scholarly journals Cylinder axis agreement: unexpected scenarios

2019 ◽  
Author(s):  
Karim Mahmoud Nabil
Keyword(s):  
Correlation Coefficient ◽  
Refractive Surgery ◽  
Pearson Correlation ◽  
Pearson Correlation Coefficient ◽  
Cylinder Axis ◽  
Intra Class Correlation ◽  
Manifest Refraction ◽  
Laser Refractive Surgery ◽  
Intra Class Correlation Coefficient

Abstract Background The purpose of this retrospective study was to evaluate cylinder axis agreement between manifest refraction (MR), cycloplegic refraction (CR), Allegro Oculyzer ІІ and Allegro Topolyzer-Vario. Methods We included 82 patients (32 males and 50 females, 28.1 ± 8.7 years old), with 156 eyes scheduled for wavefront optimized laser refractive surgery, photorefractive keratectomy (PRK) in 50 eyes and laser- assisted in situ keratomileusis (LASIK) in 106 eyes, for correction of simple, myopic, hyperopic or mixed astigmatism. Cylinder axis was determined under manifest and cycloplegic refractions and using Allegro Occulyzer ІІ and Allegro Topolyzer-Vario platforms. Cylinder axis agreement was assessed by Intra class Correlation coefficient, Pearson Correlation coefficient and by the method described by Bland and Altman. Results Intra class Correlation Coefficient and Pearson Correlation Coefficient showed statistically significant cylinder axis agreement between manifest refraction, cycloplegic refraction, Allegro Oculyzer ІІ and Allegro Topolyzer-Vario (p <0.001*). Despite statistically significant cylinder axis agreement between the four measuring tools, 4 of 156 eyes (2.5%) showed unexpected discrepancy between Allegro Oculyzer ІІ and Allegro Topolyzer-Vario cylinder axis. Conclusions Although cylinder axis shows statistically significant agreement between manifest refraction, cycloplegic refraction, Allegro Oculyzer ІІ and Allegro Topolyzer-Vario, unexpected discrepancies occur.

scholarly journals The smartphone as a tool to screen for scoliosis, applicable by everyone

2021 ◽  
Author(s):  
H. M. van West ◽  
J. Herfkens ◽  
J. P. H. J. Rutges ◽  
M. Reijman
Keyword(s):  
Correlation Coefficient ◽  
Pearson Correlation ◽  
Research Question ◽  
Bending Test ◽  
Trunk Rotation ◽  
Intra Class Correlation ◽  
Orthopedic Surgeon ◽  
Accuracy And Precision ◽  
Forward Bending ◽  
Intra Class Correlation Coefficient

Abstract Purpose (main purposes and research question) The purpose of this study is to assess the accuracy and precision of the smartphone with application and casing (Scolioscreen) compared to the Scoliometer. Methods The Axial Trunk Rotation (ATR) was measured in adolescent scoliosis patients visiting the outpatient clinic while performing the Adam Forward Bending Test. The Scolioscreen measurements were performed by the orthopedic surgeon and a parent. They were compared to the measurement with the Scoliometer by the orthopedic surgeon, the gold standard. The accuracy was determined with the Pearson’s correlation coefficient, and precision was determined by assessing the intra- and inter-variability with the intra-class correlation coefficient (ICC). Results Fifty patients with adolescent idiopathic scoliosis (44 girls) were included with a mean age of 14.1 years and a mean Cobb angle of 38.5°. The accuracy of both the parents and orthopedic surgeon was excellent with a Pearson correlation coefficient of 0.92 and 0.97, respectively. All the ICC’s, both intra- and inter-observer, were over 0.92 demonstrating excellent precision. Conclusion This study confirms the accuracy and precision of the Scolioscreen when measuring the ATR on patients with AIS. Therefore, the Scoliometer can be replaced by the more easily available Scolioscreen which can be used by both physician and parents.

scholarly journals Psychometric Properties of the Persian Version of the 6-item De Jong Gierveld Loneliness Scale in Iranian Community-dwelling Older Persons

Salmand ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 338-349
Author(s):  
Reza Hosseinabadi ◽  
◽  
Mahshid Foroughan ◽  
Gholam Reza Ghaed Amini Harouni ◽  
Razieh Zeidali Beiranvand ◽  
...  
Keyword(s):  
Factor Analysis ◽  
Correlation Coefficient ◽  
Pearson Correlation ◽  
Depression Scale ◽  
Community Dwelling ◽  
Intra Class Correlation ◽  
Cronbach Alpha ◽  
Persian Version ◽  
Loneliness Scale ◽  
Intra Class Correlation Coefficient

Objectives: Loneliness is a significant concern among the elderly and requires measurement and intervention. This study was conducted to translate and make a psychometric evaluation of the 6-item de Jong Gierveld loneliness scale in Iranian older people. Methods & Materials: This is a descriptive study carried out in 2018. After receiving permission from the tool designer, the original version of the 6-item de Jong Gierveld loneliness scale was translated into Persian by the translation and translation-back method. Then its face and content validities were determined. The final Persian version was completed by 224 eligible elderly residents in Khorramabad City, Iran. The data were analyzed using Confirmatory Factor Analysis (CFA), the Pearson correlation coefficient, the Intra-class Correlation Coefficient (ICC), and the Cronbach alpha. The SPSS and AMOS were used, and the significance was determined at the level of P≤ 0.05. Results: The Persian version of the 6-item de Jong Gierveld Loneliness Scale had an acceptable content validity (CVI=0.874). Confirmative factor analysis indicated the extraction of two factors: emotional loneliness and social loneliness (CMIN/DF=1.48, GFI=0.983, IFI=0.983, RMSEA=0.004). The overall loneliness score showed a significant correlation with the hospital anxiety and depression scale. The reliability of the scale was accepted by the intra-class correlation coefficient and the Cronbach alpha coefficient. Conclusion: The Persian version of the 6-item de Jong Gierveld loneliness scale is a reliable and valid measure of loneliness in Iranian elders.

Relationship between Invasive and Non-Invasive Hemodynamic Measures in Experimental Pulmonary Hypertension

2020 ◽  
Vol 16 (1) ◽  
pp. 47-53
Author(s):  
Vicente Benavides-Córdoba ◽  
Mauricio Palacios Gómez
Keyword(s):  
Heart Rate ◽  
Pulmonary Hypertension ◽  
Ejection Fraction ◽  
Right Ventricle ◽  
Correlation Coefficient ◽  
Pearson Correlation ◽  
Systolic Pressure ◽  
Control Group ◽  
Pearson Correlation Coefficient ◽  
Non Invasive

Introduction: Animal models have been used to understand the pathophysiology of pulmonary hypertension, to describe the mechanisms of action and to evaluate promising active ingredients. The monocrotaline-induced pulmonary hypertension model is the most used animal model. In this model, invasive and non-invasive hemodynamic variables that resemble human measurements have been used. Aim: To define if non-invasive variables can predict hemodynamic measures in the monocrotaline-induced pulmonary hypertension model. Materials and Methods: Twenty 6-week old male Wistar rats weighing between 250-300g from the bioterium of the Universidad del Valle (Cali - Colombia) were used in order to establish that the relationships between invasive and non-invasive variables are sustained in different conditions (healthy, hypertrophy and treated). The animals were organized into three groups, a control group who was given 0.9% saline solution subcutaneously (sc), a group with pulmonary hypertension induced with a single subcutaneous dose of Monocrotaline 30 mg/kg, and a group with pulmonary hypertension with 30 mg/kg of monocrotaline treated with Sildenafil. Right ventricle ejection fraction, heart rate, right ventricle systolic pressure and the extent of hypertrophy were measured. The functional relation between any two variables was evaluated by the Pearson correlation coefficient. Results: It was found that all correlations were statistically significant (p <0.01). The strongest correlation was the inverse one between the RVEF and the Fulton index (r = -0.82). The Fulton index also had a strong correlation with the RVSP (r = 0.79). The Pearson correlation coefficient between the RVEF and the RVSP was -0.81, meaning that the higher the systolic pressure in the right ventricle, the lower the ejection fraction value. Heart rate was significantly correlated to the other three variables studied, although with relatively low correlation. Conclusion: The correlations obtained in this study indicate that the parameters evaluated in the research related to experimental pulmonary hypertension correlate adequately and that the measurements that are currently made are adequate and consistent with each other, that is, they have good predictive capacity.

Comparison of Mammography and Ultrasonography for Tumor Size of DCIS of Breast Cancer

2019 ◽  
Vol 15 (2) ◽  
pp. 209-213
Author(s):  
Yu Wang ◽  
Jiantao Wang ◽  
Haiping Wang ◽  
Xinyu Yang ◽  
Liming Chang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Correlation Coefficient ◽  
Tumor Size ◽  
Ductal Carcinoma ◽  
Pearson Correlation ◽  
Dense Breast ◽  
Pathological Examination ◽  
Negative Group ◽  
The Difference

Objective: Accurate assessment of breast tumor size preoperatively is important for the initial decision-making in surgical approach. Therefore, we aimed to compare efficacy of mammography and ultrasonography in ductal carcinoma in situ (DCIS) of breast cancer. Methods: Preoperative mammography and ultrasonography were performed on 104 women with DCIS of breast cancer. We compared the accuracy of each of the imaging modalities with pathological size by Pearson correlation. For each modality, it was considered concordant if the difference between imaging assessment and pathological measurement is less than 0.5cm. Results: At pathological examination tumor size ranged from 0.4cm to 7.2cm in largest diameter. For mammographically determined size versus pathological size, correlation coefficient of r was 0.786 and for ultrasonography it was 0.651. Grouped by breast composition, in almost entirely fatty and scattered areas of fibroglandular dense breast, correlation coefficient of r was 0.790 for mammography and 0.678 for ultrasonography; in heterogeneously dense and extremely dense breast, correlation coefficient of r was 0.770 for mammography and 0.548 for ultrasonography. In microcalcification positive group, coeffient of r was 0.772 for mammography and 0.570 for ultrasonography. In microcalcification negative group, coeffient of r was 0.806 for mammography and 0.783 for ultrasonography. Conclusion: Mammography was more accurate than ultrasonography in measuring the largest cancer diameter in DCIS of breast cancer. The correlation coefficient improved in the group of almost entirely fatty/ scattered areas of fibroglandular dense breast or in microcalcification negative group.

scholarly journals Bed-Based Ballistocardiography: Dataset and Ability to Track Cardiovascular Parameters

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 156
Author(s):  
Charles Carlson ◽  
Vanessa-Rose Turpin ◽  
Ahmad Suliman ◽  
Carl Ade ◽  
Steve Warren ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Stroke Volume ◽  
Systolic Blood Pressure ◽  
Correlation Coefficient ◽  
Pearson Correlation ◽  
Health Assessment ◽  
Initial Study ◽  
Pearson Correlation Coefficient ◽  
Medical Systems ◽  
Cardiovascular Parameters

Background: The goal of this work was to create a sharable dataset of heart-driven signals, including ballistocardiograms (BCGs) and time-aligned electrocardiograms (ECGs), photoplethysmograms (PPGs), and blood pressure waveforms. Methods: A custom, bed-based ballistocardiographic system is described in detail. Affiliated cardiopulmonary signals are acquired using a GE Datex CardioCap 5 patient monitor (which collects ECG and PPG data) and a Finapres Medical Systems Finometer PRO (which provides continuous reconstructed brachial artery pressure waveforms and derived cardiovascular parameters). Results: Data were collected from 40 participants, 4 of whom had been or were currently diagnosed with a heart condition at the time they enrolled in the study. An investigation revealed that features extracted from a BCG could be used to track changes in systolic blood pressure (Pearson correlation coefficient of 0.54 +/− 0.15), dP/dtmax (Pearson correlation coefficient of 0.51 +/− 0.18), and stroke volume (Pearson correlation coefficient of 0.54 +/− 0.17). Conclusion: A collection of synchronized, heart-driven signals, including BCGs, ECGs, PPGs, and blood pressure waveforms, was acquired and made publicly available. An initial study indicated that bed-based ballistocardiography can be used to track beat-to-beat changes in systolic blood pressure and stroke volume. Significance: To the best of the authors’ knowledge, no other database that includes time-aligned ECG, PPG, BCG, and continuous blood pressure data is available to the public. This dataset could be used by other researchers for algorithm testing and development in this fast-growing field of health assessment, without requiring these individuals to invest considerable time and resources into hardware development and data collection.

Development and Validation of an Instrument to Assess Horseback Mobility in Hippotherapy

2021 ◽  
pp. 003151252110365
Author(s):  
Alessandra V. Prieto ◽  
Kênnea Martins Almeida Ayupe ◽  
Ana C. A. Abreu ◽  
Paulo J. B. Gutierres Filho
Keyword(s):  
Correlation Coefficient ◽  
Factor Structure ◽  
Internal Consistency ◽  
Rater Reliability ◽  
Intra Class Correlation ◽  
Exploratory Factor Analyses ◽  
Excellent Internal Consistency ◽  
Development And Validation ◽  
Functional Gain ◽  
Intra Class Correlation Coefficient

Improvement in rider mobility represents an important functional gain for people with disabilities undergoing hippotherapy. However, there is no validated measuring instrument to track and document the rider's progress in riding activities. In this study, we aimed to develop and establish validity evidence for an instrument to assess hippotherapy participants’ mobility on horseback. We report on this development through the stages of: (a) content validation, (b) construct validation, (c) inter- and intra-rater reliability and (d) internal consistency analysis. We evaluated its factor structure with exploratory factor analyses, calculated values for inter- and intra-rater reliability using the intra-class correlation coefficient, and calculated its internal consistency using Cronbach's alpha. We followed recommendations by the Guidelines for Reporting Reliability and Agreement Studies. We found good inter-rater reliability (intra-class correlation coefficient – ICC = 0.991–0.999) and good intra-rater reliability (ICC = 0.997–1.0), and there was excellent internal consistency (Cronbach's α = 0.937–0.999). The instrument’s factor structure grouped its three domains into one factor. As this instrument is theoretically consistent and has been found to be appropriate and reliable for its intended use, it is now available for the measurement of horseback mobility among hippotherapy riders.

scholarly journals Assessment of the Dissimilarities of EDI and SPI Measures for Drought Determination in South Africa

Water ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 82
Author(s):  
Omolola M. Adisa ◽  
Muthoni Masinde ◽  
Joel O. Botai
Keyword(s):  
South Africa ◽  
South African ◽  
Correlation Coefficient ◽  
Pearson Correlation ◽  
Standardized Precipitation Index ◽  
Drought Monitoring ◽  
Drought Indices ◽  
Drought Severity ◽  
Pearson Correlation Coefficient ◽  
Drought Duration

This study examines the (dis)similarity of two commonly used indices Standardized Precipitation Index (SPI) computed over accumulation periods 1-month, 3-month, 6-month, and 12-month (hereafter SPI-1, SPI-3, SPI-6, and SPI-12, respectively) and Effective Drought Index (EDI). The analysis is based on two drought monitoring indicators (derived from SPI and EDI), namely, the Drought Duration (DD) and Drought Severity (DS) across the 93 South African Weather Service’s delineated rainfall districts over South Africa from 1980 to 2019. In the study, the Pearson correlation coefficient dissimilarity and periodogram dissimilarity estimates were used. The results indicate a positive correlation for the Pearson correlation coefficient dissimilarity and a positive value for periodogram of dissimilarity in both the DD and DS. With the Pearson correlation coefficient dissimilarity, the study demonstrates that the values of the SPI-1/EDI pair and the SPI-3/EDI pair exhibit the highest similar values for DD, while the SPI-6/EDI pair shows the highest similar values for DS. Moreover, dissimilarities are more obvious in SPI-12/EDI pair for DD and DS. When a periodogram of dissimilarity is used, the values of the SPI-1/EDI pair and SPI-6/EDI pair exhibit the highest similar values for DD, while SPI-1/EDI displayed the highest similar values for DS. Overall, the two measures show that the highest similarity is obtained in the SPI-1/EDI pair for DS. The results obtainable in this study contribute towards an in-depth knowledge of deviation between the EDI and SPI values for South Africa, depicting that these two drought indices values are replaceable in some rainfall districts of South Africa for drought monitoring and prediction, and this is a step towards the selection of the appropriate drought indices.

Use of Multiple Visits to Increase Blood Pressure Tracking Correlations in Childhood

PEDIATRICS ◽  
1991 ◽  
Vol 87 (5) ◽  
pp. 708-711
Author(s):  
Matthew W. Gillman ◽  
Bernard Rosner ◽  
Denis A. Evans ◽  
Laurel A. Smith ◽  
James O. Taylor ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Diastolic Blood Pressure ◽  
Correlation Coefficient ◽  
Diastolic Pressure ◽  
Pearson Correlation ◽  
Systolic Pressure ◽  
Pearson Correlation Coefficient ◽  
Increase Blood Pressure ◽  
Multiple Visit

Previous studies of childhood blood pressure have shown tracking correlations, which estimate the magnitude of association between initial and subsequent measurements, to be lower than corresponding adult values. Inasmuch as this disparity could arise from failing to account for a larger week-to-week variability in children, blood pressure was measured for 4 successive years, on four weekly visits in each year, and with three measurements at each visit, using a random-zero sphygmomanometer, in a cohort of 333 schoolchildren aged 8 through 15 at entry. Ninety percent of subjects had measurements in 1 or more years of follow-up. For all follow-up periods (1, 2, and 3 years from baseline), the Pearson correlation coefficient (r) for both systolic and diastolic blood pressure rose substantially with the number of weekly visits used to calculate each subject's yearly blood pressure (P &lt; .0001). For systolic pressure, the 3-year r values for 1, 2, 3, and 4 visits were .45, .55, .64, and .69, respectively. For diastolic pressure (Korotkoff phase 4), the corresponding values were .28, .41, .47, and .54. These higher multiple-visit estimates of tracking approximate published adult values and raise the possibility that prediction of adult blood pressure from childhood measurements may be improved by averaging readings from multiple weekly visits.

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