Six sigma is a quality management system for the assessment of precision and accuracy. We aim to apply the six sigma rule to quality control (QC) of point-of-care (POC) glucose meters in a tertiary hospital.

Thirty POC glucose meters installed at Ewha Womans University Mokdong Hospital were monitored between January 2013 and March 2014. The QC data from the POC glucose meters at low and high levels were collected. The monthly mean, standard deviation, bias, coefficient of variation, and mean sigma metrics were calculated. The correlation between accuracy and precision was assessed based on the percentage bias and coefficient of variation. Comprehensive instructions on the QC and maintenance of the devices were provided in the departments with poor sigma scores. A follow-up assessment was performed after the intervention.

The mean sigma values for the low and high controls were 3.29 and 3.71, respectively. At the low and high controls, 36.6% and 10% of the glucose meters showed a sigma value <3. The causes of low sigma values included the use of expired control materials, prolonged air exposure of the sample strip, lack of user training, and errors in device maintenance. On follow-up monitoring for 3 months following QC intervention, 23.3% (low control) and 6.6% (high control) of the glucose meters scored a sigma value <3, indicating improved QC.

Sigma metrics-based QC can successfully improve accuracy and precision of POC glucose meters in an objective and quantitative manner and can be used for follow up after QC intervention.

There are 3 subtypes of natriuretic peptide (NP) receptors: type A natriuretic peptide receptor (NPRA), NPRB, and NPRC. The NPRA gene polymorphism, consisting of substition of methionine (ATG) to isoleucine (ATC) at nucleotide 1023 (M341I) of exon 3 was revealed to be associated with increased risk for essential hypertension (EH) in Japanese people. The purpose of this study is to investigate association between EH and the M341I polymorphism in the NPRA gene in Korea.

Eighty patients in whom type B natriuretic peptide (BNP) was measured were enrolled in this study. 66 patients had EH and 14 patients did not. The polymorphism of M341I was evaluated by multiplex genotyping polymerase chain reaction and by sequencing analysis.

The overall distribution of alleles was not significantly different between the control and EH groups. However, the C/C homozygous genotype was found only in the EH group. In the EH group, patient carrying the C/C homozygous genotype had the trend of having higher systolic and diastolic BP levels regardless of the previous treatment, even though other laboratory markers including BNP levels had no significant differences according to the genotypes.

This would be meaningful for the first identification of the M341I polymorphism in the NPRA gene and for the first suggestion of association of the EH with it in Korea.

According to current knowledge, apolipoprotein B/A1 (apoB/A1) ratio is like to be risk factor in coronary artery disease. There is evidence form case-control studies that apoB/A1 ratio may be a superior to LDL and HDL cholesterol in discriminating coronary artery disease case subject from control subject. However, relationship between apoB/A1 ratio and cerebral ischemic stroke is undefined. The main object of this study is to determine whether the risk of cerebral ischemic stroke is related to levels of apoB/A1.

The study group included 643 patients (Men, 372; Women, 271) who diagnosed cerebral ischemic stroke between January 2008 to December 2010. The control groups were composed of 378 patients (Men, 139; Women, 239) who diagnosed other neurological disease. The correlation between lipid profiles and odds ratio of 10 preliminary risk factors (total cholesterol, triglyceride, LDL, HDL, apoA1, apoB, apoB/A1 ratio, non HDL, total cholesterol/HDL ratio, LDL/HDL ratio) for stroke were analyzed.

ApoB/A1 ratio was significantly increased in case patients compared with control subjects. Multivariate logistic regression analysis identified decrease of apoB/A1 ratio (odds ratio [OR], 1.583; 95% confidence intercal [CI], 1.105~2.269) as significantly associated with stroke. Individual apoA1 (OR, 1.303; 95% CI, 0.967~1.755) and apoB (OR, 1.397; 95% CI, 0.773~2.523) were also not significantly associated with cerebral ischemic stroke.

Increase of apoB/A1 ratio is associated with an increase risk of cerebral ischemic stroke. Use of apoB/A1 ratio is efficient as conventional lipids, for the identification of subjects at increased risk of stroke. So apoB/A1 ratio to standard lipid profile testing could improve the evaluation of risk factors of cerebral ischemic stroke.