Initial fatigue quality confidence-interval approach for determination of inspection intervals

AIAA Journal ◽  
1996 ◽  
Vol 34 (11) ◽  
pp. 2361-2369 ◽  
Author(s):  
Andrea Pieracci
Keyword(s):  
Confidence Interval ◽  
Interval Approach

scholarly journals Confidence interval approach for evaluating bias in laboratory methods

1988 ◽  
Vol 10 (3) ◽  
pp. 144-146 ◽  
Author(s):  
K. F. Yee
Keyword(s):  
Confidence Interval ◽  
Statistical Tests ◽  
Laboratory Methods ◽  
Mean Values ◽  
Practical Concern ◽  
Alternative Approach ◽  
Interval Approach ◽  
Significant Difference ◽  
The Mean

A statistically significant difference in mean values between two laboratory quantitation methods is interpreted as a bias. Sometimes such a difference is so minute that it does not constitute any practical concern. An alternative approach is to test statistically whether the two methods are close enough, not for equality. This is to look at the confidence interval of the mean method difference and does not entail any additional statistical tests.

scholarly journals Alterations of Left Ventricular Hypertrophy in and Survival of Patients Receiving Hemodialysis: Follow-up of an Interventional Study

2001 ◽  
Vol 12 (12) ◽  
pp. 2759-2767 ◽  
Author(s):  
Gérard M. London ◽  
Bruno Pannier ◽  
Alain P. Guerin ◽  
Jacques Blacher ◽  
Sylvain J. Marchais ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Left Ventricular ◽  
Independent Effect ◽  
Lv Mass ◽  
History Of ◽  
Cv Disease ◽  
Stage Renal Disease ◽  
End Stage

ABSTRACT. Left ventricular (LV) hypertrophy (LVH) is a risk factor for mortality in patients with end-stage renal disease (ESRD). Whether the attenuation of LVH has a positive effect on survival of patients with ESRD has not been documented. The aim of this study was to determine the effect of parallel treatment of hypertension and anemia on LV mass (LVM) and to determine the effect of LVM changes on survival. A cohort of 153 patients receiving hemodialysis was studied. The duration of follow-up was 54 ± 37 mo. All patients had echocardiographic determination of LV dimensions and LVM at baseline and regular intervals until the end of the follow-up period. During the study, BP decreased from (mean ± SD) 169.4 ± 29.7/90.2 ± 15.6 to 146.7 ± 29/78 ± 14.1 mmHg (P< 0.001), and hemoglobin increased from 8.65 ± 1.65 to 10.5 ± 1.45 g/dl (P< 0.001). The LV end-diastolic diameter and mean wall thickness decreased from 56.6 ± 6.5 to 54.8 ± 6.5 mm (P< 0.001), and from 10.4 ± 1.6 to 10.2 ± 1.6 mm (P< 0.05), respectively. The LVM decreased from 290 ± 80 to 264 ± 86 g (P< 0.01). Fifty-eight deaths occurred, 38 attributed to cardiovascular (CV) disease and 20 attributed to non-CV causes. According to Cox analyses after adjustment for age, gender, diabetes, history of CV disease, and all nonspecific CV risk factors, LVM regression positively affected the survival. The hazard risk ratio associated with a 10% LVM decrease was 0.78 (95% confidence interval, 0.63 to 0.92) for all-causes mortality and 0.72 (95% confidence interval, 0.51 to 0.90) for mortality due to CV disease. These results show that a partial LVH regression in patients with ESRD had a favorable and independent effect on patients’ all-cause and CV survival.

scholarly journals Detection of Specific Antinuclear Reactivities in Patients with Negative Anti-nuclear Antibody Immunofluorescence Screening Tests

2002 ◽  
Vol 48 (12) ◽  
pp. 2171-2176 ◽  
Author(s):  
Ilse EA Hoffman ◽  
Isabelle Peene ◽  
Eric M Veys ◽  
Filip De Keyser
Keyword(s):  
Connective Tissue ◽  
Confidence Interval ◽  
Connective Tissue Disease ◽  
Indirect Immunofluorescence ◽  
Connective Tissue Diseases ◽  
Clinical Suspicion ◽  
Screening Tests ◽  
Strongly Correlated ◽  
Nuclear Antigens

Abstract Background: For detection of anti-nuclear antibodies (ANAs) and antibodies to extractable nuclear antigens (ENAs), samples frequently are screened with indirect immunofluorescence (IIF); further determination of anti-ENA antibodies is performed only when the result is positive. However, because anti-ENA reactivities are found in samples with low fluorescence intensities, we determined anti-ENA antibodies in samples with negative IIF and thus calculated the sensitivity of IIF for specific ANAs. Methods: We collected 494 samples consecutively referred by rheumatologists for routine ANA testing. IIF on HEp-2 and HEp-2000 (HEp-2 cells transfected with Ro60 cDNA) and line immunoassay (LIA) for the detection of specific ANAs were performed on all samples. Results: Fluorescence intensities and patterns on HEp-2 were strongly correlated with those on HEp-2000 [Spearman ρ = 0.852 (P &lt;0.001) and 0.838 (P &lt;0.001), respectively]. Sixty-eight of 494 samples were positive on LIA, of which only 72% (confidence interval, 68–76%) were detected with HEp-2 and 75% (confidence interval, 70–78%) with HEp-2000. Of 291 samples negative on both substrates, 12 were positive on LIA. Connective tissue diseases were diagnosed in four of these patients and suspected in at least three others. Conclusion: The HEp-2 and HEp-2000 substrates perform comparably for fluorescence intensities and patterns and for detecting specific ANAs, but some patients with negative IIF show reactivity on LIA. We recommend testing for fine reactivities, regardless of the IIF result, when the clinical suspicion for rheumatic connective tissue disease is high.

Microbiological Determination of Neomycin in Feeds: Collaborative Study

1989 ◽  
Vol 72 (2) ◽  
pp. 237-241
Author(s):  
Gerald L Stahl ◽  
D Dal Kratzer ◽  
Charles W Kasson
Keyword(s):  
Statistical Analysis ◽  
Confidence Interval ◽  
Salt Concentration ◽  
Agar Medium ◽  
Collaborative Study ◽  
Tris Buffer ◽  
Official Method ◽  
The Mean ◽  
Swine Feed

Abstract A modification of the AOAC microbiological determination of neomycin in feeds was collaboratively studied by 12 laboratories. The official method was modified by substituting a constant salt concentration diluent for the feed extract diluent, preparing the agar medium in tris buffer, and performing the test with a monolayer plating system. Each laboratory performed single assays on 8 samples in a randomized sequence. The samples included duplicates of a cattle and swine feed at 2 different marketed concentrations. The mean recovery across all laboratories was 110.7% of theory with a range of means of 69.4-128.6 across the 12 laboratories. The results of one laboratory and 2 additional values from different laboratories were deemed outliers and excluded from statistical analysis. The statistical analysis gave a confidence interval of ± 26% for individual assays.

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