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The accuracy and reliability of a novel handheld dynamic indentation probe for analysing articular cartilage.

This study investigates the accuracy and reliability of a novel handheld indentation system designed to ascertain the dynamic biomechanical properties of articular cartilage. A series of standard elastomers were assessed with both the handheld indentation system and a bench-top dynamic indentation system to assess the accuracy of the instrument. Interoperator and intraoperator experiments were undertaken to investigate the reliability of the system when used by an individual operator and by five different operators. Intraclass coefficients (Rho) were derived using a random effects model. The system was then used to ascertain the topographical variation in the shear moduli and phase lag of articular cartilage across normal ovine tibial plateaux. The system was shown to be highly accurate (R2 = 0.97), and had excellent reliability when measuring the dynamic shear modulus of articular cartilage (interoperator Rho = 0.75, intraoperator Rho = 0.79). Measurement of static shear modulus was less reliable (interoperator Rho = 0.15, intraoperator Rho = 0.52), but may be improved by monitoring the load applied to the instrument by the operator. The instrument was used to differentiate between different regions of cartilage and generated a topographical map of an ovine tibial plateau. The cartilage located beneath the menisci was 200-500% stiffer than the cartilage that was not covered by the menisci, while the phase lag was almost constant (10+/-2 SD) over the entire tibial plateau. The system was shown to be an accurate and reliable tool for rapidly assessing the dynamic biomechanical properties of articular cartilage, while being small enough to be used arthroscopically.

Animals↗

Patient selection for clinical trials: the reliability of the early spinal cord injury examination.

Patients with incomplete spinal cord injuries can spontaneously recover motor function. Because of this, phase I and II trials of invasive interventions for acute spinal cord injury will likely involve neurologically complete injuries. It is therefore important to reliably identify complete injuries as early as possible. We examined the reliability of the early examination in motor complete spinal cord injuries by retrospectively analyzing the stability of baseline neurological status determined within 2 days of injury in 103 subjects. Baseline neurological status was compared to neurological status at follow-up, preferably within one week (101 of 103 subjects). When available (n = 68), neurological status at 1 year or later was also compared. Overall, 6.2% (5/81) of motor complete, sensory complete (ASIA A) subjects converted to motor complete, sensory incomplete status (ASIA B) between the initial and follow-up assessments; however, none exhibited motor recovery (ASIA C or D). At initial follow-up, 9.3% (4/43) of ASIA A subjects with factors affecting examination reliability were reclassified as ASIA B injuries compared to 2.6% (1/38) of ASIA A subjects without such factors. At year 1 or later, 6.7% (2/30) of ASIA A subjects without factors affecting exam reliability, converted to ASIA B status. None developed volitional motor function below the zone of injury. For subjects with factors affecting exam reliability, 17.4% (4/23) of ASIA A subjects converted to incomplete status and 13.0% (3/23) regained some motor function by one year or later (ASIA C or D). These data suggest that it is possible to identify within 48 h of injury, a subset of patients with a negligible chance for motor recovery who would be suitable candidates for future clinical trials of invasive treatments.

Adult↗

Accuracy and reliability of teleophthalmology for diagnosing diabetic retinopathy and macular edema: a review of the literature.

Using teleophthalmology for the delivery of routine eye care for patients with diabetes mellitus is becoming an increasingly common practice. Paramount in the consideration of any new diagnostic test is an analysis of its diagnostic accuracy and reliability and how that compares with conventional care. This review summarizes existing data on the diagnostic accuracy and reliability of teleophthalmology and conventional clinic-based eye care for detecting diabetic retinopathy and diabetes mellitus. The sensitivity of ophthalmoscopy for detecting diabetic retinopathy performed by eye care clinicians has varied widely, with point estimates ranging from 0% to 96%. Alternatively, specificity has been universally high. The sensitivity of teleophthalmology for detecting diabetic retinopathy has been shown to be comparable, if not better, than clinic-based examinations. Sensitivity values have ranged from 50% to 93%. The specificity of teleophthalmology, like clinic-based examinations, has been consistently high. High levels of diagnostic reliability, analyzed by both simple agreement and kappa values, have been found between ophthalmoscopy and teleophthalmology for detecting and classifying diabetic retinopathy. Evaluating the accuracy of macular edema detection requires the use of dual gold standards, the clinical examination using slit-lamp biomicroscopy and stereoscopic photography. Teleophthalmology, compared with both gold standards, has, overall, been a highly sensitive and specific test. Reliability studies that compared the two gold standards with one another have found moderate to substantial levels of agreement. Based on existing data, teleophthalmology appears to be an accurate and reliable test for detecting diabetic retinopathy and macular edema.

Diabetic Retinopathy↗

Reliability of telemedicine examination.

OBJECTIVES: To assess the reliability of telemedicine examination and identify the issues to be addressed if the conduct of physical examination and the reading of images and tracings by telemedicine are to be as reliable as conventional examination and reading. METHODS: Patients were examined both conventionally and by telemedicine in 12 clinics, and the results were compared. There were 1826 matched pairs of observations. Cardiac auscultation, echocardiography, electrocardiography, electroencephalography, obstetric ultrasonography, ophthalmologic examination, physical therapy assessment, pulmonary auscultation, and the reading of chest radiographs with telemedicine cameras and monitors were studied. The main outcome measure was agreement between the telemedicine findings and a criterion standard. RESULTS: For ophthalmology, physical therapy, and cardiac auscultation, 91.2% of the conventional findings and 86.5% of the telemedicine findings were identical or similar to the criterion standard. The kappa coefficient on matched-pair analysis was 0.66. For pulmonary auscultation and reading of chest films with a telemedicine camera and monitor abnormalities were suppressed at default settings but subsequently revealed with extensive manipulation of system settings. For tracings and images, both conventional and telemedicine findings showed 92% reliability, with a kappa coefficient of 0.87. CONCLUSIONS: On the basis of these observations and the methods used, reliability varied with the type of examination, clinician experience with telemedicine, and participant knowledge of system limitations. Clinicians without experience or knowledge of system limitations missed findings of clinical importance. Improvements in equipment since the clinics were conducted in 1994 may have resolved some of these problems. Our findings raise doubts about the reliability of occasional telemedicine consultations by clinicians inexperienced in the technology.

Bias↗

Reliability of the revised functional autonomy measurement system (SMAF) for epidemiological research.

The Functional Autonomy Measurement System (SMAF) is an instrument designed to assess disabilities related to 29 functions with a four-point scale (from 0: independent to -3: dependent). For epidemiological studies, a total score and five sub-scores can be obtained. A revised version was developed adding a -0.5 level to many items to indicate an activity accomplished independently but with difficulty. The objective of the study was to verify the test-retest and inter-rater reliability of the total score and sub-scores of the SMAF. Ninety subjects were randomly recruited in nine different residential settings ranging from home to long-term-care hospitals. Half of the subjects were assessed by the same nurse within a 2-week interval (test-retest) and the other half were assessed twice by two different nurses within the same interval (inter-rater). Results show intra-class correlation coefficients (ICC) of 0.95 and 0.96 for the total scores on test-retest and inter-rater reliability, respectively. The ICC were over 0.74 for all sub-scores for both types of reliability. A small systematic bias was present for two SMAF subscores on the inter-rater reliability. The addition of a new level did not modify the reliability of the scale.

Activities of Daily Living↗

Reliability of measurements of muscle tone and muscle power in stroke patients.

OBJECTIVES: to establish the reliability of the modified Ashworth scale for measuring muscle tone in a range of muscle groups (elbow, wrist, knee and ankle; flexors and extensors) and of the Medical Research Council scale for measuring muscle power in the same muscle groups and their direct antagonists. DESIGN: a cross-sectional study involving repeated measures by two raters. We estimated reliability using the kappa statistic with quadratic weights (Kw). SETTING: an acute stroke ward, a stroke rehabilitation unit and a continuing care facility. SUBJECTS: people admitted to hospital with an acute stroke-35 patients, median age 73 (interquartile range 65-80), 20 men and 15 women. RESULTS: inter- and intra-rater agreement for the measurement of power was good to very good for all tested muscle groups (Kw = 0.84-0.96, Kw = 0.70-0.96). Inter- and intra-rater agreement for the measurement of tone in the elbow, wrist and knee flexors was good to very good (Kw = 0.73-0.96, Kw = 0.77-0.94). Inter- and intra-rater agreement for the measurement of tone in the ankle plantarflexors was moderate to good (Kw = 0.45-0.51, Kw = 0.59-0.64). CONCLUSIONS: the Medical Research Council scale was reliable in the tested muscle groups. The modified Ashworth scale demonstrated reliability in all tested muscle groups except the ankle plantarflexors. If reliable measurement of tone at the ankle is required for a specific purpose (e.g. to measure the effect of therapeutic intervention), further work will be necessary.

Aged↗

Readiness to change questionnaire: reliability study of its Spanish version.

The present study explored the reliability and validity of a Spanish version of the Readiness to Change Questionnaire (RCQ) (12-item short form) as it might be used for opportunistic intervention. The test has three scales to allocate patients to a stage of change: pre-contemplation (P), contemplation (C) or action (A). The RCQ was translated and back-translated prior to pilot administration to 15 patients. From two settings (a general hospital ward and a primary health care centre), 201 patients were identified as excessive drinkers on the Alcohol Use Disorders Identification Test. Patients known to be alcohol-dependent and attending for alcohol-related reasons were excluded. Patients completed the RCQ. Test-retest reliability after 2 days was assessed in 35 patients. A components analysis was performed. Patients were classified on RCQ scores to a stage of change. Two experts separately interviewed the patients and made an allocation to stage of change, blind to the RCQ score. Test-retest reliability was good (P: r = 0.81; C: r = 0.87; A: r = 0.86). Within the three scales, RCQ items showed fair consistency in terms of Cronbach's alpha (P: 0.58, C: 0.75, A: 0.80). Component analysis showed that together the scales accounted for 57. 4% of the variance. The experts agreed between themselves on patients' stage of change (weighted kappa 0.92) but much less with the stage of change according to RCQ (expert A, kappa = 0.44; expert B, kappa = 0.52). Omitting patients with low consumption did not improve internal reliability, and omitting those with low educational level who might have filled in the questionnaire wrongly did not improve internal reliability or agreement between RCQ and the experts. We conclude that the Spanish RCQ did not function efficiently in a population of opportunistically identified excessive drinkers.

Adult↗

Construction of reliable protein-protein interaction networks with a new interaction generality measure.

MOTIVATION: Recent screening techniques have made large amounts of protein-protein interaction data available, from which biologically important information such as the function of uncharacterized proteins, the existence of novel protein complexes, and novel signal-transduction pathways can be discovered. However, experimental data on protein interactions contain many false positives, making these discoveries difficult. Therefore computational methods of assessing the reliability of each candidate protein-protein interaction are urgently needed. RESULTS: We developed a new 'interaction generality' measure (IG2) to assess the reliability of protein-protein interactions using only the topological properties of their interaction-network structure. Using yeast protein-protein interaction data, we showed that reliable protein-protein interactions had significantly lower IG2 values than less-reliable interactions, suggesting that IG2 values can be used to evaluate and filter interaction data to enable the construction of reliable protein-protein interaction networks.

Binding Sites↗

Reliability of landmark recording on film and digital lateral cephalograms.

The aims of this study were: (a) to evaluate reliability of landmark location in digital processed images of film cephalograms of varying quality with that obtained in the films, and (b) to evaluate the pattern of error in landmark location with the two techniques. The sample consisted of 20 original cephalograms (OQ), 10 'high' quality images (Q1), and 10 'average' quality images (Q2). Measurements on films were performed using a digitizer connected to a PC and controlled by a cephalometric program, while measurements on digital images were obtained using a mouse and a cephalometric program for landmark sampling. To assess the digital images (DQ), the films were video recorded (B/W video camera), digitized (matrix = 512 x 512 x 8), stored in a PC, and displayed on a quality monitor. Fifteen cephalometric landmarks were recorded by three observers twice on each of the 20 images by the two methods. Mean x- and y-values were calculated for each landmark to obtain the best estimate of each landmark position. Comparisons between the OQ and DQ group, and between the subgroups of different film quality were performed (Wilcoxon's rank sum test). In general, measurements from the OQ images were more reliable than from the DQ images (P < 0.02). The pattern of recording error also differed between the two techniques, OQ images being more reliable along the x-axis (P < 0.01), while along the y-axis, reliability was not significantly different between the two groups. Q1 and Q2 images did not differ significantly in either group (P > 0.05). A difference was, however, observed between OQ2 and DQ2 images (P < 0.02), while this was not the case for OQ1 and DQ1 images. The generally lower reliability for measurements on the digital images could be ascribed to the much larger error, especially in the y-axis, for the Q2 images.

Cephalometry↗

Reliability of foot trajectory measures within and between testing sessions.

BACKGROUND: Impaired control of foot trajectory during the swing phase of gait is hypothesized to increase the risk of slipping or tripping. Before assessing the predictive validity of foot trajectory measures with respect to incidence of falls, it is necessary to establish their reliability. The purpose of this study is to assess within- and between-session reliability of foot trajectory measures and traditional temporal-distance measures in healthy elderly women during gait. METHODS: Sixteen healthy, elderly women (ages 65-79 years) completed six sets of five trials each of natural and fast cadence gait during a 3.5-hour period on each of 4 days. An optoelectric motion analysis system and heel switches were used to obtain both foot trajectory (minimum toe clearance during swing, vertical, and horizontal heel contact velocities) and temporal-distance measures (step width, cadence, velocity, stride length, and time). RESULTS: Within-session test-retest reliability of all variables at natural and fast speeds was good to excellent, with intraclass correlation coefficients (ICCs) of greater than 0.9 for all but one measure (fast cadence stride time). ICCs for between-session test-retest reliability were slightly lower, but still greater than 0.9 for all but two measures (fast cadence stride time and natural cadence vertical heel contact velocity). Heel contact velocities quantified at the instant of heel contact correlated strongly with values obtained by averaging over the last 2% of the gait cycle. DISCUSSION: The good to excellent within- and between-session reliability of these foot trajectory measures supports their use as a possible means of assessing subtle changes in gait motor control. Confirmation of an association between alterations in foot trajectory measures and incidence of falls awaits further study.

Aged↗

Reliability of dietary Ca and P levels and bone mineral content as predictors of bone mechanical properties at various time periods in growing swine.

Seventy-two growing pigs were fed one of nine dietary treatments that provided a range of Ca (0.4%-1.2%) and P (0.4%-1.2%) levels arranged in a two-factor central composite design. Two pigs per treatment after either 5 (T5) or 10 (T10) wk and four pigs per treatment after 15 (T15) wk were slaughtered, and the femur (F) and third (MT3) and fourth (MT4) metatarsal bones were collected for evaluation of mechanical properties (force, stress and modulus of elasticity), ash weight (ASHW), percent ash (PASH) and bone mineral content (BMC) using photon absorptiometry. Stepwise regression analysis utilized to generate best-fit equations predicted that dietary Ca and P levels could reliably predict force (R2 = 0.83), ASHW (R2 = 0.93) and BMC (R2 = 0.89) of the MT3 bones but the prediction of force differed at the various time periods. Stress (R2 = 0.41), the modulus of elasticity (R2 = 0.29) and PASH (R2 = 0.17) were not reliably predicted by dietary mineral levels. The amount of force withstood by the MT3 bone could be reliably predicted by BMC (R2 = 0.90), but stress was not reliably predicted by BMC (R2 = 0.40) even if dietary Ca levels were considered. These results indicated that dietary Ca levels between 0.6% and 1.2% and dietary P levels between 0.6% and 0.8% did not adversely affect growth, efficiency or bone development. The BMC, as determined by photon absorptiometry, was not a reliable predictor of bone strength.

Animals↗

Reliability and validity of three physical activity questionnaires in Flemish males.

The reliability and validity of three physical activity questionnaires were studied using 90 Flemish males (30 aged 30 years, 30 aged 35 years, and 30 aged 40 years). Intraclass correlations (R) and kappa values were calculated to verify within judge and between judges reliability (objectivity) and test-retest reliability (stability) of the Tecumseh Community Health Study Questionnaire, the Five City Project Questionnaire, and the Baecke Questionnaire. Results showed high for within judge and between judges reliability. R coefficients for stability varied between 0.47 and 0.95. Kappa values varied between 0.20 and 0.73. Concurrent validity was investigated by comparing three levels of professional status. Workmen had higher indices concerning physical activity during work than clerks and managers. Congruent validity, studied by means of principal-components analysis, confirmed subdivision of habitual physical activity into three entities, physical activity during work, sports activities, and general leisure time. These results indicate that reliable and valid data can be obtained in Flemish males by three interviewer-assisted physical activity questionnaires.

Adult↗

The reliability of dietary history from the distant past.

A major barrier to the conduct and interpretation of retrospective studies of diet and cancer has been uncertainty about the reliability of retrospective measures of diet from the distant past. The authors therefore conducted a study to assess the reliability of retrospective dietary reports and to determine whether the retrospective report or the report of current diet is the better indicator of past diet. Persons (n = 323) originally interviewed regarding their diets in 1975-1979 were retrospectively reinterviewed in 1984-1985. There was little difference between the retrospective reports and the reports of current diet when group means were examined as indicators of past diet. The retrospective reports tended to overestimate the past frequency of consumption for most foods, whereas the reports of current diet tended to yield underestimates. Because food frequency-based dietary history data are more useful for ranking study subjects than for generating estimates of group means, correlation analysis was used as the principal assessment of the reliability of the two indicators of past diet. The retrospective reports more closely correlated with the diet reported at the original interview than did the report of current diet (for 37 of 47 foods). Nutrient indices based on the retrospective history were also more highly correlated with those of the original diet than were indices based on the current diet. No differences were noted in the reliability of retrospective reports according to age or sex. Subjects accurately reported perceptions of changes in their consumption of most foods, yet an estimate of past diet created by adjusting current diet for perceived change did not correlate more highly with the original diet than did the retrospective report. The authors conclude that assessing current diet to make inference about diet from the distant past does not yield more reliable estimates of past diet than does the retrospective dietary history. The best estimate of diet from several years in the past may be derived directly from a retrospective dietary history which focuses on that past period of time.

Aged↗

Reliability in evaluating passive intervertebral motion.

Reliable measurements are prerequisite to the successful conduct of outcome studies. In a study of the performance of physical therapists (n = 5) in evaluating passive mobility of the vertebral column with normal subjects (n = 5), several sources of measurement variability were assessed: the reliability within and between therapists, the criteria for grading, and the subjects themselves. Intratherapist reliability was found to be dependable; intertherapist reliability was not. Problems that merit further study were identified as idiosyncratic behaviors that may develop with experience, subject characteristics, and the instrument itself. Periodic assessment of the reliability of therapists in performing evaluations is recommended because of its importance to therapeutic programming.

Clinical Competence↗

Reliability of the Fugl-Meyer assessment of sensorimotor recovery following cerebrovascular accident.

This study establishes intratester reliability for all components of physical performance and intertester reliability for the total scores of upper and lower extremity motor performance in a cumulative numerical scoring system devised by Fugl-Meyer et al. Intertester reliability was found to be high for the total scores of upper and lower extremity motor performance. All intratester and intertester reliability coefficients were high and statistically significant. Establishing the reliability of the Fugl-Meyer method of assessing recovery of function following cerebrovascular accident has increased the usefulness of this method for clinical assessment and as a tool for the comparative analysis of the effectiveness of various therapeutic interventions.

Adult↗

Reliability of the auditing process at the University of Montana's Physical Therapy Department.

Adding an audit to the problem-oriented medical record system creates feedback to ensure quality control in the health-care field. Auditing is the process of comparing observed behaviors with predefined standards. The literature does not reveal an auditing system that has been tested for reliability. A standardized problem-oriented documentation system was developed at the University of Montana Physical Therapy Clinic. This system was then audited for assessment of its reliability. Kendall's coefficient of concordance (W) was used to determine interrater and intrarater reliability. We determined this documentation system to be reliable because our minimum coefficient of .80 was met. This reliable system aids in assessing objectively the care physical therapy students provide at the University of Montana.

Humans↗

Pelvic tilt. Intratester reliability of measuring the standing position and range of motion.

The purpose of this study was to examine intratester reliability of a test designed to measure the standing pelvic-tilt angle, active posterior and anterior pelvic-tilt angles and ranges of motion, and the total pelvic-tilt range of motion (ROM). After an instruction session, the pelvic-tilt angles of the right side of 20 men were calculated using trigonometric functions. Ranges of motion were determined from the pelvic-tilt angles. Intratester reliability coefficients (Pearson r) for test and retest measurements were .88 for the standing pelvic-tilt angle, .88 for the posterior pelvic-tilt angle, .92 for the anterior pelvic-tilt angle, .62 for the posterior pelvic-tilt ROM, .92 for the anterior pelvic-tilt ROM, and .87 for the total ROM. We discuss the factors that may have influenced the reliability of the measurements and the clinical implications and limitations of the test. We suggest additional research to examine intratester reliability of measuring the posterior pelvic-tilt ROM, intertester reliability of measuring all angles and ROM, and the pelvic tilt of many types of subjects.

Adult↗

Reliability of goniometric measurements in patients with Duchenne muscular dystrophy.

Previous studies of reliability of goniometric measurements have produced varied findings suggesting the need to document further the reliability of measuring range of motion in different patient groups. The purpose of this study was to determine the intratester and intertester reliability of goniometric measurements of seven common upper and lower extremity joint limitations in children with Duchenne muscular dystrophy. Five physical therapists participated in the study. The procedure and order of measurements were standardized. Results showed that intratester reliability for all measurements was high (ICC = .81 to .94), but intertester reliability showed a wide variation (ICC = .25 to .91). The results of this study indicate the need to use the same examiner for long-term follow-up and for assessing results of specific treatment interventions.

Adolescent↗