Test-retest Conditions Research Articles

Definition and reliability of 3D acetabular and global offset measurements from bi-plane X-rays

The importance of the global offset, the sum of femoral and acetabular offset, has been underlined in the literature as a key factor for the functional outcome of total hip arthroplasty (THA). However, the acetabular offset is not defined for bi-plane X-rays, a technology providing 3D measurements of the lower limb and commonly used for patients undergoing THA. The aim of this paper is to introduce a measurement method of the 3D acetabular offset with bi-plane X-rays. Our method combines the use of technical and anatomical coordinate systems. The most appropriate definition will be selected based on the best reliability and measurement error. The consequent reliability of the global offset was also assessed. Twenty-eight patients undergoing primary THA were selected retrospectively. Two operators performed three reconstructions for each patients before and after THA. Intraclass correlation (ICC) and smallest detectable change (SDC) were computed for intra-operator, inter-operator and test–retest conditions for all combinations of technical and anatomical coordinate systems. ICCs were good to excellent. One combination was more reliable than others with a moderate mean SDC of 6.3 mm (4.3–8.7 mm) for the acetabular offset and a moderate mean SDC of 6.2 mm (5.6–6.7 mm) for the global offset. This is similar to the reliability and mean SDC of the femoral offset (4.8 mm) approved for clinical use which indicates that this method of acetabular offset measurement is appropriate. This opens a research avenue to better understand the role of the acetabular offset on THA outcomes, which seems overlooked in the literature.

Reliability of the pelvis and femur anatomical landmarks and geometry with the EOS system before and after total hip arthroplasty

Bi-plane X-ray provides 3D measurements of the lower limb based on the identification of anatomical landmarks in sagittal and frontal X-rays. In clinical practice, such measurements involve multiple operators and sessions. This study aimed at evaluating the reliability of anatomical landmarks identification and geometric parameters of the pelvis and femur measured with bi-plane X-rays before and after total hip arthroplasty (THA). Twenty-eight patients undergoing primary THA were selected retrospectively. Two operators performed three reconstructions for each patient before and after THA. Intraclass correlation (ICC) and smallest detectable change (SDC) were computed for intra-operator, inter-operator, and test–retest conditions. Most anatomical landmark positions had good to excellent SDC (< 5 mm) apart from the centre of the sacral slope, greater trochanter, and anterior superior iliac spines (up to 7.1, 16.9, and 21.5 mm respectively). Geometric parameters had moderate to excellent SDC, apart from femoral and stem torsion, pelvic incidence, and APP inclination with poor SDC (9–12°). The sagittal view had significantly higher measurement errors than the frontal view. Test–retest and inter-operator conditions had no significant differences suggesting a low influence of patient posture. Osteoarthritis and the presence of implants did not seem to influence reliability and measurement error. This study could be used as a reference when assessing lower limb structure with bi-plane X-rays.

Multi-feature mismatch negativity: How can reliable data be recorded in a short time?

ObjectiveThe aim of the study was to conduct multi-feature mismatch negativity (MMN) implementations and identify via a test–retest study the reliability of MMN responses obtained through a 5-stimulus version of the MMN paradigm. It was also aimed to identify a reliable MMN recording number by comparing the MMN responses obtained under conditions of ten and four recordings conditions while making the recording time shorter. MethodsTwenty-one healthy volunteers, aged between 18 and 36 years, were included in the study. A 5-stimulus version of the multi-feature MMN paradigm was presented to participants. Ten recordings were obtained for each participant under both test and retest conditions. The MATLAB program was utilized in the evaluation of MMN amplitude and latency. The Fz was chosen for the statistical analysis. Four of the ten recordings were chosen at random, and statistical analyses were performed again for those four recordings. ResultsThere was no statistically significant difference in amplitudes obtained from test and retest conditions with ten recordings. With four recordings, for frequency, intensity, duration, and gap deviants, there were no statistically significant differences between amplitudes obtained under test and retest conditions. However, there was a statistically significant difference between amplitudes of the location deviant. No statistically significant difference was observed among latencies under test–retest conditions with both ten and four recordings. ConclusionsThese findings demonstrate that MMN amplitudes could be used reliably as short-time evaluations with four recordings, but more recordings are required for MMN latencies. In terms of practicality, four recordings are more advantageous and comfortable for both clinicians and patients in MMN practice. SignificanceWhen behavioral tests are required, MMN is regarded as an objective test that can be used reliably for adults, children, and infants who cannot be evaluated using behavioral methods. It is concluded that conditions with four recordings aremore advantageous and comfortable for both clinicians and patients in MMN practice.

Validity and reliability of accelerations and orientations measured using wearable sensors during functional activities

Wearable sensors may enable the assessment of movement in a real-world setting, but they are not yet a standard practice in the analysis of movement due to the unknown accuracy and reliability with respect to different functional activities. Here, we established the concurrent validity and test–retest reliability of accelerations and orientations measured using affordable novel sensors during squats, jumps, walking and stair ambulation. In this observational study, participants underwent three data collection sessions during one day. Accelerations and orientations from sacrum, thigh and shank were collected using these sensors and already validated gold-standard sensors as the criterion method. We assessed validity by comparing the similarity of signal waveforms with the Linear Fit Method and by comparing mean differences in range values with the Bland–Altman plots. Reliability was assessed by calculating interclass correlation coefficient and standard error of measurements of the range values. Concurrent validity was from fair to excellent in 91% of the cases for accelerations and in 84.4% for orientations. Test–retest reliability of accelerations was from fair to excellent in 97% of cases when the sensors were attached by a researcher, and in 84.4% of cases when the sensors were attached by participants. Test–retest reliability of orientations was from fair to excellent in 88.9% of cases when the sensors were attached by a researcher, and in 68.9% of cases when the sensors were attached by participants. In conclusion, the new affordable sensors provide accurate measures of accelerations and orientations during multiple functional activities in healthy adults. Reliability of the orientations may depend on the ability to replicate the same position of the sensor under test–retest conditions.

Sound-level Monitoring Earphones With Smartphone Feedback as an Intervention to Promote Healthy Listening Behaviors in Young Adults.

More than a billion adolescents and youngsters are estimated to be at risk of acquiring recreational noise-induced hearing loss (RNIHL) due to the unsafe use of personal audio systems. RNIHL is preventable; therefore, the present study aimed to determine (i) the accuracy and reliability of dbTrack (Westone) sound-level monitoring earphones and (ii) the effect of sound-level monitoring earphones with smartphone feedback and hearing-health information as an intervention to promote healthy listening behaviors in young adults. The study consisted of two phases: the first phase investigated the accuracy and reliability of dbTrack sound-level monitoring earphones. Accuracy was determined by comparing earphone measurements to sound level meter measurements. Intradevice reliability was determined by comparing earphone measurements during test-retest conditions. Nineteen participants were recruited through convenience sampling to determine within-subject reliability by comparing in-ear sound levels measured by the earphones during test-retest conditions. For the second phase of the study, a single-group pretest-posttest design was utilized. Forty participants, recruited through snowball sampling, utilized the sound-level monitoring earphones with the accompanying dbTrack smartphone application for 4 weeks. The application's smartphone feedback was disabled during the first 2 weeks (pretest condition) and enabled during the last 2 weeks (posttest condition). Average daily intensities, durations, and sound dosages measured during pre- and posttest conditions were compared. Phase 1 dbTrack earphone measurements were within 1 dB when compared with sound level meter measurements. Earphones were also within 1 dB in repeated measures across earphones and across participants. Phase 2 posttest average daily intensity decreased by 8.7 dB (18.3 SD), duration decreased by 7.6 minutes (46.6 SD), and sound dose decreased by 4128.4% (24965.5% SD). Differences in intensity and sound dose were significantly lower with a small and medium effect size, respectively. This study's preliminary data indicate that dbTrack (Westone) sound-level monitoring earphones with a calibrated in-ear microphone can reliably and accurately measure personal audio systems sound exposure. Preliminary results also suggest that feedback on sound exposure using the accurate sound-level monitoring earphones with the accompanying dbTrack application can potentially promote safe listening behavior in young adults and reduce the risk of acquiring an RNIHL.

PET quantification of brain O-GlcNAcase with [18F]LSN3316612 in healthy human volunteers

BackgroundPrevious studies found that [18F]LSN3316612 was a promising positron emission tomography (PET) radioligand for imaging O-GlcNAcase in nonhuman primates and human volunteers. This study sought to further evaluate the suitability of [18F]LSN3316612 for human clinical research.MethodsKinetic evaluation of [18F]LSN3316612 was conducted in a combined set of baseline brain scans from 17 healthy human volunteers and test-retest imaging was conducted in 10 of these volunteers; another 6 volunteers had whole-body scans to measure radiation exposure to body organs. Total distribution volume (VT) estimates were compared for the one- and two-tissue compartment models with the arterial input function. Test-retest variability and reliability were evaluated via mean difference and intraclass correlation coefficient (ICC). The time stability of VT was assessed down to a 30-min scan time. An alternative quantification method for [18F]LSN3316612 binding without blood was also investigated to assess the possibility of eliminating arterial sampling.ResultsBrain uptake was generally high and could be quantified as VT with excellent identifiability using the two-tissue compartment model. [18F]LSN3316612 exhibited good absolute test-retest variability (12.5%), but the arithmetic test-retest variability was far from 0 (11.3%), reflecting a near-uniform increase of VT on the retest scan in nine of 10 volunteers. VT values were stable after 110 min in all brain regions, suggesting that no radiometabolites accumulated in the brain. Measurements obtained using only brain activity (i.e., area under the curve (AUC) from 150–180 min) correlated strongly with regional VT values during test-retest conditions (R2 = 0.84), exhibiting similar reliability to VT (ICC = 0.68 vs. 0.64). Estimated radiation exposure for [18F]LSN3316612 PET was 20.5 ± 2.1 μSv/MBq, comparable to other 18F-labeled radioligands for brain imaging.Conclusions[18F]LSN3316612 is an excellent PET radioligand for imaging O-GlcNAcase in the human brain. Alternative quantification without blood is possible, at least for within-subject repeat studies. However, the unexplained increase of VT under retest conditions requires further investigation.

Objective evaluation of bradykinesia in Parkinson’s disease using an inexpensive marker-less motion tracking system

Objective: Quantification of bradykinesia (slowness of movement) is crucial for the treatment and monitoring of Parkinson’s disease. Subjective observational techniques are the de-facto ‘gold standard’, but such clinical rating scales suffer from poor sensitivity and inter-rater variability. Although various technologies have been developed for assessing bradykinesia in recent years, most still require considerable expertise and effort to operate. Here we present a novel method to utilize an inexpensive off-the-shelf hand-tracker (Leap Motion) to quantify bradykinesia. Approach: Eight participants with Parkinson’s disease receiving benefit from deep brain stimulation were recruited for the study. Participants were assessed ‘on’ and ‘off’ stimulation, with the ‘on’ condition repeated to evaluate reliability. Participants performed wrist pronation/supination, hand open/close, and finger-tapping tasks during each condition. Tasks were simultaneously captured by our software and rated by three clinicians. A linear regression model was developed to predict clinical scores and its performance was assessed with leave-one-subject-out cross validation. Main results: Aggregate bradykinesia scores predicted by our method were in strong agreement (R = 0.86) with clinical scores. The model was able to differentiate therapeutic states and comparison between the test-retest conditions yielded no significant difference (p = 0.50). Significance: These findings demonstrate that our method can objectively quantify bradykinesia in agreement with clinical observation and provide reliable measurements over time. The hardware is readily accessible, requiring only a modest computer and our software to perform assessments, thus making it suitable for both clinic- and home-based symptom tracking.

Test–Retest Reliability of the Susceptibility to Driver Distraction Questionnaire

The Susceptibility to Driver Distraction Questionnaire (SDDQ) investigates voluntary and involuntary factors associated with driver distraction. The questionnaire consists of 39 items in six subscales: (a) self-reported distraction engagement, (b) attitudes toward distractions, (c) perceived control of driving while engaged in distractions, (d) injunctive social norms associated with distraction engagement, (e) descriptive social norms associated with distraction engagement, and (f) susceptibility to involuntary distractions. A sample of 43 adults, ages 25 to 39 years, was used to assess the test–retest reliability of the SDDQ. The mean time between test and retest conditions was approximately 20 days. For sub-scale averages, intraclass correlation (ICC) statistics were used to assess test–retest reliability; weighted kappa statistics were used to assess individual items. The ICC results suggest good to excellent test–retest reliability for subscales of self-reported distraction engagement, attitudes toward distractions, and descriptive social norms. Perceived control of driving while engaged in distractions had fair test–retest reliability, and the injunctive norms and susceptibility to involuntary distraction subscales had poor test–retest reliabilities. The latter two subscales may have to be redesigned; this paper provides relevant suggestions for revision in the discussion of the results. As an additional preliminary analysis, data from a sample of 10 additional participants were used to investigate the consistency of responses across longer periods of time. The mean time between test–retest conditions in this sample was approximately 8 months. In general, the findings were similar to those in the main sample. Overall, the SDDQ appears to have good test–retest reliability. A larger sample is recommended for further validation of these results, in particular across long test–retest periods.

Identification of Conductive Hearing Loss Using Air Conduction Tests Alone

The primary objective of this study was to determine whether a combination of automatically administered pure-tone audiometry and a tone-in-noise detection task, both delivered via an air conduction (AC) pathway, could reliably and validly predict the presence of a conductive component to the hearing loss. The authors hypothesized that performance on the battery of tests would vary according to hearing loss type. A secondary objective was to evaluate the reliability and validity of a novel automatic audiometry algorithm to assess its suitability for inclusion in the test battery. Participants underwent a series of hearing assessments that were conducted in a randomized order: manual pure-tone air conduction audiometry and bone conduction audiometry; automatic pure-tone air conduction audiometry; and an automatic tone-in-noise detection task. The automatic tests were each administered twice. The ability of the automatic test battery to: (a) predict the presence of an air-bone gap (ABG); and (b) accurately measure AC hearing thresholds was assessed against the results of manual audiometry. Test-retest conditions were compared to determine the reliability of each component of the automatic test battery. Data were collected on 120 ears from normal-hearing and conductive, sensorineural, and mixed hearing-loss subgroups. Performance differences between different types of hearing loss were observed. Ears with a conductive component (conductive and mixed ears) tended to have normal signal to noise ratios (SNR) despite impaired thresholds in quiet, while ears without a conductive component (normal and sensorineural ears) demonstrated, on average, an increasing relationship between their thresholds in quiet and their achieved SNR. Using the relationship between these two measures among ears with no conductive component as a benchmark, the likelihood that an ear has a conductive component can be estimated based on the deviation from this benchmark. The sensitivity and specificity of the test battery vary depending on the size of this deviation, but increase with increasing ABG size, with decreasing test frequency, and when results from multiple test frequencies are taken into account. The individual automatic tests comprising the battery were found to be reliable and valid, with strong, significant correlations between the test and retest results (r = 0.81 to 0.99; p < 0.0001) and between automatic and manual audiometry procedures (r = 0.98 to 0.99; p < 0.0001). The presence of an ABG can be predicted with a reasonably high degree of accuracy using AC tests alone. Applications of such a test battery include any clinical context in which bone conduction audiometry or specialized diagnostic equipment is unavailable or impractical. Examples of these include self-fitting hearing aids, whose efficacy relies on the ability of the device to automatically administer an in situ hearing test; self-administered adult hearing screenings in both clinical and home environments; large-scale industrial hearing conservation programs; and test environments in which ambient noise levels exceed the maximum permissible levels for unoccluded ears.

Development and Validation of the Spanish–English Language Proficiency Scale (SELPS)

This study examined the development and validation of a criterion-referenced Spanish-English Language Proficiency Scale (SELPS) that was designed to assess the oral language skills of sequential bilingual children ages 4-8. This article reports results for the English proficiency portion of the scale. The SELPS assesses syntactic complexity, grammatical accuracy, verbal fluency, and lexical diversity based on 2 story retell tasks. In Study 1, 40 children were given 2 story retell tasks to evaluate the reliability of parallel forms. In Study 2, 76 children participated in the validation of the scale against language sample measures and teacher ratings of language proficiency. Study 1 indicated no significant differences between the SELPS scores on the 2 stories. Study 2 indicated that the SELPS scores correlated significantly with their counterpart language sample measures. Correlations between the SELPS and teacher ratings were moderate. The 2 story retells elicited comparable SELPS scores, providing a valuable tool for test-retest conditions in the assessment of language proficiency. Correlations between the SELPS scores and external variables indicated that these measures assessed the same language skills. Results provided empirical evidence regarding the validity of inferences about language proficiency based on the SELPS score.

Reliability issues regarding the beginning, middle and end of continuous emotion ratings to music

Continuous self-reported emotion expressed by four pieces of music were collected on a two-dimensional (valence and arousal) emotion space in a repeated measures (test-retest conditions) design. Initial orientation time (IOT), test-retest reliability and afterglow were examined. Median IOT was 8 seconds. Valence ratings took up to 25 (median 4), and for arousal up to 35 (median 12) seconds. Slower tempi seemed to require longer IOT. Test-retest reliability examined correlation coefficients, and compared periods of sample-by-sample good agreement in response between Test and Retest condition. About 80% of responses were reliable in both the Test and Retest conditions regardless of response dimension. Pearson correlations demonstrated better test-retest reliability for arousal responses than for valence. Retest condition ratings were within 8% of Test condition rating within participant. Average standard deviations for ratings collapsed across dimension, stimulus and conditions was 12.2% of the ratings scale range. Afterglow effects – large outliers in spread of scores just after the end of a piece – were identified. The reliability of continuous emotional response is therefore considered to be quite good, but caution must be taken as to how to deal with the opening and ending of continuous emotional response data.

High-Frequency Pure-Tone Audiometry in Children: A Test–Retest Reliability Study Relative to Ototoxic Criteria

Good test-retest reliability of high frequency (≥ 8 kHz) pure-tone audiometry (HFPTA) is essential to detect significant changes in hearing threshold caused by ototoxicity. While the test-retest reliability of HFPTA in adults has been extensively studied, such investigations in children are scant. This study aimed to evaluate the test-retest reliability of the HFPTA in normal-hearing children with particular reference to the criteria for ototoxicity. Participants were 125 children aged between 4 and 13 yr, with normal hearing in the 0.25 to 4 kHz range and normal tympanometric findings. The participants were divided into three age groups, 4 to 6 yr (16M; 16F); 7 to 9 yr (22M; 30F); and 10 to 13 yr (24M; 17F), for investigating possible age effects in the test-retest reliability of HFPTA. The instrumentation for the HFPTA procedure was an Interacoustics AC40 audiometer with Koss R/80 high-frequency headphones, calibrated to meet Australian standards. Hearing thresholds at 8, 9, 10, 11.2, 12.5, 14, and 16 kHz were measured in a sound-treated chamber using a modified Hughson-Westlake procedure with a 5 dB step size. Testing began with an ear and test frequency selected at random; the subsequent test frequencies were randomly selected. After acquisition of hearing threshold data at all frequencies, the other ear was tested using the same procedure. After the first HFPTA test, the headphones were removed and carefully replaced. A second HFPTA test was performed with the ear order reversed. The order of testing the ear for the next participant was reversed. Good test-retest reliability of HFPTA was achieved with no significant difference in mean HFPTA thresholds across test and retest conditions for all age groups. An age effect in the test-retest reliability of HFPTA was evident with the 4- to 6-yr-old, 7- to 9-yr-old, and 10- to 13-yr-old children demonstrating normal variability of thresholds (within ±10 dB) in 89.9%, 93.0%, and 97% of ears tested, respectively. When the variability of test-retest thresholds was assessed at each frequency, the 4 to 6 yr group showed significantly lower percentage of normal variability at 14 kHz. In identifying significant deterioration of hearing thresholds across test-retest conditions in relation to the ASHA (1994) ototoxicity criteria, the three age groups (youngest to oldest) demonstrated false-positive rates of 24.6%, 11%, and 7.6%, respectively. : Overall, this study demonstrated high test-retest reliability of HFPTA in all but the 4 to 6 yr group. With a false-positive rate of 24.6% for ototoxicity for the youngest group, it is recommended that the HFPTA should not be used alone in assessing the possibility of a genuine threshold shift for this age group. If possible, the HFPTA should be supplemented with an objective test of auditory function to confirm the diagnosis. For children aged 7 yr or older, the HFPTA test is promising as a useful tool to identify hearing impairment in the extended high-frequency range (>8 kHz). However, interpretation of HFPTA findings in serial testing for monitoring hearing in a child should be made with due attention being given to the frequency of the stimulus, age of the child, and the associated nonzero false-positive rates.

A preliminary study of the neural effects of behavioral therapy for substance use disorders

BackgroundThe mechanisms by which behavioral therapies for substance use disorders (SUDs) exert their effects and the components of treatment that contribute most to substance use outcome remain unclear. Disruptions to aspects of impulse control and attention have been hypothesized to contribute to the development and maintenance of addiction; moreover, alterations in these processes may underlie responses to treatment. MethodsIndividuals participating in a randomized clinical trial evaluating computer-assisted cognitive behavioral therapy (CBT) for substance abuse participated in fMRI Stroop before and after treatment. A non-substance-using comparison group performed the same task under test–retest conditions. ResultsThe patient group demonstrated decreased Stroop-related BOLD signal in regions including the anterior cingulate, inferior frontal gyrus and midbrain at post-treatment relative to pre-treatment, and displayed a greater decrease in the subthalamic nucleus and surrounding regions compared to healthy controls following test–retest. ConclusionsBehavioral therapies may be associated with reduction in substance use and effects on neural systems involved in cognitive control, impulsivity, motivation and attention.

Test-Retest Reliability of the Acoustic Stapedial Reflex Test in Healthy Neonates

The acoustic stapedial reflex (ASR) test has been shown to provide useful information about the function of the auditory system. However, the reliability of this test when applied to healthy neonates has not been systematically studied. This study aimed to evaluate the test-retest reliability of the ASR test in newborn babies shortly after birth. Using a cross-sectional design, 219 healthy neonates, aged between 24 and 192 hr, who passed an automated auditory brain stem response screening test, were recruited and assessed using transient-evoked otoacoustic emissions (TEOAEs), high-frequency (1000 Hz) tympanometry, and ASR tests. One randomly selected ear from each neonate was tested. ASRs were elicited by presenting a 2 kHz pure tone and broadband noise (BBN) separately to the test ear in an ipsilateral stimulation mode using a Madsen Otoflex diagnostic immittance meter. A total of 194 (86/108 males/females; 115/79 left/right) ears, which met a set of inclusion criteria, were included in the test-retest reliability analysis for the 2-kHz tone stimulus. In addition, 123 (62/61 males/females; 77/46 left/right) ears were included in the test-retest reliability analysis for the BBN stimulus. The ASR threshold (ASRT) for each stimulus was measured. The ASR procedure was then repeated to acquire retest data. Ipsilateral ASRs were elicited in 91.3% (200/219) of neonates, whereas the remaining 8.7% (19/219) exhibited flat tympanograms (no identifiable peak) and absent reflexes with a "refer" outcome in the TEOAE test. The mean ASRT (76.2 dB HL averaged over 194 ears) for the 2 kHz pure tone was higher than that for the BBN (64.9 dB HL averaged over 123 ears). The findings, based on the results of an analysis of variance with repeated measure, showed that the ASRTs for the retest condition did not differ significantly from those of the first test for both stimuli (p > 0.05). The ASR test also showed high test-retest reliability as demonstrated by intracorrelation coefficients across the test-retest conditions of 0.83 for the 2 kHz pure tone and 0.76 for the BBN stimulus. This study demonstrated that ASRs could be consistently elicited from healthy neonates who showed a single-peaked configuration in the high-frequency tympanometry test and passed the automated auditory brain stem response and TEOAE tests. The findings showed that the ASRTs did not vary significantly across the test-retest conditions, and the high intracorrelation coefficients illustrate the reliability of the ASR test. Given the high test-retest reliability, the ASR test holds promise as a useful diagnostic/screening instrument in ascertaining the hearing status in neonates.

Test–Retest Reliability of Acoustic Reflex Test in 6-Week-Old Healthy Infants

The aim of this study was to investigate the test-retest reliability of acoustic reflex (AR) test measured from a group of 6-week-old infants who passed a transient evoked otoacoustic emission test and an automated auditory brainstem response screening test. Ipsilateral acoustic reflex thresholds for a 2 kHz pure tone and broadband noise were recorded from 70 infants using a Madsen Otoflex Diagnostic Immittance meter with a probe tone of 1000 Hz. The mean AR thresholds obtained in the first test were 67.3 and 80.9 dB HL for the broadband noise and 2 kHz tone, respectively. The results for the retest condition did not differ significantly from those of the first test. The AR test also showed high test-retest reliability as demonstrated by intracorrelation coefficients across the test-retest conditions of 0.783 and 0.780 for the broadband noise and 2 kHz pure tone stimuli, respectively. Findings from this study suggest that the AR test could be used to establish reliable AR thresholds in 6-week-old infants.

Comparison of Short-Term and Long-Term Variability in Nasalance Scores

To evaluate long-term nasalance score variability while accounting for short-term variation associated with subject performance and headgear change variability. STIMULI: Turtle and Mouse Passages. Short-term immediate test-retest nasalance score variability was assessed with no headgear change (NCHG) and with change of headgear (CHG). Long-term variability was assessed with scores obtained in the morning and afternoon of the same day, 1 day apart, and 1 week apart. Scores from the long-term conditions necessarily reflect variability associated with headgear change plus variability, which may be attributed to time. Twenty-six adults (19 to 70 years of age) with normal speech and resonance. Forty-six nasalance scores per subject. Mean nasalance difference scores across conditions were compared. Three contrasts were significantly different, each involving comparison of nasalance difference scores in the NCHG condition to difference scores from a CHG condition. Overall, long-term variability was slightly greater than short-term variability. For the Turtle Passage, in the short-term CHG condition, 92% of repeated scores were within five points. In the long-term conditions, 83% to 89% of scores were within five points. For the Mouse Passage, 88% of repeated scores in the CHG condition were within five points. In the long-term conditions, 81% to 83% of scores were within five points. Nasalance scores obtained over time showed slightly greater variability than scores obtained in immediate test-retest conditions; however, variability did not increase as the length of time between measures increased.

Effects of Ambient Acoustic Noise on the Auditory Steady-State Response Thresholds in Normally Hearing Adults

The effect of noise on auditory steady-state response (ASSR) has not been systematically studied, despite the fact that ASSR thresholds are sometimes measured in noisy environments. This study examined the effects of noise (speech babble) on the ASSR thresholds obtained from 31 normal hearing adults aged from 17 to 36 years (mean = 25 years). The ASSR thresholds at 0.5, 1, 2 and 4 kHz were measured in the right ear only using the Biologic MASTER system twice in quiet and in the presence of 55 dB A and 75 dB A of speech babble. The results showed no change in mean ASSR thresholds across the test-retest conditions in quiet. The mean ASSR thresholds obtained in the quiet conditions were 23.8, 22.5, 18.2 and 20.4 dB HL at 0.5, 1, 2 and 4 kHz, respectively. No significant shift in ASSR thresholds across all test frequencies was found when 55 dB A of speech babble was presented. However, when 75 dB A of noise was applied, the mean ASSR thresholds were significantly shifted by 9.5, 3.8, 4.2 and 5.8 dB at 0.5, 1, 2 and 4 kHz, respectively.

Cross-cultural adaptation of the JPF-Questionnaire for German-speaking patients with functional temporomandibular joint disorders

Clinical research related to the management of the syndrome of temporomandibular joint pain and dysfunction would be facilitated enormously between researchers in different locations around the world if a small number of patient-oriented questionnaires were to achieve wide acceptance. It would make comparison of therapeutic results possible. For this reason, a cross-cultural version of the Jaw Pain and Function (JPF)-Questionnaire was developed and validated for use in German-speaking patients with functional temporomandibular disorders. The scale was translated from the English into the German language and translated back into English again, pretested and reviewed by a committee. The German version of the JPF-Questionnaire was tested on 137 patients with temporomandibular disorders. Reliability and concurrent construct validity were assessed using Pearson's correlation coefficients. The concurrent validity was assessed by evaluating the relation of the questionnaire's summary score (the internal criterion) to data on maximum interincisal distance (the external criterion). Spearman's and correlation coefficients were statistically significant for the comparison of the summary score with maximal mouth opening (r=-0.213; p=0.036). Test-retest reliability for the JPF-Questionnaire was also assessed by Spearman's correlation coefficients: at first admission at the clinic (time a, mean=20.23+/-16.42, median=16), then at the time of administration 1 day later at home (time b, mean=17.98+/-16.29, median=13), and 7 days later at home (time c, mean=17.90+/-15.77, median=13). They were r=0.91 (p=0.0001) for the initial administration with the repetition 1 day later, r=0.90 (p=0.0001) for the initial administration with the repetition 1 week later, and r=0.93 (p=0.0001) for the correlation between the two repetitions. Test - retest reliability measured by mean-against-difference graphs was not satisfactory for time (a) versus time (b) and time (a) versus time (c) but there was a good test-retest reliability for time (b) versus time (c). The use of this instrument can be recommended in future clinical trials, as the German version of the JPF-Questionnaire seems to be valid and--under the same test-retest conditions--reliable for the assessment of temporomandibular joint disorders.

Reliability of segmental accelerations measured using a new wireless gait analysis system

The purpose of this study was to determine the inter- and intra-examiner reliability, and stride-to-stride reliability, of an accelerometer-based gait analysis system which measured 3D accelerations of the upper and lower body during self-selected slow, preferred and fast walking speeds. Eight subjects attended two testing sessions in which accelerometers were attached to the head, neck, lower trunk, and right shank. In the initial testing session, two different examiners attached the accelerometers and performed the same testing procedures. A single examiner repeated the procedure in a subsequent testing session. All data were collected using a new wireless gait analysis system, which features near real-time data transmission via a Bluetooth network. Reliability for each testing condition (4 locations, 3 directions, 3 speeds) was quantified using a waveform similarity statistic known as the coefficient of multiple determination (CMD). CMD's ranged from 0.60 to 0.98 across all test conditions and were not significantly different for inter-examiner (0.86), intra-examiner (0.87), and stride-to-stride reliability (0.86). The highest repeatability for the effect of location, direction and walking speed were for the shank segment (0.94), the vertical direction (0.91) and the fast walking speed (0.91), respectively. Overall, these results indicate that a high degree of waveform repeatability was obtained using a new gait system under test-retest conditions involving single and dual examiners. Furthermore, differences in acceleration waveform repeatability associated with the reapplication of accelerometers were small in relation to normal motor variability.

PinQ: A valid, reliable and reproducible quality-of-life measure in children with bladder dysfunction

Objective Recently, a cross-cultural continence-specific paediatric quality-of-life measurement tool (PinQ) has been developed and tested psychometrically. The aim of this study was to evaluate the test re-test reliability of this new tool in a cohort of children with bladder dysfunction in order to evaluate the reproducibility of scores. A secondary aim was to compare the parent-completed proxy version with child-reported scores. Methods PinQ was translated and back-translated from English into Chinese and Dutch and scrutinized for cultural and linguistic appropriateness or ambiguity. Forty children aged 6–15 years from both countries were asked to self-complete the measure at first consultation and then again 14 days later. No new treatment was implemented between data collection points. On the initial visit, parents also completed a proxy version of PinQ. Intraclass correlations (one-way random effects model) were used to analyze the data. Results The intraclass correlation coefficient (ICC) for comparison between items and factors showed little variability in scoring. One item was not reproducible and was removed from the tool. Overall proxy scores varied little from the child-reported scores. However, the impact on the child of his/her parent's concern about the bladder problem was poorly perceived (ICC = 0.18) as was the impact on the child's sense of self-worth (0.17). Conclusion PinQ has been shown to be reliable under test re-test conditions when completed by children from the age of 6 years. Proxy PinQ suggests that parents accurately evaluate the effect of bladder dysfunction on wellbeing in their children. A 20-item measurement tool will now be introduced clinically and subjected to sensitivity testing for treatment outcome and diagnostic grouping.