Changes In Quality Control Research Articles

Minimally invasive coronary artery bypass grafting via left anterior minithoracotomy: Setup, results, and evolution of a new surgical procedure

ObjectiveMinimally invasive total arterial coronary artery bypass grafting offers the advantages of total arterial revascularization through an anterolateral minithoracotomy. However, the procedure is technically challenging and associated with a learning curve. The purpose of our study was to evaluate the progress and development of our program over an 8-year period. MethodsWe collected prospective data on all patients who underwent procedure at our institution from January 2015 to December 2023. Our program underwent several modifications during this study period, including optimization of surgical exposure using various available instruments, efficient intraoperative time management, utilization of a standard technique for all off-pump coronary artery bypass procedures, and close team member mentoring. Changes in quality control consisted of transitioning from routine postoperative coronary imaging to clinically indicated imaging. The influence of these interventions was assessed by focusing on in-hospital mortality as the primary end point, and operative time and perioperative myocardial infarction as secondary end points, over 2 time periods consisting of patients operated on during the first and second 4-year study period (Group 1, n = 137 and Group 2, n = 142). ResultsA total of 279 consecutive patients underwent elective, total arterial minimally invasive total arterial coronary artery bypass grafting at our institution over the study period. The mean age of patients was 66 ± 7 years, with 86% being men (n = 241) and 33.1% having diabetes (n = 77). Triple vessel disease was present in 53% of the cohort (n = 123) and left main disease was prevalent in 43% of patients (n = 101). The overall 30-day mortality was 0.4% (n = 1). Compared with the initial 4-year period, the rate of perioperative myocardial infarction decreased 3-fold (4.3% vs 1.4%; P = .1) and there was a statistically significant reduction in operating time (275 ± 59.5 and 246 ± 72.6 minutes; P < .001) in the most recent group of patients. ConclusionsTotal arterial minimally invasive total arterial coronary artery bypass grafting is a feasible surgical approach that can be performed with very good results, even during the initial learning curve phase. An evolving educational program can provide a smooth transition from off-pump coronary artery bypass grafting to minimally invasive total arterial coronary artery bypass grafting, when performed in selected patients in high-volume cardiac centers.

Quality controls, bias, and seasonality of CO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; columns in the boreal forest with Orbiting Carbon Observatory-2, Total Carbon Column Observing Network, and EM27/SUN measurements

Abstract. Seasonal CO2 exchange in the boreal forest plays an important role in the global carbon budget and in driving interannual variability in seasonal cycles of atmospheric CO2. Satellite-based observations from polar orbiting satellites like the Orbiting Carbon Observatory-2 (OCO-2) offer an opportunity to characterize boreal forest seasonal cycles across longitudes with a spatially and temporally rich data set, but data quality controls and biases still require vetting at high latitudes. With the objective of improving data availability at northern, terrestrial high latitudes, this study evaluates quality control methods and biases of OCO-2 retrievals of atmospheric column-averaged dry air mole fractions of CO2 (XCO2) in boreal forest regions. In addition to the standard quality control (QC) filters recommended for the Atmospheric Carbon Observations from Space (ACOS) B8 (B8 QC) and ACOS B9 (B9 QC) OCO-2 retrievals, a third set of quality control filters were specifically tailored to boreal forest observations (boreal QC) with the goal of increasing data availability at high latitudes without sacrificing data quality. Ground-based reference measurements of XCO2 include observations from two sites in the Total Carbon Column Observing Network (TCCON) at East Trout Lake, Saskatchewan, Canada, and Sodankylä, Finland. OCO-2 retrievals were also compared to ground-based observations from two Bruker EM27/SUN Fourier transform infrared spectrometers (FTSs) at Fairbanks, Alaska, USA. The EM27/SUN spectrometers that were deployed in Fairbanks were carefully monitored for instrument performance and were bias corrected to TCCON using observations at the Caltech TCCON site. The B9 QC were found to pass approximately twice as many OCO-2 retrievals over land north of 50∘ N than the B8 QC, and the boreal QC were found to pass approximately twice as many retrievals in May, August, and September as the B9 QC. While boreal QC results in a substantial increase in passable retrievals, this is accompanied by increases in the standard deviations in biases at boreal forest sites from ∼1.4 parts per million (ppm) with B9 QC to ∼1.6 ppm with boreal QC. Total average biases for coincident OCO-2 retrievals at the three sites considered did not consistently increase or decrease with different QC methods, and instead, responses to changes in QC varied according to site and satellite viewing geometries. Regardless of the quality control method used, seasonal variability in biases was observed, and this variability was more pronounced at Sodankylä and East Trout Lake than at Fairbanks. Long-term coincident observations from TCCON, EM27/SUN, and satellites from multiple locations would be necessary to determine whether the reduced seasonal variability in bias at Fairbanks is due to geography or instrumentation. Monthly average biases generally varied between −1 and +1 ppm at the three sites considered, with more negative biases in spring (March, April, and May – MAM) and autumn (September and October – SO) but more positive biases in the summer months (June, July, and August – JJA). Monthly standard deviations in biases ranged from approximately 1.0 to 2.0 ppm and did not exhibit strong seasonal dependence, apart from exceptionally high standard deviation observed with all three QC methods at Sodankylä in June. There was no evidence found to suggest that seasonal variability in bias is a direct result of air mass dependence in ground-based retrievals or of proximity bias from coincidence criteria, but there were a number of retrieval parameters used as quality control filters that exhibit seasonality and could contribute to seasonal dependence in OCO-2 bias. Furthermore, it was found that OCO-2 retrievals of XCO2 without the standard OCO-2 bias correction exhibit almost no perceptible seasonal dependence in average monthly bias at these boreal forest sites, suggesting that seasonal variability in bias is introduced by the bias correction. Overall, we found that modified quality controls can allow for significant increases in passable OCO-2 retrievals with only marginal compromises in data quality, but seasonal dependence in biases still warrants further exploration.

Does a change in quality control results influence the sensitivity of an anti-HCV test?

Background Laboratories use quality control (QC) testing to monitor the extent of normal variation. Assay lot number changes contribute the greatest amount of variation in infectious disease serology testing. An unexpected change in six lots of an anti-HCV assay allowed the determination of the effect these lot changes made to the assay's clinical sensitivity. Methods Two sets of seroconversion samples comprising of 44 individual samples and 9 external quality assessment scheme (EQAS) samples, all positive to anti-HCV, were tested in affected and unaffected assay lots, and the difference in the quantitative and qualitative results of the samples was analyzed. Results Of 44 low-positive seroconversion samples tested in affected and unaffected assay lots, only three samples had results reported below the assay cutoff when tested on two of the six affected assay lot. A further sample had results below the cutoff for only one affected lot. None of the EQAS samples reported false-negative results. Samples having a signal to cutoff value of less than 6.0 generally had lower results in the affected lots compared with the unaffected lots. Conclusions Unexpected changes in QC reactivity related to variation, in particular assay lot changes, may affect patient results. This study demonstrated that QConnect Limits facilitated the detection of an unexpectedly large variation in QC test results, allowed for the identification of the root cause of the change, and showed that the risk associated with the change was low but credible. The use of evidence-based QC program is essential to detect changes in test systems.

IQCP: Guideline and Helpful Tools for Implementation.

This article will help laboratories understand what changed with external quality control testing, why it changed, who changed it, when the changes became effective, and how these changes affect clinical laboratories. The new Individualized Quality Control Plan (IQCP) option that became effective January 1, 2016, will be explained. Three other quality control changes that took effect January 1, 2016, and dramatically affect quality control requirements for antimicrobial susceptibility testing, identification test systems, and exempt culture media will also be explained. Guidelines and tools are provided that can assist laboratories in determining what is eligible for IQCP and how to design an IQCP program.

Morphological and bioenergetic demands underlying the mitophagy in post-mitotic neurons: the pink–parkin pathway

Evidence suggests a striking causal relationship between changes in quality control of neuronal mitochondria and numerous devastating human neurodegenerative diseases, including Parkinson’s disease, Alzheimer’s disease, Huntington’s disease, and amyotrophic lateral sclerosis. Contrary to replicating mammalian cells with a metabolism essentially glycolytic, post-mitotic neurons are distinctive owing to (i) their exclusive energetic dependence from mitochondrial metabolism and (ii) their polarized shape, which entails compartmentalized and distinct energetic needs. Here, we review the recent findings on mitochondrial dynamics and mitophagy in differentiated neurons focusing on how the exceptional characteristics of neuronal populations in their morphology and bioenergetics needs make them quite different to other cells in controlling the intracellular turnover of these organelles.

Evaluation of Long‐Term Retention and Detection of Oxytetracycline Marks in Walleye Otoliths Using Genetic Methodology

AbstractBecause neither genetic population assignments nor oxytetracycline (OTC) mark identifications are 100% accurate, genetic methods were modeled alone and in combination with OTC mark observations to identify the source of walleyes Sander vitreus in a supplemented population and to evaluate the accuracy of OTC mark examination in distinguishing stocked fish that had been treated with OTC from those produced naturally in the lake. Readers examined otoliths from 3,663 fish from two year‐classes that were sampled up to 5 years after stocking. A subset of 1,578 of the examined individuals were also assigned to source populations based on genotypes at eight microsatellite loci using baseline genetic data from the stocking source and the recipient population (the measure of genetic divergence [FST] = 0.07 between populations before stocking). The models indicated that OTC mark observation errors occurred in all samples and that the error rates varied among samples and readers. Model estimates of overall false‐negative error rates ranged from 11.4% to 17.2%, and estimates of overall false‐positive error rates ranged from 8.9% to 16.7%. Over the ages of walleyes inspected (3 months to age 5), there was neither a systematic increase in mark errors with age nor a decrease in mark intensities; thus, the OTC marks present at 3 months appeared to be permanent. Any true mark absence was due to inefficient OTC immersion treatment or the loss of a successfully applied mark before the first sample was inspected as fingerlings. The presence of both false positives and false negatives in all samples indicates that mark detection error did consistently contribute to the overall mark error rates. Thus, changes in quality control are justified for both OTC immersion treatment and mark detection procedures.

Effects of Contamination of Biobased Hydraulic Fluids with Mineral Oil

Abstract There are many occasions for biobased hydraulic fluids to be contaminated with mineral oil, caused either by incomplete flushing during conversion from mineral oil to bio-oil, or by carelessness during maintenance and refilling. With high contamination levels, problems like foaming, poor air release, or filter clogging have been reported. In experiments at IFAS (Institute for Fluid Power Drives and Controls) of RWTH Aachen University, relevant properties of biobased oils contaminated with different levels of various mineral oils have been analyzed. It was found, that the degree of deterioration correlates not to the amount of mineral oil added, but to the amount of metals introduced through the mineral oil’s additives. Deterioration effects may take several hours or days to develop. The effects are specific for different bio-oil products. As a practical consequence, some changes in quality control, product documentation, and standardization are recommended.

Evaluation of Fixed Quality Control Range of Bayer Rapidpoint 400 Blood Gas and Electrolyte Analyzer with Six Sigma Metrics

Bayer Rapidpoint 400 analyzer for point of care testing (POCT) uses fixed quality control (QC) range even when the lot number of a cartridge for quality control changes. To evaluate the fixed QC range recommended by the manufacturer, we analyzed internal QC data of 9 analyzers with Six Sigma metrics. We investigated QC data of 9 analyzers over 5 months from May to September, 2004 for 8 parameters (pH, pCO(2), pO(2), Na(+), K(+), iCa(++), Cl(-), and glucose). One hundred eighty six groups of QC data were analyzed with capability index (C(p)=total allowable error (TEa)/3 standard deviation (SD)) and capability index considering bias (C(pk),=(TEa-bias)/3 SD). Acceptability was evaluated with criteria of 1.33 C(pk), 4 sigma level or quality criteria of the Clinical Laboratory Improvement Amendments of 1988 (CLIA'88). In 80.7% (150 of 186 groups), both C(p) and C(pk) were at or above 1.33, which indicated that the use of fixed QC range was adequate. In 19.3% (36 of 186 groups), C(pk) was below 1.33, which indicated the inadequacy of fixed QC range. Among them 14.5% (27 of 186 groups) showed C(p) below 1.33, indicating that the errors had a random factor and 4.8% (9 of 186 groups) had C(p) at or above 1.33, indicating that the errors had a systematic factor. The quality criteria mandated by CLIA '88 was satisfied in about 80% of study groups using fixed QC ranges, but in about 20%, more strict instrument maintenance and specimen handling by operators, and quality improvement of QC materials by manufacturer was required.

Improvement in mammography quality control: 1987-1995.

To assess possible changes in quality control (QC) practices at mammography sites in the United States. Mammography site surveys were conducted in 1990, 1992, and 1995 through the Colorado Mammography Advocacy Project (CMAP). Data from mammography sites applying for American College of Radiology (ACR) accreditation were collected between August 1987 and August 1993 through the ACR Mammography Accreditation Program. Data from both of these surveys were analyzed to assess temporal changes in mammography QC practices in the United States between 1987 and 1995. CMAP results indicated statistically significant improvement in medical physicist QC practices between 1990 and 1992 and in technologist QC practices between 1990 and 1995. Improvements in radiologic technologist QC practices coincided with increases in radiologic technologist continuing education in mammography. ACR results indicated statistically significant improvement in technologist QC practices between 1988 and 1992. There have been substantial improvements in QC practices at mammography sites in the United States during the past decade.

Quality Control of Operational Physical Retrievals of Satellite Sounding Data

Abstract Earlier work identified serious errors and biases in the operational temperature and moisture satellite retrievals produced by statistical methods. We show that similar errors and biases are found in the physical retrievals produced operationally since September 1988. We report experiments on quality control algorithms to deal with the errors in the satellite data. The quality control changes resulting from this work were implemented in the European Centre for Medium Range Weather Forecasts (ECMWF) system in January 1989. The performance of the quality control changes in the period after the change has been satisfactory.

A general method for constructing automated procedures for testing quickest detection of a change in quality control

A general method for constructing automated procedures for testing quickest detection of a change in quality control