized quality control measurements can be performed regardless of the operator skill level.

In conclusion, the automatic measurement of quality control samples using the scheduling function of the BT-50 is equivalent to the manual method, and the stability of quality control samples after opening vials was found to be good and the cooling function was sufficient in this study. Based on these results, we believe that the BT-50 significantly contributes to the efficiency of hematology testing workflow, reduces operator manual tasks, improves TAT, and standardizes quality control measurements.

Corresponding author: Sho Mokuda, MD, PhD, Division of Laboratory Medicine, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan, Phone: +81-82-257-1577; Fax: +81-82-257-1577, E-mail:

Acknowledgments

We would like to express my deepest gratitude to everyone for their guidance, support, and invaluable feedback throughout the entire process of this research.

  1. Research ethics: Not applicable.

  2. Informed consent: Not applicable.

  3. Author contributions: The authors have accepted responsibility for the entire content of this manuscript and approved its submission.

  4. Competing interests: Rie Nakai and Fumiaki Hayashi are employees of Sysmex Corporation. All other authors state no conflict of interest.

  5. Research funding: This study was supported by funding from JSPS KAKENHI (grant numbers 22K08599 to S. Mokuda).

  6. Data availability: The raw data can be obtained on request from the corresponding author.

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Received: 2024-02-15
Accepted: 2024-05-05
Published Online: 2024-05-17
Published in Print: 2024-11-26

© 2024 the author(s), published by De Gruyter, Berlin/Boston

This work is licensed under the Creative Commons Attribution 4.0 International License.

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  4. Reviews
  5. Molecular allergology: a clinical laboratory tool for precision diagnosis, stratification and follow-up of allergic patients
  6. Nitrous oxide abuse direct measurement for diagnosis and follow-up: update on kinetics and impact on metabolic pathways
  7. Opinion Papers
  8. A vision to the future: value-based laboratory medicine
  9. Point-of-care testing, near-patient testing and patient self-testing: warning points
  10. Navigating the path of reproducibility in microRNA-based biomarker research with ring trials
  11. Point/Counterpoint
  12. Six Sigma – is it time to re-evaluate its value in laboratory medicine?
  13. The value of Sigma-metrics in laboratory medicine
  14. Genetics and Molecular Diagnostics
  15. Analytical validation of the amplification refractory mutation system polymerase chain reaction-capillary electrophoresis assay to diagnose spinal muscular atrophy
  16. Can we identify patients carrying targeted deleterious DPYD variants with plasma uracil and dihydrouracil? A GPCO-RNPGx retrospective analysis
  17. General Clinical Chemistry and Laboratory Medicine
  18. Comparison of ChatGPT, Gemini, and Le Chat with physician interpretations of medical laboratory questions from an online health forum
  19. External quality assessment performance in ten countries: an IFCC global laboratory quality project
  20. Multivariate anomaly detection models enhance identification of errors in routine clinical chemistry testing
  21. Enhanced patient-based real-time quality control using the graph-based anomaly detection
  22. Performance evaluation and user experience of BT-50 transportation unit with automated and scheduled quality control measurements
  23. Stability of steroid hormones in dried blood spots (DBS)
  24. Quantification of C1 inhibitor activity using a chromogenic automated assay: analytical and clinical performances
  25. Reference Values and Biological Variations
  26. Time-dependent characteristics of analytical measurands
  27. Cancer Diagnostics
  28. Expert-level detection of M-proteins in serum protein electrophoresis using machine learning
  29. An automated workflow based on data independent acquisition for practical and high-throughput personalized assay development and minimal residual disease monitoring in multiple myeloma patients
  30. Cardiovascular Diseases
  31. Analytical validation of the Mindray CL1200i analyzer high sensitivity cardiac troponin I assay: MERITnI study
  32. Diabetes
  33. Limitations of glycated albumin standardization when applied to the assessment of diabetes patients
  34. Patient result monitoring of HbA1c shows small seasonal variations and steady decrease over more than 10 years
  35. Letters to the Editor
  36. Inaccurate definition of Bence Jones proteinuria in the EFLM Urinalysis Guideline 2023
  37. Use of the term “Bence-Jones proteinuria” in the EFLM European Urinalysis Guideline 2023
  38. Is uracil enough for effective pre-emptive DPD testing?
  39. Reply to: “Is uracil enough for effective pre-emptive DPD testing?”
  40. Accurate predictory role of monocyte distribution width on short-term outcome in sepsis patients
  41. Reply to: “Accurate predictory role of monocyte distribution width on short-term outcome in sepsis patients”
  42. Spurious parathyroid hormone (PTH) elevation caused by macro-PTH
  43. Setting analytical performance specifications for copeptin-based testing
  44. Serum vitamin B12 levels during chemotherapy against diffuse large B-cell lymphoma: a case report and review of the literature
  45. Evolution of acquired haemoglobin H disease monitored by capillary electrophoresis: a case of a myelofibrotic patient with a novel ATRX mutation

Articles in the same Issue

  1. Frontmatter
  2. Editorial
  3. External quality assurance (EQA): navigating between quality and sustainability
  4. Reviews
  5. Molecular allergology: a clinical laboratory tool for precision diagnosis, stratification and follow-up of allergic patients
  6. Nitrous oxide abuse direct measurement for diagnosis and follow-up: update on kinetics and impact on metabolic pathways
  7. Opinion Papers
  8. A vision to the future: value-based laboratory medicine
  9. Point-of-care testing, near-patient testing and patient self-testing: warning points
  10. Navigating the path of reproducibility in microRNA-based biomarker research with ring trials
  11. Point/Counterpoint
  12. Six Sigma – is it time to re-evaluate its value in laboratory medicine?
  13. The value of Sigma-metrics in laboratory medicine
  14. Genetics and Molecular Diagnostics
  15. Analytical validation of the amplification refractory mutation system polymerase chain reaction-capillary electrophoresis assay to diagnose spinal muscular atrophy
  16. Can we identify patients carrying targeted deleterious DPYD variants with plasma uracil and dihydrouracil? A GPCO-RNPGx retrospective analysis
  17. General Clinical Chemistry and Laboratory Medicine
  18. Comparison of ChatGPT, Gemini, and Le Chat with physician interpretations of medical laboratory questions from an online health forum
  19. External quality assessment performance in ten countries: an IFCC global laboratory quality project
  20. Multivariate anomaly detection models enhance identification of errors in routine clinical chemistry testing
  21. Enhanced patient-based real-time quality control using the graph-based anomaly detection
  22. Performance evaluation and user experience of BT-50 transportation unit with automated and scheduled quality control measurements
  23. Stability of steroid hormones in dried blood spots (DBS)
  24. Quantification of C1 inhibitor activity using a chromogenic automated assay: analytical and clinical performances
  25. Reference Values and Biological Variations
  26. Time-dependent characteristics of analytical measurands
  27. Cancer Diagnostics
  28. Expert-level detection of M-proteins in serum protein electrophoresis using machine learning
  29. An automated workflow based on data independent acquisition for practical and high-throughput personalized assay development and minimal residual disease monitoring in multiple myeloma patients
  30. Cardiovascular Diseases
  31. Analytical validation of the Mindray CL1200i analyzer high sensitivity cardiac troponin I assay: MERITnI study
  32. Diabetes
  33. Limitations of glycated albumin standardization when applied to the assessment of diabetes patients
  34. Patient result monitoring of HbA1c shows small seasonal variations and steady decrease over more than 10 years
  35. Letters to the Editor
  36. Inaccurate definition of Bence Jones proteinuria in the EFLM Urinalysis Guideline 2023
  37. Use of the term “Bence-Jones proteinuria” in the EFLM European Urinalysis Guideline 2023
  38. Is uracil enough for effective pre-emptive DPD testing?
  39. Reply to: “Is uracil enough for effective pre-emptive DPD testing?”
  40. Accurate predictory role of monocyte distribution width on short-term outcome in sepsis patients
  41. Reply to: “Accurate predictory role of monocyte distribution width on short-term outcome in sepsis patients”
  42. Spurious parathyroid hormone (PTH) elevation caused by macro-PTH
  43. Setting analytical performance specifications for copeptin-based testing
  44. Serum vitamin B12 levels during chemotherapy against diffuse large B-cell lymphoma: a case report and review of the literature
  45. Evolution of acquired haemoglobin H disease monitored by capillary electrophoresis: a case of a myelofibrotic patient with a novel ATRX mutation
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