• 제목/요약/키워드: Bland-Altman plots

검색결과 41건 처리시간 0.029초

Comparison of Reproducibility of Linear Measurements on Digital Models among Intraoral Scanners, Desktop Scanners, and Cone-beam Computed Tomography

  • Jo, Deuk-Won;Kim, Mijoo;Kim, Reuben H.;Yi, Yang-Jin;Lee, Nam-Ki;Yun, Pil-Young
    • Journal of Korean Dental Science
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    • 제15권1호
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    • pp.1-8
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    • 2022
  • Purpose: Intraoral scanners, desktop scanners, and cone-beam computed tomography (CBCT) are being used in a complementary way for diagnosis and treatment planning. Limited patient-based results are available about dimensional reproducibility among different three-dimensional imaging systems. This study aimed to evaluate dimensional reproducibility among patient-derived digital models created from an intraoral scanner, desktop scanner, and two CBCT systems. Materials and Methods: Twenty-nine arches from sixteen patients who were candidates for implant treatments were enrolled. Different types of CBCT systems (KCT and VCT) were used before and after the surgery. Polyvinylsiloxane impressions were taken on the enrolled arches after the healing period. Gypsum casts were fabricated and scanned with an intraoral scanner (CIOS) and desktop scanner (MDS). Four test groups of digital models, each from CIOS, MDS, KCT, and VCT, respectively, were compared to the reference gypsum cast group. For comparison of linear measurements, intercanine and intermolar widths and left and right canine to molar lengths were measured on individual gypsum cast and digital models. All measurements were triplicated, and the averages were used for statistics. Bland-Altman plots were drawn to assess the degree of agreement between each test group with the reference gypsum cast group. A linear mixed model was used to analyze the fixed effect of the test groups compared to the reference group (α=0.05). Result: The Bland-Altman plots showed that the bias of each test group was -0.07 mm for CIOS, -0.07 mm for MDS, -0.21 mm for VCT, and -0.25 mm for KCT. The linear mixed model did not show significant differences between the test and reference groups (P>0.05). Conclusion: The linear distances measured on the digital models created from CIOS, MDS, and two CBCT systems showed slightly larger than the references but clinically acceptable reproducibility for diagnosis and treatment planning.

20대 성인의 보행 후 휴식시간에 따른 진동식 자동혈압계와 수은혈압계의 안정혈압 도달 시점 (Time for Young Adults to Reach Resting Blood Pressure after Walking as measured by an Automatic and a Mercury Sphygmomanometer)

  • 최민정;송경애
    • 기본간호학회지
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    • 제21권4호
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    • pp.370-379
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    • 2014
  • Purpose: The purpose of this study was to identify the time for young adults to reach resting blood pressure after walking as measured by an automatic and a mercury sphygmomanometer. Methods: Participants were 33 nursing students in their 20s. Blood pressure after walking was measured every minute on both arms simultaneously for a total of 6 times after walking for 12 minutes on a treadmill at ratings of perceived exertion (RPE) of 11. Data were analyzed using paired t-test, Bland-Altman plots and repeated measures ANOVA. Results: Systolic blood pressure after walking was the same as measurements corresponding to resting blood pressure after 3 minutes of resting if measured with the automatic sphygmomanometer and 4 minutes of resting if measured with the mercury sphygmomanometer. Conclusions: In order to measure the resting blood pressure for healthy young adults who performed low-density walking for 12 minutes on flat land, the measurement needs to be made after a resting time of at least 3 minutes in the case of an automatic sphygmomanometer and 4 minutes in the case of a mercury sphygmomanometer.

Evaluation of the clinical accuracy of six portable blood glucose meters in dogs

  • Shin, Min-Keun;Kim, Hakhyun;Yun, Taesik;Kang, Ji-Houn;Kang, Byeong-Teck
    • 대한수의학회지
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    • 제60권3호
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    • pp.123-131
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    • 2020
  • Portable blood glucose meters (PBGMs) are widely used because of their practicality. However, the accuracy of PBGMs has frequently been questioned. The objectives of this study were to evaluate factors that might interfere with measurements made using PBGMs, and to assess the clinical utility of 6 PBGMs. The glucose concentrations measured using the PBGMs were compared with those obtained using a reference method. The agreement between the measured values was assessed using Spearman correlation analysis, Passing-Bablok regression analysis, Bland-Altman plots, and consensus error grid analysis. Mann-Whitney and Kruskal-Wallis tests were performed to identify the parameters affecting glucose measurement. The results indicated that all of the PBGMs tested perform adequately for use in veterinary practice. In most cases, measurements made using PBGM corresponded well with the blood glucose values obtained using the reference method. Error grid analysis revealed that most of the PBGM values fell within zones A and B. However, some measurements of blood glucose concentrations < 80 mg/dL fell into zone C. PCV, and triglyceride and total protein concentration, significantly affected the output of some of the PBGMs. Therefore, clinicians should be aware of the characteristics of the PBGM that they use.

The reliability of an easy measuring method for abutment convergence angle with a computer-aided design (CAD) system

  • Seo, Yong-Joon;Kwon, Taek-Ka;Han, Jung-Suk;Lee, Jai-Bong;Kim, Sung-Hun;Yeo, In-Sung
    • The Journal of Advanced Prosthodontics
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    • 제6권3호
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    • pp.185-193
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    • 2014
  • PURPOSE. The purpose of this study was to evaluate the intra-rater reliability and inter-rater reliability of three different methods using a drawing protractor, a digital protractor after tracing, and a CAD system. MATERIALS AND METHODS. Twenty-four artificial abutments that had been prepared by dental students were used in this study. Three dental students measured the convergence angles by each method three times. Bland-Altman plots were applied to examine the overall reliability by comparing the traditional tracing method with a new method using the CAD system. Intraclass Correlation Coefficients (ICC) evaluated intra-rater reliability and inter-rater reliability. RESULTS. All three methods exhibited high intra-rater and inter-rater reliability (ICC>0.80, P<.05). Measurements with the CAD system showed the highest intra-rater reliability. In addition, it showed improved inter-rater reliability compared with the traditional tracing methods. CONCLUSION. Based on the results of this study, the CAD system may be an easy and reliable tool for measuring the abutment convergence angle.

The Test-Retest Reliability of Subjective Visual Horizontal Testing: Comparisons between Solid and Dotted Line Images

  • Zakaria, Mohd Normani;Wahat, Nor Haniza Abdul;Zainun, Zuraida;Sakeri, Nurul Syarida Mohd;Salim, Rosdan
    • Journal of Audiology & Otology
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    • 제24권2호
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    • pp.107-111
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    • 2020
  • The present study aimed to determine the test-retest reliability of subjective visual horizontal (SVH) testing when tested with solid and dotted line images. In this repeated measures study, 36 healthy young Malaysian adults (mean age=23.3±2.3 years, 17 males and 19 females) were enrolled. All of them were healthy and had no hearing, vestibular, balance, or vision problems. The SVH angles were recorded from each participant in an upright body position using a computerized device. They were asked to report their horizontality perception for solid and dotted line images (in the presence of a static black background). After 1 week, the SVH procedure was repeated. The test-retest reliability of SVH was found to be good for both solid line [intraclass correlation (ICC)=0.80] and dotted line (ICC=0.78). As revealed by Bland-Altman plots, for each visual image, the agreements of SVH between the two sessions were within the clinically accepted criteria (±2°). The SVH testing was found to be temporally reliable, which can be clinically beneficial. Both solid and dotted lines in the SVH testing are reliable to be used among young adults.

The Test-Retest Reliability of Subjective Visual Horizontal Testing: Comparisons between Solid and Dotted Line Images

  • Zakaria, Mohd Normani;Wahat, Nor Haniza Abdul;Zainun, Zuraida;Sakeri, Nurul Syarida Mohd;Salim, Rosdan
    • 대한청각학회지
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    • 제24권2호
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    • pp.107-111
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    • 2020
  • The present study aimed to determine the test-retest reliability of subjective visual horizontal (SVH) testing when tested with solid and dotted line images. In this repeated measures study, 36 healthy young Malaysian adults (mean age=23.3±2.3 years, 17 males and 19 females) were enrolled. All of them were healthy and had no hearing, vestibular, balance, or vision problems. The SVH angles were recorded from each participant in an upright body position using a computerized device. They were asked to report their horizontality perception for solid and dotted line images (in the presence of a static black background). After 1 week, the SVH procedure was repeated. The test-retest reliability of SVH was found to be good for both solid line [intraclass correlation (ICC)=0.80] and dotted line (ICC=0.78). As revealed by Bland-Altman plots, for each visual image, the agreements of SVH between the two sessions were within the clinically accepted criteria (±2°). The SVH testing was found to be temporally reliable, which can be clinically beneficial. Both solid and dotted lines in the SVH testing are reliable to be used among young adults.

Coronary Artery Lumen Segmentation Using Location-Adaptive Threshold in Coronary Computed Tomographic Angiography: A Proof-of-Concept

  • Cheong-Il Shin;Sang Joon Park;Ji-Hyun Kim;Yeonyee Elizabeth Yoon;Eun-Ah Park;Bon-Kwon Koo;Whal Lee
    • Korean Journal of Radiology
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    • 제22권5호
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    • pp.688-698
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    • 2021
  • Objective: To compare the lumen parameters measured by the location-adaptive threshold method (LATM), in which the inter- and intra-scan attenuation variabilities of coronary computed tomographic angiography (CCTA) were corrected, and the scan-adaptive threshold method (SATM), in which only the inter-scan variability was corrected, with the reference standard measurement by intravascular ultrasonography (IVUS). Materials and Methods: The Hounsfield unit (HU) values of whole voxels and the centerline in each of the cross-sections of the 22 target coronary artery segments were obtained from 15 patients between March 2009 and June 2010, in addition to the corresponding voxel size. Lumen volume was calculated mathematically as the voxel volume multiplied by the number of voxels with HU within a given range, defined as the lumen for each method, and compared with the IVUS-derived reference standard. Subgroup analysis of the lumen area was performed to investigate the effect of lumen size on the studied methods. Bland-Altman plots were used to evaluate the agreement between the measurements. Results: Lumen volumes measured by SATM was significantly smaller than that measured by IVUS (mean difference, 14.6 mm3; 95% confidence interval [CI], 4.9-24.3 mm3); the lumen volumes measured by LATM and IVUS were not significantly different (mean difference, -0.7 mm3; 95% CI, -9.1-7.7 mm3). The lumen area measured by SATM was significantly smaller than that measured by LATM in the smaller lumen area group (mean of difference, 1.07 mm2; 95% CI, 0.89-1.25 mm2) but not in the larger lumen area group (mean of difference, -0.07 mm2; 95% CI, -0.22-0.08 mm2). In the smaller lumen group, the mean difference was lower in the Bland-Altman plot of IVUS and LATM (0.46 mm2; 95% CI, 0.27-0.65 mm2) than in that of IVUS and SATM (1.53 mm2; 95% CI, 1.27-1.79 mm2). Conclusion: SATM underestimated the lumen parameters for computed lumen segmentation in CCTA, and this may be overcome by using LATM.

요침사 현미경검사를 위한 표본제작의 표준화 연구 (A Study on the Standardization of Sample Preparation for Urine Sediment Microscopic Examination)

  • 이혁재;김대헌;이민혁
    • 대한임상검사과학회지
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    • 제56권2호
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    • pp.135-146
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    • 2024
  • 요검사는 검사실에서 일상적으로 수행되는 기본적인 검사이다. 연구에서 새로운 프로토콜을 포함한 두 가지 수동 현미경검사 방법을 표준화된 chamber 방법과 비교하였다. 시험지검사와 자동 침사물 분석기에서 적혈구 양성 201개와 백혈구 양성인 201개 검체로 구성된 총 402개 검체를 분석 대상으로 선정했다. 적혈구 및 백혈구에 대한 표준화된 chamber 방법과 새로운 프로토콜 방법 간의 상관계수는 모두 r=0.98로, 높은 수준의 상관관계를 나타냈다. 이 두 방법 간의 동일 등급에 대한 쌍별 일치율은 적혈구의 경우 86.1%, 백혈구의 경우 88.6%였으며, 한 등급 차이 내 일치율은 모두 99.5%였다. 반면, 표준화된 chamber 방법과 중·소규모 검사실 방법 간의 일치율은 적혈구의 경우 11.9%, 백혈구의 경우 13.4%로, 동일 등급 일치율이 현저히 낮았고, 한 등급 차이 내 일치율은 각각 67.2%와 74.1%로 나타났다. 급내상관계수 및 Bland-Altman plot을 사용한 분석에서는 새로운 프로토콜이 다른 세 가지 수동 현미경검사 방법에 비해 우수한 일치도를 보인 것으로 확인되었다. 표준화된 chamber 방법과의 높은 상관관계와 일치도를 고려해 볼 때, 새로운 프로토콜 방법을 소변 침사물 표본제작의 표준화된 절차로 권장한다.

Validity of palatal superimposition of 3-dimensional digital models in cases treated with rapid maxillary expansion and maxillary protraction headgear

  • Choi, Jin-Il;Cha, Bong-Kuen;Jost-Brinkmann, Paul-Georg;Choi, Dong-Soon;Jang, In-San
    • 대한치과교정학회지
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    • 제42권5호
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    • pp.235-241
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    • 2012
  • Objective: The purpose of this study was to evaluate the validity of the 3-dimensional (3D) superimposition method of digital models in patients who received treatment with rapid maxillary expansion (RME) and maxillary protraction headgear. Methods: The material consisted of pre- and post-treatment maxillary dental casts and lateral cephalograms of 30 patients, who underwent RME and maxillary protraction headgear treatment. Digital models were superimposed using the palate as a reference area. The movement of the maxillary central incisor and the first molar was measured on superimposed cephalograms and 3D digital models. To determine whether any difference existed between the 2 measuring techniques, intra-class correlation (ICC) and Bland-Altman plots were analyzed. Results: The measurements on the 3D digital models and cephalograms showed a very high correlation in the antero-posterior direction (ICC, 0.956 for central incisor and 0.941 for first molar) and a moderate correlation in the vertical direction (ICC, 0.748 for central incisor and 0.717 for first molar). Conclusions: The 3D model superimposition method using the palate as a reference area is as clinically reliable for assessing antero-posterior tooth movement as cephalometric superimposition, even in cases treated with orthopedic appliances, such as RME and maxillary protraction headgear.

Intra-Rater Test-Retest Reliability of Ely's Test Using Smartphone in Patients With Lumbar Extension-Rotation Syndrome

  • Park, Kyue-Nam;Ha, Sung-Min;Chung, Sung-Dae;Kim, Si-Hyun;Jang, Jun-Hyeok
    • 한국전문물리치료학회지
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    • 제19권4호
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    • pp.46-54
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    • 2012
  • Ely's test is commonly used to assess rectus femoris muscle flexibility. however, a reliability limit of this test was demonstrated by a previous study. In this study, we present an alternative method using an application for a digital horizontal level in a smartphone (DHLS) to complement the reliability limit of Ely's test. The aim of this study was to examine the reliability of Ely's test using DHLS on the pelvis, compared to using visual observation (VO) of pelvic and hip motions. Nineteen patients with lumbar extension-rotation syndrome were recruited for this study. An examiner examined the rectus femoris flexibility (both pass/fail and goniometer scoring) through Ely's test using both DHLS and VO. A retest session was completed two hours later for within-day reliability and seven days later for between-day intra-rater test-retest reliability. Results showed higher Kappa values for pass/fail scoring and higher intraclass correlation coefficient values for goniometer scoring in Ely's test using DHLS, compared to using VO. Measurement error and Bland and Altman plots further demonstrated the degree of intra-rater variance during Ely's test using DHLS in a clinical setting, compared to using VO. These results demonstrated that Ely's test using DHLS showed acceptable reliability compared to using VO. Ely's test using DHLS could be widely used for measuring the rectus femoris muscle flexibility in patients with lumbar extension-rotation syndrome, although the inter-rater reliability needs to be established first.