Limiting the testing of urea: Urea along with every plasma creatinine test?

BACKGROUND: We found that it is not necessary to simultaneously detect both creatinine (CREA) and urea until the concentration of CREA is lower than the certain level. To reduce urea testing, we suggest measuring urea only when CREA or estimated glomerular filtration rate (eGFR) exceeds a predetermined limit. MATERIALS AND METHODS: CREA and urea data were analyzed consisting of almost all of people age above 65 years old check-up (n=95441) in Shuyang countryside, and inpatients (n=101631), outpatients (n=18474) and Routine Health Check-up (n=20509) in Shuyang People's Hospital. The proportions of elevated urea were derived. The data used in this study was generated from people more than 13 years old in both outpatients and inpatients. RESULTS: When the limits for initiating urea testing were used at 85 µmol/L CREA and 120 mL/min/1.73 m2 eGFR, the percentage of unnecessary urea test are 94.5% and 64.7% (elderly health check-up), 67.9% and 84.5% (outpatients), 88.5% and 73.2% (inpatients), 92.2% and 81.7% (routine health check-up). The missing rate of urea are 1%, 2.5%, 4.6% and 9.2%, 0.1%, 0.4%, 0.9% and 1.8%, 0.4%, 0.8%, 1.4%, and 2.5%, 0.05%, 0.1%, 1.1%, and 0.8% of ureas exceeding 9.28 mmol/L and 8.3 mmol/L in above each group, respectively. If the CREA≤85 µmol/L or eGFR≥90 mL/min/1.73 m2 , there is 97.5% urea <10.1 mmol/L, the proportion of elevated urea missed is 2.5%. CONCLUSIONS: We suggest that the initiating urea testing should be based on the upper limit of Reference Intervals serum CREA of females or a 120 mL/min/1.73 m2 eGFR limit. Conservatively, the urea testing would be reduced by 65% at least.

Establishing Reference Intervals of Aspartate Aminotransferase-to-Platelet Ratio Index for Apparently Healthy Elderly.

BACKGROUND: Aspartate aminotransferase (AST) to platelet ratio index (APRI) serves as a parameter in evaluating liver fibrosis in current clinical practice. However, reference standard (reference intervals, RIs) or baseline levels of APRI have not been previously reported. The purpose of this paper is to establish the reference intervals of APRI in apparently healthy elderly people from the region of Shuyang, China. METHODS: Blood specimens were collected from local elderly residents (selected 51,263 elderly Han Shuyang Chinese from 65 to 97 years old, 32.97% males and 67.03% females) by standard procedures. Complete blood counts were determined by Sysmex XE-2100 analyzer and the AST values were measured by a TBA2000FR automatic biochemical analyzer (Toshiba Co., Ltd., Japan). The 95% reference intervals were calculated by using the non-parametric method according to the document: Defining, Establishing, and Verifying Reference Intervals in the Clinical Laboratory; Approved Guideline-Third Edition (C28-A3) of CLSI. RESULTS: RIs established for healthy elderly include: 0.1398-0.6266 for males and 0.1282-0.5798 for females (0.1284-0.5086 for 65-74 years old; 0.1209-0.5704 for > or = 75 years old). Ris of APRI for elderly males were higher than those of females, and values of APRI increased with increasing age for females. CONCLUSIONS: We established scientific and reasonable RIs of APRI for the healthy elderly in our region.

Reference Intervals of Alpha-Fetoprotein and Carcinoembryonic Antigen in the Apparently Healthy Population.

BACKGROUND The aim of this study was to calculate 95% reference intervals and double-sided limits of serum alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA) according to the CLSI EP28-A3 guideline. MATERIAL AND METHODS Serum AFP and CEA values were measured in samples from 26 000 healthy subjects in the Shuyang area receiving general health checkups. The 95% reference intervals and upper limits were calculated by using MedCalc. RESULTS We provided continuous reference intervals from 20 years old to 90 years old for AFP and CEA. The reference intervals were: AFP, 1.31-7.89 ng/ml (males) and 1.01-7.10 ng/ml (females); CEA, 0.51-4.86 ng/ml (males) and 0.35-3.45ng/ml (females). AFP and CEA were significantly positively correlated with age in both males (r=0.196 and r=0.198) and females (r=0.121 and r=0.197). CONCLUSIONS Different races or populations and different detection systems may result in different reference intervals for AFP and CEA. Continuous reference intervals of age changes are more accurate than age groups.

Reference intervals for total bilirubin, ALT, AST and creatinine in healthy Chinese elderly.

BACKGROUND: The aim of this study was to establish the reference intervals (RIs) of total bilirubin (TBIL), alanine aminotransferase (ALT), aspartate transaminase (AST), and creatinine (CREA) for apparently healthy elderly (Han ethnicity) in Shuyang, China. MATERIAL AND METHODS: A total of 54 912 blood specimens from elderly residents age 65-104 years were collected by standard procedures in Shuyang county of Jiangsu province. TBIL, ALT, AST, and CREA for each participant were determined by automatic biochemical analyzer. Distribution and differences of TBIL, ALT, AST, and CREA were analyzed and compared between the elderly of the same age of different sexes and different ages of the same sex. RIs of TBIL, ALT, AST, and CREA were compared with the current RIs. The RIs and 95% confidence intervals were calculated using nonparametric method (2.5th-97.5th percentiles) according to the guideline of the Clinical and Laboratory Standards Institute. RESULTS: RIs established for the healthy elderly include: TBIL 7.8~30.6 µmol/L for males and 7.3~26.1 µmol/L for females; ALT 8.7~47.3 U/L for males and 8.4~45.2 U/L for females; AST 15.7~46.9 U/L for males and 15.1~46.2 U/L for females; and CREA 45.1~100.9 µmol/L for males and 38.7~85.0 µmol/L for females. Reference intervals of TBIL, ALT, AST, and CREA for male elderly were higher than those of females, and values of CREA increased with increasing age. CONCLUSIONS: We have established a panel of locally relevant RIs. It is necessary to establish scientific and reasonable RIs of TBIL, ALT, AST, and CREA for the healthy elderly in our region, which will provide a reference for clinicians and inspection officers.

A Novel LDLC Equation is Superior to the NIH LDLC Equation and the Friedewald Equation.

Background: LDLC equations have varying levels of underestimation for the calculated LDLC. Therefore, underestimating LDLC should be avoided as much as possible. We need to establish LDLC equations that underestimate LDLC as little as possible. Methods: We established the equations with a healthy cohort from Shuyang Hospital and validated the equations with an unselected patient cohort from The Second People's Hospital of Lianyungang. We established the novel LDLC equations by using the regression equation. The relationship between two markers was analysed using Pearson's approach. The 95% limits of measuring agreement within ±2 SD for the LDLC equations was performed using Bland‒Altman analysis. ROC curve analysis was used to predict LDLC levels and the accuracy of the LDLC equation for determining the direct LDLC levels at LDLC cut-offs was assessed. Results: We obtained two novel LDLC equations (LDL_nonHDLC equation=-0.899+1.195*nonHDLC-0.00347*nonHDLC2 and LDL_TC(total cholesterol) equation=-2.775+1.29*TC -0.00990* TC 2). The correlation coefficient between the novel LDLC equation and the direct LDLC measurements is not lower than that between the LDL_NIH equation and the direct LDLC measurements. The AUCs of our novel LDLC equations were greater than those of the LDL_NIH equation and the LDL_F equation at the LDLC cut-offs for clinical decision-making. The measuring agreement in the methods of the LDL_nonHDL equation is superior to that of the LDL_NIH equation. Conclusion: LDLC calculated by the novel LDL_nonHDL equation exhibited superiority over the LDL_NIH equation. Combining the LDL_NIH equation and our novel LDLC equation may improve accuracy and avoid undertreatment of high LDLC levels.

"One-gate" design should be used for the study of the diagnostic efficacy of biological markers.

1. The first draft of this article proposes "Please authors answer a question: was there only 43 patients with diagnosed gastric cancer from April 2018 to July 2018?" Is it to know whether the researchers chose 43 patients because of fewer cases or intentionally fewer? The reviewer's "response reviewers" admitted "it's better to add a benign disease group" and "chose 43 patients with diagnosed gastric cancer randomly for our validation," which confirmed my opinion "have design flaws both in enroll subjects and the number of cases". So after getting the reply from the original author, I deleted the above sentence. This time amend "43 patients" on line 43 to "43 patients which random selection rather than all patients in the study time window". 2. Some revision has been highlighted in red. 3. We re-edit the article sentence by sentence in English to make it more in line with the English expression.