• 제목/요약/키워드: Bland-Altman Plot

검색결과 59건 처리시간 0.03초

농업인의 휴식대사량 측정 및 휴식대사량 예측공식의 정확도 평가 (The Measurements of the Resting Metabolic Rate (RMR) and the Accuracy of RMR Predictive Equations for Korean Farmers)

  • 손희령;연서은;최정숙;김은경
    • 대한지역사회영양학회지
    • /
    • 제19권6호
    • /
    • pp.568-580
    • /
    • 2014
  • Objectives: The purpose of this study was to measure the resting metabolic rate (RMR) and to assess the accuracy of RMR predictive equations for Korean farmers. Methods: Subjects were 161 healthy Korean farmers (50 males, 111 females) in Gangwon-area. The RMR was measured by indirect calorimetry for 20 minutes following a 12-hour overnight fasting. Selected predictive equations were Harris-Benedict, Mifflin, Liu, KDRI, Cunningham (1980, 1991), Owen-W, F, FAO/WHO/UNU-W, WH, Schofield-W, WH, Henry-W, WH. The accuracy of the equations was evaluated on the basis of bias, RMSPE, accurate prediction and Bland-Altman plot. Further, new RMR predictive equations for the subjects were developed by multiple regression analysis using the variables highly related to RMR. Results: The mean of the measured RMR was 1703 kcal/day in males and 1343 kcal/day in females. The Cunningham (1980) equation was the closest to measured RMR than others in males and in females (males Bias -0.47%, RMSPE 110 kcal/day, accurate prediction 80%, females Bias 1.4%, RMSPE 63 kcal/day, accurate prediction 81%). Body weight, BMI, circumferences of waist and hip, fat mass and FFM were significantly correlated with measured RMR. Thus, derived prediction equation as follow : males RMR = 447.5 + 17.4 Wt, females RMR = 684.5 - 3.5 Ht + 11.8 Wt + 12.4 FFM. Conclusions: This study showed that Cunningham (1980) equation was the most accurate to predict RMR of the subjects. Thus, Cunningham (1980) equation could be used to predict RMR of Korean farmers studied in this study. Future studies including larger subjects should be carried out to develop RMR predictive equations for Korean farmers.

무선 보행 분석을 위한 블루투스 기반 관성 측정 장치의 활용 타당성 분석 (Validation on the Application of Bluetooth-based Inertial Measurement Unit for Wireless Gait Analysis)

  • 황소리;성주환;박희수;한성민;윤인찬
    • 대한의용생체공학회:의공학회지
    • /
    • 제41권3호
    • /
    • pp.121-127
    • /
    • 2020
  • The purpose of this paper is to review the validation on the application of low frequency IMU(Inertial Measurement Unit) sensors by replacing high frequency motion analysis systems. Using an infrared-based 3D motion analysis system and IMU sensors (22 Hz) simultaneously, the gait cycle and knee flexion angle were measured. And the accuracy of each gait parameter was compared according to the statistical analysis method. The Bland-Altman plot analysis method was used to verify whether proper accuracy can be obtained when extracting gait parameters with low frequency sensors. As a result of the study, the use of the new gait assessment system was able to identify adequate accuracy in the measurement of cadence and stance phase. In addition, if the number of gait cycles is increased and the results of body anthropometric measurements are reflected in the gait analysis algorithm, is expected to improve accuracy in step length, walking speed, and range of motion measurements. The suggested gait assessment system is expected to make gait analysis more convenient. Furthermore, it will provide patients more accurate assessment and customized rehabilitation program through the quantitative data driven results.

근위 갈매기 절골술 시행 전과 후의 원위 중족골 관절면각의 측정에 대한 신뢰성의 변화 (Change of Reliability for Distal Metatarsal Articular Angle Measurement before and after Proximal Chevron Osteotomy)

  • 박철현;이동열
    • 대한족부족관절학회지
    • /
    • 제20권4호
    • /
    • pp.145-151
    • /
    • 2016
  • Purpose: To evaluate the reliability of preoperative and postoperative distal metatarsal articular angle (DMAA) measurements and to determine whether such reliability is different in accordance with the foot and ankle fellowship and the number of years in practice. Materials and Methods: Between July 2012 and June 2014, a total of 20 patients (24 feet) were treated with proximal chevron osteotomy and distal soft tissue procedure for symptomatic hallux valgus deformity. DMAA were measured twice with an interval of two weeks between the preoperative and postoperative dorsoplantar radiographs by four observers; two of whom were foot and ankle surgeons (A and B), one knee surgeon, and one senior resident. The intraobserver reproducibility and interobserver reliability were assessed by intraclass correlation coefficients. Moreover, the limit of agreement between the preoperative and postoperative DMAA measurements were assessed using a Bland-Altman plot. Results: The intraobserver reproducibility of the foot and ankle surgeon A, knee surgeon, and senior resident improved from 0.796, 0.575, and 0.586 preoperatively to 0.968, 0.864, and 0.864 postoperatively, respectively. The interobserver reliability of foot and ankle surgeon A-B, foot and ankle surgeon A-knee surgeon, and foot and ankle surgeon A-senior resident improved from 0.874, 0.688, and 0.677 preoperatively to 0.971, 0.917, and 0.838 postoperatively, respectively. Conclusion: The intra- and interobserver reliabilities for DMAA measurement improved after proximal chevron osteotomy. Therefore, the necessity of additional procedures to correct the increased DMAA should be reevaluated after proximal chevron osteotomy in the hallux valgus with an increased DMAA.

가속도계를 이용한 미취학아동의 신체활동 평가 - 자료요약주기의 재통합 측정치와의 비교를 포함하여 - (Physical Activity Assessment of Preschool Children Using Accelerometer - Including Comparison of Reintegrating Counts of Different Epoch Lengths -)

  • 김지연;최연정;주문정;김은경
    • 대한영양사협회학술지
    • /
    • 제22권3호
    • /
    • pp.214-224
    • /
    • 2016
  • The purpose of this study was to assess the physical activity of preschool children using an accelerometer and investigate differences related to epoch length setting during use of the accelerometer. Subjects of the study were 26 children (12 boys and 14 girls) at the age of 5, enrolled in one preschool located in Gangneung. From 9:00 a.m. to 4:00 p.m. (7 hours period), every child wore a total of four accelerometers (ActiGraph $GT3X^+$, USA), including three attached to the left hip (with epoch length set at 5 seconds, 15 seconds, and 30 seconds). For comparison purposes, a forth was attached to the opposite position, with epoch length set at 5 seconds. Data collected using 15s epoch and 30s epoch (single larger epoch) were compared with those obtained after reintegration of 5s to 15s epoch, 5s to 30s epoch, and 15s to 30s epoch, respectively (smaller epochs reintegrated). According to the results of this study, there were no significant differences in VM between 30s epoch and 5s to 30s epoch reintegrated and in MVPA (moderate-to-vigorous physical activity), between 15s epoch and 5s to 15s epoch reintegrated. From the Bland-Altman plot, reintegration of 15s to 30s epoch in VM and reintegrations of 15s to 30s epoch and 5s to 15s epoch in MVPA can be recommended for assessing physical activity in preschool children. Further research is needed into the reintegration method while using an accelerometer for assessment of energy expenditure in children.

Development and Assessment of New RT-qPCR Assay for Detection of HIV-1 Subtypes

  • Lim, Kwanhun;Park, Min;Lee, Min Ho;Woo, Hyun Jun;Kim, Jong-Bae
    • 대한의생명과학회지
    • /
    • 제22권3호
    • /
    • pp.83-97
    • /
    • 2016
  • The measurement of viral load in HIV-1 infected patients is essential for the establishment of a therapeutic strategy. Several commercial assays have shown shortcomings in quantifying rare genotypes of HIV-1 such as minor groups of N and O. In this study, the HIV-1 RT-qPCR assay was developed. The primers and probe of HIV-1 were designed to target the pol gene and to increase the detection efficiency of various subtypes including group N and O. The HIV-1 quantitative RT-qPCR assay was assessed for its analytical performance and clinical evaluation. The LoD was determined to 33.9 IU/ml. The LoD of several subtypes including A, C, D, CRF_01AE, F, CRF_02AG, G and H, were determined to less than 40 IU/ml. The HIV-1 quantitative RT-qPCR assay was evaluated using the China National Reference Panel of HIV-1 RNA to determine the analytical performance. The results were all within the acceptable range. The clinical evaluation was performed at Hunan CDC in China. The clinical evaluation results were compared with those of the China domestic commercial kit. A significant correlation (fresh samples; $R^2=0.84$, P<0.001, frozen samples; $R^2=0.76$, P<0.001) between the two systems was observed for 64 fresh samples and 76 frozen samples with viral loads, and the Bland-Altman plot showed good agreement (98.4%, 96.1%, respectively). In conclusion, the HIV-1 quantitative RT-qPCR assay had comparable analytical performance with several commercial kits. The study provides basic data for the research of HIV-1 diagnosis and the development of P < HIV-1 molecular diagnostic assay.

Reliability and Validity of the Femorotibial Mechanical Axis Angle in Primary Total Knee Arthroplasty: Navigation versus Weight Bearing or Supine Whole Leg Radiographs

  • Kim, Seong Hwan;Park, Yong-Beom;Song, Min-Ku;Lim, Jung-Won;Lee, Han-Jun
    • Knee surgery & related research
    • /
    • 제30권4호
    • /
    • pp.326-333
    • /
    • 2018
  • Purpose: To evaluate the reliability and validity of the femorotibial mechanical axis angle from radiographs in the weight bearing (WB) and supine positions compared with navigation-measured values. Materials and Methods: Sixty-eight cases of navigation-assisted total knee arthroplasty (TKA) were included. The pre- and postoperative whole leg radiographs (WLRs) in WB and supine positions were compared with the initial and final navigation values. Results: The mean mechanical axis angle from the preoperative WBWLR and navigation were not statistically different (p=0.079) and were correlated strongly with each other (intraclass correlation [ICC], 0.818). However, on postoperative measurements, although the WBWLR and navigation values were not different (p=0.098), they were not correlated with each other (ICC, 0.093). The standard error of measurement was $1.8^{\circ}{\pm}3.6^{\circ}$ for the preoperative WBWLR and $2.5^{\circ}{\pm}4.8^{\circ}$ for the postoperative WBWLR. The validity that was determined by the Bland-Altman plot was not acceptable for both pre- and postoperative measurements. Conclusions: The preoperative WBWLR could provide accurate but not precise measurement value of the femorotibial mechanical axis angle for navigation-assisted TKA, and postoperative measurements in navigation were not comparable with radiographic measurements. The lack of agreement was found between the radiographic and navigation measurements of the coronal alignment regardless of pre- or postoperative evaluation although the accuracy was found acceptable. Level of Evidence : Level 4.

A simple and novel equation to estimate the degree of bleeding in haemorrhagic shock: mathematical derivation and preliminary in vivo validation

  • Chon, Sung-Bin;Lee, Min Ji;Oh, Won Sup;Park, Ye Jin;Kwon, Joon-Myoung;Kim, Kyuseok
    • The Korean Journal of Physiology and Pharmacology
    • /
    • 제26권3호
    • /
    • pp.195-205
    • /
    • 2022
  • Determining blood loss [100% - RBV (%)] is challenging in the management of haemorrhagic shock. We derived an equation estimating RBV (%) via serial haematocrits (Hct1, Hct2) by fixing infused crystalloid fluid volume (N) as [0.015 × body weight (g)]. Then, we validated it in vivo. Mathematically, the following estimation equation was derived: RBV (%) = 24k / [(Hct1 / Hct2) -1]. For validation, non-ongoing haemorrhagic shock was induced in Sprague-Dawley rats by withdrawing 20.0%-60.0% of their total blood volume (TBV) in 5.0% intervals (n = 9). Hct1 was checked after 10 min and normal saline N cc was infused over 10 min. Hct2 was checked five minutes later. We applied a linear equation to explain RBV (%) with 1 / [(Hct1 / Hct2) -1]. Seven rats losing 30.0%-60.0% of their TBV suffered shock persistently. For them, RBV (%) was updated as 5.67 / [(Hct1 / Hct2) -1] + 32.8 (95% confidence interval [CI] of the slope: 3.14-8.21, p = 0.002, R2 = 0.87). On a Bland-Altman plot, the difference between the estimated and actual RBV was 0.00 ± 4.03%; the 95% CIs of the limits of agreements were included within the pre-determined criterion of validation (< 20%). For rats suffering from persistent, non-ongoing haemorrhagic shock, we derived and validated a simple equation estimating RBV (%). This enables the calculation of blood loss via information on serial haematocrits under a fixed N. Clinical validation is required before utilisation for emergency care of haemorrhagic shock.

The Reliability and Validity of the Digital Goniometer and Smart Phone to Determine Trunk Active Range of Motion in Stroke Patients

  • Park, Hee-yong;Hwang, Ui-jae;Kwon, Oh-yun
    • 한국전문물리치료학회지
    • /
    • 제29권3호
    • /
    • pp.225-234
    • /
    • 2022
  • Background: Trunk movements are an important factor in activities of daily living; however, these movements can be impaired by stroke. It is difficult to quantify and measure the active range of motion (AROM) of the trunk in patients with stroke. Objects: To determine the reliability and validity of measurements using a digital goniometer (DG) and smart phone (SP) applications for trunk rotation and lateral flexion in stroke patients. Methods: This is an observational study, in which twenty participants were clinically diagnosed with stroke. Trunk rotation and lateral flexion AROM were assessed using the DG and SP applications (Compass and Clinometer). Intrarater reliability was determined using intraclass correlation coefficients (ICCs) with 95% confidence intervals. Pearson correlation coefficient was used to determine the validity of the DG and SP in AROM measurement. The level of agreement between the two instruments was shown by Bland-Altman plot and 95% limit of agreement (LoA) was calculated. Results: The intrarater reliability (rotation with DG: 0.96-0.98, SP: 0.98; lateral flexion with DG: 0.97-0.98, SP: 0.96) was excellent. A strong and significant correlation was found between DG and SP (rotation hemiplegic side: r = 0.95; non-hemiplegic side: r = 0.90; lateral flexion hemiplegic side: r = 0.88; non-hemiplegic side: r = 0.78). The level of agreement between the two instruments was rotation (hemiplegic side: 23.02° [LoA 17.41°, -5.61°]; non-hemiplegic side: 31.68° [LoA 23.87°, -7.81°]) and lateral flexion (hemiplegic side: 20.94° [LoA 17.48°, -3.46°]; non-hemiplegic side: 27.12° [LoA 18.44°, -8.68°]). Conclusion: Both DG and SP applications can be used as reliable methods for measuring trunk rotation and lateral flexion in patients with stroke. Although, considering the level of clinical agreement, DG and SP could not be used interchangeably for measurements.

Knee Joint Isokinetic Rehabilitation Exercise Equipment Usability Evaluation

  • Byoung-Kwon Lee;Seung-Hwa Jung;Hye-Ri Shin;Dong-Wook Han;Chang-Young Kim;Jong-Min Woo;Dae-Sung Park
    • Physical Therapy Rehabilitation Science
    • /
    • 제11권4호
    • /
    • pp.414-420
    • /
    • 2022
  • Objective: In this study, the test-retest reliability and validity were presented to evaluate the usability of isokinetic rehabilitation equipment for the knee joint. Design: Cross-sectional design, reliability & validity study. Methods: Thirty healthy adults participated in the study. A CSMI dynamometer was used as a standardized measuring device to present the validity of the equipment. It was measured based on the dominant leg. The average peak torque value was selected as the measurement variable. After the measurement, a questionnaire was conducted on safety, satisfaction, and performance through the usability evaluation questionnaire. Results: The knee joint isokinetic rehabilitation equipment showed high reliability with Intraclass Correlations Coefficients (ICC) =0.883~0.956. In order to check the validity of the equipment, the 95% confidence interval of the mean difference limit was confirmed by the Bland & Altman plot. As a result, all three angular velocities showed a smaller confidence interval in the flexion than in extension. There were less than 10 plots that were not included in 2 Standard Deviation (SD) between all measurements. As a result of the usability evaluation questionnaire, the average of the safety domain(4.9±0.4), satisfaction domain(4.1±0.8), performance domain(4.3±0.8). Conclusions: If the product is improved by supplementing the items identified in the usability evaluation process, it is judged that it can be used as a useful device in various knee joint rehabilitation fields.

Evaluating the Reliability of Short-Form Berg Balance Scales and Short-Form Postural Assessment Scales in Chronic Stroke Survivors

  • Seung-Heon An;Dae-Sung Park
    • Physical Therapy Rehabilitation Science
    • /
    • 제13권2호
    • /
    • pp.143-151
    • /
    • 2024
  • Objective: This study aims to assess the test-retest reproducibility of the Short Form Berg Balance Scale (SF-BBS) and the Short Form Postural Assessment Scale for Stroke (SF-PASS) among chronic stroke survivors, focusing on their reliability for consistent measurements over time. Design: A cross-sectional study design Methods: Thirty chronic stroke survivors participated in this study, undergoing evaluations with SF-BBS and SF-PASS scales at two different points, separated by a seven-day interval. The analysis focused on test-retest reliability, employing statistical measures such as the Intra-Class Coefficient (ICC2,1), Standard Error of Measurement (SEM), Minimal Detectable Change (MDC), and MDC%, the Bland-Altman plot to assess the limits of agreement and the extent of random measurement error. Results: The study found notable test-retest reproducibility for both SF-BBS and SF-PASS, with ICC values demonstrating strong reliability (0.932 to 0.941, with a confidence interval of 0.889 to 0.973). SEM values for SF-BBS and SF-PASS were reported as 1.34 and 0.61, respectively, indicating low measurement error. MDC values of 3.71 for SF-BBS and 1.69 for SF-PASS suggest that the scales have an acceptable level of sensitivity to change, with reliability metrics falling below 20% of the maximum possible score. Conclusions: The findings suggest that both SF-BBS and SF-PASS exhibit high intra-class correlation coefficients, indicating strong test-retest reliability. The SEM and MDC values further support the scales' reproducibility and reliability as tools for evaluating mobility and dynamic balance in chronic stroke survivors. Therefore, these scales are recommended for clinical use in this population, providing reliable measures for assessing progress in rehabilitation.