scholarly journals Probabilities for Spearman rank correlation coefficients

1974 ◽  
Vol 6 (3) ◽  
pp. 357-357
Author(s):  
Jerrold H. Zar
Keyword(s):  
Rank Correlation ◽  
Correlation Coefficients ◽  
Spearman Rank Correlation ◽  
Spearman Rank

Difference of seasonal variation between glycated albumin and glycated haemoglobin

2018 ◽  
Vol 55 (5) ◽  
pp. 583-587 ◽  
Author(s):  
Karin Tanaka ◽  
Shu Meguro ◽  
Masami Tanaka ◽  
Junichiro Irie ◽  
Yoshifumi Saisho ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Plasma Glucose ◽  
Seasonal Variations ◽  
Glycated Albumin ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Glycated Haemoglobin ◽  
Spearman Rank Correlation ◽  
Spearman Rank ◽  
Average Temperature

Background Glycated albumin reflects 2–3-week glycaemic controls, and in addition to glycated haemoglobin, it has been used as a glycaemic control indicator. We presumed that glycated albumin also has seasonal variations and is related to temperature, similar to glycated haemoglobin. Methods The subjects were diabetic outpatients from April 2007 to March 2013. This resulted in the enrolment of 2246 subjects and the collection of a total of 53,968 measurements. Mean glycated haemoglobin, glycated albumin, and plasma glucose were calculated for each month over six years. The associations of the measures with each other and the average temperature for each month in Tokyo were assessed using Spearman rank correlation coefficients. Results Plasma glucose was highest in January and lowest in May. Glycated haemoglobin was highest in March and lowest in September. Glycated albumin was highest in May and lowest in December. Glycated albumin tended to have a disjunction with plasma glucose in winter. Glycated haemoglobin had seasonal variation, but glycated albumin did not. Plasma glucose and glycated haemoglobin showed significant negative correlations with temperature (rs = −0.359, P < 0.001, rs = −0.449, P < 0.001, respectively), but glycated albumin did not. However, glycated albumin was inter-correlated with plasma glucose (rs = 0.396, P < 0.001) and glycated haemoglobin (rs = 0.685, P < 0.001), and glycated haemoglobin was inter-correlated with plasma glucose (rs = 0.465, P < 0.001). Conclusion Glycated albumin and glycated haemoglobin showed different seasonal variations from each other over the six-year study period. Thus, further studies to identify factors that contribute to glycated albumin are needed.

scholarly journals What do babies eat? Evaluation of a food frequency questionnaire to assess the diets of infants aged 6 months

2008 ◽  
Vol 11 (7) ◽  
pp. 751-756 ◽  
Author(s):  
LD Marriott ◽  
SM Robinson ◽  
J Poole ◽  
SE Borland ◽  
KM Godfrey ◽  
...  
Keyword(s):  
Food Frequency Questionnaire ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Population Based ◽  
Spearman Rank Correlation ◽  
Nutrient Intakes ◽  
Food Frequency ◽  
Spearman Rank ◽  
Healthy Infants ◽  
Mean Differences

AbstractObjectiveTo evaluate the relative validity of a food frequency questionnaire (FFQ) for assessing nutrient intakes in 6-month-old infants.Design and settingThe FFQ was developed to assess the diets of infants born to women in the Southampton Women’s Survey (SWS), a population-based survey of young women and their offspring. The energy and nutrient intakes obtained from an interviewer-administered FFQ were compared with those obtained from a 4-day weighed diary.Subjects and methodsA sub-sample of 50 infants aged 6 months from the SWS had their diets assessed by both methods. The FFQ recorded the frequencies and amounts of milks, baby foods, regular foods and drinks consumed by the infants over the previous seven days. The diaries recorded the weights of all foods and drinks consumed by the infants on four separate days within 15 days following FFQ completion.ResultsSpearman rank correlation coefficients for intakes of energy, macronutrients and 18 micronutrients, determined by the two methods, ranged from r = 0·39 to 0·86; adjustment for energy intake tended to increase the correlation coefficients, range ra = 0·55 to 0·89. Bland–Altman statistics showed that mean differences between methods were in the range of −12·5 % to +12·5 % except for vitamin B12 (−18·9 %).ConclusionAlthough there were differences in absolute energy and nutrient intakes between methods, Spearman rank correlation coefficients indicated reasonable agreement in the ranking of intakes. The interviewer-administered FFQ is a useful tool for assessing energy and nutrient intakes of healthy infants aged about 6 months.

scholarly journals Reliability of a Brief Intercept Survey for Trail Use Behaviors

2009 ◽  
Vol 6 (6) ◽  
pp. 775-780 ◽  
Author(s):  
Philip J. Troped ◽  
Heather A. Whitcomb ◽  
Brent Hutto ◽  
Julian A. Reed ◽  
Steven P. Hooker
Keyword(s):  
Rank Correlation ◽  
Correlation Coefficients ◽  
Spearman Rank Correlation ◽  
Current Form ◽  
Retest Reliability ◽  
Spearman Rank ◽  
Trail Use ◽  
Percent Agreement ◽  
Intercept Survey ◽  
Test Retest Reliability

Purpose:This study assessed test-retest reliability of an interviewer-administered trail survey.Methods:An intercept survey was conducted with adults using 2 paved trails in Indiana and South Carolina (N = 295; mean age = 46.9 ± 18 y). The survey included items on frequency and duration of trail use for recreation and transportation, other patterns of trail use, and sociodemographic characteristics. Fifty-five adults completed the survey twice (2−16 d apart; mean = 7.4 ± 2.6 d). Test-retest reliability was assessed with Spearman rank correlation coefficients, Kappa coefficients, and percent agreement.Results:Kappa coefficients and percent agreement for 9 categorical items ranged from 0.65 to 0.96 and from 64.0% to 98.2%, respectively. Among these items, the lowest Kappas were found for perceived safety (0.65) and reported duration of visits for recreational purposes (0.67). Spearman rank correlation coefficients for travel distance to and on the trail and frequency of trail use during the past 7 days and past 4 weeks ranged from 0.62 to 0.93.Conclusion:Though further assessments of this survey with different populations and types of trails may be warranted, its overall high reliability indicates it can be used by researchers and practitioners in its current form.

scholarly journals The correlation between the distribution of tourism assets and the location of tourist accommodation in Łódź Province

Turyzm ◽  
2018 ◽  
Vol 28 (2) ◽  
pp. 73-84
Author(s):  
Sylwia Żakowska ◽  
Katarzyna Podhorodecka
Keyword(s):  
Final Stage ◽  
Statistical Data ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Spearman Rank Correlation ◽  
Spearman Rank ◽  
Research Results ◽  
Tourist Accommodation ◽  
The Relationship

This article presents the correlation between natural and non-natural tourism assets and the distribution of tourist accommodation in the 24 powiats (districts) of Łódź Province. The authors, having divided these assets into natural and non-natural, discusses their occurrence in individual powiats. Next, tourist accommodation in Łódź Province is described, along with a presentation of statistical data. An important part of the paper is the presentation of the research results obtained by means of the point bonitation method. At the final stage, Spearman rank correlation coefficients is calculated, showing the strength of the relationship between selected tourism assets and the distribution of tourist accommodation.

Identification of Potential Surrogate Endpoints in Randomized Clinical Trials of Aggressive Non-Hodgkin Lymphoma: Correlation of Complete Response, Time-to-Event and Overall Survival Data.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3699-3699
Author(s):  
Linda M. Lee ◽  
Lisa Wang ◽  
Michael Crump
Keyword(s):  
Cell Lymphoma ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Surrogate Endpoints ◽  
Controlled Trials ◽  
Spearman Rank Correlation ◽  
Free Survival ◽  
Spearman Rank ◽  
Aggressive Histology ◽  
Spearman Rank Correlation Coefficient

Abstract Abstract 3699 Poster Board III-635 Background Aggressive histology non-Hodgkin lymphomas (NHLs) are generally treated with curative intent. Establishing appropriate surrogate endpoints for overall survival (OS) may permit more rapid evaluation and approval of new agents for aggressive NHL. Treatment failure endpoints including event-free survival (EFS) or progression-free survival (PFS) permit earlier reporting of results, but their ability to predict OS is unknown. The purpose of this study is to correlate different efficacy endpoints with the goal of identifying an appropriate surrogate endpoint for OS. Methods Randomized controlled trials (RCTs) of previously untreated aggressive histology NHL published between 1990-2009 were identified through a systematic literature search using MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials databases. Eligible RCTs included at least 2-arms comparing different systemic treatments with ≥100 patients/arm. Studies investigating the effect of autologous stem-cell transplant and those exclusively involving T-cell lymphoma, mantle cell lymphoma or HIV-associated lymphoma were excluded. Baseline characteristics, design, treatment arms, efficacy endpoints, and results were extracted from each published RCT. Reported survival endpoints were defined as PFS, EFS, or OS according to established (ie: per protocol) definitions in the International Working Group Revised Response Criteria for Lymphoma. Absolute differences in efficacy endpoints were determined and nonparametric Spearman rank correlation coefficients were calculated to determine the association between differences in: 1) CR and each of EFS, PFS and OS and 2) EFS or PFS and OS. Results Thirty-eight RCTs were identified representing 85 treatment arms and 16,103 patients. The median follow up was 55 months (range 20-108). The most commonly used primary endpoint was OS (55%) followed by EFS (32%), but use of CR as a primary endpoint was infrequent (5%). Differences in CR strongly correlated with differences in 3-yr EFS with a Spearman rank correlation coefficient of 0.88 (95% CI: 0.57 to 0.97). The Spearman rank correlation coefficients between differences in CR and differences in 3-yr PFS and 5-yr OS were 0.62 (95% CI: 0.21 to 0.84) and 0.50 (95% CI, 0.23 to 0.74), respectively. Differences in intermediate endpoints, 3-yr PFS or EFS, were high correlated with differences in 5 yr OS with a Spearman rank correlation coefficient of 0.90 (95%CI, 0.73-0.96). Similarly strong correlations were noted when 3-yr PFS and 3-yr EFS were each correlated with 5-yr OS separately. Linear regression determined that a 10% improvement in CR is estimated to correspond with a 9±1% improvement in 3-yr EFS and that a 10% improvement in 3-yr EFS or PFS would predict for a 7±1% improvement in 5-yr OS. Conclusions In RCTs of initial treatment for aggressive NHL, improvements in 3-yr EFS/PFS are highly correlated with improvements in 5-yr OS. Changes in CR rates are a strong predictor for changes in 3-yr EFS, but not for changes in 5-yr OS. This may inform future trial design since EFS or PFS appear to be appropriate surrogate endpoints for OS in this patient population. Disclosures: No relevant conflicts of interest to declare.

About the improving the technique of timber products quality assessment

2017 ◽  
Vol 6 (4) ◽  
pp. 173-178
Author(s):  
Задраускайте ◽  
Natalya Zadrauskayte ◽  
Гузенко ◽  
Natal'ya Guzenko
Keyword(s):  
Data Processing ◽  
Quality Assessment ◽  
Cross Section ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Current Approach ◽  
Research Data ◽  
Spearman Rank Correlation ◽  
Spearman Rank ◽  
Timber Products

In the study 100 boards of each cross-section have been measured with their subsequent certification and calculating the Spearman rank correlation coefficients on the principle “each with each”. Further data processing showed the existence of interdependencies between the location of defects on various sides of the timber cross-section. As a result of the research, data has been obtained allowing to change the current approach to sorting timber and to base normalization and quality assessment not on all four sides of timber, as being currently sorted, but only on one face and one edge.

scholarly journals Effect of Spectral CT on Tumor Microvascular Angiogenesis in Renal Cell Carcinoma

2021 ◽  
Author(s):  
Bei Zhang ◽  
Qiong Wu ◽  
Xiang Qiu ◽  
Xiaobo Ding ◽  
Jin Wang ◽  
...  
Keyword(s):  
Renal Cell Carcinoma ◽  
Cell Carcinoma ◽  
Tumor Angiogenesis ◽  
Renal Cell ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Spectral Ct ◽  
Spearman Rank Correlation ◽  
Spearman Rank ◽  
The Mean

Abstract Background: To examine the value of spectral CT quantitative parameters in renal cell carcinoma (RCC) microvascular angiogenesis.Methods: The authors evaluated 32 patients with pathologically confirmed RCC who underwent triple-phase contrast-enhanced CT with spectral CT imaging mode from January 2017 to December 2019. Quantitative parameters including the parameters derived from iodine concentration (IC) and water concentration (WC) of 120 keV monochromatic images. The microvascular density (MVD), microvascular area (MVA) and etc. al. of specimens were evaluated. The correlation between IC and WC (including average values and random values) with microvascular parameters were analyzed using Pearson or Spearman rank correlation coefficients.Results: The MVD of all tumors was 26.00 (15.00-43.75) vessels per field at ×400 magnification. The MVD of RCC correlated positively with the mean IC, mean WC, mean NWC, mean NIC, random IC, random NIC in renal cortical phase, WCD1, WCD2, NWCD2 and ICD1 (Spearman rank correlation coefficients, r range, 0.362–0.533; all p < 0.05). The MVA of all tumors was (16.16±8.98) % per field at ×400 magnification. The MVA of RCC correlated positively with the mean IC, mean WC, mean NWC, mean NIC, random IC, random NIC in renal cortical, mean WC and mean NWC in renal parenchymal phase, WCD1, WCD2, WCD3, NWCD2, and NWCD3 (Pearson or Spearman rank correlation coefficients, r range, 0.357–0.576; all p < 0.05). Microvascular grading correlated positively with the mean NWC, mean NIC and random NIC in renal cortical phase, mean NWC in renal parenchymal phase, NWCD2, WCD3, NWCD3, NICD2 and NICD3 (Spearman rank correlation coefficients, r range, 0.367–0.520; all p < 0.05). As for tumor diameter (55.19±19.15), μm, only NWCD3 was associated with it (Spearman rank correlation coefficients, r = 0.388; p < 0.05). Conclusions: IC and WC indexes derived from spectral CT, especially the renal cortical phase, difference between renal cortical phase and parenchymal phase were useful indicators for evaluating tumor angiogenesis. Moreover, the difference of the derived parameters of WC in different phases has stronger correlation with tumor angiogenesis than that of IC.

scholarly journals Cross-validation and robustness of daylight glare metrics

2019 ◽  
Vol 51 (7) ◽  
pp. 983-1013 ◽  
Author(s):  
J Wienold ◽  
T Iwata ◽  
M Sarey Khanie ◽  
E Erell ◽  
E Kaftan ◽  
...  
Keyword(s):  
Statistical Tests ◽  
Characteristic Curve ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
The United States ◽  
Future Research ◽  
Spearman Rank Correlation ◽  
Spearman Rank ◽  
Main Input ◽  
Saturation Effects

This study evaluates the performance and robustness of 22 established and newly proposed glare prediction metrics. Experimental datasets of daylight-dominated workplaces in office-like test rooms were collected from studies by seven research groups in six different locations (Argentina, Denmark, Germany, Israel, Japan and the United States). The variability in experimental setups, locations and research teams allowed reliable evaluation of the performance and robustness of glare metrics for daylight-dominated workplaces. Independent statistical methods were applied to individual datasets and also to one combined dataset to evaluate the performance and robustness of the 22 glare metrics. As performance and robustness are not established in literature, we defined performance as: (1) the ability of the metric value to describe the glare scale (evaluated by Spearman rank correlation), and (2) the ability of the metric to distinguish between disturbing and non-disturbing situations (evaluated by diagnostic receiver operating characteristic curve analysis tests). Furthermore, we defined robustness as the ability of a metric to deliver meaningful results when applied to different datasets and to fail as few as possible statistical tests. Average Spearman rank correlation coefficients in the range of 0.55–0.60 as well as average prediction rates to distinguish between disturbing and non-disturbing glare of 70–75% for several of the metrics indicate their reliability. The results also show that metrics considering the saturation effect as a main input in their equation perform better and are more robust in daylight-dominated workplaces than purely contrast-based metrics or purely empirical metrics. In this study, the daylight glare probability (DGP) delivered the highest performance amongst the tested metrics and was also found to be the most robust. Future research should aim to optimise the terms of glare equations which combine contrast and saturation effects, such as DGP, PGSV or UGRexp, to achieve metrics that also perform reliably in dimmer lighting conditions than the ones explored in this study.

scholarly journals Cerebral State Index during Propofol Anesthesia

2006 ◽  
Vol 105 (1) ◽  
pp. 28-36 ◽  
Author(s):  
Erik W. Jensen ◽  
Hector Litvan ◽  
Miren Revuelta ◽  
Bernardo E. Rodriguez ◽  
Pere Caminal ◽  
...  
Keyword(s):  
Bispectral Index ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Sedation Score ◽  
Spearman Rank Correlation ◽  
Spearman Rank ◽  
Effect Site ◽  
Prediction Probability ◽  
Effect Site Concentration ◽  
State Index

Background The objective of this study was to prospectively test the Cerebral State Index designed for measuring the depth of anesthesia. The Cerebral State Index is calculated using a fuzzy logic combination of four subparameters of the electroencephalographic signal. The performance of the Cerebral State Index was compared with that of the Bispectral Index and the A-Line ARX Index. Methods This study applied raw data from two previously published clinical protocols. The patients in protocol 1 were given a continuous propofol infusion, 300 ml/h, until 80% of burst suppression occurred. In protocol 2, a stepwise increased target-controlled infusion of propofol was administered to patients until loss of response to noxious stimuli while the Observer's Assessment of Alertness and Sedation was registered every 4 min. The Cerebral State Index was calculated off-line from the recorded electroencephalographic data. The Spearman rank correlation coefficient between electronic indices and the effect site concentration of propofol was calculated along with the prediction probability of each index to predict the Observer's Assessment of Alertness and Sedation level. Results The Spearman rank correlation coefficients between the Cerebral State Index, Bispectral Index, and A-Line ARX Index and the propofol effect site concentration were -0.94, -0.89, and -0.82, respectively, in protocol 1, whereas the prediction probability values between the Cerebral State Index, Bispectral Index, and A-Line ARX Index and the Observer's Assessment of Alertness and Sedation score in protocol 2 were 0.92, 0.93, and 0.91, respectively. Conclusion The Cerebral State Index detects well the graduated levels of propofol anesthesia when compared with the propofol effect site concentration and the Observer's Assessment of Alertness and Sedation score.

Sign in / Sign up

Export Citation Format

Share Document