Analytical comparison between two automated biochemical analyzer systems: Roche Cobas 8000 and Mindray BS2000M

Summary Background. The values of biomarkers play a central role in routine clinical decision-making. Whereas, the performances of different automated chemical analyzers remain unclear. To determine the performances of different platforms, we evaluated the capability between Roche Cobas 8000 and Mindray BS2000M. Methods. A total of 1869 remaining serum samples were collected. CK, LDH-1, RBP, Cys-c, IgA, IgM and IgG were assessed by using paired-t test, Passing-Bablok regression analysis and Bland Altman analysis according to CLSI EP5-A3. Results. There were significant in average bias of all items between two machines (P < 0.001). Due to the 95% confidence interval of intercept A included 0, CK, LDH-1, Cys-c and IgG were not show systemic error in Passing-Bablok regression analysis. Except for IgA, the r values and correlation coefficient of all items were higher than 0.91, which showed that the correlation and consistency is good. The Bland-Altman analysis showed that two instruments had more than 95% of the points apart from CK, LDH-1, and IgA. Conclusions. It can be considered that the two instruments have good correlation and consistency in CK, LDH-1, RBP, Cys-c, IgM and IgG, and the two instruments are interchangeable and can replace each other.

Identifying epithelial borders in cholesteatoma surgery using narrow band imaging

Purpose To quantify changes in the perceived epithelial border with narrow band imaging (NBI) and white light imaging (WLI) during cholesteatoma surgery and to objectify possible benefits of NBI in otology. Methods Perioperative digital endoscopic images were captured during combined approach tympanoplasty at our tertiary referral center using WLI and NBI (415 nm and 540 nm wavelengths). Sixteen otologic surgeon defined the epithelial borders within 16 identical WLI and NBI photos. Pixels of these selections were calculated to analyze the quantitative difference between WLI and NBI. A questionnaire also analyzed the qualitative differences. Results Sixteen otologic surgeons participated in the study. Stratified per photo, only two photos yielded a significant difference: less pixels were selected with NBI than WLI. A Bland–Altman plot showed no systemic error. Stratified per otologist, four participants selected significantly more pixels with WLI than with NBI. Overall, no significant difference between selected pixels was found. Sub-analyses of surgeons with more than 5 years of experience yielded no additional findings. Despite these results, 60% believed NBI could be advantageous in defining epithelial borders, of which 83% believed NBI could reduce the risk of residual disease. Conclusion There was no objective difference in the identification of epithelial borders with NBI compared to WLI in cholesteatoma surgery. Therefore, we do not expect the use of NBI to evidently decrease the risk of residual cholesteatoma. However, subjective assessment does suggest a possible benefit of lighting techniques in otology. Level of evidence 3.

Method comparison of Particle Enhanced Immunoturbidimetry (PEIT) with High Performance Liquid Chromatography (HPLC) for glycated hemoglobin (HbA1c) analysis

Background and objective High Performance Liquid Chromatography (HPLC) technique is considered as a gold standard for HbA1c analysis however all laboratories cannot adopt it due to certain limitations. Our aim was to compare Particle Enhanced Immunoturbidimetry (PEIT) method with High Performance Liquid Chromatography (HPLC) for HbA1c analysis. Method All blood samples were analyzed by HPLC assay on a Bio-Rad D-10 analyzer and PEIT on an Erba XL-200 analyzer. Precision studies were undertaken and Coefficient of Variation (%CV) calculated. Systemic Error (SE), Random Error (RE) and Total Error (TEcalc) were obtained. The Total Allowable Error (TEa) set by the National Glycohemoglobin Standardization Program (NGSP) for HbA1c is 6%.The acceptable evaluation method is where TEcalc is less than TEa. Results The Precision studies were satisfactory with Coefficient of Variation (%CV) being less than 4% for both techniques. Mean HbA1c levels were slightly higher from HPLC than PEIT 9.07 ± 2.23% and 8.93 ± 2.10% respectively, although the difference was minimal. RE was 1.41%, TEcalc was 1.55%, which was less than TEa set by the NGSP. Both methods strongly correlated with the correlation coefficient (r) 0.9716, p < 0.0001. Conclusion Our study showed HbA1c analysis by PEIT technique is precise, accurate, rapid and convenient and can be employed as an alternative to HPLC technique in countries where cost is a major problem for diagnosis and treatment.

Quest over the Sampling Error of COSMIC Radio Occultation Temperature Climatologies

The sampling error caused by the uneven distribution of radio occultation (RO) profiles in both space and time domains is an important error source of RO climatologies. In this paper, the sampling error RO temperature climatologies is investigated using the 4-year (2007-2010) data from the Constellation Observing System for Meteorology, Ionosphere, and Climate mission. The error is divided into three parts, including local time component (LTC), temporal component (TC), and spatial component (SC). The characteristics of the three components are investigated. Results show that: 1) The LTC part of the total sampling error is characterized by a pattern of periodic positive and negative deviations, with a full cycle of about four months. The most significant LTC values are found in the area around 60° N/S and the polar regions. 2) The TC part is mainly associated with the extent of day-to-day temperature variability and the daily number of RO profiles observed in each month. The most pronounced TC part is shown in high latitude areas in wintertime, where the day-to-day temperature variability is high. 3) The SC part shows distinct features in different altitude ranges. It is characterized by a systemic error in the lower troposphere (2-8 km) but exhibits a seasonal trend at the altitude range from 8 to 40 km. 4) the total sampling error is dominated by the TC and SC parts in the troposphere and lower stratosphere, while in the upper stratosphere, it is dominated by the LTC part.

The hip asphericity angle: a novel angle for measurement of Cam-FAI correction

The alpha angle is routinely used for the diagnosis and quantitative description of the Cam deformity of the hip. However, a reliable identification of the femoral neck axis as its reference line can be difficult. Moreover, most cam resections include a reduction of the femoral neck diameter with an automatic posteromedial angulation of the femoral neck axis. In consequence, the reference axes for the pre- and postoperative alpha angles are different, and a comparison of both angles underlies a systematic error to relatively higher postoperative alpha angles. In order to avoid this systemic error, we propose the hip asphericity (HA) angle with a reference axis independent of the amount of bony resection. Two retrospective groups were formed, a ‘femoroacetabular impingement (FAI) group’ that had hip arthroscopy for cam resection and a ‘Control group’ without cam deformity. The alpha and HA angles were measured by three examiners. The measurements were repeated 1 month later. In the FAI group, offset correction was calculated using both angles. Statistically significant differences for both the alpha and the HA angles were found between the control and the preoperative FAI group as well as between the preoperative and postoperative FAI groups. The HA angle-correction by a mean of 27.5° was significantly higher in comparison to the alpha angle correction by a mean of 25.4°. The intertester and intratester reliability of both angles were not significantly different. The HA angle is a new and reliable radiographic parameter for measuring cam deformity and proves superior in measuring cam correction.

Public Election Polls are 95% Confident but only 60% Accurate

In this paper, we investigate the calibration of public election polls.We present a definition of poll accuracy based on whether the poll’s margin of error spans the true election outcome. Most polls provide a 95% confidence interval along with the poll results, we sought to find whether their accuracy is as high as their confidence lev-els claim. Furthermore, we also wanted to see how this accuracy evolves over time as polls are conducted closer to the actual election.We find that even a week away from the election, polls claiming95% confidence are only accurate 60% of the time. Moreover, we conclude that these polls would in fact need margins of error twice their reported width in order to be truly 95% confident. This pro-vides a unique insight into the adjustment polls need over time and quantifies the systemic error polls contain beyond what the traditional statistics captures.

Generation of Atmospheric Constants over Some Locations in West Africa: A Theoretical Aid for Measuring Instruments Design

The performance of AERONET or AMMA in West Africa over the past two decades had been successful but not without its challenges. These challenges had resulted in the loss of large volume of useful data. The frequent failures of ground measuring devices over West Africa have been linked to the manufacturer and christened 'manufacturer-error'. In this paper, it was proposed that the frequent failure of ground measuring devices is due to systemic-error. To address the systemic-error, we propose that the configuration of the constants-embedded in the compact flash of the measuring devices is not compatible with the atmospheric conditions of the West African climate. A statistical investigation was carried out on both the ground and satellite dataset to determine the aerosols retention capacity within the West African space. A dispersion model was developed to incorporate salient assumptions and parameters like the Unified number. Fourteen and thirteen years dataset were obtained from Multi-angle Imaging SpectroRadiometer (MISR) and AERONET respectively. Five locations were considered in this study; Ilorin-Nigeria, Ouagadougou-Burkina Faso, Lome-Togo, Conakry-Guinea and Niamey-Niger which are positioned on latitude 8.5 oN, 12.37 oN, 6.17 oN, 9.55 oN, 13.5 oN and longitude 4.53 oE, 1.53 oW, 1.35 oE, 13.67 oW, 2.12 oE respectively. It was observed that the same aerosols retention occurred in West Africa region between 2003 and 2005. Also, it was observed that the high aerosols retention over the locations portray danger to the life form, such as unbearable thermal comfort, increased heat flux, partial famine e.t.c. Hence, the proper documentation and execution of the correct atmospheric constants over locations of West Africa is a novel concept.