WS/T 404.4-2018Reference intervals for common clinical biochemistry tests - Part 4: Serum total bilirubin and direct bilirubin (English PDF)

5.1 General principles

5.1.1 The clinical laboratory should prefer the reference interval for this document.

Note 1. The reference workload establishes the research workload and cost, and the clinical laboratory reference interval is more objective and feasible than the establishment of the reference interval.

Note 2. This reference interval is based on the results of the multi-center study of the Chinese adult population. The results of the total bilirubin test in the study can be traced back to internationally accepted reference methods or targets.

See Appendix B for quasi-substances.

Note 3. There is no internationally recognized metrology traceability of direct bilirubin. Users who do not have a reference interval in this document can transfer reference intervals.

Used on the basis of verification.

5.1.2 The necessary verification or evaluation should be carried out before using the reference interval of this document.

Note 1. The applicability of the external reference interval in the laboratory depends mainly on the comparability of the test results and the applicability of the population when the laboratory and reference intervals are established.

Note 2. Only a constant system bias (correctness of test results) affects the applicability of the reference interval. Excessive intra-laboratory variation is true.

The laboratory analyzes the quality problem, not the reference interval applicability problem.

Note 3. The reference interval of this document is based on the results of serum tests. If the type of specimen used in clinical laboratories is plasma, an appropriate assessment should be made.

Whether to use this reference interval.

5.2 Evaluation, verification and use of reference intervals

5.2.1 Perform reference interval assessment and verification in accordance with the relevant provisions of WS/T 402.

5.2.2 If the laboratory confirms that the test results are comparable to the reference interval and the population is applicable, the reference interval of this document can be directly quoted.

If you are unsure or need to verify the referenced reference intervals based on the requirements of the laboratory management system, you can do the following.

a) screening not less than 20 qualified reference individuals, see A.2.2 for screening criteria;

b) Collect, process and analyze samples according to the laboratory procedures;

c) check and eliminate outliers in an appropriate manner (if available, select additional reference individuals);

Note. The outlier test uses the Dixon method. first, the test results are sorted by size and the range R is calculated, and then the maximum and minimum values are respectively calculated.

The difference between the values D; if D/R >= 1/3, the maximum or minimum value is regarded as the outlier value; the remaining data is repeated for the outlier detection Test until all outliers are removed.

d) If 20 qualified reference individuals are selected, compare 20 test results with the reference interval, if the data beyond the reference interval is not exceeded If there are 2, then pass the verification; if there are more than 2, then another 20 qualified reference individuals will be tested according to the above criteria.

certificate. If there are more than 20 reference individuals, if the data beyond the reference interval does not exceed 10%, the verification is passed; if more than 10% of the data is exceeded for the reference interval, select at least 20 qualified reference individuals and re-verify according to the above criteria. Verification result If the requirements are met, the reference interval can be used directly, otherwise the reason should be found.

5.3 Handler when the reference interval fails verification

5.3.1 For cases that have not been verified, the quality of the analysis, especially the accuracy, should be evaluated first, if it is confirmed that the quality of the analysis is caused by the detection system.

Problem, the analysis system should be improved or replaced. Analytical quality assessment can be used, but is not limited to the following.

a) analysis of interoperable certified reference materials or other suitable reference materials;

b) participate in a suitable accuracy verification plan or standardization plan;

c) Compare with other systems or methods with reliable performance.

5.3.2 If it is proved that the cause of the crowd (such as ethnicity, high altitude, special living habits, etc.) has not been verified, it should be WS/T 402.

The requirements establish or reference a suitable reference interval.

Appendix A

(informative appendix) Information about the interval establishment process A.1 Steps for establishing a reference interval this document refers to the interval established by the multi-center research method according to the requirements of WS/T 402, and mainly includes the following steps.

a) selecting reference individuals to form a reference sample group;

b) collecting and processing blood samples to obtain serum samples;

c) detecting serum samples to obtain a reference value;

d) Statistically process the reference values and establish a reference interval.

A.2 Reference individual selection A.2.1 Selection of reference sample groups the design reference population is the adult healthy population in China. The reference sample group is selected from Northeast (Shenyang), North China (Beijing), Northwest (West).

Urban and rural residents in 6 districts of An), East China (Shanghai), South China (Guangzhou) and Southwest (Chengdu), with a total of about 720 selected reference individuals per region Name, the number of reference individuals per decade of age is at least 120, male to female ratio is 1.1, age range is 20 to 79 years old A.2.2 Selection of reference individuals, each center collects enough possible reference individuals in the area, collects informed consent, and conducts screening of reference individuals to form a reference.

Sample group.

Screening reference individuals through questionnaires, physical examinations, and laboratory tests to meet the following requirements.

a) consciously healthy;

b) No diseases. acute and chronic infections (acute upper respiratory tract infections, pneumonia, tuberculosis, etc.), digestive diseases (cirrhosis, Hepatitis, fatty liver disease, cholelithiasis, cholecystitis, chronic diarrhea, inflammatory bowel disease, etc., kidney disease (chronic kidney disease, Acute kidney injury, etc., metabolic and nutritional diseases (diabetes, metabolic syndrome, dyslipidemia and lipoprotein abnormalities, high urine) Acidemia and gout, etc., rheumatic diseases (rheumatoid arthritis, systemic lupus erythematosus, etc.), thyroid disease (thyroid Hyperthyroidism, hypothyroidism, etc., blood system diseases (anemia, leukemia, etc.), atherosclerosis and blood vessels Disease, heart disease, myopathy, malignancy, burns and muscle damage, obesity or weight loss [BMI (body mass index) >= 28 kg/m2 or < 18.5kg/m2], hypertension (systolic blood pressure >=140mmHg and/or diastolic blood pressure >=90mmHg);

c) No operation within 6 months, no blood donation, blood transfusion or massive blood loss within 4 months, no medication within 2 weeks;

d) no alcohol (long-term drinking or heavy drinking within 2 weeks), smoking (smoke amount > 20/d);

e) no recent strenuous exercise or heavy physical labor;

f) Women are not pregnant or breastfeeding.

Note. Reference individuals did not pass genetic testing to rule out Gilbert syndrome, Dubin-Johnson syndrome, Rotor syndrome, and Crigler-Najjar syndrome Congenital benign hyperbilirubinemia.

A.3 Blood sample collection and processing the principle of blood sample collection and processing is carried out in accordance with the relevant requirements of WS/T 225-2002. The specific requirements are as follows.

a) Reference individual preparation. maintain normal living habits three days before blood collection, do not exercise vigorously and heavy physical labor, dinner the day before blood collection After the second day of the morning, fasting before blood collection, fasting time 8 h ~ 14 h;

b) Blood collection. The subject takes a sitting position and uses a vacuum blood collection method to collect blood from the anterior elbow vein;

c) Blood sample treatment. The sample is separated in time within 2 hours after collection, and the hemolysis, jaundice or chyle sample is checked and eliminated. Serum Analysis was performed within 2 h after separation.

A.4 Analysis of serum samples A.4.1 Analysis System. A variety of analytical systems commonly used in clinical laboratories in China.

Note. The metrological traceability of the analysis system used in the establishment of this reference interval and its test results is shown in Appendix B. See the correctness verification of the test results of each analysis system.

A.4.2.

A.4.2 Analysis system performance evaluation. The analysis system performs analytical performance evaluation before analysis of reference individual serum samples. According to instruments and reagents the operating procedures specified in the specification run the analysis system. Precision assessment. analysis of two levels of quality control, one batch per day, repeated 4 times, Determination 5 d; correctness verification. analysis of certified reference materials for correctness verification. Precision and accuracy meet the relevant requirements of WS/T 403.

A.4.3 Analysis of serum samples and quality control. Analytical performance meets the requirements for serum sample analysis, and each serum sample is analyzed once.

Precision control uses two levels of quality control substances, and each quality analysis substance is analyzed before and after the independent analysis batch; periodic analysis of certified reference materials Correctness assessment.

A.5 Reference value processing and reference interval establishment A.5.1 Outliers check. Each group of outliers is checked and eliminated according to the Dixon method.

A.5.2 Group judgment. According to the nested ANOVA method, the group-group test is carried out on the reference values of gender, age and region, and the judgment is necessary.

Groups, which combine the reference values that do not need to be grouped to determine the actual reference sample group.

Note. By statistical analysis, total bilirubin and direct bilirubin were not statistically different between different age groups and different regions; total bilirubin reference interval Sex grouping is required; the direct bilirubin reference interval is grouped by the detection system.

A.5.3 Reference limit and reference interval establishment. Calculate the 95th percentile of the reference sample group reference value as the reference upper limit by non-parametric method, not Set the reference lower limit. According to the clinical opinion, the reference limit is appropriately rounded to form a reference interval.

Appendix B

(informative appendix) Quantitative traceability of serum total bilirubin, direct bilirubin detection method and test results the metrological traceability of the test methods and test results of serum total bilirubin and direct bilirubin is shown in Table B.1.

Table B.1 Metrological traceability of test methods and test results for serum total bilirubin and direct bilirubin

Project method metrology traceability Total bilirubin diazo method/citrate oxidation method NIST SRM916a Direct bilirubin diazo method -references [1] WS/T 225-2002 Clinical Chemistry Examination Collection and Processing of Blood Specimens [2] WS/T 403-2012 Clinical biochemical test routine project analysis quality index [3] Wang Jiyao. Internal Medicine. 2nd Edition. Beijing. People's Medical Publishing House, 2010 [4] Donald S. Young. Influence of pre-analytical factors on clinical test results. Version 3. Li Yan, et al. Translation. Beijing. People's Military Medical Press, 2009 [5] Clinical and Laboratory Standards Institute (CLSI).Defining, establishing, and Verifying reference intervals in the clinical laboratory.Approved Guideline-Third Edition.

CLSI document C28-A3c.CLSI, Wayne, PA, USA, 2010 [6] Ichihara K, Boyd JC, IFCC Committee on Reference Intervals and Decision Limits (C-RIDL).

An appraisal of statistical procedures used in derivation of reference intervals. Clin Chem Lab Med, 2010, 48. 1537-1551