Repeatability Intraclass Correlation Research Articles

Repeatability of Pulse Oximetry Measurements in Children During Triage in 2 Ugandan Hospitals.

In low- and middle-income countries, health workers use pulse oximeters for intermittent spot measurements of oxygen saturation (SpO2). However, the accuracy and reliability of pulse oximeters for spot measurements have not been determined. We evaluated the repeatability of spot measurements and the ideal observation time to guide recommendations during spot check measurements. Two 1-minute measurements were taken for the 3,903 subjects enrolled in the study conducted April 2020-January 2022 in Uganda, collecting 1 Hz SpO2 and signal quality index (SQI) data. The repeatability between the 2 measurements was assessed using an intraclass correlation coefficient (ICC), calculated using a median of all seconds of non-zero SpO2 values for each recording (any quality, Q1) and again with a quality filter only using seconds with SQI 90% or higher (good quality, Q2). The ICC was also recalculated for both conditions of Q1 and Q2 using the initial 5 seconds, then the initial 10 seconds, and continuing with 5-second increments up to the full 60 seconds. Lastly, the whole minute ICC was calculated with good quality (Q2), including only records where both measurements had a mean SQI of more than 70% (Q3). The repeatability ICC with condition Q1 was 0.591 (95% confidence interval [CI]=0.570, 0.611). Using only the first 5 seconds of each measurement reduced the repeatability to 0.200 (95% CI=0.169, 0.230). Filtering with Q2, the whole-minute ICC was 0.855 (95% CI=0.847, 0.864). The ICC did not improve beyond the first 35 seconds. For Q3, the repeatability rose to 0.908 (95% CI=0.901, 0.914). Training guidelines must emphasize the importance of signal quality and duration of measurement, targeting a minimum of 35 seconds of adequate-quality, stable data. In addition, the design of new devices should incorporate user prompts and force quality checks to encourage more accurate pulse oximetry measurements.

The Combination of MR Elastography and Proton Density Fat Fraction Improves Diagnosis of Nonalcoholic Steatohepatitis.

Nonalcoholic fatty liver disease (NAFLD) is rapidly increasing worldwide. It is subdivided into nonalcoholic fatty liver (NAFL) and the more aggressive form, nonalcoholic steatohepatitis (NASH), which carries a higher risk of developing fibrosis and cirrhosis. There is currently no reliable non-invasive method for differentiating NASH from NAFL. To investigate the ability of magnetic resonance imaging (MRI)-based imaging biomarkers to diagnose NASH and moderate fibrosis as well as assess their repeatability. Prospective. Sixty-eight participants (41% women) with biopsy-proven NAFLD (53 NASH and 15 NAFL). Thirty participants underwent a second MRI in order to assess repeatability. 3.0 T; MR elastography (MRE) (a spin-echo echo-planar imaging [SE-EPI] sequence with motion-encoding gradients), MR proton density fat fraction (PDFF) and R2* mapping (a multi-echo three-dimensional gradient-echo sequence), T1 mapping (a single-point saturation-recovery technique), and diffusion-weighted imaging (SE-EPI sequence). Quantitative MRI measurements were obtained and assessed alone and in combination with biochemical markers (cytokeratin-18 [CK18] M30, alanine transaminase [ALT], and aspartate transaminase [AST]) using logistic regression models. Models that could differentiate between NASH and NAFL and between moderate to advanced fibrosis (F2-4) and no or mild fibrosis (F0-1), based on the histopathological results, were identified. Independent samples t-test, Pearson's chi-squared test, area under the receiver operating characteristic curve (AUROC), Spearman's correlation, intra-individual coefficient of variation, and intraclass correlation coefficient (ICC). Statistical significance was set at P < 0.05. There was a significant difference between the NASH and NAFL groups with liver stiffness assessed with MRE, CK18 M30, and ALT, with an AUROC of 0.74, 0.76, and 0.70, respectively. Both MRE and PDFF contributed significantly to a bivariate model for diagnosing NASH (AUROC=0.84). MRE could significantly differentiate between F2-4 and F0-1 (AUROC=0.74). A model combining MRE with AST improved the diagnosis of F2-4 (AUROC=0.83). The ICC for repeatability was 0.94 and 0.99 for MRE and PDFF, respectively. MRE can potentially diagnose NASH and differentiate between fibrosis stages. Combining MRE with PDFF improves the diagnosis of NASH. 2 TECHNICAL EFFICACY: Stage 2.

Assessment of Repeatability, Reproducibility, and Performances of T2 Mapping-Based Radiomics Features: A Comparative Study.

Magnetic resonance imaging (MRI)-based radiomics features (RFs) quantify tumors radiological phenotypes but are sensitive to postprocessing parameters, including the intensity harmonization technique (IHT), while mappings enable objective quantitative assessment. To investigate whether T2 mapping could improve repeatability, reproducibility, and performances of radiomics compared to conventional T2-weighted imaging (T2WI). Prospective. Twenty-six healthy adults. Respiratory-trigged radial turbo spin echo (TSE) multiecho T2 mapping (prototype) and conventional TSE T2WI of the abdomen were acquired twice at 1.5 T. T2 maps were reconstructed using a two-parameter exponential fitting model. Volumes-of-interest (VOIs) were manually drawn in six tissues: liver, kidney, pancreas, muscle, bone, and spleen. After co-registration, conventional T2WIs were processed with two IHTs (standardization [std] and histogram-matching [HM]) resulting in four paired input image types: initial T2WI, T2WIstd , T2WIHM , and T2-map. VOIs were propagated to extract 45 RFs from MRI-1 and MRI-2 of each image type (LIFEx, v5.10). Influence of the input data type on RF values was evaluated with analysis of variance. RFs test-retest repeatability and reproducibility over multiple segmentations were evaluated with intra-class correlation coefficient (ICC). Correlations between k-means clusters and the six tissues depending on the RFs dataset were investigated with adjusted-Rand-index (ARI). About 41 of 45 (91.1%) RFs were significantly influenced by the input image type (P values < 0.05), which was the most influential factor on repeatability of RFs (P-value < 0.05). Repeatability ICCs from T2-map displayed intermediate values between the initial T2WI (range: 0.407-0.736) and the T2WIHM (range: 0.724-0.817). The number of RFs with interobserver and intraobserver reproducibility ICCs ≥ 0.90 was 37/45 (82.2%) for T2WIHM , 33/45 (73.3%) for T2WIstd , 31/45 (68.9%) for T2 map, and 25/45 (55.6%) for the initial T2WI. T2 map provided the best tissue discrimination (ARI=0.414 vs. 0.157 with T2WIHM ). T2 mapping provided RFs with moderate to substantial repeatability and reproducibility ICCs, along with the most preserved discriminative information. 1 TECHNICAL EFFICACY: 1.

Investigation of the Validity and Reliability of a Placement Quality Survey for Measuring Rural Student Work Integrated Learning Placement Quality

This study assessed the validity and reliability of the Placement Quality Survey (PQS) for measuring rural student clinical placement quality among allied health students attending rural placements. Secondly, the association of the PQS with students’ choice of rural placements and rural self-efficacy was determined. Students attending 5–8-week placements completed a paper-based questionnaire and were also invited to complete it again later the same day for reliability testing. Reliability and validity were tested. Analysis of variance was used to investigate relationships between PQS items and composite scores with student discipline, venue of student placement, and rural self-efficacy. Occupational therapy, physiotherapy and speech pathology students (N = 163) participated. From the exploratory factor analysis a single factor was extracted which accounted for 62.1% of the variance. The standard one factor confirmatory factor analysis demonstrated reasonable fit but with the addition of a covariance term provided a good fit. Increased preference for rural placements was demonstrated for eight out of nine nine-item PQS items. Rural self-efficacy increased quality ratings, supporting construct validity. The Cronbach’s alpha indicated a high level of internal consistency. All item-to-item correlations indicated a high level of consistency. Test-retest Pearson’s correlations and intraclass correlation coefficients of repeatability indicated the reliability of the scale over time. This study validated the PQS in a sample of rural allied-health students. The results provided support for reliability. The study addresses the critical need for placement quality data to improve allied health students’ experiences and learning outcomes on placements and encourage systematic quality improvement processes.

Repeatability of pupil size measurements with NIDEK OPD‐Scan III in myopic children

AbstractObjectiveTo investigate the repeatability of pupil size measurements, determined from the NIDEK OPD‐Scan III, of myopic eyes in children wearing single‐vision spectacles (SVS), undergoing orthokeratology (OK) and receiving combined treatment of 0.01% atropine and orthokeratology (AOK).MethodsA single examiner took two sets of mesopic pupil size measurements from the right eyes of 80 children (SVS:16, OK: 34, AOK: 30) (mesopic 1 and mesopic 2) and two sets of photopic (photopic 1 and photopic 2) pupil size measurements (internal light source) using the NIDEK OPD‐Scan III. Each set was taken at a single visit, 15 min apart. Subjects in the OK and AOK groups had undergone treatment for at least 6 months, and the SVS subjects had no previous myopia treatment other than wearing spectacles. Repeatability of measurements was analysed using intraclass correlation coefficient (ICC), Bland‐Altman (BA) plot, and coefficient of repeatability (CoR).ResultsMesopic 1 and 2 values were not significantly different among the three groups (p = 0.56, 0.77), hence the data were pooled for each set of measurements (mean [±S.D.] values were 7.09 ± 0.61 and 7.12 ± 0.61 mm, respectively) for further analyses. ICC for repeated mesopic pupil size measurements was 0.98 (95% CI, 0.98–0.99). No significant correlation was found between the means of the mesopic 1 and 2 measurements and their differences (Pearson's r = −0.02, p = 0.83). A BA plot also demonstrated narrow 95% limits of agreement, with a CoR of 0.28 mm.Mean photopic 1 and 2 measurements for the AOK group (3.74 ± 0.46; 3.73 ± 0.43 mm, respectively) were significantly larger (p = 0.01; 0.009) than those of the SVS and OK groups, but no significant difference was found between the latter two groups (p &gt; 0.05). Hence, photopic 1 and 2 measurements for the SVS and OK groups were pooled (SVS‐OK) for further analyses. ICC for repeatability of the photopic measurements was 0.98 (95% CI, 0.96 to 0.99) for the SVS‐OK and AOK groups. The differences between photopic 1 and 2 measurements were not significantly correlated with their means, either in the AOK group (Pearson's r = −0.25, p = 0.19), or in the pooled SVS‐OK group (Pearson's r = −0.04, p = 0.78). BA plots also showed narrow 95% limits of agreement, and CoR was 0.25 mm and 0.23 mm in the AOK and pooled SVS‐OK groups, respectively.ConclusionMesopic and photopic pupil size measurement using the NIDEK OPD‐Scan III was highly repeatable and suitable for use on children.

Repeatability and Reproducibility of Total Retinal Blood Flow Measurements Using Bi-Directional Doppler OCT.

PurposeTo investigate the repeatability and reproducibility of total retinal blood flow measurements using a custom-built dual-beam bidirectional Doppler optical coherence tomography (OCT) system in healthy subjects.MethodsRepeatability and reproducibility were analyzed in 10 and 34 healthy subjects, respectively. For repeatability, measurements were taken twice within 30 minutes, for reproducibility, twice within two to five weeks. Two analysis approaches were compared for calculation of absolute blood velocities: a previously published approach resulting in values for total arterial (QA,abs) and total venous blood flow (QV,abs) and a novel approach taking into account that there is a fixed relation between the phase shift in the two OCT channels (QA,new, QV,new). Repeatability and reproducibility were quantified using intraclass correlation coefficients (ICCs).ResultsFor QA,abs and QV,abs, ICC values between 0.78 and 0.84 were obtained. QA,new and QV,new values revealed better repeatability and reproducibility as compared to the convential appoach. Repeatability ICCs for QA,new and QV,new were between 0.91 and 0.93, and reproducibility ICCs were between 0.87 and 0.91 indicating excellent reproducibility. Good agreement was observed between total retinal blood flow values as measured from retinal arteries and retinal veins.ConclusionsMeasurement of total retinal blood flow using dual-beam Doppler OCT shows excellent reproducibility, which can further be improved by using a novel algorithm for calculating blood velocities in retinal vessels.Translational RelevanceOur data indicate that dual-beam Doppler OCT can be used for longitudinal studies. Hence, quantitative retinal blood flow may be established as a biomarker for progression vascular eye diseases.

Diffusion MRI Derived per Area Vessel Density as a Surrogate Biomarker for Detecting Viral Hepatitis B-Induced Liver Fibrosis: A Proof-of-Concept Study.

Liver vessel density can be evaluated by an imaging biomarker diffusion-derived vessel density (DDVD): DDVD/area(b0b2) = Sb0/ROIarea0 - Sb2/ROIarea2, where Sb0 and Sb2 refer to the liver signal when b is 0 or 2 (s/mm2); ROIarea0 and ROIarea2 refer to the region of interest (ROI) on b = 0 or 2 images; and Sb2 may be replaced by Sb15 (b = 15). This concept was validated in this study. Liver diffusion images were acquired at 1.5 T. For a scan-rescan repeatability study of six subjects, b values of 0 and 2 were used. The validation study was composed of 26 healthy volunteers and 19 consecutive suspected chronic viral hepatitis B patients, and diffusion images with b values of 0, 2, 15, 20, 30, 45, 50, 60, 80, 100, 200, 300, 600, and 800 were acquired. Four patients did not have liver fibrosis, and the rest were four stage 1, three stage 2, four stage 3, and one stage 4 patients, respectively. The intraclass correlation coefficient for repeatability was 0.994 for DDVD/area(Sb0Sb2) and 0.978 for DDVD/area(Sb0Sb15). In the validation study, DDVD/area(Sb0Sb2) and area(Sb0Sb15) were 14.80 ± 3.06 and 26.58 ± 3.97 for healthy volunteers, 10.51 ± 1.51 and 20.15 ± 2.21 for stage 1-2 fibrosis patients, and 9.42 ± 0.87 and 19.42 ± 1.89 for stage 3-4 fibrosis patients. For 16 patients where IVIM analysis was performed, a combination of DDVD/area, PF, and Dfast achieved the best differentiation for nonfibrotic livers and fibrotic livers. DDVD/area were weakly correlated with PF or Dfast. Both DDVD/area(Sb0Sb2) and area(Sb0Sb15) are useful imaging biomarkers to separate fibrotic and nonfibrotic livers, with fibrotic livers having lower measurements.

Mid inter-epicondyle trochlea intersection (MIELTI): Proposal of a new index for identifying the deepest part of the trochlea

BackgroundTibial tuberosity trochlear groove distance (TT-TG) is an important radiological measurement in patellofemoral instability (PFI). Where instability is recurrent, a value ≥20 mm is considered an indication for tubercle medialisation. Trochlear dysplasia commonly accompanies PFI. It can make identification of the deepest part of the trochlea difficult, which makes the TT-TG difficult or impossible to assess. To address this, we propose a new method of identifying the deepest part of trochlea based on the femoral epicondyles. It is named the tibial tuberosity mid inter-epicondyle trochlea intersection distance (TT-MIELTI). MethodsThe TT-TG and TT-MIELTI of 30 consecutive non-dysplastic knee MRIs were compared, excluding 96 knees with dysplasia, sulcus angles ≥135°, a tibial tuberosity anterior cortex which was not fully demonstrated, artefact, fracture, or Osgood Schlatter's disease. To assess inter-observer reliability three blinded researchers measured the TT-TG and the TT-MIELTI of all 30 knees. To assess intra-observer repeatability one researcher repeated the measurements after six weeks. ResultsThe intraclass correlation coefficient (ICC) test demonstrated good to excellent values for all measurements (TT-TG and TT-MIELTI correlation ICC 0.94–0.97; TT-TG inter-observer reliability ICC = 0.85, intra-observer repeatability ICC = 0.90; TT-MIELTI inter-observer reliability ICC = 0.86, intra-observer repeatability ICC = 0.89. All p values < .001.) ConclusionsIn non-dysplastic knees the mid inter-epicondyle trochlea intersection (MIELTI) accurately identifies the deepest part of the trochlea, and TT-MIELTI is a reliable alternative to the TT-TG. Re-assessment in dysplastic knees would be of benefit to establish its usefulness in the clinical setting.

Validity and Repeatability of Single-Sensor Loadsol Insoles during Landing.

Clinically feasible methods for quantifying landing kinetics could help identify patients at risk for secondary anterior cruciate ligament injuries. The purpose of this study was to evaluate the validity and between-day repeatability of the loadsol insole during a single-hop and bilateral stop-jump. Thirty healthy recreational athletes completed seven single-hops and seven stop-jumps while simultaneous loadsol (100 Hz) and force plate (1920 Hz) measurements were recorded. Peak impact force, loading rate, and impulse were computed for the dominant limb, and limb symmetry was calculated between limbs for each measure. All outcomes were compared between the loadsol and force plate using intraclass correlation coefficients (ICC) and Bland–Altman plots. Fifteen participants completed a second day of testing to assess between-day repeatability of the loadsol. Finally, an additional 14 participants completed the first day of testing only to assess the validity of the newest generation loadsol, which sampled at 200 Hz. At 100 Hz, validity ICC results were moderate to excellent (0.686–0.982), and repeatability ICC results were moderate to excellent (0.616–0.928). The 200 Hz loadsol demonstrated improved validity ICC (0.765–0.987). Bland–Altman plots revealed that the loadsol underestimated load measures. However, this bias was not observed for symmetry outcomes. The loadsol device is a valid and repeatable tool for evaluating kinetics during landing.

Automation of the Fetal Right Myocardial Performance Index to Optimise Repeatability

Objectives: To compare the repeatability and degree of absolute agreement of an automated fetal right myocardial performance index (MPI) algorithm with manual measurements along with the impact of MPI observer experience on these two aspects. Methods: Prospective cross-sectional study of 65 uncomplicated singleton pregnancies from 22 to 39 weeks' gestation. Image analysis of double-waveform right MPI measurements was conducted first with a MATLAB automated MPI software and then independently by an experienced and an inexperienced observer. Intraclass correlation coefficients (ICCs) and 95% confidence intervals (95% CI) were used to evaluate manual and automated intra- and interobserver repeatability. In addition, Bland-Altman plots were used to determine the degree of absolute agreement. Results: Successful automation was performed on 63 cases (97%) showing repeatability ICCs of: 0.83 manual intraobserver; 0.77 manual interobserver; 1.00 automated. The degree of absolute agreement between manual and automated values was: inexperienced observer ICC 0.43 (95% CI 0.21-0.62); experienced observer ICC 0.76 (95% CI 0.63-0.85). Conclusion: Automation of right MPI demonstrates a superior reproducibility over manual measurements and reduces the experience required for successful analysis. This may lend a greater clinical applicability to MPI, and future studies to develop an automated universal reference range would be useful.

P06.05: Automation of the fetal right myocardial performance index (RMPI) to optimise repeatability

To compare the repeatability of an automated fetal right myocardial performance index (MPI) algorithm with manual measurements and to evaluate the degree of absolute agreement between values. A secondary aim is to determine the impact of MPI observer experience on these two aspects. A prospective cross-sectional study. Spectral Doppler double waveform, right MPI images were acquired, using a Voluson E8 from 65 uncomplicated singleton pregnancies at 22–39 weeks gestation. Three clearest cardiac cycles were selected from each case, by an experienced operator. Exported raw format images were analysed first with a MATLAB automated MPI software and then independently by an experienced and an inexperienced observer. Intraclass correlation coefficients (ICCs) and 95% confidence intervals (95% CI) were used to evaluate manual and automated intra- and inter-observer repeatability. Absolute agreement between the manual and corresponding automated MPI values was evaluated using ICCs, 95% CI and Bland-Altman plots. Successful automation was performed on 63 cases (97%) showing repeatability ICCs of: 0.83 for manual intra-observer; 0.77 for manual inter-observer and 1.00 for automated repeatability. The degree of absolute agreement between manual and automated values was: inexperienced observer ICC 0.43 (95% CI 0.21–0.62); experienced observer ICC 0.76 (95% CI 0.63–0.85). Right MPI may be a potentially useful tool in the early detection of cardiac dysfunction in a range of pathologies. Automation is precise, sensitive, demonstrates a superior reproducibility over manual measurements and reduces the experience required for successful analysis. This may lend a greater clinical applicability to MPI in functional fetal echocardiography, and future studies to develop a universal reference range based on automation would be useful. We aim for this, along with our Left MPI algorithm, to be made available as an open-source software application to apply to images from any ultrasound machine.

Reliability of Entire Corneal Thickness Mapping in Normal Post-Laser in situ Keratomileusis and Keratoconus Eyes Using Long Scan Depth Spectral Domain Optical Coherence Tomography

Purpose: To investigate the repeatability and reproducibility of mapping the entire corneal thickness using spectral domain optical coherence tomography (SD-OCT). Methods: Thirty normal eyes, 30 post-laser in situ keratomileusis (LASIK) surgery eyes, and 30 keratoconus eyes were analyzed. A custom-built long scan depth SD-OCT device was used to obtain entire corneal images. Ten-millimeter-diameter corneal thickness maps were generated by an automated segmentation algorithm. Intraclass correlation coefficients of repeatability (ICC₁) and reproducibility (ICC₂), and coefficients of repeatability (CoR₁) and reproducibility (CoR₂), were calculated to quantify the precision and accuracy of corneal pachymetry measurements using the Bland-Altman method. Results: For SD-OCT measurements in healthy subjects, CoR₁ and CoR₂ were less than 5.00 and 5.53 μm. ICC₁ and ICC₂ were more than 0.997 and 0.996. For SD-OCT measurements in LASIK patients, CoR₁ and CoR₂ were less than 5.09 and 5.34 μm. ICC₁ and ICC₂ were more than 0.997 and 0.996. For SD-OCT measurements in keratoconus patients, CoR₁ and CoR₂ were less than 11.57 and 10.92 μm. ICC₁ and ICC₂ were more than 0.995 and 0.996. Conclusions: The measurements of corneal pachymetric mapping by long scan depth SD-OCT can be assessed over the entire corneal area with good repeatability and reproducibility.

Three - dimensional ultrasound evaluation of tongue volume

Abstract: Background: The purpose of this study was to find a three - dimensional (3D) ultrasound technique for tongue volume estimation, to compare male and female groups and to find the correlation between tongue volume and body characteristics.Methods: 3D ultrasound was performed within a group of 14 men and a group of 18 women with norm-occlusion. The collected data were analysed by annexed software and the tongue volume was estimated. The repeatability as well as intra- and inter-rater agreement was determined by calculating intra-class correlation coefficient. The Student t-test was used to determine if there were significant differences in tongue volume and body characteristics between the male and the female groups. Pearson correlation coefficients were used to assess the relationship between tongue volume and body characteristics.Results: The 3D ultrasound estimation of tongue volume was highly repeatable in terms of good intraclass correlation coefficients of repeatability (ICC: 0,997) as well as intra- and inter-rater reliabilities (ICC: 0,998 and 0,993 respectively). The male group were significantly taller, heavier and with higher BMI than the female group, and had significantly larger tongue volumes (mean of 89.2 cm3 in males vs. 67.2 cm3 in females). Only the body weights and BMIs in the male group correlated with the tongue volume.Conclusion: This study did demonstrate a valid and reproducible 3D ultrasound technique for tongue volume assessment.

Urethral length measurement in women during sonographic urethrocystography - an analysis of repeatability and reproducibility.

There has been a rise in the use of sonographic urethrocystography in patients with a full bladder. So far, no publications have been made on the analysis of repeatability and reproducibility of the measurements performed during this procedure.AimAn assessment of repeatability and reproducibility of urethral length measurements during sonographic urethrocystography in females with a full bladder in the introital approach, using real-time two-dimensional transvaginal ultrasound.Material and methodsThe ultrasound was performed in accordance with a standardized technique in female patients with a full bladder containing 200–300 mL of liquid. A total of 92 patients were included in the analysis.ResultsThe Intraclass Correlation Coefficient for repeatability and reproducibility of urethral length measurements in sonographic urethrocystography ranged between 0.9217 and 0.9873 (p = 0.0000). The analysis of ultrasound urethral length measurements taken by two different physicians at an interval of several months confirmed their very high compatibility (ICC = 0.81, p = 0.000).ConclusionsVery good repeatability and reproducibility of urethral length findings during sonographic urethrocystography performed in accordance with the presented technique support the possible use of this type of examination in both clinical practice and research.

Differences in Central Corneal Thickness between Spectral Domain-Optical Coherence Tomography and Ultrasound Pachymetry in Patients with Dry Eye Disease.

Purpose. To compare central corneal thickness (CCT) values via Spectral Domain-Optical Coherence Tomography (SD-OCT) and ultrasonic pachymetry in patients with severe dry eye disease (DED) to determine the level of agreement between these 2 methods. Methods. The paired samples t-test was used to compare CCT values in severe DED patients. Matching analysis between methods was performed using intraclass correlation coefficient (ICC). Intrasession reliability of the measurement methods was calculated via the concordance correlation coefficient (CCC), variation equivalent, and Pearson's correlation coefficient. The Bland-Altman procedure was used to graphically represent the differences between CCT values. Results. The study included 56 eyes of 24 female and 4 male patients. Mean age of the patients was 50.9 ± 11.3 years. Mean CCT via Cirrus SD-OCT was 523.82 ± 30.98 μm versus 530.050 ± 31.85 μm via ultrasonic pachymetry (paired samples t-test, P < 0.001). The Bland-Altman plot showed good agreement between the examiners. The ICC for repeatability was 0.974. The CCC between the 2 methods' CCT values was 0.973. The variation equivalent was 0.976 and Pearson's correlation coefficient was 99.3%, which also indicated high correlation between the 2 methods' measurements. Conclusions. The present findings show that in patients with severe DED Cirrus SD-OCT provides reliable intraobserver CCT values.

In Vivo and in Vitro Evaluations of Repeatability and Accuracy of VITA Easyshade® Advance 4.0 Dental Shade-Matching Device.

The objective of this study was to evaluate the intra-device repeatability and accuracy of dental shade-matching device (VITA Easyshade® Advance 4.0) using both in vitro and in vivo models. For the repeatability assessment, the in vivo model utilized shade-matching device to measure the central region of the labial surface of right maxillary central incisors of 10 people twice. The following tooth colors were measured: B1, A1, A2, A3, C1 and C3. The in vitro model included the same six Vitapan Classical tabs. Two measurements were made of the central region of each shade tab. For the accuracy assessment, each shade tab from 3 Vitapan Classical shade guides was measured once. CIE L*a*b* values were determined. Intraclass correlation coefficients (ICCs) were used to analyze the in vitro and in vivo intra-device repeatability of the shade-matching device. The difference between in vitro and in vivo models was analyzed. Accuracy of the device tested was calculated. The mean color differences for in vivo and in vitro models were 3.51 and 1.25 E units, respectively. The device repeatability ICCs for in vivo measurements ranged from 0.858 to 0.971 and for in vitro from 0.992 to 0.994. Accuracy of the device tested was 93.75%. Within the limitations of the experiment, VITA Easyshade®Advance 4.0 dental shade-matching device enabled reliable and accurate measurement. It can be a valuable tool for the determination of tooth colours.

Agreement between Orbscan II, VuMAX UBM and Artemis-2 very-high frequency ultrasound scanner for measurement of anterior chamber depth

BackgroundThe aim was to compare the anterior chamber depth (ACD) measurements taken with Orbscan II, ultrasound biomicroscopy (UBM) and the Artemis-2 VHF (very-high-frequency) ultrasound scanner in normal subjects.MethodsIn this prospective study, one eye from each of 60 normal subjects was randomly selected. Three subjects dropped out of the study because they were apprehensive about the UBM examination; their data were excluded entirely. Measurements of ACD were taken with the Orbscan II, UBM and Artemis-2 VHFUS. Results were obtained for coefficient of variance (CV) and intra-class correlation coefficient (ICC), and statistical analysis was by repeated-measures analysis of variance (ANOVA) for intra-observer repeatability. ANOVA and Bland–Altman analyses were used to determine limits of agreement (LOA) between the three instruments.ResultsThe average ACD (± standard deviation) was 3.13 ± 0.34 mm, 2.96 ± 0.27 mm and 2.87 ± 0.31 mm for the Orbscan II, UBM and Artemis-2 VHFUS, respectively. The repeatability scores were 0.015 ± 0.014%, 0.08 ± 0.09% and 0.07 ± 0.06% for the Orbscan II, UBM and Artemis-2 VHFUS, respectively. The ICC for repeatability of Orbscan II, UBM and Artemis-2 VHFUS measurements was high and equal to 0.99%. The intra-observer repeatability scores of the ACD measurement p-values using Orbscan II, UBM and Artemis-2 VHFUS were 0.12, 0.70 and 0.10, respectively. The mean difference and standard deviations for ACD measurements using Orbscan II vs UBM, Orbscan II vs Artemis-2 VHFUS and UBM vs Artemis-2 VHFUS were 0.17 ± 0.31 mm, 0.27 ± 0.34 mm and 0.10 ± 0.18 mm, respectively. LOAs were 0.78 to -0.44 mm, 0.93 to -0.39 mm and 0.45 to -0.26 mm. ANOVA revealed a statistically significant difference between the Orbscan II, UBM and Artemis-2 VHFUS (p < 0.0001).ConclusionsMeasurements by the three instruments show high repeatability. UBM and the Artemis-2 VHFUS can be used interchangeably, but the Orbscan II cannot be used interchangeably with UBM or the Artemis-2 VHFUS.

An automated hand-held elastometer for quantifying the passive stiffness of the levator ani muscle in women

Design and develop an automated, hand-held instrument (elastometer) to assess in vivo passive stiffness of the pelvic floor muscle. The elastometer system consisted of a hand piece, real-time controller, and laptop computer. A cable connected the hand-piece to the controller, which communicated with a laptop computer via an ethernet connection. Force sensitivity calibration and displacement accuracy were determined experimentally using a spring load and an Instron mechanical tester. A test re-test series quantified the in vivo repeatability (within a procedure) and reproducibility (between procedures after a 5 min delay) of passive stiffness in volunteers (n = 20). Stiffness was determined from the gradient of the force-displacement curve for each cycle. The force-aperture spring measurements from the elastometer showed consistent (r(2) = 1.0000) agreement with those measured by the Instron. The difference between spring stiffness as measured by the elastometer and the Instron (388.1 N/m cf. 388.5 N/m, respectively) was negligible. The intra-class correlation coefficient for repeatability within procedures was 0.986 95% CI (0.964-0.994) n = 20, and reproducibility between procedures ICC 0.934 (95% CI 0.779-0.981) n = 12. Bland-Altman analysis determined a bias of 0.3 and 18.5 N/m, for repeatability and reproducibility respectively. Neither bias is likely to be clinically significance. The elastometer demonstrated very good repeatability and accuracy in the measurement of force/displacement during in vitro testing. There was a high degree of repeatability and reproducibility in stiffness measurements in a test re-test series. Our results demonstrate the elastometer is accurate and reliable and thereby suitable for larger clinical trials.

Test-retest Reliability and Intratest Repeatability of Measuring Cervical Range of Motion Using Inertial Measurement Unit

Objectives : To assess the test-retest reliability and the intratest repeatability in measuring the cervical range of motion of healthy subjects with wireless microelectromechanical system inertial measurement unit(MEMS-IMU) system and to discuss the feasibility of this system in the clinical setting to evaluate the cervical spine musculoskeletal . Methods : 12 healthy people who were evaluated as noor mild-disability with neck disability index were participated. Their cervical motion were measured with IMU twice in consecutive two days for the test-retest reliability study. Intratest repeatability was calculated in the two tests separately. The calculated intraclass correlation coefficients(ICC) were discussed and compared with the those of the previous studies. Results : Cervical range of motion data were acquired and statistically processed: left rotation(61.64°), right rotation(65.12°), extension(61.98°), flexion(52.81°), left bending(39.31°), right bending(41.08°). ICCs were 0.77∼0.98(intratest repeatability) and 0.74∼0.93 (test-retest reliability) in the primary motion. In the coupling motion, intratest repeatability ICCs were 0.93∼ 0.99(transverse primary plane), 0.88∼0.97(saggital primay plane), and 0.77∼0.93(coronal primary plane). Test-retest reliability of coupling motion were 0.90∼0.97(transverse primary plane), 0.00∼0.72(saggital primary plane), and 0.04∼0.76(coronal primary plane). Conclusions : Several types of range-of-motion devices are now on use in many fields including medicine, but the practicality of the devices in clinical use is questionable for the convenient and economical aspects. In this study, we presented the reliability of cervical range of motion test with the developed wireless MEMS-IMU system and discussed its potential utility in clinical use.

P158 Cough Sound Intensity: The Development of a Novel Measure of Cough Severity

Introduction and ObjectivesCough sound analysis is currently used for the assessment of cough frequency; it is not known if it could be used to assess cough intensity. We investigated the...