Altman Method Research Articles

The Effects of Attentional Focus on Test–Retest Reliability of Jumping Tasks

ABSTRACT This study examined the test–retest reliability of the standing long jump (SLJ) and the countermovement jump (CMJ) following consistent and non-consistent attentional focus cuing instructions in physically active young adults (n = 30). The systematic error (as standardize change in mean), random error (as typical error), the Bland and Altman method (limits of agreement, LOA), intraclass correlation coefficient (ICC), and two-way ANOVA with repeated measures were used to evaluate the reliability of measurements. Jump distance in the SLJ and jump height in the CMJ demonstrated acceptable reliability within the consistent and non-consistent attentional conditions. However, the consistent attentional condition resulted in smaller systematic errors, lower random errors, stronger ICCs, and narrower LOAs in comparison to the non-consistent condition. The present findings indicate that providing a consistent focus of attention instructions produced more reliable jump distance and jump height compared to providing a non-consistent focus of attention instructions to physically active adults.

Estimation of Engagement in Moderate-to-Vigorous Physical Activity from Direct Observation: A Proposal for School Physical Education.

This study aimed to test an observational momentary time sampling tool to estimate in-class moderate-to-vigorous physical activity (MVPA), in terms of validity, reliability and agreement between observational momentary time sampling and accelerometry, and to develop a regression equation to estimate MVPA from observational momentary time sampling. The sample comprised 78 pupils (38 girls), mean age 14.0 ± 1.1 years. Measurements were taken in three similar Physical Education classes, on three different days. To monitor MVPA, we applied the observational momentary time sampling method. Students wore an ActiGraph GT3X+ accelerometer. Reliabilities were determined by the intraclass correlations, the agreement between methods was analyzed using the Bland–Altman method, and a multiple regression analysis was performed to estimate the equation. The observational momentary time sampling showed good reliability across time (0.59 < r < 0.72, p < 0.001). It was significantly correlated with accelerometry (r = 0.51, p < 0.001). The MVPA assessed via accelerometer could be predicted from the following equation: Y = 44.3 + 0.47⋅(MVPA observational momentary time sampling method) + 8.0⋅(sex; with 0 = girls and 1 = boys). This observational momentary time sampling method is a stable and reliable tool to estimate MVPA. A regression equation using the score of observational momentary time sampling and sex can be used to better estimate the real MVPA.

Agreement and reliability of repeated bedside respiratory muscle strength measurements in acute and subacute stroke.

Many stroke trials include maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and sniff nasal inspiratory pressure (SNIP) outcome measurements. However, data on agreement and reliability of repeated MIP, MEP, and SNIP measurements in acute and subacute stroke patients are scarce. This study employed a test-retest design. Eighteen patients (seven female) with mean (SD) age 59 (14.5) years were recruited from neurological wards. Median (range) time since first stroke was 50.5 (21-128) days. MIP, MEP, and SNIP were measured repeatedly in three testing sessions (S1-3) conducted within 24h and following international standards. Intra-rater agreement between testing sessions was analyzed using the Bland-Altman method. Test-retest reliability was analyzed using intra-class correlation coefficient (ICC). Association between individual measurement variability, time poststroke, and level of stroke impairment was analyzed using Spearman's rho. Mean difference and 95% limits of agreement for MIP were -0.40 (-23.02, 22.22) cmH2 O between S1 and S2, and 2.14 (-12.79, 16.99) cmH2 O between S2 and S3; for MEP, -4.56 (-29.01, 19.90) cmH2 O between S1 and S2, and 0.29 (-24.28, 24.87) cmH2 O between S2 and S3; and for SNIP, -10.56 (-38.48, 17.37) cmH2 O between S1 and S2, and -6.06 (-27.32, 15.20) cmH2 O between S2 and S3. ICCs for MIP, MEP, and SNIP were ≥0.9 throughout. There were no strong correlations between individual measurement variability and time poststroke or level of stroke impairment. MIP, MEP, and SNIP in acute and subacute stroke patients show good test-retest reliability for group averages; however, absolute agreement can vary considerably for some individuals.

Does Body Position Affect Ultrasound Measurements of Bladder-Wall Elasticity?

Ultrasound bladder vibrometry (UBV) parameters have been shown in previous studies to strongly correlate with measurements from urodynamic studies. Just like urodynamic studies, UBV can be performed in supine and sitting positions. The objective of this study is to compare UBV parameters obtained in the two different positions using statistical methods. We recruited eight volunteers with healthy bladders for this purpose. The elasticity, group velocity squared and thickness of the bladder were the UBV parameters of interest, and their values were recorded at different bladder volumes for each volunteer. The results presented indicate that the measurements made in the two positions are in agreement using the Bland–Altman method and a parameter q which compares the values at each bladder volume for each volunteer. UBV parameters were also repeatable for measurements recorded in the supine and sitting positions.

Horizontal and anterior chamber diameter for phakic intraocular lens sizing

ABSTRACT Clinical relevance Proper selection of phakic intraocular lens diameter is necessary to avoid complications related with excessive vaulting after its implantation. Background Horizontal corneal diameter, measured as white‐to‐white distance, is one of the parameters used for phakic intraocular lens diameter calculation. Agreement was assessed between three parameters: white‐to‐white distance obtained with swept source optical coherence tomography, and white‐to‐white distance obtained with Scheimpflug camera and angle‐to‐angle parameter obtained with anterior segment optical coherence tomography. Methods This study included 55 eyes of 43 patients. The white‐to‐white distance was measured with two biometry techniques: swept source optical coherence tomography and Scheimpflug camera. The angle‐to‐angle was measured with anterior segment optical coherence tomography. Analysis of agreement was performed by the Bland–Altman method. For every patient, simulation of Visian Implantable Collamer Lens (ICL) sizing was performed using the Online Calculation and Ordering System with different white‐to‐white distance or angle‐to‐angle. Results Statistically significant differences were found between swept source optical coherence tomography biometer and anterior segment optical coherence tomography (p = 0.001) and between swept source optical coherence tomography and Scheimpflug camera (p < 0.001). However, there was a good correlation between swept source optical coherence tomography and Scheimpflug camera (intraclass correlation co‐efficient = 0.623), with a shift toward higher white‐to‐white distance values on swept source optical coherence tomography. A relatively high correlation intraclass correlation co‐efficient (0.772) and lack of statistically significant differences (p = 0.068) between anterior segment optical coherence tomography and Scheimpflug camera results were observed. Simulation of phakic intraocular lens sizing showed that swept source optical coherence tomography white‐to‐white distance should not be used interchangeably with Scheimpflug camera white‐to‐white distance or angle‐to‐angle. Conclusion White‐to‐white distance measured with swept source optical coherence tomography was significantly different from values obtained with other methods. Angle‐to‐angle may support ICL sizing, helping in verification of white‐to‐white distance values obtained with other devices.

Validity of the IND IsoDyno isokinetic dynamometer maximum peak angular torque measure for right knee joint flexion and extension movement

Context: IND IsoDyno isokinetic dynamometer is a newly designed dynamometer to measure the isokinetic strength of the knee joint. It is a cost-effective, clinically feasible, and easily available dynamometer which manifests its benefits over the preexisting one. Aim: The aim of this study was to assess the validity of IND IsoDyno isokinetic dynamometer with respect to maximum peak angular torque. Settings and Design: Criterion-related validity (concurrent validity). Materials and Methods: We considered IND IsoDyno isokinetic dynamometer as an index test and TecnoBody IsoMove isokinetic dynamometer as our reference standard. In this study, we assessed the validity of the IND IsoDyno isokinetic dynamometer and compared the obtained maximum peak angular torque values of the prototype device. Five volunteers were tested at 60° per second on concentric mode for knee flexion and extension on both the IsoMove and a new isokinetic dynamometer IND IsoDyno. Data for values of maximum peak angular torque were recorded. Statistical Analysis Used: Interclass correlation coefficient (ICC) and standard errors of measurement (SEM) were analyzed using IBM SPSS version 26. Bland and Altman's method of analysis was done. Results: ICC and SEM revealed a high level of reproducibility and precision in the device's maximum peak torque measurements. The 95% confidence interval (CI) interval falls between the limits of agreement on Bland and Altman's plot. Conclusions: Within the limitations of the study, IND IsoDyno isokinetic dynamometer provided a mechanically valid measure of maximum peak angular torque on multiple trials performed on various subjects.

Systolic Blood Pressure in Anesthetized Dogs - Agreement between Measurements by Two Noninvasive Monitors

Background: The oscillometric monitor is a noninvasive method used for measuring blood pressure in dogs and cats. Despite widely used, there is a large variability in the accuracy of oscillometric monitors, which may also be influenced by the location of the blood pressure cuff. The Doppler ultrasound is another non-invasive method that was shown to measure blood pressure with good accuracy and precision in small animals. The present study aimed to determine the agreement between systolic arterial pressure (SAP) measured by the Prolife P12 oscillometric monitor with two cuff locations and the Doppler ultrasound in anesthetized dogs.Materials, Methods &amp; Results: Dogs scheduled for routine anesthetic procedures were included in the study, which was carried out in two phases. In Phase 1, SAP values measured by the Doppler were compared with those measured by the Prolife P12 monitor with the cuff placed at the thoracic limb for both methods. In Phase 2, SAP values measured by the Doppler were compared with those measured by the Prolife P12 monitor, with the cuff placed at the thoracic limb for the Doppler and at the base of the tail for the P12. The cuff width corresponded to approximately 40% of limb or tail circumference. On all occasions, three consecutive measurements of SAP were recorded, followed by a single measurement of SAP by the P12, and then other three measurements were performed with the Doppler. The arithmetic mean of the six SAP measurements with the Doppler was compared with the SAP value measured by the P12 monitor (paired measurements). Agreement between SAP values measured by the Doppler and the P12 monitor was analyzed by the Bland Altman method for calculation of the bias (Doppler – P12) and standard deviation (SD) of the bias. The percentages of differences between the methods with an error ≤ 10 mmHg and ≤ 20 mmHg and Pearson’s correlation coefficients were also calculated. Results were compared with the criteria from the American College of Veterinary Internal Medicine (ACVIM) for validation of noninvasive blood pressure methods. A total of 33 dogs were included in Phase 1 and 15 were included in Phase 2. During Phases 1 and 2, 179 and 87 paired measurements were recorded, respectively. Most of the measurements were recorded during normotension (SAP = 90-130 mmHg): 113/179 in Phase 1 and 52/87 in Phase 2. The bias (± SD) for Phases 1 and 2 were -2.7 ± 14.1 mmHg and 7.2 ± 25.8 mmHg. The percentages of differences ≤ 10 mmHg and ≤ 20 mmHg were: Phase 1, 61% and 83%; Phase 2, 41% and 70%. Correlation coefficients were 0.81 and 0.67 for Phases 1 and 2, respectively. According to the ACVIM criteria, maximum values accepted for bias are 10 ± 15 mmHg, the percentages of differences ≤ 10 mmHg and ≤ 20 mmHg should be ³ 50% and ³ 80%, respectively, and the correlation coefficient should be ³ 0.9. Discussion: When the blood pressure cuff was placed at the thoracic limb, SAP values measured by the P12 monitor met most of the ACVIM criteria, demonstrating good agreement with SAP values measured by the Doppler. The only requirement not met was the correlation coefficient which was 0.81 whereas the recommended is ³ 0.9. Conversely, when the cuff was placed at the base of the tail, SAP values measured by the P12 monitor did not meet most of the ACVIM criteria indicating that, in anesthetized dogs, SAP measurements with the P12 monitor should be performed with the cuff placed at the thoracic limb. One limitation of this study was that most measurements fell in the normotensive range and the results should not be extrapolated for hypotensive and hypertensive conditions. In conclusion, the Prolife P12 oscillometric monitor demonstrated good agreement with SAP values measured by the Doppler and provides acceptable values in normotensive anesthetized dogs.Keywords: arterial blood pressure, nonivasive blood pressure, anesthetic monitoring.Título: Pressão arterial sistólica em cães anestesiados - concordância entre mensurações por dois métodos não invasivosDescritores: pressão arterial, pressão arterial não invasiva, monitoração anestésica.

Aortic flow below and visceral circulation during aortic counterpulsation: Evaluation of an in vitro model.

This study aimed to test a computer-driven cardiovascular model for the evaluation of the visceral flow during intra-aortic balloon pump (IABP) assistance. The model includes a systemic and pulmonary circulation as well as a heart contraction model. The straight polyurethane tube aorta had a single visceral while four windkessel components mimicked resistance compliance of the brachiocephalic, renal and sub-mesenteric, pulmonary, and systemic circulation. Twelve flow probes were placed in the circuit to measure pressures and flows with the IABP on and off. With the balloon off, the meantime to reach the steady state was 48 ± 16 s; with the balloon on, this figure was 178 ± 20 s. The stability of pressure and flow signals was obtained after 72 ± 11 min. The number of cycles of stability of the system was 93 [86-103]. Measurements were reliable either with samples of 10 or 20 beats. Bland Altman method demonstrated the reliability of measurements. Finally, all measurements were comparable to published in vivo data. The presented mock circulation was reliable and gave values with high accuracy both at baseline and during mechanical assistance. This system allows evaluation of the mesenteric flow during IABP, under different clinical/hemodynamic conditions. Nonetheless, its translational potential needs to be further evaluated.

Agreement between noninvasive oscillometric and invasive blood pressure measurements in isoflurane-anesthetized guinea pigs (Cavia porcellus)

ObjectiveTo assess the agreement between an oscillometric device and invasive blood pressure (IBP) measurements in anesthetized healthy adult guinea pigs. Study designProspective experimental study. AnimalsA total of eight adult Hartley guinea pigs. MethodsAll animals were anesthetized; a carotid artery was surgically exposed and catheterized for IBP measurements. A size 1 cuff placed on the right thoracic limb was connected to an oscillometric device for noninvasive blood pressure (NIBP) assessment. Concurrent pairs of systolic (SAP), diastolic (DAP) and mean (MAP) arterial pressures were recorded simultaneously with both methods every 3 minutes for 30 minutes. Agreement between IBP and NIBP measurements was determined using the Bland–Altman method, considering the recommended standards for the validation of NIBP measurement devices proposed by the American College of Veterinary Internal Medicine (ACVIM). ResultsThe bias and the 95% limits of agreement were: –14 (–31 to 3) mmHg, –2 (–14 to 10) mmHg and –1 (–13 to 11) mmHg for SAP, DAP and MAP, respectively. Conclusions and clinical relevanceThe oscillometric device used in this study to measure NIBP did not meet ACVIM criteria for validation. It showed good agreement for DAP and MAP but not for SAP measurements. Considering the small size of these animals and the resulting difficulty in performing percutaneous arterial catheterization, this device might be a useful tool to assess MAP and DAP during anesthetic procedures in adult guinea pigs.

Strategic management of organizational resources using predicting the organization's bankruptcy level: New approach using Monte Carlo Simulation

Abstract Purpose: There are several methods to predict organization bankruptcy; each of them has different accuracy. Another considerable note in investigating organization bankruptcy is the data considered for the study. The goal of this study is to determine which model is the most accurate in predicting organization bankruptcy. Research methodology: In this study, the initial data were used to compare predicting Monte Carlo processes that simulate bankruptcy models to compare models and results more accurately. Simulated data coefficient modification of Mckee, CA-SCORE, Springate, Zmijewski, Shirata, and Altman methods were implemented in some healthy and bankrupt organizations. After that, the results of each modified model were considered to determine the predicting bankruptcy accuracy. Results: Using the final Mckee's method, predicting organization bankruptcy was done in an organization and the results show that the given organization is on a trend of bankruptcy in 2025. Limitations: This research was only described in knowledge-based organizations. Contribution: The Mckee genetic method is more accurate than other methods. Also, modifying coefficient and by using simulated data shows that CA-SCORE and Shirata methods are not able to predict the organization's bankruptcy by using simulated data.

Prognostic value and time course evolution left ventricular global longitudinal strain in septic shock: an exploratory prospective study.

Our main objective was to describe the course of GLS during the first days of septic shock and to assess the agreement between GLS values and longitudinal strain measured in apical four chambers. A prospective observational single centre study was conducted at the Nimes University Hospital's ICU. All patients admitted for a diagnosis of septic shock without pre-existing heart disease were eligible. Echocardiography (LVEF and GLS) was performed on the first day, and repeated once between day 3 and day 5 then once between day 6 and day 8. We enrolled 40 consecutive patients. Four patients were excluded. In overall population, GLS at T1 was impaired (- 11.0%, IQR(interquartile range) [- 15; - 10]). On T2 exams, a significant improvement of the GLS (- 11% vs - 16% p = 0.02) was observed whereas LVEF remained stable over time. A good agreement between GLS and longitudinal strain measured on a four chambers view was found. Based on the Bland and Altman method, the mean of differences for T1 exams was 0.1 (95% CI [- 0.6; 0.8]) with limits of agreement ranging from - 4 to 4. Myocardial strain is depressed at the early phase of septic shock and improves over time. A single measurement of LS4C view appears sufficient at bedside.

Interchangeability between Respiratory Variations of Subclavian Vein and Pulse Pressure Variation in Ventilated Patients in the Operating Room.

ObjectiveFor mechanically ventilated patients, the best predictors of fluid responsiveness are dynamic parameters. Many methods that reflect cardiopulmonary interactions have been proposed to evaluate the preload dependency. In this study, we describe the interchangeability between respiratory variations of the subclavian (ΔSCV) vein and pulse pressure variation (PPV) in sedated and mechanically ventilated patients benefiting from kidney transplantation.MethodsThe ΔSCV via infraclavicular transthoracic echocardiography and PPV measurements were recorded simultaneously by a single operator. The Bland–Altman method assessed the interchangeability between ΔSCV and PPV.ResultsA total of 27 patients were prospectively included in the study. The Bland–Altman analysis showed a bias of +1.6 % for ΔSCV measurements vs. PPV. The limit of agreements was, respectively, −4% and 8%. The agreement between PPV >13% and ΔSCV >13% was 100%, and the agreement between PPV<9% and ΔSCV<9% was 58%. No misclassification (PPV<9% [0%] and PPV>13% [0%]) was observed.ConclusionΔSCV and PPV are interchangeable when assessing preload dependency in mechanically ventilated patients benefiting from kidney transplantation. ΔSCV appears to be a suitable tool because it is non-invasive, simple, easy and almost always available.

Cross-validation of prediction equations for estimating the body fat percentage in adults with obesity.

An accurate estimation of the body fat percentage (BF%) in patients with obesity is of clinical importance. Therefore, we aim to assess the validity of anthropometric-based BF predictive equations in treatment-seeking patients in an outpatient setting. BF% was assessed by Tanita MC-780MA bioimpedance (BIA) and considered as a reference method, and anthropometric-based predictive equations were used in BF% estimations among 275 adults of both genders, in the outpatient clinic of the Department of Nutrition and Dietetics at Beirut Arab University (Lebanon). The mean differences between the measured and estimated BF% values were calculated to assess the accuracy of five equations, and the Bland-Altman method was used to assess the level of agreement. In both males and females, all predictive equations gave significantly different estimates of BF% when compared to those measured by BIA. On the other hand, in both genders, the mean difference between the BF% value estimated by the Jackson equation and that measured using BIA, was not significant, and agreement was confirmed using Bland-Altman plots. We suggest the Jackson equation for accurate BF% estimation in both genders of patients with obesity in the Lebanese population. However, future studies are still urgently needed to develop and validate new predictive equations suitable for BF% estimations, taking into account ethnicity (i.e., the Arab population).

Validity of Bioimpedance Equations to Evaluate Fat-Free Mass and Muscle Mass in Severely Malnourished Anorectic Patients.

Background: Bioelectrical impedance analysis (BIA) is a simple and rapid technique to measure body composition (BC). Validity of BIA in patients with low body mass index (BMI) remains controversial. We assessed the validity of several BIA equations to evaluate fat-free mass (FFM), fat mass (FM) and muscle mass in patients with anorexia nervosa (AN) by using dual X ray absorptiometry (DXA) as reference. Methods: Sixteen BIA equations developed for FFM and appendicular lean mass (ALM) were applied on electrical data measured by BIA in AN patients with BMI <16 kg/m². BIA and DXA were done the same day after overnight fasting. Results were compared with the Bland–Altman method, Pearson correlation and a Lin concordance test. Results: Data from 115 female AN patients (14.6 ± 1.2 kg/m²; 32.3 ± 14.5 years) were included. FM and FFM assessed by DXA were, respectively, 4.2 ± 2.4 kg and 35.5 ± 3.8 kg. The best results were obtained with Sun’s equation: respectively for FM and FFM, Bland Altman bias at 0.548 and 0.706 kg, Pearson correlation r at 0.86 and 0.86 and Lin concordance coefficient at 0.81 and 0.84. However, confidence intervals (CI) at 95% were high (−2.73–3.83 kg for FM; −4.55–3.13 kg for FFM). Other equations also showed high 95% CI. Accuracy was acceptable for Sun and Bedogni equations for FFM (approximately 66%) but very low for FM prediction considering all equations (<15%). Concerning ALM evaluated at 14.88 ± 2.04 kg by DXA, only Scafoglieri and Yoshida equations showed acceptable values: bias (−0.2 and 2.8%), Pearson r (0.89 and 0.86), Lin concordance coefficient (0.82 and 0.82) and accuracy (83.5 and 82.6%). Confidence intervals at 95% were high for both equations (−2.1–2.0 for Scafoglieri equation and −1.6–2.4 for Yoshida equation). Conclusion: In AN patients with BMI < 16 kg/m², no BIA equation tested was adapted to evaluate BC at the individual level.

Accuracy and inter-reader agreement of breast MRI for cancer staging using 0.08 mmol/kg of gadobutrol

BackgroundEvidence on gadolinium brain accumulation after contrast-enhanced MRI prompted research in dose reduction. PurposeTo estimate accuracy and inter-reader reproducibility of tumor size measurement in breast MRI using 0.08 mmol/kg of gadobutrol. MethodsWe retrospectively analyzed all women who underwent 1.5-T breast MRI for cancer staging at our department with 0.08 mmol/kg of gadobutrol. Two readers (R1 and R2, 12 and 3 years-experience) measured the largest lesion diameter. Accuracy was estimated both as correlation with pathology and rate of absolute (>5 mm) overestimation and underestimation, inter-reader reproducibility using the Bland–Altman method. Data are given as median and interquartile range. ResultsThirty-six patients were analyzed (median age 56 years, 49–66) for a total of 38 lesions, 24 (63%) mass enhancement, 14 (37%) non-mass enhancement. Histopathological median size (mm) of all lesions was 15 (9–25): 13 (9–19) for mass lesions, 19 (11–39) for non-mass lesions. On MRI, R1 measured (mm) 14 (10−22) for all lesions, 13 (10–19) for mass lesions, 19 (11–49) for non-mass lesions. MRI-pathology correlation was very high for all lesion categories (ρ ≥ 0.766). On MRI, R1 overestimated lesion size in 6 cases (16%), and underestimated in 3 (8%); R2, overestimated 7 cases (18%) and underestimated 3 cases (8%). At inter-reader reproducibility analysis (mm): bias 0.9, coefficient of reproducibility 13 for all lesions; −0.1 and 6 for mass lesions; 2.5 and 20 for non-mass lesions. ConclusionsBreast MRI may be performed using 0.08 mmol/kg of gadobutrol with high accuracy and acceptable inter-reader agreement.

An efficient and accurate parallel hybrid acoustic signal correction method for transcranial ultrasound

Phased-control focused ultrasound transducers provide a new and noninvasive treatment method for brain disease. However, improving the accuracy of phase correction and reducing the calculation time during treatment have always been contradictory constraints. In this paper, a hybrid acoustic signal correction (HASC) method combined with k-Wave stage and holography stage was introduced for phase correction and simulation of transcranial focused ultrasound. The k-Wave stage is mainly used to calculate the sound field in a heterogeneous medium (skull), which divides the sound field calculation process into paths that can be calculated in parallel, and the transcranial correction phase can also be obtained during the calculation. The holography stage is sufficient to simulate the acoustic field in the homogenous intracranial medium after ultrasound transmitting through the skull. The agreement of the k-space corrected pseudospectral time domain method and HASC method was assessed by statistical methods: linear regression between the two methods provided a slope of 0.9735, intercept of 0.0078, and R2 of 0.9982. The Bland–Altman method provided a bias of 0.0015 and 95% limits of agreement 0.065 apart. We demonstrated that the difference in sound intensity at the focal point corrected by HASC and time reversal phase correction method was 0.2% and 0.5% in the results of simulation and experiment, respectively. Not only that, the phase calculation time by the HASC phase correction method can be reduced to 11 min on a multi GPU array, which has clinical potential for ultrasound treatment of brain therapy.

Instrumental validity and intra/inter-rater reliability of a novel low-cost digital pressure algometer.

BackgroundPain assessment is a key measure that accompanies treatments in a wide range of clinical settings. A low-cost valid and reliable pressure algometer would allow objective assessment of pressure pain to assist a variety of health professionals. However, the pressure algometer is often expensive, which limits its daily use in both clinical and research settings.ObjectivesThis study aimed to assess the instrumental validity, and the intra- and inter-rater reliability of an inexpensive digital adapted pressure algometer.MethodsA single rater applied 60 random compressions on a force platform. The pressure pain thresholds of 20 volunteers were collected twice (3 days apart) by two raters. The main outcome measurements were as follows: the maximal peak force (in kPa) and the pressure pain threshold (adapted pressure algometer vs. force platform). Cronbach’s α test was used to assess internal consistency. The standard error of measurement provided estimates of measurement error, and the measurement bias was estimated with the Bland–Altman method, with lower and upper limits of agreement.ResultsNo differences were observed when comparing the compression results (P = 0.51). The validity and internal intra-rater consistencies ranged from 0.84 to 0.99, and the standard error of measurement from 0.005 to 0.04 kPa. Very strong (r = 0.73–0.74) to near-perfect (r = 0.99) correlations were found, with a low risk of bias for all measurements. The results demonstrated the validity and intra-rater reliability of the digitally adapted pressure algometer. Inter-rater reliability results were moderate (r = 0.55–0.60; Cronbach’s α = 0.71–0.75).ConclusionThe adapted pressure algometer provide valid and reliable measurements of pressure pain threshold. The results support more widespread use of the pressure pain threshold method among clinicians.

Androgens by immunoassay and mass spectrometry in children with 46,XY disorder of sex development.

ObjectiveSteroid measurement is a challenge in pediatric endocrinology. Currently, liquid chromatography with tandem mass spectrometry (LC-MS/MS) is considered a gold standard for this purpose. The aim of this study was to compare both LC-MS/MS and immunoassay (IA) for androgens before and after human recombinant chorionic gonadotropin (rhCG) stimulus in children with 46,XY disorders of sex development (DSD).Methods Nineteen patients with 46,XY DSD were evaluated; all of them were prepubertal and non-gonadectomized. Testosterone, dihydrotestosterone (DHT), DHEA and androstenedione were measured by IA and LC-MS/MS before and 7 days after rhCG injection. The correlation between IA and LC-MS/MS was analyzed by the intraclass correlation coefficient (ICC) and Spearman’s rank correlation coefficient (SCC). For concordance analysis the Passing and Bablok (PB) regression and the Bland and Altman (BA) method were used.ResultsTestosterone showed excellent correlation (ICC = 0.960 and SCC = 0.964); DHT showed insignificant and moderate correlations as indicated by ICC (0.222) and SCC (0.631), respectively; DHEA showed moderate correlation (ICC = 0.585 and SCC = 0.716); and androstenedione had poor and moderate correlations in ICC (0.363) and SCC (0.735), respectively. Using the PB method, all hormones showed a linear correlation, but proportional and systematic concordance errors were detected for androstenedione, systematic errors for testosterone and no errors for DHEA and DHT. By the BA method, there was a trend of IA to overestimate testosterone and androstenedione and underestimate DHEA and DHT when compared to LC-MS/MS.ConclusionTraditional IA should be replaced by LC-MS/MS for the androgens measurement in prepubertal children whenever is possible.

Comparison of perfused volume segmentation between cone-beam CT and 99mTc-MAA SPECT/CT for treatment dosimetry before selective internal radiation therapy using 90Y-glass microspheres

PurposeTo compare the reliability and accuracy of the pre-treatment dosimetry predictions using cone-beam computed tomography (CBCT) versus 99mTc-labeled macroaggregated albumin (MAA) SPECT/CT for perfused volume segmentation in patients with hepatocellular carcinoma treated by selective internal radiation therapy (SIRT) using 90Y-glass microspheres. Materials and methodsFifteen patients (8 men, 7 women) with a mean age of 68.3±10.5 (SD) years (range: 47–82 years) who underwent a total of 17 SIRT procedures using 90Y-glass microspheres for unresectable hepatocellular carcinoma were retrospectively included. Pre-treatment dosimetry data were calculated from 99mTc-MAA SPECT/CT using either CBCT or 99mTc-MAA SPECT/CT to segment the perfused volumes. Post-treatment dosimetry data were calculated using 90Y imaging (SPECT/CT or PET/CT). The whole liver, non-tumoral liver, and tumor volumes were segmented on CT or MRI data. The mean absorbed doses of the tumor (DT), non-tumoral liver, perfused liver (DPL) and perfused non-tumoral liver were calculated. Intra- and interobserver reliabilities were investigated by calculating Lin's concordant correlation coefficients (ρc values). The differences (biases) between pre- and post-treatment dosimetry data were assessed using the modified Bland–Altman method (for non-normally distributed variables), and systematic bias was evaluated using Passing–Bablok regression. ResultsThe intra- and interobserver reliabilities were good-to-excellent (ρc: 0.80–0.99) for all measures using both methods. Compared with 90Y imaging, the median differences were 5.8Gy (IQR: −12.7; 16.1) and 5.6Gy (IQR: −13.6; 10.2) for DPL-CBCT and DPL-99mTc-MAA SPECT/CT, respectively. The median differences were 1.6Gy (IQR: −29; 7.53) and 9.8Gy (IQR: −28.4; 19.9) for DT-CBCT and DT-99mTc-MAA SPECT/CT respectively. Passing–Bablok regression analysis showed that both CBCT and 99mTc-MAA SPECT/CT had proportional biases and thus tendencies to overestimate DT and DPL at higher post-treatment doses. ConclusionCBCT may be a reliable segmentation method, but it does not significantly increase the accuracy of dose prediction compared with that of 99mTc-MAA SPECT/CT. At higher doses both methods tend to overestimate the doses to tumors and perfused livers.

Linear measurements of CBCT superimposition

Objectives: To assess accuracy and reliability of linear measurements for analysis of CBCT superimposition and determine if linear measurements are enough without requiring advanced analytical tools. Methods: Pre and post-operative CBCT scans of 20 orthodontic cases were used for CBCT superimposition. The gold standard was linear CBCT measurements on the axial section of each separate scan (pre and post) before superimposition. Voxel based and point based superimposition were done using Dolphin 3D (Dolphin Imaging and Management, Chatsworth, California, USA), In Vivo (Anatomage, San Jose, California, USA), and Ondemand 3D (Ondemand 3D; Cybermed Co., Seoul, Korea). Analysis of the superimposition was obtained on axial section of the superimposed models. Results were compared to the gold standard using error assessment according to Dahlberg error, Bland &Altman method and intra-class correlation coefficient. Results: Dolphin side by side method showed 25.4% relative Dahlberg error (RDE), 4.28 limit of agreement (LOA) and 0.768 intra-class correlation coefficient (ICC). In-Vivo point method showed 26.75% RDE, 4.48 LOA and 0.87 ICC. Whereas In-Vivo volume showed 24.66% RDE, 4.15 LOA and 0.822 ICC. On Demand showed 28.44%, 4.78 LOA and 0.7 ICC. Intra observer reliability of all methods regardless of the observers are poor. Conclusion: There is weak accuracy of the linear measurements on axial plane of CBCT superimposed models and it is not recommended alone for analysis.