Comparative studies confirm the high quality of UNIVAC tubes
In order to verify the high quality of UNIVAC® vacuum tubes, we turned to Doctor of Medical Sciences, Professor Lina Anatolievna Khorovskaya with a request to compare our tubes with tubes of one of the recognized leaders in the world market. Lina Anatolyevna is a leading expert in the field of laboratory research quality management not only in our country, but also in the world. Professor L. A. Khorovskaya has for many years been a member of the Committee of Science of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) for Education and the Office for Analytical Quality.
In order to verify the high quality of UNIVAC® vacuum tubes, we turned to Doctor of Medical Sciences, Professor Lina Anatolievna Khorovskaya with a request to compare our tubes with tubes of one of the recognized leaders in the world market. Lina Anatolyevna is a leading expert in the field of laboratory research quality management not only in our country, but also in the world. Professor L. A. Khorovskaya has for many years been a member of the Committee of Science of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) for Education and the Office for Analytical Quality. Lina Anatolyevna Khorovskaya kindly agreed to fulfill our request and together with the head of the CDL GBUZ Clinical Hospital of St. Luke, St. Petersburg Inna Olegovna Schmidt conducted comparative studies of Univac tubes (Eiliton, Russia) and Vacuette (Greiner, Austria) in patients who were on treatment in this clinic during May 2016
The studies were carried out in accordance with the protocol of the Institute of Clinical and Laboratory Standards (CLSI GP-34A), which is widely used in many countries to compare test tubes of new brands with the gold standard - vacuum systems from world famous manufacturers. The results of such studies allow medical laboratories to choose high-quality tubes that will not distort the results of laboratory tests.
Blood samples for the study were obtained from 163 patients (40 patients each for assessing biochemical, hematological and coagulological parameters and 43 patients for assessing glucose from stabilizer tubes). From each patient, samples were taken in 4 tubes based on 2 tubes of each manufacturer for measurement in duplicate.
Blood was taken using the standard phlebotomy procedure, in accordance with the requirements of the CLSI protocol and methodological recommendations of the All-Russian public organization “Association of Russian Nurses”.
A total of 6 732 measurements of laboratory parameters were performed, including:
- 2,880 studies on 18 biochemical parameters, 1,440 measurements for test tubes of each manufacturer;
- 172 glucose measurements from a specially designed type of test tube included, 86 for each type of test tube;
- 3 360 studies on a hematology analyzer according to 21 indicators, 1,680 measurements for each type of test tube;
- 320 coagulological research measurements by 4 hemostasis indicators, 160 measurements for each manufacturer’s test tube.
Samples were measured in normal mode no later than 2 hours after the biomaterial was taken on the following instruments: RX Imola Randoх biochemistry analyzer (Ireland), MEK 7227 hematology analyzer Nihon Kohden (Japan) and ACL Elite Pro coagulological analyzer (Instrumentation Laboratory, USA).
In the study of comparability, we used the bias (B), standard deviation (SD) and coefficient of variation (CV%) duplicates, which were analyzed in the measurement intervals of low, medium and high values, which are important for the practitioner to interpret the results. The statistical significance of the differences in the measurement results was evaluated using Student's t-test for paired samples. To compare CV% duplicate convergence and overall error (TE%), the Fisher test (F-test) was used. Analytical accuracy parameters were compared with international quality criteria based on a database of biological variation.
Based on the results of the study, the following conclusions were made:
1. Comparison of the results of studies made from vacuum tubes for biochemical studies with the activator of coagulation of silica brands Vacuette and Univac (red cap, volume 6 ml).
The studied indicators: the activity of alanine aminotransferase (ALT), aspartate aminotransferase (AST), amylase, alkaline phosphatase (ALP), total creatine kinase (CC), the concentration of total bilirubin, creatinine, total protein, total cholesterol, high density lipoprotein cholesterol (HDL cholesterol) uric acid, glucose, iron, total calcium, potassium, sodium, chlorides.
- In a comparative study of the 18 most popular biochemical parameters in clinical practice, it was shown that the results obtained with Univac tubes are well comparable with those obtained with Vacuette vacuum tubes.
- Isolated cases of discrepancies in the study of electrolytes of total calcium and potassium were identified for patients who were in critical condition in the intensive care unit and received intensive chemotherapy. A possible cause of the variation is the interference of drugs and intoxication products.
2. Comparison of blood glucose test results from Vacuette and Univac vacuum tubes with sodium fluoride and potassium oxalate as glucose stabilizers (gray cap, volume 6 ml).
- The results of measuring blood glucose concentration made from Vacuette and Univac vacuum tubes with glucose stabilizers on a RX Imola Randoх biochemical analyzer (Ireland) are completely comparable for all the studied samples in the entire concentration range (hypo-, normo-, and hyperglycemic intervals).
3. Comparison of the results of hematological studies made from Vacuette and Univac vacuum tubes with EDTA K2 (pale lilac lid, volume 2 ml). The studied parameters: erythrocytes (RBC), hemoglobin (Hb), hematocrit (Htc), average erythrocyte volume (MCV), average erythrocyte hemoglobin content (MCH), average erythrocyte hemoglobin concentration (MCHC), erythrocyte volume variation coefficient (RDW, %), white blood cells (WBC), neutrophils (Neutabs / Neut,%), lymphocytes (Lymphabs / Lymph,%), eosinophils (Eosabs / Eos,%), basophils (Basoabs / Baso,%), monocytes (Monoabs / Mono, %), platelets (Plt), platelet count (Pct), average platelet volume (MPV).
- When comparing the results of studies of 21 hematological parameters in the blood samples of patients taken in Univac and Vacuette tubes, insignificant differences were revealed in 7 parameters (MCV, MCHC, RDW, Lymphabs,% Lymph,% Eos and MPV), which did not affect the clinical interpretation of the parameters general blood test.
- When analyzing the convergence of measurements in duplicates in test tubes of different manufacturers, small discrepancies were revealed for red blood cell counts, which should be taken into account when diagnosing anemic conditions. The resulting variability may be due to differences in vacuum tube manufacturing techniques..
4. Comparison of the results of coagulological studies performed with Vacuette and Univac vacuum tubes with sodium citrate 3.2% (blue cap, volume 4.5 ml). The studied parameters: activated partial thromboplastin time (APTT), prothrombin time (PT), international normalized ratio (INR) and fibrinogen.
- Comparison of the results of the APTT, PV, INR and fibrinogen studies in the samples of patients taken from Univac tubes compared to the Vacuette allowed us, despite the statistically significant differences in the APTT study, to obtain clinically comparable data that correctly interpret all parameters of the blood test.
- Variability of the convergence index was detected only when testing fibrinogen when testing in Vacuette tubes, while for Univac tubes this indicator was within acceptable limits.
Thus, the results of comparing the studied biochemical, hematological and coagulological parameters of a blood test in Univac (Eiliton, Russia) and Vacuette (Greiner, Austria) tubes demonstrated good comparability of the results for the vast majority of the studied parameters. Single differences in the parameter values in the reference interval zone did not significantly affect the clinical interpretation of the data, which allows us to conclude that the quality of the tubes of the indicated manufacturers is similar.