Bias Plots Research Articles

Comparison of age estimates from scales, fin rays, and otoliths of the introduced Peipsi whitefish, Coregonus maraenoides (Actinopterygii: Salmoniformes: Salmonidae), collected from the Iskar Reservoir (Danube River Basin)

Background. Peipsi whitefish, Coregonus maraenoides Polyakov, 1874, is an endemic species of Lake Peipsi (Chudskoe) in Estonia and Russia. In the mid-1970s, it was introduced into the biggest Bulgarian artificial body of water—the Iskar Reservoir (Danube River basin). A recent survey confirmed the existence of a self-sustaining population of the Peipsi whitefish in the dam lake. Establishing a suitable method for determining Peipsi whitefish age would allow fishery managers and biologists to extract valuable information on various population parameters. Therefore, the aim of the presently reported study was to test the suitability of scales, pectoral fin rays, and otoliths for the most reliable age determining of Peipsi whitefish. Materials and methods. Age estimates were obtained from transverse sections of sagittal otoliths and pectoral fins, and scales from 54 Peipsi whitefish, collected between October and March 2016–2017. Two readers estimated ages from all three structures independently. The precision and bias of age estimates between readers and among structures were compared using age bias plots, coefficient of variation (CV), percent agreement (PA), and level of readability. Mean consensus ages from two readers for each structure were compared. Results. Mean consensus age estimates obtained by analysing the scales (2.0 years) were significantly lower than those obtained by analysing the fin rays (2.6) and otoliths (2.7). Between-reader percent agreement was lower and the coefficient of variation was higher for otoliths (PA = 22.2%; CV = 27.6) compared with scales (PA = 46.6%; CV = 10.02) and pectoral fin rays (PA = 67.4%; CV = 10.12). Comparison of age estimates from the different structures revealed the highest PA and the lowest CV values between otoliths and pectoral fin rays (PA = 62.6%; CV = 10.03%), while the lowest PA and highest CV (PA = 35%, CV = 25.03) were observed between age estimates from fin rays and scales (CV, P > 0. 005). The otolith and scale ages agreed for 46.7% and CV was 21.5. The scales were considered by both readers with the highest level of readability (88.9%) than the pectoral fin rays (70.4%) and otoliths (50%). Conclusion. The use of fin rays is recommended for the age estimation of C. maraenoides from the Iskar Reservoir but further work is needed to validate the accuracy of ageing methodology for small, under one-year old Peipsi whitefish.

Lipoprotein(a) particle number assay without error from apolipoprotein(a) size isoforms

BackgroundLipoprotein(a) [Lp(a)] is an important cardiovascular risk factor, but clinical immunoassays are flawed. Apolipoprotein(a) [apo(a)], the characteristic protein of Lp(a), contains a variable number of kringle repeats (size isoforms) that make accurate measurement of Lp(a) difficult. We developed a sandwich enzyme immunoassay that uses a murine monoclonal anti-apo(a) antibody for capture and a polyclonal anti-apolipoprotein B (apo B) for detection. Because Lp(a) contains one molecule each of apo(a) and apo B, the assay measures the number of Lp(a) particles [Lp(a)-P] in the circulation without bias due to apo(a) size isoforms. MethodsAfter developing and choosing the best anti-apo(a) clone for Lp(a) capture, we identified suitable reagents and ELISA conditions, and validated assay performance (precision, linearity, limit of detection, interferences, and apo(a) size isoform bias). ResultsThe Lp(a)-P assay was precise with within-run precision of 5.5% to 7.2% and total imprecision of 6.9% to 12.1%. The assay had a limit of detection of 13 nmol/l and was linear from 2 to 499 nmol/l. There was no interference from plasminogen or apolipoprotein B up to 80 and 200 mg/dl, respectively, and bias plot showed no bias related to apo(a) size (kringle 4 type 2 repeats). ConclusionsLp(a)-P assay is sensitive, precise and linear over a wide analytical range and is a suitable alternative for laboratories concerned about inaccuracy due to apo(a) size polymorphism and the poor performance of immunoturbidimetric assays.

Origin of depressed fill factor in organic solar cells due to S-shape current–voltage characteristics

Often, a depressed fill factor is observed in organic solar cells (OSCs), which is usually known as S-shaped current-voltage (J−V) characteristics. To investigate the origin of the depressed fill factor further, a poly[N-9-heptadecanyl-2,7-carbazole-alt-5,5-(4,7-di-2-thienyl-2,1,3-benzothiadiazole)]:[6,6]-phenyl C71 butyric acid methyl ester based OSC has been characterized through impedance spectroscopy. In addition, the photocurrent vs the applied effective bias plot reveals that the S-shaped J−V characteristics primarily reduce the diffusion current of the device. The present study shows that the diffusion current dominated section of photocurrent reduces with a slope of 2 in the depressed fill factor section given that the slope may further increase as per the impact of the S-shape. The reduction in the diffusion constant (Dn) in the S-shaped region supports the decrease in the diffusion current, which is observed through the photocurrent analysis. It is observed that, in the S-shaped section of the current-voltage characteristics, the transport time for free carriers increases up to 443 μs. The larger Urbach energy for the active layer of an S-shaped device demonstrates higher subbandgap disorder. Therefore, it is concluded that the accumulation of the charge carriers within the device and disorder in the active layer leads to the S-shaped current–voltage characteristics as well as poor carrier extraction.

Performance Evaluation of a New Mobile POC Lipids Analyzer

Hyperlipidemia, excessive amounts of fat and fatty substances in the blood, is a major risk factor for cardiovascular disease. The measuring of fat or fatty substance in blood is usually obtained through a blood lipid test which includes total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL) and high-density lipoprotein (HDL). In the Medical Device industry, Point-of-care (POC) methods provide fast, portable and easy to use devices suitable for rapid determination of Lipid levels. Here, we evaluated the analytical performance of PixoTest POCT Lipid System (iXensor Co., Ltd.), a newly developed POC lipid panel analyzer. PixoTest POCT Analyzer accuracy evaluation with the Cobas c111 Analyzer (Roche Diagnostics Ltd.) as a reference method was carried out according to CLSI EP 09-A3 guidelines. This study enrolled one hundred and twenty (120) subjects and conducted over three (3) clinical sites (40 subjects each), administered through nine (9) trained operators (total) performed under manufacturer’s protocol using three (3) reagent lots per blood sample (capillary & venous). Linear regression, bias plot and other statistical analyses were extrapolated from the test data in this study. Passing-Bablok regression analysis of the data between PixoTest POCT System and Roche Cobas c111 Analyzer with the venous blood showed a slope of 1.03, an intercept of − 0.1 and correlation coefficient of 0.99. The results for capillary blood showed a slope of 1.01, an intercept of − 0.04 and correlation coefficient of 0.99. Passing-Bablok regression analysis of the data (n = 120) from the comparison between the PixoTest POCT System and Roche Cobas c111 Analyzer with the TC venous blood of total 3 lots at 3 sites showed a slope of 0.99, an intercept of − 0.337 and correlation coefficient of 0.995 and the TC capillary blood showed a slope of 0.99, an intercept of − 0.105 and correlation coefficient of 0.984. TG venous blood of total 3 lots at 3 sites showed a slope of 0.99, an intercept of 0.0246 and correlation coefficient of 0.998 and TG capillary blood showed a slope of 0.99, an intercept of − 0.329 and correlation coefficient of 0.998. HDL venous blood showed a slope of 0.99, an intercept of − 0.0297 and correlation coefficient of 0.987 and the HDL capillary blood showed a slope of 0.99, an intercept of − 0.0403 and correlation coefficient of 0.989. The evaluation results of PixoTest POCT system’s accuracy, linearity, and correlation with Roche Cobas c111 Analyzer, the PixoTest POCT System displayed great performance results for all evaluated data points. Thus, the PixoTest POCT System is capable of providing accurate and reliable lipid measurements in the POC setting.

Mobile Health for Diagnosis-PixoTest HbA1c POCT System

Glycated hemoglobin (HbA1c) has been recommended as a standard indicator of long-term glycemic control for diabetic and non-diabetic patients, within the in vitro diagnostic (IVD) industry that is focused on the development of point-of-care (POC) methods with improved operational convenience and shorter measurement time. In this study, we evaluated the measurement accuracy performance of a recently commercialized POC HbA1c analyzer, PixoTest POCT System (iXensor Co., Ltd.) that is portable, intuitive and wireless data transmission enabled. For PixoTest POCT accuracy evaluation, TOSOH G7 Analyzer (TOSOH Bioscience GmbH) was used as a reference method and performed in accordance with CLSI EP 09-A3 guidelines. This study enrolled one hundred and twenty (120) subjects from three clinical sites (40 subjects each), administered through nine (9) trained operators (total) performed under manufacturer’s protocol using three reagent lots per blood sample (capillary & venous). Linear regression, bias plot and other statistical analyses were extrapolated from the test data. Passing-Bablok regression analysis of the data between PixoTest POCT System and TOSOH G7 Analyzer with the venous blood showed a slope of 1.03 and an intercept of − 0.1 and a correlation coefficient of 0.99. The results for capillary blood showed a slope of 1.01 and an intercept of − 0.04 and a correlation coefficient of 0.99. The PixoTest POCT System’s performance is similar to TOSOH G7 Analyzer in accuracy and linearity. Therefore, the system’s HbA1c test capability is ideal for the management of chronic disease, as a user convenient and efficient POC solution.

Periodicity of the growth-band formation in vertebrae of juvenile scalloped hammerhead shark Sphyrna lewini from the Mexican Pacific Ocean.

The age of 296 juvenile scalloped hammerhead sharks Sphyrna lewini caught by several fisheries in the Mexican Pacific Ocean from March 2007 to September 2017 were estimated from growth band counts in thin-sectioned vertebrae. Marginal-increment analysis (MIA) and centrum-edge analysis (CEA) were used to verify the periodicity of formation of the growth bands, whereas elemental profiles obtained from LA-ICP-MS transect scans in vertebrae of 15 juveniles were used as an alternative approach to verify the age of the species for the first time. Age estimates ranged from 0 to 10+ years (42-158.7 cm total length; LT ). The index of average percentage error (IAPE 3.6%), CV (5.2%), bias plots and Bowker's tests of symmetry showed precise and low-biased age estimation. Both MIA and CEA indicated that in the vertebrae of juveniles of S. lewini a single translucent growth band was formed during winter (November-March) and an opaque band during summer (July-September), a period of faster growth, apparently correlated with a higher sea surface temperature. Peaks in vertebral P and Mn content spatially corresponded with the annual banding pattern in most of the samples, displaying 1.19 and 0.88 peaks per opaque band, respectively, which closely matched the annual deposition rate observed in this study. Although the periodicity of growth band formation needs to be verified for all sizes and ages representing the population of the species in the region, this demonstration of the annual formation of the growth bands in the vertebrae of juveniles should lead to a re-estimation of the growth parameters and productivity of the population to ensure that it is harvested at sustainable levels.

Evaluation of Regional Air Quality Models over Sydney and Australia: Part 1—Meteorological Model Comparison

The ability of meteorological models to accurately characterise regional meteorology plays a crucial role in the performance of photochemical simulations of air pollution. As part of the research funded by the Australian government’s Department of the Environment Clean Air and Urban Landscape hub, this study set out to complete an intercomparison of air quality models over the Sydney region. This intercomparison would test existing modelling capabilities, identify any problems and provide the necessary validation of models in the region. The first component of the intercomparison study was to assess the ability of the models to reproduce meteorological observations, since it is a significant driver of air quality. To evaluate the meteorological component of these air quality modelling systems, seven different simulations based on varying configurations of inputs, integrations and physical parameterizations of two meteorological models (the Weather Research and Forecasting (WRF) and Conformal Cubic Atmospheric Model (CCAM)) were examined. The modelling was conducted for three periods coinciding with comprehensive air quality measurement campaigns (the Sydney Particle Studies (SPS) 1 and 2 and the Measurement of Urban, Marine and Biogenic Air (MUMBA)). The analysis focuses on meteorological variables (temperature, mixing ratio of water, wind (via wind speed and zonal wind components), precipitation and planetary boundary layer height), that are relevant to air quality. The surface meteorology simulations were evaluated against observations from seven Bureau of Meteorology (BoM) Automatic Weather Stations through composite diurnal plots, Taylor plots and paired mean bias plots. Simulated vertical profiles of temperature, mixing ratio of water and wind (via wind speed and zonal wind components) were assessed through comparison with radiosonde data from the Sydney Airport BoM site. The statistical comparisons with observations identified systematic overestimations of wind speeds that were more pronounced overnight. The temperature was well simulated, with biases generally between ±2 °C and the largest biases seen overnight (up to 4 °C). The models tend to have a drier lower atmosphere than observed, implying that better representations of soil moisture and surface moisture fluxes would improve the subsequent air quality simulations. On average the models captured local-scale meteorological features, like the sea breeze, which is a critical feature driving ozone formation in the Sydney Basin. The overall performance and model biases were generally within the recommended benchmark values (e.g., ±1 °C mean bias in temperature, ±1 g/kg mean bias of water vapour mixing ratio and ±1.5 m s−1 mean bias of wind speed) except at either end of the scale, where the bias tends to be larger. The model biases reported here are similar to those seen in other model intercomparisons.

Comparison of the Efficacy Between Closed Incisional Negative-Pressure Wound Therapy and Conventional Wound Management After Total Hip and Knee Arthroplasties: A Systematic Review and Meta-Analysis

BackgroundWound-related problems after total hip arthroplasty (THA) and total knee arthroplasty (TKA) can cause periprosthetic joint infections. We sought to evaluate the effect of closed incisional negative-pressure wound therapy (ciNPWT) on wound complications, skin blisters, surgical site infections (SSIs), reoperations, and length of hospitalization (LOH). MethodsStudies comparing ciNPWT with conventional dressings following THA and TKA were systematically searched on MEDLINE, Embase, and the Cochrane Library. Two reviewers performed the study selection, risk of bias assessment, and data extraction. Funnel plots were employed to evaluate publication bias and forest plots to analyze pooled data. ResultsTwelve studies were included herein. The odds ratios (ORs) for wound complications and SSIs indicated a lack of publication bias. ciNPWT showed significantly lower risks of wound complication (OR, 0.44; 95% confidence interval [CI], 0.22-0.9; P = .027) and SSI (OR, 0.39; 95% CI, 0.23-0.68; P < .001) than did conventional dressings. ciNPWT also yielded a significantly lower reoperation rate (OR, 0.38; 95% CI, 0.21-0.69; P = .001) and shorter LOH (mean difference, 0.41 days; 95% CI, −0.51 to −0.32; P < .001). However, the rate of skin blisters was higher in ciNPWT (OR, 4.44; 95% CI, 2.24-8.79; P < .001). ConclusionAlthough skin blisters were more likely to develop in ciNPWT, the risks of wound complication, SSI, reoperation, and longer LOH decreased in ciNPWT compared with those in conventional dressings. This finding could alleviate the potential concerns regarding wound-related problems after THA and TKA.

A metrics‐based analysis of seasonal daily precipitation and near‐surface temperature within seven Coordinated Regional Climate Downscaling Experiment domains

We compare ensemble mean daily precipitation and near‐surface temperatures from regional climate model simulations over seven Coordinated Regional Climate Downscaling Experiment domains for the winter and summer seasons. We use Taylor diagrams to show the domain‐wide pattern similarity between the model ensemble and the observational data sets. We use the Climatic Research Unit (CRU) and the University of Delaware gridded observations and ERA‐Interim reanalysis data as an additional observationally based estimate of historical climatology. Taylor diagrams determine the relative skill of the seven sets of simulations and quantify these results in terms of center pattern root‐mean square error and correlation coefficient. Results suggest that there is good agreement between the models and the CRU, in terms of their respective seasonal cycles, as shown in Taylor diagrams and bias plots. There is also good agreement between both gridded observation sets. In addition, downscaled ERA‐Interim precipitation is closer to observations than raw ERA‐Interim precipitation. Domains located in the low latitudes and those having high topography appear to have larger biases, especially precipitation.

Age and Assay Related Changes of Laboratory Thyroid Function Tests in the Reference Female Population.

SummaryBackgroundLaboratory thyroid function tests play a central role in the diagnosis of thyroid disorders. The aim of our cross-sectional study was to determine reference values for thyroid tests in a rigorously selected group of Montenegrin females, investigate the impact of possible age-related changes and the influence of the interassay bias between three frequently used immunoassays.MethodsFemale subjects were randomly selected, aged between 20 and 69 and 946 of them met the selection criteria. TSH, fT3, fT4, thyroid peroxidase and thyroglobulin antibodies were measured. Eighty samples were further analyzed on two other immunochemistry platforms.ResultsMedian TSH progressively increased with age, there was no difference in fT3, while fT4 was significantly higher in the two oldest groups compared to the others. When using the age-related 97.5 percentile of TSH the percentage of reclassification was highest in the 20–29 years of age group (5.2%, p<0.05). In the oldest band, 7.7% had TSH values above cohort-specific and below the age-related upper reference limit. Bland-Altman bias plots revealed the highest interassay absolute mean difference between compared TSH assays of 24.5% and for fT4 assays of 13.8%.ConclusionsThe correlation coefficients between fT3 assays from different manufacturers were low. Serum TSH and fT4 concentrations increased with age and the implementation of age-specific TSH reference intervals would be of interest. The bias between the three commercial immunoassays indicated that the standardization of thyroid function tests is a task of great importance.

Performance of two portable blood glucose meters for measuring blood glucose concentration in tigers (Panthera tigris) and lions (Panthera leo).

OBJECTIVE To investigate the performance of a portable blood glucose meter (PBGM) designed for use in humans (hPBGM) and a PBGM designed for use in dogs and cats (vPBGM) when measuring blood glucose (BG) concentration in tigers (Panthera tigris) and lions (Panthera leo). DESIGN Method comparison and diagnostic accuracy study. SAMPLES 53 blood samples from tigers (n = 27) and lions (26). PROCEDURES BG concentration was measured with 2 identical hPBGMs, 2 identical vPBGMs, and a reference laboratory analyzer. Bland-Altman bias plots and Passing-Bablok regression analysis were used to assess agreement. Sensitivity, specificity, and positive and negative predictive values with corresponding 95% confidence intervals were calculated for use in assessing diagnostic accuracy of the investigated PBGMs. RESULTS Bias (95% limits of agreement) was -4.3 mg/dL (-46.3 to 37.6 mg/dL) for the hPBGM, -9.3 mg/dL (-64.6 to 46.0 mg/dL) for the vPBGM on canine setting, and 2.3 mg/dL (-47.9 to 52.6 mg/dL) for the vPBGM on feline setting. The hPBGM had better overall repeatability (coefficient of variation, 3.73%) than the vPBGM on canine (9.29%) or feline (9.44%) setting. Total error for the hPBGM, vPBGM on canine setting, and vPBGM on feline setting was 11.8%, 27.7%, and 20.9%, respectively. None of the PBGMs complied with the maximum allowable total error suggested by current guidelines when measuring BG in tigers and lions with hypo-, normo-, or hyperglycemia. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that the PBGMs evaluated were inadequate for measuring BG concentration in tigers and lions.

Immunoturbidimetric Assay for Determination of Peripheral Blood C Reactive Protein on the Pentra MS CRP Hematology Analyzer

The Pentra MS CRP hematology analyzer (hereinafter the Pentra analyzer) can simultaneously provide 5-part leukocyte differential and C-reactive protein (CRP). The aim of the study was to investigate the performance of CRP determination by the Pentra analyzer. The precision, limit of quantitation (LoQ), carryover, linearity, stability, and comparability of the Pentra analyzer were determined. The Passing-Bablok regression analysis and the Bland-Altman graphs illustrated the correlation for CRP concentration analyzed by the Pentra analyzer and BN-II analyzer. The within-run precision of CRP determination by the Pentra analyzer had a CV < 2.0% in peripheral blood, which met the requirements of the instructions (CV ≤ 10%). The Pentra analyzer had a total CV of 5.35% and 5.52% at a CRP concentration of 4.1 and 80 mg/L, respectively. The LoQ value for the Pentra analyzer was 0.96 mg/L. The carryover was 0.57% for peripheral blood and 0.86% for plasma by the analyzer. The stability of CRP results was good, when the anticoagulation samples were stored at room temperature or 4°C within 48 hours (deviation < 5%). The linearity range for whole blood samples was 0 - 188.13 mg/L (r² = 0.9992). There was high correlation of the CRP results analyzed with the Pentra analyzer and BN II analyzer. The Passing-Bablok regression analysis and the Bland-Altman graphs showed the bias plot display excellent agreement between the two assays (the mean value for the Pentra 2.19 mg/L and the BN-II 2.35 mg/L, n = 101). The results of CRP determination by the Pentra analyzer have the advantages of accuracy and reliability, and it is suitable for routine use in emergency laboratory and small to medium-size laboratories.

A cross-talk on compositional dynamics and codon usage patterns of mitochondrial CYB gene in Echinodermata

Codon usage bias (CUB) refers to a phenomenon in which some synonymous codons are used in mature mRNA at a higher frequency than other members codifying the same amino acid. CUB is mainly determined by mutation pressure and natural selection. We used bioinformatic tools to analyze the protein coding sequences of mitochondrial CYB gene in different classes of Echinodermata to understand the patterns of codon usage. The ENC values of CYB gene in five different classes of Echinodermata were 41.64, 30.33, 43.63, 41.11, and 41.33, which suggested that the CUB of this gene was low. The relative synonymous codon usage (RSCU) values showed that the patterns of over-represented and under-represented codons were different among different classes. Correspondence analysis indicated that the plots of CYB gene were different across classes, suggesting that the pattern of codon usage was also different among five classes under study. Highly significant correlation (p < .01) between overall nucleotide composition and its 3rd codon position indicated that both mutational pressure and natural selection had an influence on the codon usage bias of CYB gene. Furthermore, PR-2 bias plot analysis showed that both mutation pressure and natural selection might have affected the pattern of codon usage in CYB gene of Echinodermata.

Precision of Calcified Structures Used for Estimating Age of Chain Pickerel

AbstractWith the exception of Northern Pike Esox lucius, there is a paucity of information on the precision of age estimates based on calcified structures for esocid species, especially Chain Pickerel E. niger. We estimated ages for 42 Chain Pickerel from Stevens Creek Reservoir on the Savannah River, South Carolina–Georgia. Ages were estimated using sectioned pelvic, pectoral, dorsal, and anal fin rays, scales, cleithra (sectioned and whole), and otoliths to assess precision between repeated readings (four readers). Precision was evaluated by calculating agreement among readers, CV, and mean absolute difference (MAD) in estimates between reader pairs. We tested for differences in precision of estimates among structures using linear mixed models with CV or MAD as the response. Finally, we used age bias plots to evaluate whether there were structure or reader‐related systematic biases in estimates. Coefficient of variation and MAD were significantly related to structure type (CV: P = 0.006, MAD: P = 0.001) and mean estimated age (CV: P &lt; 0.001, MAD: P = 0.025). Precision was poor for all structures and poorest for age‐0 fish; however, all analyses indicated that otoliths provided the most precise estimates. We observed agreement in estimates among all readers for 40% of the otoliths examined and consensus agreement for 74% of the estimates. Coefficient of variation for otoliths declined from 67% for fish with a mean estimated age of 0 years to 5% for age‐4 fish. Conversely, MAD for otoliths increased from 0.34 years for fish with a mean estimated age of 0 to 0.46 years for age‐4 fish. Estimates from all structures, except pectoral rays, were negatively biased compared with estimates from otoliths. We recommend the use of otoliths for age estimation of Chain Pickerel, but managers and researchers should be cognizant of and evaluate the potential effects of variability in age estimates among readers on their analyses.

Accuracy of Patient Perception of Supine Sleep.

For clinicians involved in investigating and treating sleep disorders, understanding the accuracy of patient recall of supine sleep would allow informed comparisons between polysomnography (PSG) and patient-reported sleep in patients with supine-predominant obstructive sleep apnea. This study aims to assess the accuracy of patient perception of supine sleep. Prospective observational cohort study, assessing patient perception of total sleep and supine sleep, including duration. Data were analyzed utilizing descriptive statistics, bias-plot (Bland-Altman) analysis, and Spearman correlation (rs) to analyze relationships among continuous data. Total number of patients who underwent PSG was 518, with data from 368 of these patients analyzed. Most of these patients underwent diagnostic PSG (49.2%). Patients were excluded because of missing or incomplete data (n = 133) or immobility (n = 17). Some patients (n = 97, 26%) did not perceive supine sleep, with 34 (35% of those with unperceived supine sleep or 9% of whole group) of these having more than 60 minutes of PSG supine sleep (range 0-305.5 minutes). All "unsure" patients (n = 8, 2.2%) had significant supine sleep recorded (31.5-257.5 minutes). For the presence of any PSG supine sleep, questioning had a sensitivity of 77.9%, specificity 72.7% with positive predictive value of 96.7% and negative predictive value of 24.5%. There was a significant correlation (rs = 0.63, P < .0001) between perceived and PSG supine sleep, but wide limits of agreement (-246.9 to 194.2 minutes). In patients undergoing in-laboratory PSG, the perception of supine sleep predicts the presence of PSG supine sleep. However, questioning patients has a poor negative predictive value and patient estimates of supine sleep duration are inaccurate.

Evaluation of the CKD-EPI creatinine based glomerular filtration rate estimating equation in Black African and Indian adults in KwaZulu-Natal, South Africa

BackgroundThe estimation of glomerular filtration rate (GFR) plays a vital role in assessment of the renal function. This study evaluated the performance of the CKD-EPIcreat and MDRD equations in the South African Kwa-Zulu Natal population. ObjectivesThe objectives if the study were to compare the of CKD-EPIcreat and MDRD equations in the selected population to the measured GFR using Sodium Technetium-99 m-diethylene-triamine-pentaacetate clearance derived GFR. MethodRecords of adult patients with measured GFR performed at the Nuclear Medicine Department at Inkosi Albert Luthuli Central Hospital, Durban, South Africa from 1 April 2014 to 31 March 2016 were reviewed. eGFR for all included patients was calculated using the MDRD equation without African American correction factor and the CKD-EPIcreat equation with and without the African American correction factor for the Black African patients. Statistical comparison of the eGFR with measured GFR was performed with Bland Altman bias plots, Wilcoxon match pairs signed ranks test and accuracy within 10% and 30%.ROC curve analysis assessed the sensitivity and specificity at eGFR <90 and < 60 ml/min/1.73m2. ResultsAfter exclusion, 287 patients were included for analysis with sufficient numbers for only the Black African and Indian patients. None of the equations showed accuracy of eGFR within 30% of measured GFR for 90% of patients. In the Black African population, the CKD-EPIcreat equation without the correction factor performed best. 17% and 14.4% of the Black African participants would be reclassified with the CKD-EPIcreat equation without and with the African American correction factor respectively compared to mGFR at a cut-off of 60 mls/min/1.73m2. ConclusionNone of the evaluated equations attained the 2002 KDOQI benchmark of P30 >90%. 11.1–17% of individuals would have been incorrectly classified using the CKD-EPIcreat equation.

MethodCompare: An R package to assess bias and precision in method comparison studies.

Bland and Altman's limits of agreement have been used in many clinical research settings to assess agreement between two methods of measuring a quantitative trait. However, when the variances of the measurement errors of the two methods are different, limits of agreement can be misleading. MethodCompare is an R package that implements a new statistical methodology, developed by Taffé in 2016. MethodCompare produces three new plots, the "bias plot", the "precision plot", and the "comparison plot" to visually evaluate the performance of the new measurement method against the reference method. The method is illustrated on three simulated examples. Note that the Taffé method assumes that there are several measurements from reference standard and possibly as few as one measurement from the new method for each individual.

Effectiveness and Safety of Compound Chinese Medicine plus Routine Western Medicine in In-Stent Restenosis: A Meta-Analysis and Systematic Review.

Objective To examine the effects and safety of oral compound Chinese medicine (CCM) plus routine western medicine (RWM) in in-stent restenosis (ISR). Methods Various electronic databases (CBM, CNKI, VIP, Wanfang, PubMed, EMBASE, and Cochrane Library) were searched until April 2017. The quality of the included studies was evaluated, and meta-analyses were performed using RevMan5.3 and STATA 12.0 software. Moreover, funnel plot and Egger's publication bias plots were analysed to identify publication bias and adverse reactions were reported. A sensitive analysis was carried out according to the quality score. Results In all, 40 RCTs involving 4536 patients were selected for this review. The pooled estimates of three studies showed that the benefit to the number of ISRs (NoR) was more substantial for CCM plus RWM than for RWM alone (RR 0.24, 95% CI 0.10 to 0.57, P = 0.001; I2 = 0%, P = 0.81). The rate of ISR was significantly lower for CCM plus RWM than for the same RWM alone (RR 0.44, 95% CI 0.37 to 0.53, P < 0.00001; I2 = 0%, P = 0.95). CCM plus RWM benefitted the rate of ISR when a CM placebo plus RWM was used as the control intervention (RR 0.34, 95% CI 0.20 to 0.57, P < 0.0001; I2 = 0%, P = 0.95). The difference of adverse reactions was not significant. For secondary outcomes, the CCM plus RWM group did not reduce the rates of revascularization and cardiac death, but it did reduce the rate of recurrent angina over the results observed in the RWM alone group. In addition, funnel plot and Egger's publication bias plot indicated that there was publication bias. The association between the use of CCM plus RWM and RWM alone remained significant after the sensitivity analysis excluding studies with low quality score (quality score ⩽ 4) with a pooled RR of 0.41 (95% CI, 0.34–0.50). Conclusion Oral CCM plus RWM clearly benefitted patients with percutaneous coronary intervention (PCI) because it prevented and treated ISR better than was observed for either RWM alone or a CM placebo plus RWM.

Therapies for Meibomian Gland Dysfunction: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Introduction:Meibomian Gland Dysfunction (MGD) is a common, often overlooked, chronic condition affecting eyes for which various therapies are being evaluated. Considering the absence of a systematic review and meta-analysis, the present review was carried out.Methods:An appropriate search strategy eligibility criteria were framed and electronic databases were scrutinized for appropriate literature. Randomized Controlled Trials (RCTs) enrolling patients diagnosed with MGD were included. Outcome measures were Tear Break Up Time (TBUT), Schirmer’s test, Meibomian Gland (MG) secretion score, MG plugging score, OSDI and SPEED. Cochrane’s tool was used to assess the risk of bias and Forest plot were generated either with fixed or random effects model, with Standardized Mean Difference (SMD).Results:TBUTs, Schirmer’s test and OSDI scores for systemic antimicrobials with placebo were 1.58 [1.33, 1.83], 2.93 [0.78, 5.09] and -3.58 [-4.28, -2.89] respectively. No quantitative synthesis was attempted for either mebiomian plugging or meibomian secretion scores and no significant changes were observed with any other outcome parameter.Conclusion:Only the systemic antimicrobials were found to improve the clinical features of meibomian gland dysfunction. Varying effects of different therapeutic agents (heat therapies, omega-3-fatty acids and castor oil) were identified for MGD but the risk of bias pertaining to randomization and allocation concealment was found to be associated with most of the current RCTs. More high quality evidence is required to confirm the findings of the present review.

River suspended sediment modelling using the CART model: A comparative study of machine learning techniques

Suspended sediment load (SSL) modelling is an important issue in integrated environmental and water resources management, as sediment affects water quality and aquatic habitats. Although classification and regression tree (CART) algorithms have been applied successfully to ecological and geomorphological modelling, their applicability to SSL estimation in rivers has not yet been investigated. In this study, we evaluated use of a CART model to estimate SSL based on hydro-meteorological data. We also compared the accuracy of the CART model with that of the four most commonly used models for time series modelling of SSL, i.e. adaptive neuro-fuzzy inference system (ANFIS), multi-layer perceptron (MLP) neural network and two kernels of support vector machines (RBF-SVM and P-SVM). The models were calibrated using river discharge, stage, rainfall and monthly SSL data for the Kareh-Sang River gauging station in the Haraz watershed in northern Iran, where sediment transport is a considerable issue. In addition, different combinations of input data with various time lags were explored to estimate SSL. The best input combination was identified through trial and error, percent bias (PBIAS), Taylor diagrams and violin plots for each model. For evaluating the capability of the models, different statistics such as Nash-Sutcliffe efficiency (NSE), Kling-Gupta efficiency (KGE) and percent bias (PBIAS) were used. The results showed that the CART model performed best in predicting SSL (NSE=0.77, KGE=0.8, PBIAS<±15), followed by RBF-SVM (NSE=0.68, KGE=0.72, PBIAS<±15). Thus the CART model can be a helpful tool in basins where hydro-meteorological data are readily available.