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Results for “Performance benchmarking”

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PubMed1997

[Efficacy of increase of cardiac index during exercise in the chronic phase of various cardiovascular diseases: evaluation by exercise tolerance and brain natriuretic peptide].

Cardiac index is widely used as a parameter of cardiac function for cardiovascular patients, but its value is limited when measured in the resting supine position, because it never demonstrates the maximal cardiac index performance. The incremental increase in cardiac index (delta CI) was evaluated during incremental exercise (delta work rate: delta WR), delta CI/delta WR, in patients with chronic congestive heart failure, and compared to brain natriuretic peptide (BNP), which is known to be increased in patients with chronic left ventricular dysfunction. The subjects were 18 heart failure patients (16 males and 2 females, mean age [+/-SD] 63.8 +/- 8.9 years). Symptom-limited cardiopulmonary exercise test using cycle ergometer was performed. Cardiac index was calculated with the Benchmark Exercise Test device using oxygen uptake, carbon dioxide output and respired flow. Blood samples were taken in the resting state before the exercise test. A positive correlation was obtained between delta CI/delta WR and peak oxygen uptake (peak VO2) (r = 0.71, p < 0.01), and delta CI/delta WR and peak oxygen pulse (r = 0.66, p < 0.01). A negative correlation was obtained between delta CI/delta WR and BNP (r = 0.45) in the resting state. Peak VO2 (20.9 +/- 7.5 vs 13.9 +/- 2.7 ml/min/kg, p < 0.05), peak cardiac index (7.2 +/- 1.7 vs 5.5 +/- 0.9 l/min/m2, p < 0.05), and delta CI/delta WR (20.1 +/- 8.1 vs 12.4 +/- 2.5 ml/m2/W, p < 0.05) were significantly higher in the group with normal BNP (mean [+/-SD] 11.0 +/- 3.2 pg/ml) than in the group with high BNP (40.7 +/- 22.7 pg/ml). Delta CI/delta WR reflects the grade of exercise tolerance and may be useful for evaluating exercise capacity in patients with congestive heart failure.

Aged↗

PubMed2005

TOPS: the Optimum Performance Scale approach to improving nursing home performance.

Although nursing homes, a major and expensive institution in American life, are dedicated to caring for our elders when they need nursing care, they largely fail in that mission. Instead, nursing homes are widely feared as the place where elders go to die, neglected. Staffing is chronically short, as staff do not see nursing homes as preferred places to work. Society's efforts to cure this situation have generally failed, in that we all paid for decades of foundation support, academic research, expert consultants, and government financial support and regulation in an effort to improve nursing homes, without getting significant results. Nursing homes taken as a whole have proven strongly resistant to even incremental improvements, let alone wholesale change, and as a result the failure persists. Most nursing homes are blind to the possibility of success. The issue and problem highlighted by these general failures of outside pressure to bring improvement, coupled with general blindness to potential success is: How can we get the nursing home industry to improve itself. The response outlined in this article is TOPS, The Optimum Performance System. TOPS works by delivering to participating managers (and their staff and board) a personal computer application (the TOPS Tool) that compares the performance of the participant to its peers, including descriptions of what all participants have done to produce their performance. The comparison is holistic, measuring all the main components of performance (quality of living medical health, and cost) and all the sources of performance (management and operations, facilities, and community relations). The instinctual competitive needs of each manager will urge them to use this knowledge to improve their own performance.

Aged↗

PubMed2006

Benchmarking a memetic algorithm for ordering microarray data.

This work introduces a new algorithm for "gene ordering". Given a matrix of gene expression data values, the task is to find a permutation of the gene names list such that genes with similar expression patterns should be relatively close in the permutation. The algorithm is based on a combined approach that integrates a constructive heuristic with evolutionary and Tabu Search techniques in a single methodology. To evaluate the benefits of this method, we compared our results with the current outputs provided by several widely used algorithms in functional genomics. We also compared the results with our own hierarchical clustering method when used in isolation. We show that the use of images, corrupted with known levels of noise, helps to illustrate some aspects of the performance of the algorithms and provide a complementary benchmark for the analysis. The use of these images, with known high-quality solutions, facilitates in some cases the assessment of the methods and helps the software development, validation and reproducibility of results. We also propose two quantitative measures of performance for gene ordering. Using these measures, we make a comparison with probably the most used algorithm (due to Eisen and collaborators, PNAS 1998) using a microarray dataset available on the public domain (the complete yeast cell cycle dataset).

Algorithms↗

PubMed2002

Laparoscopic cholecystectomy: quality of care and benchmarking. Results of a single-institution specialized in laparoscopy compared with those of a nationwide study in Switzerland.

BACKGROUND: Quality control is an important issue in surgery. Therefore, we assessed the outcome of laparoscopic cholecystectomies (LC) performed at our institution specialized in laparoscopic surgery in order to do a benchmarking. METHODS: The perioperative courses of the first 1000 LCs performed in Aarberg hospital were recorded, analyzed, and compared with the results of a recent study including 10, 174 patients published by the Swiss Association of Laparoscopic and Thoracoscopic Surgery (SALTS). RESULTS: The following quality indicators were compared with the corresponding SALTS rates: primary conversion rate 1.5% (SALTS 8.2%; p <0.01); conversion rate for intraoperative complications 6.5% (63.8%; p <0.01); intraoperative complication rate 22.2% (34.4%; p <0.01); postoperative morbidity rate 8.1% (10.4%; n.s.); in-hospital mortality rate 0.1% (0.2%; n.s.); and reoperation rate 0.8% (1.7%; n.s.). CONCLUSIONS: LC has reached a high quality level in its widespread use, but in a small specialized center even a higher quality level can be achieved. Favorable results seem to depend on structural advantages of a surveyable unit in association with a continuously motivated surgical team.

Adolescent↗

PubMed2004

Benchmarking tools for the alignment of functional noncoding DNA.

BACKGROUND: Numerous tools have been developed to align genomic sequences. However, their relative performance in specific applications remains poorly characterized. Alignments of protein-coding sequences typically have been benchmarked against "correct" alignments inferred from structural data. For noncoding sequences, where such independent validation is lacking, simulation provides an effective means to generate "correct" alignments with which to benchmark alignment tools. RESULTS: Using rates of noncoding sequence evolution estimated from the genus Drosophila, we simulated alignments over a range of divergence times under varying models incorporating point substitution, insertion/deletion events, and short blocks of constrained sequences such as those found in cis-regulatory regions. We then compared "correct" alignments generated by a modified version of the ROSE simulation platform to alignments of the simulated derived sequences produced by eight pairwise alignment tools (Avid, BlastZ, Chaos, ClustalW, DiAlign, Lagan, Needle, and WABA) to determine the off-the-shelf performance of each tool. As expected, the ability to align noncoding sequences accurately decreases with increasing divergence for all tools, and declines faster in the presence of insertion/deletion evolution. Global alignment tools (Avid, ClustalW, Lagan, and Needle) typically have higher sensitivity over entire noncoding sequences as well as in constrained sequences. Local tools (BlastZ, Chaos, and WABA) have lower overall sensitivity as a consequence of incomplete coverage, but have high specificity to detect constrained sequences as well as high sensitivity within the subset of sequences they align. Tools such as DiAlign, which generate both local and global outputs, produce alignments of constrained sequences with both high sensitivity and specificity for divergence distances in the range of 1.25-3.0 substitutions per site. CONCLUSION: For species with genomic properties similar to Drosophila, we conclude that a single pair of optimally diverged species analyzed with a high performance alignment tool can yield accurate and specific alignments of functionally constrained noncoding sequences. Further algorithm development, optimization of alignment parameters, and benchmarking studies will be necessary to extract the maximal biological information from alignments of functional noncoding DNA.

Animals↗

PubMed2005

Infra-inguinal revascularization surgical site infections: Australasian benchmark.

BACKGROUND: Infra-inguinal revascularization surgery remains one of the most commonly performed major vascular procedures in contemporary practice. Surgical site infections (SSI) are a common cause of morbidity in this patient cohort and generate high rates of limb loss and mortality when vascular graft involvement occurs. An overall reduction in North American SSI has been attributed to the establishment of national benchmarks. A comparable Australasian benchmark does not exist. The purpose of the present study was to assess the methods used by Australasian vascular units to determine SSI rates and to instigate the development of an acceptable benchmark. METHODS: A structured questionnaire pertaining to SSI after infra-inguinal revascularization surgery was sent to 26 Australasian vascular units. Data requested included the number and type of lower extremity revascularization procedures performed. Units were also asked to report the methods employed for defining and detecting wound infections and to document their SSI rate. The incidence of SSI causation by methicillin-resistant Staphylococcus aureus (MRSA) was also sought. RESULTS: The total number of revascularizations performed annually varied from 28 to 179 between units. The SSI rates ranged from 0 to 38%. The incidence of MRSA involvement varied from <1% to 56%. The SSI surveillance methodology varied considerably between units. CONCLUSIONS: The present study confirms the significant incidence of SSI after infra-inguinal revascularization surgery in contemporary vascular practice. Standardized definitions and surveillance protocols are required to facilitate inter- and intrahospital comparisons. A possible benchmark infection rate may be 10-20%.

Australia↗

PubMed2006

ON the influence of parameter theta- on performance of RBF neural networks trained with the dynamic decay adjustment algorithm.

The dynamic decay adjustment (DDA) algorithm is a fast constructive algorithm for training RBF neural networks (RBFNs) and probabilistic neural networks (PNNs). The algorithm has two parameters, namely, theta(+) and theta(-). The papers which introduced DDA argued that those parameters would not heavily influence classification performance and therefore they recommended using always the default values of these parameters. In contrast, this paper shows that smaller values of parameter theta(-) can, for a considerable number of datasets, result in strong improvement in generalization performance. The experiments described here were carried out using twenty benchmark classification datasets from both Proben1 and the UCI repositories. The results show that for eleven of the datasets, the parameter theta(-) strongly influenced classification performance. The influence of theta(-) was also noticeable, although much less, on six of the datasets considered. This paper also compares the performance of RBF-DDA with theta(-) selection with both AdaBoost and Support Vector Machines (SVMs).

Algorithms↗

PubMed2001

Altered operant responding for motor reinforcement and the determination of benchmark doses following perinatal exposure to low-level 2,3,7,8-tetrachlorodibenzo-p-dioxin.

Pregnant Holtzman rats were exposed to a single oral dose of 0, 20, 60, or 180 ng/kg 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the 18th day of gestation. Their adult female offspring were trained to respond on a lever for brief opportunities to run in specially designed running wheels. Once they had begun responding on a fixed-ratio 1 (FR1) schedule of reinforcement, the fixed-ratio requirement for lever pressing was increased at five-session intervals to values of FR2, FR5, FR10, FR20, and FR30. We examined vaginal cytology after each behavior session to track estrous cyclicity. Under each of the FR values, perinatal TCDD exposure produced a significant dose-related reduction in the number of earned opportunities to run, the lever response rate, and the total number of revolutions in the wheel. Estrous cyclicity was not affected. Because of the consistent dose-response relationship at all FR values, we used the behavioral data to calculate benchmark doses based on displacements from modeled zero-dose performance of 1% (ED(01)) and 10% (ED(10)), as determined by a quadratic fit to the dose-response function. The mean ED(10) benchmark dose for earned run opportunities was 10.13 ng/kg with a 95% lower bound of 5.77 ng/kg. The corresponding ED(01) was 0.98 ng/kg with a 95% lower bound of 0.83 ng/kg. The mean ED(10) for total wheel revolutions was calculated as 7.32 ng/kg with a 95% lower bound of 5.41 ng/kg. The corresponding ED(01) was 0.71 ng/kg with a 95% lower bound of 0.60. These values should be viewed from the perspective of current human body burdens, whose average value, based on TCDD toxic equivalents, has been calculated as 13 ng/kg.

Administration, Oral↗

PubMed2001