Correlation coefficients: the Pearson correlation and Spearman’s rho

2015 ◽  
Vol 27 (2) ◽  
pp. 268-276 ◽  
Author(s):  
Bart C. Bongers ◽  
Maarten S. Werkman ◽  
Donna Blokland ◽  
Maria J.C. Eijsermans ◽  
Patrick van der Torre ◽  
...  

Purpose:To determine criterion validity of the pediatric running-based anaerobic sprint test (RAST) as a nonsophisticated field test for evaluating anaerobic performance in healthy children and adolescents.Methods:Data from 65 healthy children (28 boys and 37 girls between 6 and 18 years of age, mean ± SD age: 10.0 ± 2.8 years) who completed both the pediatric RAST and the 30-s Wingate anaerobic test (WAnT) on a cycle ergometer in a randomized order were analyzed. Peak power (PP) and mean power (MP) were the primary outcome measures for both tests.Results:There were no significant sex-differences in PP and MP attained at the pediatric RAST and the WAnT. Age was strongly correlated to pediatric RAST and WAnT performance (Spearman’s rho values ranging from 0.85 to 0.90, with p < .001 for all coefficients). We found high correlation coefficients between pediatric RAST performance and WAnT performance for both PP (Spearman’s rho: 0.86; p < .001) and MP (Spearman’s rho: 0.91; p < .001).Conclusion:The pediatric RAST can be used as a valid and nonsophisticated field test for the assessment of anaerobic performance in healthy children and adolescents. For clinical evaluative purposes, we suggest to use MP of the pediatric RAST when assessing glycolytic power in the absence of the WAnT.


2018 ◽  
Vol 6 (3) ◽  
pp. 383
Author(s):  
Meytika Fauziah Sugiartanti ◽  
Duriyanto Oesman ◽  
Ulfa Elfiah

Wound healing need protein as basis for the formation of collagen network. The important component of protein is albumin. The aim of this study was to investigate albumin serum’s effect on wound healing in patients postoperative laparotomy and lumbotomy at dr. Soebandi Hospital Jember. The method of study was analytic observational with cross sectional design. Total samples in this study were 9 samples. The results showed that the higher albumis, the faster wound healing. Data analysis using bivariate analyzing Spearman's Rho test showed that the significance (p)=0.011 and correlation coefficients (r)=0.791. Thus, it can be concluded that there were a strong albumin serum’s effect of wound healing in patients postoperative laparotomy and lumbotomy at RSD dr. Soebandi Jember.  


2020 ◽  
Vol 29 (3) ◽  
pp. 429-435
Author(s):  
Patricia C. Mancini ◽  
Richard S. Tyler ◽  
Hyung Jin Jun ◽  
Tang-Chuan Wang ◽  
Helena Ji ◽  
...  

Purpose The minimum masking level (MML) is the minimum intensity of a stimulus required to just totally mask the tinnitus. Treatments aimed at reducing the tinnitus itself should attempt to measure the magnitude of the tinnitus. The objective of this study was to evaluate the reliability of the MML. Method Sample consisted of 59 tinnitus patients who reported stable tinnitus. We obtained MML measures on two visits, separated by about 2–3 weeks. We used two noise types: speech-shaped noise and high-frequency emphasis noise. We also investigated the relationship between the MML and tinnitus loudness estimates and the Tinnitus Handicap Questionnaire (THQ). Results There were differences across the different noise types. The within-session standard deviation averaged across subjects varied between 1.3 and 1.8 dB. Across the two sessions, the Pearson correlation coefficients, range was r = .84. There was a weak relationship between the dB SL MML and loudness, and between the MML and the THQ. A moderate correlation ( r = .44) was found between the THQ and loudness estimates. Conclusions We conclude that the dB SL MML can be a reliable estimate of tinnitus magnitude, with expected standard deviations in trained subjects of about 1.5 dB. It appears that the dB SL MML and loudness estimates are not closely related.


2020 ◽  
Vol 4 (1) ◽  
pp. 51-63
Author(s):  
Peter Neuhaus ◽  
Chris Jumonville ◽  
Rachel A. Perry ◽  
Roman Edwards ◽  
Jake L. Martin ◽  
...  

AbstractTo assess the comparative similarity of squat data collected as they wore a robotic exoskeleton, female athletes (n=14) did two exercise bouts spaced 14 days apart. Data from their exoskeleton workout was compared to a session they did with free weights. Each squat workout entailed a four-set, four-repetition paradigm with 60-second rest periods. Sets for each workout involved progressively heavier (22.5, 34, 45.5, 57 kg) loads. The same physiological, perceptual, and exercise performance dependent variables were measured and collected from both workouts. Per dependent variable, Pearson correlation coefficients, t-tests, and Cohen's d effect size compared the degree of similarity between values obtained from the exoskeleton and free weight workouts. Results show peak O2, heart rate, and peak force data produced the least variability. In contrast, far more inter-workout variability was noted for peak velocity, peak power, and electromyography (EMG) values. Overall, an insufficient amount of comparative similarity exists for data collected from both workouts. Due to the limited data similarity, the exoskeleton does not exhibit an acceptable degree of validity. Likely the cause for the limited similarity was due to the brief amount of familiarization subjects had to the exoskeleton prior to actual data collection. A familiarization session that accustomed subjects to squats done with the exoskeleton prior to actual data collection may have considerably improved the validity of data obtained from that device.


Author(s):  
Jan Christoff Visagie ◽  
Michael M. Jones ◽  
Herman L. Linde

The South African workplace is confronted with many leadership challenges, specifically those relating to the employment relationship between subordinates and their supervisors. A high-quality relationship is essential, considering the work-family spillovers employees experience. Limited research has been conducted on the potential positive and negative consequences of the leader-member exchange (LMX) dyadic relationship. In this study, we used a cross-sectional research design, and drew an employee sample (N = 120) from a commuter transport engineering company. A five-point Likert scale was employed and statistical analyses were carried out using the SAS statistical program. We calculated Pearson correlation coefficients and used structural equation modelling to test the proposed conceptual model to indicate possible correlations between the different variables. The main finding of the study was that the nature of the LMX relationship quality in the relevant company appeared to be high and positively related to work-home enrichment but negatively related to work-home conflict and role overload. The article concludes by making a number of suggestions to respond to challenges.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 525.1-525
Author(s):  
S. Tsiami ◽  
E. Ntasiou ◽  
C. Krogias ◽  
R. Gold ◽  
J. Braun ◽  
...  

Background:Carpal tunnel syndrome (CTS) is the most common nerve compression syndrome and a common extra-articular manifestation of rheumatoid arthritis (RA). Different causes of CTS are known, among them inflammatory and non-inflammatory pathologies. Electroneurography (ENG) of the median nerve, the method of choice to diagnose CTS, measures impairment of nerve conduction velocity without explaining its underlying cause. However, because the electrical stimulation is often not well tolerated, ENG results may come out inconclusive. Using greyscale ultrasonography (GS-US) provides anatomic information including a structural representation of the carpal tunnel.Objectives:To investigate the performance of nerve GS-US in the diagnosis of CTS in patients with RA.Methods:Consecutive patients with active RA under suspicion of CTS presenting to a large rheumatologic center were included. Both hands were examined by an experienced neurologist including ENG and a GS-US (ML linear probe with 6-15 Hz) of the median nerve. An established grading system for ENG (1), and an established system for GS-US based on cut-offs for the nerve cross sectional area (CSA) [mild: 0,11-0,13cm2, moderate: 0,14-0,15 cm2, severe: > 0,15 cm2 CTS (2)] were used. In addition, the Boston Carpal Tunnel Syndrome Questionnaire (BCTSQ) was used to assess CTS symptoms (3).Results:Both hands of 58 patients with active RA (n=116) and clinical suspicion of CTS (in 38 cases bilaterally) were included. After clinical examination, CTS was suspicious in 96 hands (82.8%), and 59 of all hands had a final diagnosis of CTS (50.9%). Of the latter, 43 hands (72.9%) had a positive ENG and 16 (27.1%) a positive GS-US finding only, while 30 hands (50.8%) were positive in both examinations.There was a good correlation of the cross-sectional area (CSA) as well as the CSA-ratio to the ENG findings: the larger the CSA, the more severe was the CTS as assessed by ENG (Spearman’s rho=0.554; p<0.001). The more severe the GS-US findings of CTS were, the more definite were the distal motor latency (Spearman’s rho=0.554; p<0.001) and sensible nerve conduction velocity of the median nerve (Spearman’s rho=-0.5411; p<0.001).In the 46 hands positive in GS-US, tenosynovial hypertrophy of the flexor tendons was detected in 19 hands (41.3%), 7 of which (36.8%) also showed an additional cystic mass. In these 19 patients, clinical complains were more severely present than in patients with non-inflammatory CTS, as assessed by the BCTSQ with a total score of 68.8±13.4 vs. 59.3±13.7, respectively (p=0.007).Conclusion:In patients with active RA and clinical complains of CTS, ultrasound examinations provide additional information about inflammation which is helpful for a diagnosis of CTS. Thus, ENG and nerve GS-US should be used complementary for a diagnostic workup of CTS in RA patients with a suspicion of CTS. Power-Doppler may further improve the diagnostic performance of GS-US.References:[1]Padua L et al. Acta Neurol Scand 1997; 96:211–217[2]El Miedany et al., Rheumatology (Oxford). 2004 Jul; 43(7):887-895[3]Levine DW et al. J Bone Joint Surg Am 1993; 75: 1585-1592Figure 1.BCTSQ scores in patients with diagnosis of CTS and absence or presence of RA-related tenosynovial hypertrophyDisclosure of Interests:None declared


2021 ◽  
pp. 1-16
Author(s):  
Ibtissem Gasmi ◽  
Mohamed Walid Azizi ◽  
Hassina Seridi-Bouchelaghem ◽  
Nabiha Azizi ◽  
Samir Brahim Belhaouari

Context-Aware Recommender System (CARS) suggests more relevant services by adapting them to the user’s specific context situation. Nevertheless, the use of many contextual factors can increase data sparsity while few context parameters fail to introduce the contextual effects in recommendations. Moreover, several CARSs are based on similarity algorithms, such as cosine and Pearson correlation coefficients. These methods are not very effective in the sparse datasets. This paper presents a context-aware model to integrate contextual factors into prediction process when there are insufficient co-rated items. The proposed algorithm uses Latent Dirichlet Allocation (LDA) to learn the latent interests of users from the textual descriptions of items. Then, it integrates both the explicit contextual factors and their degree of importance in the prediction process by introducing a weighting function. Indeed, the PSO algorithm is employed to learn and optimize weights of these features. The results on the Movielens 1 M dataset show that the proposed model can achieve an F-measure of 45.51% with precision as 68.64%. Furthermore, the enhancement in MAE and RMSE can respectively reach 41.63% and 39.69% compared with the state-of-the-art techniques.


Author(s):  
Qiaoyong Liu ◽  
Yiqian Jiang ◽  
Lijun Shen ◽  
Jiming Zhu

AbstractObjectiveTo investigate the thyroid volume (Tvol) and to explore factors that affects it among 12 to 15-year-olds attending a rural middle school in east Hangzhou, China.MethodsA cross-sectional survey of middle school students attending a rural middle school in east Hangzhou, China was conducted. Height, weight and other physical development related indicators in middle school students were measured. The thyroid size was measured using ultrasound, and the thyroid volume calculated.ResultsThe median (P25, P75) of the thyroid volume in 596 middle school students from a rural middle school in east Hangzhou, China was 6.69 (5.66, 7.98) mL. Our study enrolled 305 male students (51.2%) and 291 female students (48.8%). The height, weight and thyroid volume of middle school students increased with age. Univariate analysis revealed that height, weight, body mass index (BMI) and body surface area (BSA) were positive correlated with thyroid volume (p<0.01).The correlation between BSA and thyroid volume was significant (Spearman’s rho=0.473, p<0.01). Multiple linear regression analysis revealed that BSA was positive and significantly correlated with the thyroid volume (p<0.05). Regression equation was Y=−2.532 + 6.186×BSA.ConclusionThe thyroid volume is not only affected by age, but it is also affected by growth and development. Goiter cannot only be assessed based on age, gender and thyroid volume. However, this study established that BSA not only presented the strongest correlation with thyroid volume (Spearman’s rho=0.473), but also had a strong correlation with physical development, taking into account the growth and development of middle school students, and showed greater stability. Therefore, we recommend inclusion of BSA as a reference standard in the measurement of the thyroid volume.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Zhe Li ◽  
Guanzhi Liu ◽  
Run Tian ◽  
Ning Kong ◽  
Yue Li ◽  
...  

Abstract Background Our objective was to obtain normal patellofemoral measurements to analyse sex and individual differences. In addition, the absolute values and indices of tibial tuberosity-trochlear groove (TT-TG) distances are still controversial in clinical application. A better method to enable precise prediction is still needed. Methods Seventy-eight knees of 78 participants without knee pathologies were included in this cross-sectional study. A CT scan was conducted for all participants and three-dimensional knee models were constructed using Mimics and SolidWorks software. We measured and analysed 19 parameters including the TT-TG distance and dimensions and shapes of the patella, femur, tibia, and trochlea. LASSO regression was used to predict the normal TT-TG distances. Results The dimensional parameters, TT-TG distance, and femoral aspect ratio of the men were significantly larger than those of women (all p values < 0.05). However, after controlling for the bias from age, height, and weight, there were no significant differences in TT-TG distances and anterior-posterior dimensions between the sexes (all p values > 0.05). The Pearson correlation coefficients between the anterior femoral offset and other indexes were consistently below 0.3, indicating no relationship or a weak relationship. Similar results were observed for the sulcus angle and the Wiberg index. Using LASSO regression, we obtained four parameters to predict the TT-TG distance (R2 = 0.5612, p < 0.01) to achieve the optimal accuracy and convenience. Conclusions Normative data of patellofemoral morphology were provided for the Chinese population. The anterior-posterior dimensions of the women were thicker than those of men for the same medial-lateral dimensions. More attention should be paid to not only sex differences but also individual differences, especially the anterior condyle and trochlea. In addition, this study provided a new method to predict TT-TG distances accurately.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 992.1-992
Author(s):  
C. Rogier ◽  
B. Van Dijk ◽  
E. Brouwer ◽  
P. De Jong ◽  
A. Van der Helm - van Mil

Background:Early diagnosis and management of patients with inflammatory arthritis(IA) are critical to improve long-term patient-outcomes. Assessment of joint swelling at joint examination is the reference of IA-identification; early access clinics are constructed to promote this early recognition of IA. However, due to the COVID-19 pandemic the face-to-face capacity of such services is severely reduced. The accuracy of patient-reported swelling in comparison to joint examination has been extensively evaluated in established RA (ρ 0.31-0.67), but not in patients suspected for IA.[1]Objectives:To promote evidence based care in the era of telemedicine, we determined the accuracy of patient-reported joint swelling for actual presence of IA in persons suspected of IA by general practitioners(GP).Methods:Data from two Dutch Early Arthritis Recognition Clinics were studied. These are screening clinics (1.5-lines-setting) where GPs send patients in case of doubt on IA. At this clinic patients were asked to mark the presence of swollen joints on a mannequin with 52 joints. For this study the DIP joints and the metatarsal joints were excluded and, therefore, a total of 42 joints were assessed for self-reported joint swelling. Clinically apparent IA of ≥1 joint determined by the physician was the reference to calculate sensitivity, specificity, positive and negative likelihood ratios (LR+,LR-), and positive and negative predictive values (PPV, NPV) on patient-level. Pearson correlation coefficients(ρ) were determined. Predictive values depend on the prevalence of a disease in a population. Because the prevalence of IA in a 1.5-lines-setting will differ from a primary care setting, post-test probabilities of IA were estimated for two lower prior-test probabilities as example, namely 20% (estimated probability in patients GPs belief IA is likely) and 2% (prior-test probability with less preselection by GPs), using likelihood ratios and nomograms.Results:A total of 1637 consecutive patients were studied. Median symptom duration was 13 weeks. 76% of patients marked ≥1swollen joint at the mannequin. 41% of patients had ≥1swollen joint at examination by rheumatologists. ρ was 0.20(patient-level)-0.26(joint-level).The sensitivity of patients-reported joint swelling was high, 87%, indicating that the majority of patients with IA had marked swelling on the mannequin. However the specificity was 31%, indicating that 69% of persons without IA had also done so. The LR+ was 1.25; the LR- 0.43. The PPV was 46%, the NPV 77%. Thus the PPV increased hardly (from 41% to 46%) and the NPV somewhat (from 59% to 77%). Also in settings with prior-test probabilities of 20% and 2%, estimated PPVs (from respectively 20% and 2% to 24% and 2%) and NPVs (from respectively 80% and 98% to 90% and 99%) hardly increased.Conclusion:Patient-reported joint swelling had little value in distinguishing patients with/without IA for different prior-test probabilities, and is less valuable in comparison to self-reported flare detection in established RA.References:[1]Barton JL, Criswell LA, Kaiser R, et al. Systematic review and metaanalysis of patient self-report versus trained assessor joint counts in rheumatoid arthritis. J Rheumatol 2009;36:2635-2641.Disclosure of Interests:None declared


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