Conjugated bilirubin as a reflex test for increased total bilirubin in apparently healthy population

Overutilization in laboratory medicine: tackling the problem with quality improvement science

Overutilization of tests and treatments is a widespread problem in contemporary heath care, and laboratory medicine is no exception. It is estimated that 10-70% of laboratory tests may be unnecessary, with estimates in the literature varying depending on the situation and the laboratory test. Inappropriate use of laboratory tests can lead to further unnecessary testing, adverse events, inaccurate diagnoses, and inappropriate treatments. Altogether, this increases the risk of harm to a patient, which can be physical, psychological, or financial in nature. Overutilization in healthcare is driven by complex factors including care delivery models, litigious practice environments, and medical and patient culture. Quality improvement (QI) methods can help to tackle overutilization. In this review, we outline the global healthcare problem of laboratory overutilization, particularly in the developed world, and describe how an understanding of and application of quality improvement principles can help to address this challenge.

A Novel Method for Estimating Low-Density Lipoprotein (LDL) Levels: Total Cholesterol and Non-High-Density Lipoprotein (HDL) Can Be Used to Predict Abnormal LDL Level in an Apparently Healthy Population

BACKGROUND We aimed to predict the abnormal LDL level by using TG, TC, HDL, and non-HDL in this study. MATERIAL AND METHODS Triglyceride (TG), total cholesterol (TC), high-density lipoprotein (HDL), and low-density lipoprotein (LDL) data were obtained from the Laboratory Information System (LIS) for 4 years (Oct 1, 2013 to Sept 30, 2017) from among 34 270 healthy Chinese patients at Shuyang People's Hospital. TG, TC, HDL, and LDL (direct clearance method) were measured using a TBA2000FR biochemical analyzer. The non-HDL was calculated as TC minus HDL. Correlations between TG, TC, non-HDL, and LDL were analyzed using Spearman's rank correlation. Receiver operating characteristics (ROC) curve analysis was used to evaluate the predictive utility of TG, TC, and non-HDL for the abnormal LDL level (<130 mg/dL). RESULTS Both TC (r=0.870) and non-HDL (r=0.893) were significantly positively correlated with LDL. The area under curve of TC and non-HDL can be used to predict abnormal LDL levels. Optimal thresholds were 182.5 mg/Dl (4.72 mmol/L) for TC and 135.3 mg/Dl (3.50 mmol/L) for non-HDL. Based on these optimal thresholds, less than 0.5% and 0.4% of tests with elevated LDL were missed using TC and non-HDL, respectively, but the value of these missed LDL levels was not very high (<147.3 mg/dL). CONCLUSIONS If the value of non-HDL is less than 135.3 mg/Dl (3.50 mmol/L) and/or TC is less than 182.5 mg/Dl (4.72 mmol/L) for the apparently healthy populations, the LDL level will be less than 130 mg/Dl (3.36 mmol/L). TC and non-HDL can be used to predict the abnormal LDL level in apparently healthy populations.

Conjugated bilirubin as a reflex test for increased total bilirubin in apparently healthy population

BACKGROUND

Total, unconjugated and conjugated bilirubin levels are usually ordered together in health check-up populations. The aim of this study was to investigate whether using increased total bilirubin (TBIL) as a reflex test can reduce conjugated bilirubin (CBIL) test.

METHODS

Medical records of 8433 males and 4496 females who visited Shuyang People's Hospital for health check-ups were retrospectively reviewed and the fasting serum TBIL, unconjugated bilirubin (UBIL) and CBIL of patients were extracted. Reference intervals for TBIL, UBIL, CBIL and C/TBIL were established using Q_2.5 to Q_97.5 . The relationship between TBIL and CBIL was analyzed by Spearman's approach. Receiver operating characteristics (ROC) curve analysis was used to evaluate the predictive accuracy of TBIL for abnormal CBIL and UBIL.

RESULTS

The reference intervals for TBIL in males and females were 6.9-29.3 μmol/L and 6.1-23.8 μmol/L, respectively. For CBIL, the reference intervals were 1.9-10.4 μmol/L and 1.6-8.8 μmol/L for males and females, respectively. CBIL was significantly positively correlated with TBIL, either in males (r=.75) or females (r=.73). Area under curve (AUC) of TBIL for predicting abnormal CBIL was 0.99 in both male and females. The optimal threshold of TBIL for predicting abnormal CBIL and UBIL were 21.0 μmol/L in males and 17.0 μmol/L in females. At these thresholds, <2% of subjects with abnormal CBIL or CBIL might be missed, but approximately 87% of the CBIL test could be eliminated.

CONCLUSION

Conjugated bilirubin measurement is not needed for the apparently healthy males with TBIL <21.0 μmol/L or females with TBIL <17.0 μmol/L.