Smallest Detectable Difference Research Articles

Reproducibility of Quantitative Double-Echo Steady-State T2 Mapping of Knee Cartilage.

Cartilage T2 can detect joints at risk of developing osteoarthritis. The quantitative double-echo steady state (qDESS) sequence is attractive for knee cartilage T2 mapping because of its acquisition time of under 5 minutes. Understanding the reproducibility errors associated with qDESS T2 is essential to profiling the technical performance of this biomarker. To examine the combined acquisition and segmentation reproducibility of knee cartilage qDESS T2 using two different regional analysis schemes: 1) manual segmentation of subregions loaded during common activities and 2) automatic subregional segmentation. Prospective. 11 uninjured participants (age: 28 ± 3 years; 8 (73%) female). 3-T, qDESS. Test-retest T2 maps were acquired twice on the same day and with a 1-week interval between scans. For each acquisition, average cartilage T2 was calculated in four manually segmented regions encompassing tibiofemoral contact areas during common activities and 12 automatically segmented regions from the deep-learning open-source framework for musculoskeletal MRI analysis (DOSMA) encompassing medial and lateral anterior, central, and posterior tibiofemoral regions. Test-retest T2 values from matching regions were used to evaluate reproducibility. Coefficients of variation (%CV), root-mean-square-average-CV (%RMSA-CV), and intraclass correlation coefficients (ICCs) assessed test-retest T2 reproducibility. The median of test-retest standard deviations was used for T2 precision. Bland-Altman (BA) analyses examined test-retest biases. The smallest detectable difference (SDD) was defined as the BA limit of agreement of largest magnitude. Significance was accepted for P < 0.05. All cartilage regions across both segmentation schemes demonstrated intraday and interday qDESS T2 CVs and RMSA-CVs of ≤5%. T2 ICC values >0.75 were observed in the majority of regions but were more variable in interday tibial comparisons. Test-retest T2 precision was <1.3 msec. The T2 SDD was 3.8 msec. Excellent CV and RMSA-CV reproducibility may suggest that qDESS T2 increases or decreases >5% (3.8 msec) could represent changes to cartilage composition. Stage 2.

Improving the measurement properties of the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R): deriving a valid measurement total for the calculation of change

Background The Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R) total score is a widely used measure of functional status in Amyotrophic Lateral Sclerosis/Motor Neuron Disease (ALS), but recent evidence has raised doubts about its validity. The objective was to examine the measurement properties of the ALSFRS-R, aiming to produce valid measurement from all 12 scale items. Method Longitudinal ALSFRS-R data were collected between 2013-2020 from 1120 people with ALS recruited from 35 centers, together with other scales in the Trajectories of Outcomes in Neurological Conditions-ALS (TONiC-ALS) study. The ALSFRS-R was analyzed by confirmatory factor analysis (CFA), Rasch Analysis (RA) and Mokken scaling. Results No definite factor structure of the ALSFRS-R was confirmed by CFA. RA revealed the raw score total to be invalid even at the ordinal level because of multidimensionality; valid interval level subscale measures could be found for the Bulbar, Fine-Motor and Gross-Motor domains but the Respiratory domain was only valid at an ordinal level. All four domains resolved into a single valid, interval level measure by using a bifactor RA. The smallest detectable difference was 10.4% of the range of the interval scale. Conclusion A total ALSFRS-R ordinal raw score can lead to inferential bias in clinical trial results due to its non-linear nature. On the interval level transformation, more than 5 points difference is required before a statistically significant detectable difference can be observed. Transformation to interval level data should be mandatory in clinical trials.

Reliability and Measurement Error of the Qualitative Analysis of Single Leg Loading (QASLS) Tool For Unilateral Tasks.

Movement quality assessment is popular within clinical and sporting practice, due to the contribution diminished or suboptimal movement quality is believed to have on musculoskeletal (MSK) injury risk. Various movement quality assessments exist, many are limited to bilateral or jumping movements evaluation. Qualitative analysis of single leg loading (QASLS) is a new clinical assessment tool for unilateral tasks that utilizes a dichotomous scoring system of ten questions relating to the segmental body regions of the trunk, lower and upper limb. To determine the intra and inter-rater, within- and between-session reliability of the QASLS tool during two unilateral movement tasks, and provide insight to measurement error and smallest detectable difference (SDD). Reliability Study. Fifteen healthy females (mean age 19 years SD2; height 167 cm, +/- 6; weight 56 kg, +/- 6) completed two unilateral tasks, single leg squat (SLS) and single leg landing (SLL), within session data collection occurred on the same day, with between session data collection occurring seven days later. Tasks were scored with the QASLS tool via video playback. Intra-Class correlation coefficients (ICCk,3) were used to measure within and between session reliability, and Kappa coefficients and percentage of exact agreement (PEA%) were used to determine intra and inter-rater reliability. Standard error of measurement (SEM) and the SDD for the compound score of each limb was calculated. Within session reliability of QASLS scores was good (ICC = 0.82-0.86) for SLS and moderate (ICC = 0.67-0.87) for SLL. Between session reliability was moderate (ICC = 0.69-0.87) for SLS and excellent (ICC = 0.92-0.93) for SLL. SEM was less than 1 point, and SDD for compound score ranging from 1.0-2.5 points. Intra-rater agreement of compound QASLS score was near perfect (k = 0.85-100; PEA% 90-100%) and agreement of individual components was substantial- near perfect (k = 0.13-0.74; PEA% 78-100%). Inter-rater agreement for compound QASLS scores ranged from non-substantial (k = 0.13-0.74; PEA% 43.3-90%) for SLS and non-slight (k =0.03-0.17; PEA% 43.3-60%) for SLL. The QASLS movement analysis tool can be used to analyze movement quality during two unilateral loading tasks with moderate to excellent within and between session reliability. PEA% was acceptable for inter-rater agreement, however rater education training is recommended to develop more acceptable levels of reliability. 3.

129Xe MRI Ventilation Defects in Asthma: What is the Upper Limit of Normal and Minimal Clinically Important Difference?

The minimal clinically important difference (MCID) and upper limit of normal (ULN) for MRI ventilation defect percent (VDP) were previously reported for hyperpolarized 3He gas MRI. Hyperpolarized 129Xe VDP is more sensitive to airway dysfunction than 3He, therefore the objective of this study was to determine the ULN and MCID for 129Xe MRI VDP in healthy and asthma participants. We retrospectively evaluated healthy and asthma participants who underwent spirometry and 129XeMRI on a single visit; participants with asthma completed the asthma control questionnaire (ACQ-7). The MCID was estimated using distribution- (smallest detectable difference [SDD]) and anchor-based (ACQ-7) methods. Two observers measured VDP (semiautomated k-means-cluster segmentation algorithm) in 10 participants with asthma, five-times each in random order, to determine SDD. The ULN was estimated based on the 95% confidence interval of the relationships between VDP and age. Mean VDP was 1.6 ± 1.2% for healthy (n=27) and 13.7 ± 12.9% for asthma participants (n=55). ACQ-7 and VDP were correlated (r=.37, p=.006; VDP=3.5·ACQ+4.9). The anchor-based MCID was 1.75% while the mean SDD and distribution-based MCID was 2.25%. VDP was correlated with age for healthy participants (p=.56, p =.003; VDP=.04·Age-.01). The ULN for all healthy participants was 2.0%. By age tertiles, the ULN was 1.3% ages 18-39 years, 2.5% for 40-59 years and 3.8% for 60-79 years. The 129Xe MRI VDP MCID was estimated in participants with asthma; the ULN was estimated in healthy participants across a range of ages, both of which provide a way to interpret VDP measurements in clinical investigations.

Patient Disease Trajectories in Rheumatoid Arthritis Patients Treated with Baricitinib 4-mg in FourPhase 3 Clinical Studies.

We sought to identify and compare treatment response groups based on individual patient responses (rather than group mean response) over time on the Clinical Disease Activity Index (CDAI) for rheumatoid arthritis (RA), in patients treated with baricitinib 4-mg in 4phase 3studies. Trajectory subgroups were identified within each study using growth mixture modeling. Following grouping, baseline characteristics and disease measures were summarized and compared. In each study, three response trajectories were identified. In the three studies of patients naïve to biological disease-modifying anti-rheumatic drugs (bDMARDs) patients had, on average, high disease activity, as measured by CDAI. In these studies, a group of rapid responders (65-71% of patients) had the lowest baseline CDAI scores and achieved mean CDAI ≤ 10 by week 16. Gradual responders (10-17%) had higher baseline CDAI, but generally achieved low disease activity (CDAI ≤ 10) by week 24. A group of partial responders (18-22%) had higher baseline CDAI and did not achieve mean CDAI ≤ 10. In bDMARD-experienced patients, the subgroups were rapid responders, who achieved mean CDAI ≤ 10 (42% of patients); partial responders, with mean CDAI decrease of ~ 15 points from baseline (42% of patients); and limited responders (15% of patients). Changes in modified total sharp score (mTSS; assessed only in biologic-naïve patients) were below the smallest detectable difference at 24/52weeks for > 90% of patients in each group, excepting partial responders in RA-BEGIN (≥ 75% no detectable change). In patients receiving baricitinib 4-mg, lower baseline CDAI was generally associated with rapid response, while higher baseline CDAI scores were generally seen for patients who either reached treatment targets more gradually, or who had a partial or limited response. Maintenance of response was observed with continued baricitinib treatment in all response groups and generally included maintenance of mTSS.

Validation and interval scale transformation of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) in patients undergoing knee arthroplasty, using the Rasch model

ObjectivesInterval scale reduce measurement bias compared to ordinal scale. We aimed to evaluate the fit of Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) to the Rasch model and derive the transformation table for interval scale measurement. MethodsData from osteoarthritis patients listed for knee arthroplasty (KA) pre-operatively, and at 6- and 12- months post-operative was used. WOMAC was calibrated for fit to the Rasch model for monotonicity, homogeneity, local item independence and absence of differential item functioning (DIF) in a randomly selected 900 patients, 300 from each time point; parameter estimates were then imported into the full data set. Responsiveness was reported through Standard Error of Measurement (SEM); Smallest Detectable Difference (SDD), %SDD and effect sizes (ES) between baseline and 6-months. WOMAC was transformed from ordinal to interval values. Results1136 patients (mean age 65.9 years, 69.9% female) were included. WOMAC pain (0−20), function (0−68) and total scores (0−96) had adequate fit to Rasch model with good reliability (Person Separation Index: 0.76, 0.80 and 0.79). No item deletion was required. The SEM, SDD, %SDD and ES of WOMAC total were 4.4, 6.9, 10.1, and 1.97. No significant DIF was seen for age, sex, body mass index, type of KA, languages, and education level. WOMAC pain, function and total scores were transformed to interval scales. ConclusionWOMAC total, pain and function scales had adequate fit to the Rasch model, providing unidimensional measure with good reliability and responsiveness. Transformation of WOMAC to interval scale measurement is applicable to other studies.

Sound Localization Ability in Dogs.

The minimum audible angle (MAA), defined as the smallest detectable difference between the azimuths of two identical sources of sound, is a standard measure of spatial auditory acuity in animals. Few studies have explored the MAA of dogs, using methods that do not allow potential improvement throughout the assessment, and with a very small number of dog(s) assessed. To overcome these limits, we adopted a staircase method on 10 dogs, using a two-forced choice procedure with two sound sources, testing angles of separation from 60° to 1°. The staircase method permits the level of difficulty for each dog to be continuously adapted and allows for the observation of improvement over time. The dogs' average MAA was 7.6°, although with a large interindividual variability, ranging from 1.3° to 13.2°. A global improvement was observed across the procedure, substantiated by a gradual lowering of the MAA and of choice latency across sessions. The results indicate that the staircase method is feasible and reliable in the assessment of auditory spatial localization in dogs, highlighting the importance of using an appropriate method in a sensory discrimination task, so as to allow improvement over time. The results also reveal that the MAA of dogs is more variable than previously reported, potentially reaching values lower than 2°. Although no clear patterns of association emerged between MAA and dogs' characteristics such as ear shape, head shape or age, the results suggest the value of conducting larger-scale studies to determine whether these or other factors influence sound localization abilities in dogs.

Low-dose CT hounsfield units: a reliable methodology for assessing vertebral bone density in radiographic axial spondyloarthritis

ObjectiveStudying vertebral bone loss in radiographic axial spondyloarthritis (r-axSpA) has been challenging due to ectopic bone formation. We cross-sectionally analysed low-dose CT (ldCT) trabecular bone density Hounsfield units (HU) measurements...

Reliability of the Modified Star Excursion Balance Test in individuals with Down Syndrome

Neuromotor problems such as hypotonia, incoordination, impaired sensory-motor integration lead to significant delays in motor skills and balance development in individuals with Down Syndrome (DS). Balance control is essential for performing many motor skills independently and safely. Standardised testing of balance control can contribute significantly to the rehabilitation of individuals with DS. The purpose of this study was to determine intrarater and interrater reliability of the Modified Star Excursion Balance Test (SEBT) for individuals with DS. Thirteen individuals with DS were recruited in this study. Intraclass correlation coefficients (ICC [3,1]) with 95% confidence intervals, standard error of measurement (SEM), the smallest detectable difference (SDD) and the Spearman rank correlation coefficient were calculated. In all directions of the Modified SEBT, no statistically significant difference was found between two raters’ first and second measurements (p > 0.05). Interrater reliability for all reach directions of the Modified SEBT was high, with ICC ranging from 0.990 to 0.998.95% confidence intervals, SEM and SDD ranged from 0.924 to 0.999, 0.180–2.434 and 3.270–6.747, respectively. The Modified SEBT are reliable for evaluating dynamic balance in individuals with DS aged between 6 and 24 years.

Reproducibility of the Six-Minute Walk Test in Children and Youth With Juvenile Idiopathic Arthritis.

While the 6-minute walk test is increasingly being used in research to evaluate submaximal exercise capacity of children with juvenile idiopathic arthritis (JIA), psychometric properties with this population have not been well evaluated. We undertook this study to evaluate reproducibility (agreement and test-retest reliability) and to determine standard error of measurement (SEM) and smallest detectable difference (SDD) in children and youth with JIA. Participants (n=22, mean ± SD age 13.1 ± 1.1 years, 63.6% female) completed a 6-minute walk test as part of their routine clinical assessment, and then repeated the 6-minute walk test at mean ± SD 8 ± 1.2 days later, in the same clinical setting with the same rater. The intraclass correlation coefficient (95% confidence interval) was 0.86 (0.66-0.94); the SEM and SDD were 23.5 and 65.1 meters, respectively. These results provide evidence of good-excellent reproducibility of the 6-minute walk test with children and youth with JIA and support the use of the 6-minute walk test as a measure of submaximal exercise capacity in clinical practice and research.

Comparison of EQ-5D-3L and 5L versions following operative fixation of closed ankle fractures

PurposeTo undertake the first testing and comparison of measurement properties for the EuroQol EQ-5D-3L and 5L in patients with ankle problems.MethodsThe cross-sectional postal survey of 959 patients aged ≥ 18 years, who underwent surgical treatment (ORIF) for unstable and closed ankle fractures in Eastern Norway. Both the EQ-5D-3L and 5L were included in a postal questionnaire in 2015, 3–6 years post surgery. Missing data, floor and ceiling effects, and response consistency were assessed. Tests of validity included comparisons with scores for the SF-36 and widely used ankle-specific instruments. The 5L version was assessed for test–retest reliability.ResultsThere were 567 (59%) respondents; 501 completed both versions and 182 (61%) the 5L retest questionnaire. The 5L outperformed the 3L in tests of data quality and classification efficiency. Correlations with scores for other instruments largely met expectations, those for the 5L being slightly higher. All 5L scores had acceptable levels of reliability. For the 5L index, the smallest detectable differences for group and individual comparisons were 0.02 and 0.20, respectively.ConclusionThe 5L outperformed the 3L in terms of data quality, number of health states assessed and tests of validity. The 5L is recommended in research and other applications following surgery for ankle fracture but further testing including responsiveness to change is recommended at clinically relevant follow-up periods.

Scale Banking for Patient-Reported Outcome Measures That Measure Functioning in Rheumatoid Arthritis: A Daily Activities Metric.

Functioning is an important outcome for the management of rheumatoid arthritis (RA). Heterogeneity of respective patient-reported outcome measures (PROMs) challenges direct comparisons between their results. This study aimed to standardize reporting of such PROMs measuring functioning in RA to facilitate comparability. Common-item nonequivalent group design with the Health Assessment Questionnaire (HAQ) as a common scale across data sets from various countries (including the UK, Turkey, and Germany) to establish a common metric was used. Other PROMs included are the physical function items of the Multidimensional HAQ (MDHAQ), the Disabilities of the Arm, Shoulder, and Hand questionnaire, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the World Health Organization Disability Assessment Schedule II (WHODAS II), the Medical Outcomes Study Short Form 36 (SF-36) health survey, and 4 short forms (20, 10, 6, and 4 physical function items) from the Patient-Reported Outcomes Measurement Information System. As the HAQ includes mobility, self-care, and domestic life items, this study focuses on these 3 domains. PROMs were described using standard error of measurement (SEM) and smallest detectable difference (SDD). A Rasch measurement model was used to create the common metric. The range of the SEM was 0.2 (MDHAQ) to 7.4 (SF-36 health survey physical functioning domain). The SDD revealed a range from 9.7% (WOMAC rating scale) to 33.5% (WHODAS physical functioning domain). PROMs co-calibration revealed fit to the Rasch measurement model. A transformation table was developed to allow exchange between PROM scores. Scores between the daily activity PROMs commonly used in RA can now be compared. Factors such as SEM and SDD help to determine the choice of a PROM in clinical practice and research.

Type of active video-games training does not impact the effect on balance and agility in children with and without developmental coordination disorder: A randomized comparator-controlled trial

Aim To compare the effect of the Nintendo Wii-Fit and Xbox Kinect on motor performance and to assess differential effects in children with Developmental Coordination Disorder (DCD) and typical development (TD). Method In an assessor-blinded randomized comparator-controlled design, 68 participants (34 DCD and 34 TD) aged 7–10 years, were randomly assigned to train on one of two devices (34 Wii-Fit; 34 Xbox Kinect). Results Repeated measure ANOVA revealed a significant main effect of time on balance and agility variables (MABC-2, Wii Yoga stance, PERF-FIT side-hop, PERF-FIT ladder-stepping; all p ≤ 0.02), but not on running variables (BOT2-sprint, 10 × 5 m sprint and PERF-FIT ladder running; p > 0.05). No significant interactions were observed, indicating similar changes on both devices. Overall, 35% of the TD children and 76% of the children with DCD improved on one or more of the outcomes beyond the smallest detectable difference. However, at the individual level, larger differences in improvement were found in the Kinect group compared to the Wii between TD and DCD groups. Conclusion Both Wii-Fit and Kinect devices can be used to train with similar results on motor performance. An important percentage (76%) of children with DCD improved on at least one motor task after training.

Validity and reliability of the Greek version of modified Baecke questionnaire

ObjectivesThe purpose of this study was to translate and investigate the validity and reliability of the modified Baecke Physical Activity Questionnaire (mBQ) in the Greek adult population. Study designThis is a cross-cultural study. MethodsThe cross-cultural adaptation of the mBQ was performed according to official guidelines. The prefinal Greek translation was tested in 30 healthy participants. The reliability was determined (n = 100) by filling out the mBQ, two times, 1 week apart. For validation (n = 45), the scores between the mBQ and the International Physical Activity Questionnaire (IPAQ) were compared, and the correlation between mBQ and VO2max and between mBQ and interview (METS) were assessed. ResultsHigh statistical significant of test–retest reliability was found (intraclass correlation coefficient = 0.84; standard error of measurement = 0.48; smallest detectable difference = 16.7%; Cronbach's alpha = 0.92). Statistical significant correlation between the mBQ and the IPAQ (r = 0.425, P = 0.005), high correlation between the mBQ and METS (r = 0.691, P = 0.000), and moderate correlation between mBQ and VO2max (r = 0.388, P = 0.08) were found. ConclusionThe Greek mBQ was found to be reliable and valid for assessing the level of physical activity in the Greek population. Clinicaltrials.gov identifierNCT04890756.

The Effect of External Power Output and Its Reliability on Propulsion Technique Variables in Wheelchair Users With Spinal Cord Injury.

The purpose of this study was to assess 1) how treadmill slope variance affected external power output (PO) and propulsion technique reliability; and 2) how PO is associated with propulsion technique. Eighteen individuals with spinal cord injury performed two wheelchair treadmill exercise blocks (0% and 1% treadmill slope, standardized velocity) twice on two separate days. PO, velocity, and 14 propulsion technique variables were measured. In a follow-up study, N = 29 performed wheelchair treadmill drag tests. Target and actual slope were documented and PO, intraclass correlation coefficients (ICC) and smallest detectable differences (SDD) were calculated. Within and between visits, the reliability study ICCs were perfect for velocity (1.0), weak for PO (0.33-0.46), and acceptable (>0.70) for five (0% slope) and 10 (1% slope) propulsion technique variables, resulting in SDDs of 35-196%. Measured PO explained 56-90% of the variance in key propulsion technique variables. In the follow-up, PO ICCs were weak (0.43) and SDDs high. Bias between target and actual slope appeared random. In conclusion, PO variability accounts for 50-90% of the variability in propulsion technique variables when speed and wheelchair set-up are held constant. Therefore, small differences in PO between interventions could mask the effect of the interventions on propulsion technique.

COMPARISON OF 3D QUANTITATIVE OSTEOARTHRITIS IMAGING BIOMARKERS: A STUDY USING PAIRED CT AND MR IMAGES FROM THE IMI-APPROACH STUDY

MRI bone surface area and femoral bone shape (B-score) measures have been employed as quantitative endpoints in DMOAD clinical trials. The B-score (typical range -2 to +7) has been shown to be an objective, automated assessment of OA status, with clinical risk defined for current and future pain, functional limitation and total knee replacement. Computerized Tomography (CT) imaging is more commonly used for 3D visualization of bony anatomy due to its high bone-soft tissue contrast. Also, CT images are not subject to the geometric distortion in MR images due to field inhomogeneities, a problem addressed in DMOAD clinical trials by positioning the knee near the magnet isocenter. Measurement of 3D joint space width (3DJSW) has been previously reported using CT images but is possible from MR images. To test the robustness of the B-score, bone area and 3DJSW imaging endpoints to the choice of imaging modality, we compared the results of automated analysis of CT and MR image pairs acquired at baseline and 24-month timepoints. We used image data from the IMI-APPROACH exploratory, 2-year prospective cohort study. High resolution CT images were acquired at baseline and 24-months. These were matched with 3D T1w MR images with fat-sat or WE sequences. CT and MR images were acquired within a mean of 12 days of each other. Additional test-retest MR images with repositioning were available from 37 subjects. Kellgren-Lawrence Grades (KLG) were read centrally from screening weight-bearing x-rays. Femur and tibia bones were automatically segmented with sub-voxel accuracy from CT or MR images using active appearance models, a machine learning model trained to search images (Imorphics, Manchester, UK). Bone area measurement was produced for MF.tAB, LF.tAB, MT.tAB and LT.tAB regions. Average 3DJSW was measured in central regions of the medial or lateral tibial plateaus, normal to the tibial surface. Linear regression was used to test for correlation between measures. Limits of agreement and systematic bias were tested using Bland-Altman analysis. Smallest detectable difference (SDD) for MR B-score was computed from test-retest image pairs using Bland-Altman analysis. Images acquired from the same subject at both baseline and 24-month timepoints were treated as independent. Baseline and 24-month CT-MR pairs of the same knee were available from 231 and 203 subjects respectively. 338 were female knees (78%). KLG was KLG0 (19%); KLG1 (31%); KLG2 (30%); KLG3 (16%); KLG4 (3%) with 5 knees ungraded (1%). SDD of the B-score measure was 0.227. MRI B-score measures were highly correlated with CT (R2 = 0.97) and showed good agreement with a relatively small bias of 0.1. All 4 area measures were highly correlated (R2 = 0.96-0.97) and showed negative bias (MR smaller). Both 3DJSW measures showed a positive bias for MR (medial bias = 1.04mm, R2 = 0.58; lateral bias = 0.42mm, R2 = 0.47). The results suggest that B-score may be measured reliably using either modality. However, it is likely that the bone surface identified using MR and CT will be at slightly different positions within the bone/cartilage boundary. A consistent negative bias suggests the MR bone boundary is inside the CT boundary. This is consistent with the positive bias in favor of MR for 3DJSW. However, the MR-CT difference for medial 3DJSW is larger than for lateral 3DJSW, possibly due to a difference in knee pose during acquisition (fully extended for CT, flexed for MR) – the tibia is more externally rotated with respect to the femur in the fully extended knee. AB and MB are employees of Imorphics. This work has received support from the EU/EFPIA Innovative Medicines Initiative Joint Undertaking (APPROACH grant n° 115770). CORRESPONDENCE ADDRESS: alan.brett@stryker.com

Neck proprioception assessment with a laser beam device: reliability in participants without neck pain and differences between participants with and without neck pain

BackgroundProprioception deficits have previously been reported in patients with non-specific chronic neck pain (NSCNP), with a comprehensive and valid battery of tests still required. This study aimed to investigate the test-retest and inter-rater reliability of cervical proprioception in participants without NSCNP and to examine differences in proprioception between participants with and without NSCNP. Twenty participants without NSCNP and 20 age- and sex-matched participants with NSCNP were recruited. Proprioception tests were sequentially performed in random order, in four head-to-neutral movement directions (starting positions at mid-flexion, mid-extension and mid-right/mid-left rotation head-neck positions and end position at neutral head-neck posture) and two head-to-target movement directions (starting position from neutral head-neck posture and end positions at right and left 45° rotation), with a laser beam device secured onto their forehead. Participants performed all tests in sitting at a 1-m distance from a whiteboard. The average deviations of the laser beam mark from set targets marked on the whiteboard represented proprioception deficits. The two-way random, absolute agreement model of the intraclass correlation coefficient (ICC), the standard error of the measurement (SEM) and the smallest detectable difference (SDD) were used as measures of reliability. Between-group differences were examined with the independent samples t test.ResultsThe reliability of the laser beam device in participants without neck pain varied from poor to good. The following tests demonstrated good reliability: test-retest ‘Head-to-neutral from flexion’ (ICC: 0.77–0.78; SDD: 5.73–6.84 cm), inter-rater ‘Head-to-neutral from flexion’ (ICC: 0.80–0.82; SDD: 6.20–6.45 cm) and inter-rater ‘Head-to-neutral from right/left rotation’ (ICC: 0.80–0.84; SDD: 5.92–6.81 cm). Differences between participants with and without NSCNP were found only in head-to-neutral from flexion (4.10–4.70 cm); however, those were within the limits of the SDD values of the HtN from flexion test.ConclusionsThe laser beam device can be reliably used in clinical practice only in the aforementioned head-neck movement directions, based on the findings of the present study. The between-group differences noted involved only the head mid-flexion to neutral test, possibly denoting proprioception deficits only in this movement direction, for reasons that require further evaluation.

Paraspinal strength and electromyographic fatigue in patients with sub-acute back pain and controls: Reliability, clinical applicability and between-group differences.

BACKGROUNDParaspinal muscle strength and fatigue are considered important in low back pain (LBP) prevention and rehabilitation. High reliability of paraspinal strength and electromyographic (EMG)-fatigue parameters has not been universally reported. Moreover, the discriminative validity of these parameters requires further exploration, under the threat of potentially poor reliability of the methods examined.AIMTo investigate the reliability and discriminative validity of paraspinal strength and EMG-related fatigue in subjects with recurrent LBP and healthy participants.METHODSTest-retest measurements were performed in 26 healthy and 66 LBP volunteers, for reliability. Paraspinal isometric maximal and mean strength were determined with a maximum voluntary isometric contraction (MVIC) protocol, performed in a custom-made device. For the fatigue test, participants performed a 60% MIVC level continuous isometric contraction of the paraspinals, in conjunction with EMG analysis from 4 muscle sites of the lumbar spine. Initial median frequency (IMF), the median frequency slope (MFslope), as well as the root mean square (RMS) slope EMG parameters were used as fatigue measures. Data were analysed with repeated measures ANOVA for test-retest differences. For reliability, the intraclass correlation coefficient (ICC3,1), standard error of the measurement (SEM) and the smallest detectable difference (SDD) were reported. Group-related differences for fatigue measures were analysed with a Multivariate Analysis of Covariance, with age, weight and strength as covariates.RESULTSIsometric strength presented statistically significant between-day differences (P < 0.01), however these did not exceed 10% (healthy: 7.2%/LBP-patients: 9.7%) and ICC reliability values were excellent, yet test-retest error was increased for the patient group (healthy: ICC3,1: 0.92-0.96, SEM: 5.72-5.94 Hz, SDD: 18.51%-18.57%/LBP-patients: ICC3,1: 0.91-0.96, SEM: 6.49-6.96, SDD: 30.75%-31.61%). For the frequency data, IMF reliability was excellent (healthy: ICC3,1: 0.91-0.94, SEM: 3.45-7.27 Hz, SDD: 9.56%-20.14%/patients: ICC3,1: 0.90-0.94, SEM: 6.41-7.59 Hz, SDD: 17.75%-21.02%) and of MF raw and normalised slopes was good (healthy: ICC3,1: 0.78-0.82, SEM: 4.93-6.02 Hz, SDD: 13.66-16.67%/LBP-patients: ICC3,1: 0.83-0.85, SEM: 6.75-7.47 Hz, SDD: 18.69%-20.69%). However, the reliability for RMS data presented unacceptably high SDD values and were not considered further. For discriminative validity, less MVIC and less steep MFslopes were registered for the patient group (P < 0.01).CONCLUSIONReliability and discriminative ability of paraspinal strength and EMG-related frequency parameters were demonstrated in healthy participants and patients with LBP.

Ultrasonography Method of Deep Cervical Muscles and Thickness Measurement Reliability in Cervicogenic Headache and Healthy Subjects:APilot Study

Introduction: In Cervicogenic Headache (CGH), motor control of muscles is impaired and deep upper neck muscles (extensor and flexor muscles) become atrophied. In this research, thickness measurement of Longus Capitis (LCap), Rectus Capitis Posterior Major (RCPM), and Obliquus Capitis Superior (OCS) muscles were conducted and intra-rater reliability of the thickness measurement of these muscles was assessed in CGH and healthy subjects.&#x0D; Materials and Methods: Twenty subjects, including 10 healthy subjects (19-32 years old) and 10 CGH patients (20-35 years old) participated in this study. LCap thickness was measured at the level of C3-C4 in the supine position and posterior muscles (RCPM and OCS) thickness at the C1-C2 level in the sitting position. All ultrasound images were captured by a linear probe with a 50-mm footprint in B mode option and frequency range of 9-12 Hz. Intraclass Correlation Coefficients (ICC), Standard Error Of Measurement (SEM), and the Smallest Detectable Difference (SDD) were calculated for data analysis.&#x0D; Results: The ICC for thickness measurement of LCap was from 0.70 to 0.91 (good to excellent), for RCPM thickness was from 0.69 to 0.94 and for OCS muscle thickness was from 0.87 to 0.98. SEM values for LCap were between 0.08 and 0.25 and the SDD values between 0.22 and 0.71. SEM values for RCPM were between 0.22 and 0.43 and these values were reported for OCS muscle between 0.19 and 0.45.&#x0D; Conclusion: The results indicated that the presented position and the level of ultrasonography in this study are appropriate and ultrasound is a reliable tool to measure the deep upper neck muscle thickness in CGH and healthy subjects.

Test-Retest Reliability and Consistency of HVPG and Impact on Trial Design: A Study in 289 Patients from 20 Randomized Controlled Trials.

Portal hypertension (PH) is a major driver for cirrhosis complications. Portal pressure is estimated in practice by the HVPG. The assessment of HVPG changes has been used for drug development in PH. This study aimed at quantifying the test-retest reliability and consistency of HVPG in the specific context of randomized controlled trials (RCTs) for the treatment of PH in cirrhosis and its impact on power calculations for trial design. We conducted a search of published RCTs in patients with cirrhosis reporting individual patient-level data of HVPG at baseline and after an intervention, which included a placebo or an untreated control arm. Baseline and follow-up HVPGs in the control groups were extracted after digitizing the plots. We assessed reliability and consistency and the potential impact of study characteristics. We retrieved a total of 289 before and after HVPG measurements in the placebo/untreated groups from 20 RCTs. The time span between the two HVPG measurements ranged between 20minutes and 730days. Pre-/post-HVPG variability was lower in studies including only compensated patients; therefore, modeled sample size calculations for trials in compensated cirrhosis were lower than for decompensated cirrhosis. A higher proportion of alcohol-associated cirrhosis and unicentric trials was associated with lower differences between baseline and follow-up measurements. The smallest detectable difference in an individual was 26% and 30% in compensated and decompensated patients, respectively. The test-retest reliability of HVPG is overall excellent. Within-individual variance was higher in studies including higher proportions of decompensated patients. These findings should be taken into account when performing power analysis for trials based on the effects on HVPG or when considering HVPG as a tool to guide therapy of PH.