Types and frequency of preanalytical errors in haematology lab

Determining the rate and reasons for specimen rejection among specimens referred for HIV viral load determination through referral linkage to Debre Tabor Comprehensive Specialized Hospital, north-central, Ethiopia,2023: Retrospective study

Background

The preanalytical phase encompasses the time between the clinician's test order to the sample being ready for analysis. Of all errors during the laboratory diagnostic process,70 % appeared in the pre-analytical phase. In clinical laboratories, it is crucial to ensure proper specimen collection and handling, which is essential to guarantee quality assessment, monitoring process standardization, improving performance, and ensuring patient safety. Despite this importance, no study has been conducted in the study area to investigate the rate and reasons for human immunodeficiency virus viral load sample rejection.

Objective

To determine the rate of human immunodeficiency virus viral load sample rejection (number of preanalytical errors) documented during the preanalytical phase and articulate possible causes for specimen rejection.

Material and methods

A retrospective study was conducted at Debre Tabor Comprehensive Specialized Hospital from January 1st to January 31, 2023. During the study period, 5950 samples were extracted from the human immunodeficiency virus viral load laboratory sample tracking log books, which were sent to the hospital for viral load testing between August 2021 to November 2022. The collected data were cleaned and entered into EPI data version 4.6 before transferred it to STATA version 14.0 for analysis. Descriptive statistics such as frequencies, percentages, and cross-tabulations were used to summarize the findings.

Results

The study found that improper sample handling was common during the preanalytical phase. According to the current study, 3.6 % of the sample was rejected at pre analytical stage. The most common reasons for specimen rejection were using inappropriate containers (64.0 %) uncentrifuged specimens (20.4 %); hemolyzed specimens (7.0 %); insufficient specimen volume (6.2 %); clotted specimens (1.9 %); and specimen labeling problems (0.5 %).

Conclusion

This study found that the most common preanalytical error was using an inappropriate sample collection container, followed by uncentrifuged samples, Therefore, it is recommended that mentorship programs be developed to educate staff on the preanalytical phase of laboratory testing, specifically on sample collection, storage, and transportation for HIV viral load testing. Additionally, the quality management system of laboratory processes should be strengthened to ensure accuracy and minimize errors.

Prevalence and types of preanalytical error in hematology laboratory of a tertiary care hospital in South India

BACKGROUND

An important component of laboratory medicine is preanalytical phase. Since laboratory report plays a major role in patient management, more importance should be given to the quality of laboratory tests.

AIM

The present study was undertaken to find the prevalence and types of preanalytical errors at a tertiary care hospital in South India.

MATERIALS AND METHODS

In this cross-sectional study, a total of 118,732 samples ([62,474 outpatient department [OPD] and 56,258 inpatient department [IPD]) were received in hematology laboratory. These samples were analyzed for preanalytical errors such as misidentification, incorrect vials, inadequate samples, clotted samples, diluted samples, and hemolyzed samples.

RESULTS

The overall prevalence of preanalytical errors found was 513 samples, which is 0.43% of the total number of samples received. The most common preanalytical error observed was inadequate samples followed by clotted samples. Overall frequencies (both OPD and IPD) of preanalytical errors such as misidentification, incorrect vials, inadequate samples, clotted samples, diluted samples, and hemolyzed samples were 0.02%, 0.05%, 0.2%, 0.12%, 0.02%, and 0.03%, respectively.

CONCLUSION

The present study concluded that incorrect phlebotomy techniques due to lack of awareness is the main reason for preanalytical errors. This can be avoided by proper communication and coordination between laboratory and wards, proper training and continuing medical education programs for laboratory and paramedical staffs, and knowledge of the intervening factors that can influence laboratory results.

Quantitative assessment of prevalence of pre-analytical variables and their effect on coagulation assay. Can intervention improve patient safety?

BACKGROUND

Very few Indian studies exist on evaluation of pre-analytical variables affecting "Prothrombin Time" the commonest coagulation assay performed. The study was performed in an Indian tertiary care setting with an aim to assess quantitatively the prevalence of pre-analytical variables and their effects on the results (patient safety), for Prothrombin time test. The study also evaluated their effects on the result and whether intervention, did correct the results.

METHODS

The firstly evaluated the prevalence for various pre-analytical variables detected in samples sent for Prothrombin Time testing. These samples with the detected variables wherever possible were tested and result noted. The samples from the same patients were repeated and retested ensuring that no pre-analytical variable is present. The results were again noted to check for difference the intervention produced.

RESULTS

The study evaluated 9989 samples received for PT/INR over a period of 18 months. The prevalence of different pre-analytical variables was found to be 862 (8.63%). The proportion of various pre-analytical variables detected were haemolysed samples 515 (5.16%), over filled vacutainers 62 (0.62%), under filled vacutainers 39 (0.39%), low values 205 (2.05%), clotted samples 11 (0.11%), wrong labeling 4 (0.04%), wrong vacutainer use 2 (0.02%), chylous samples 7 (0.07%) and samples with more than one variable 17 (0.17%). The comparison of percentage of samples showing errors were noted for the first variables since they could be tested with and without the variable in place. The reduction in error percentage was 91.5%, 69.2%, 81.5% and 95.4% post intervention for haemolysed, overfilled, under filled and samples collected with excess pressure at phlebotomy respectively.

CONCLUSION

Correcting the variables did reduce the error percentage to a great extent in these four variables and hence the variables are found to affect "Prothrombin Time" testing and can hamper patient safety.

Current Methods of Haemolysis Detection and Reporting as a Source of Risk to Patient Safety: a Narrative Review

AIM

Haemolysis has a major impact on patient safety as the need for a replacement specimen increases the risk of injury and infection, delays test results and extends the duration of hospital stays. Consistency of haemolysis detection and reporting can facilitate the generation of benchmark data used to develop quality practices to monitor and reduce this leading cause of pre-analytical laboratory error. This review aims to investigate current methods of haemolysis detection and reporting.

METHOD

Due to known heterogeneity and immaturity of the research field, a scoping search was conducted using PUBMED, Embase, Medline and CINAHL. Articles published between 2000 and 2014 that reported haemolysis rates in specimens from the general population were included.

RESULTS

Of the 50 studies that met the inclusion criteria, 20 detected haemolysis using the Haemolysis Index (HI), 19 by visual inspection and 13 by undefined methods. There was large intra-study variation in the plasma free haemoglobin level used to establish haemolysis (HI: mean±SD 846±795 mg/L, range 150-3000 mg/L; Visual: 850±436 mg/L, 500-3000 mg/L). Sixteen studies reported the analyte of interest, with only three studies reporting a haemoglobin level at which the specimen would be rejected.

CONCLUSION

Despite haemolysis being a frequent and costly problem with a negative impact on patient care, there is poor consistency in haemolysis detection and reporting between studies. Improved consistency would facilitate the generation of benchmark data used to create quality practices to monitor and reduce this leading cause of pre-analytical laboratory error.

Preanalytical Errors in Hematology Laboratory- an Avoidable Incompetence

BACKGROUND

Quality assurance in the hematology laboratory is a must to ensure laboratory users of reliable test results with high degree of precision and accuracy. Even after so many advances in hematology laboratory practice, pre-analytical errors remain a challenge for practicing pathologists. This study was undertaken with an objective to evaluate the types and frequency of preanalytical errors in hematology laboratory of our center.

METHODS

All the samples received in the Hematology Laboratory of Dayanand Medical College and Hospital, Ludhiana, India over a period of one year (July 2013-July 2014) were included in the study and preanalytical variables like clotted samples, quantity not sufficient, wrong sample, without label, wrong label were studied.

RESULTS

Of 471,006 samples received in the laboratory, preanalytical errors, as per the above mentioned categories was found in 1802 samples. The most common error was clotted samples (1332 samples, 0.28% of the total samples) followed by quantity not sufficient (328 sample, 0.06%), wrong sample (96 samples, 0.02%), without label (24 samples, 0.005%) and wrong label (22 samples, 0.005%).

CONCLUSION

Preanalytical errors are frequent in laboratories and can be corrected by regular analysis of the variables involved. Rectification can be done by regular education of the staff.