Alkaline phosphatase activity in normal and scorbutic bones.
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Alkaline Phosphatase↗
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Results for “OBSERVATION”
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Motor facilitation while observing hand actions: specificity of the effect and role of observer's orientation.
Action observation enhances cortico-spinal excitability. Here we tested the specificity of this effect and the role played by the orientation of the observer. Ten normal subjects observed video clips of right hand performing three different finger movements (thumb ab-/adduction, index ab-/adduction, index extens-/flexion) in two different orientations (Away, i.e., natural hand-orientation facing out from the observer; or Toward, i.e., unnatural hand-orientation facing toward the observer). Motor-evoked potentials (MEPs) induced by transcranial magnetic stimulation (TMS) were recorded from the abductor pollicis brevis (APB) and the first dorsal interosseus (FDI) muscles. Movement direction of the index finger was recorded using force transducers. Facilitation of MEP size was significantly greater for APB during observation of thumb movements and for FDI during observation of index finger movements. Facilitation of MEP size was significantly greater when the hand presented on screen was facing out from and corresponding to that of the observer (Away orientation). The direction of the index finger movement evoked by TMS shifted toward extension/flexion versus ab-/adduction matching the observed movement. Our results give further evidence that observation of a movement enhances motor output to the muscles involved in the movement and facilitates the observed action. In addition, we provide novel evidence about the high degree of specificity of this observation-induced motor cortical modulation. The degree of modulation depends on hand orientation. The modulation is maximal when the observed action corresponds to the orientation of the observer.
Adult↗
Intra-observer, inter-observer and inter-scanner variations in brain MRI volume measurements in multiple sclerosis.
INTRODUCTION: Measurement of brain volume on magnetic resonance imaging (MRI) scans is regarded as an objective marker of multiple sclerosis (MS) severity with the potential to monitor treatment efficacy accurately. This study was performed to assess the variability of brain MRI volume measurements. PATIENTS AND METHODS: We studied nine patients with relapsing-remitting MS, who were imaged on two occasions (separated by an interval of 24 h) using two different MR scanners and fast fluid-attenuated inversion recovery (fast-FLAIR) sequences. The whole brain volume computed from each image was measured three times by three observers using a seed-growing technique based on signal intensity thresholding. Intra-observer, inter-observer and inter-scanner variabilities were expressed as coefficients of variations (COVs). The inter-scanner variability included not only the intra-observer variation but also the repositioning variability and the variation in observed brain volume caused by different scanner hardware and sequence implementations. RESULTS: There was no statistically significant difference in patients' brain volume values between observers (P=0.82) or between scanners (P=0.30). The mean intra-observer COV was 1.2% (s.e.=0.4%), the mean inter-observer COV was 1.8% (s.e.=0.8%) and the mean inter-scanner COV was 2.4% (s.e.=1.2%). The intra-observer variance was not statistically different from those found between observers (P=0.83) or scanners (P=0.44). CONCLUSION: The intra-observer variability in brain volume measurements found in this study was within the range of intra-observer variability found in previous studies. This study shows that the use of different observers and MR scanners has only a small influence on the measured brain volume and does not affect the reproducibility of this measurement greatly.
Adult↗
Reliability of radiographic observations recorded on a proforma measured using inter- and intra-observer variation: a preliminary study.
AIM: The aim of this preliminary study was to test the reliability of radiographic evaluation of features of endodontic interest using a newly devised data collection system. METHODOLOGY: Twelve endodontic MSc postgraduate students and one specialist endodontist examined sample radiographs derived from a random selection of 42 patients seen previously on an Endodontic New Patient Clinic (EDI). Each student examined a random selection of 8-9 roots on periapical radiographs of single- and multirooted teeth, with and without previous root canal therapy and 3-4 dental panoramic tomograms (DPTs). A total of 100 roots were examined. A proforma was used to record observations on 67 radiographic features using predefined criteria. Intra-observer agreement was tested by asking the students to re-examine the radiographs. The principle investigator and the specialist endodontist examined the same radiographs and devised a Gold Standard using the same criteria. This was compared with the student assessments to determine inter-observer variation. The postgraduates then attended a revision session on the use of the form. Each student subsequently examined 8-9 different roots from the pool of radiographs. A further assessment of inter-observer variation was made by comparing these observations with the Gold Standard. RESULTS: Of the 67 radiographic features, only 25 had sufficient response to allow statistical analysis. Kappa values for intra- and inter-observer variation were estimated. These varied depending on the particular radiographic feature being assessed. Fifteen out of 25 intra-observer recordings showed 'good' or 'very good' Kappa agreement, but only three out of 25 inter-observer observations achieved 'good' or 'very good' values. Inter-observer variation was improved following the revision session with 16 out of 25 observations achieving 'good' or 'very good' Kappa agreement. CONCLUSIONS: Modification to the proforma, the criteria used, and training for radiographic assessment were considered necessary to improve the accuracy and reproducibility of the observations entered.
Data Collection↗
Inter-observer and intra-observer variability of the Oxford clinical cataract classification and grading system.
Intra-observer (within observers) and inter-observer (between observers) variability of the Oxford Clinical Cataract Classification and Grading System were studied. Twenty cataracts were examined and scored independently by four observers. On a separate occasion two of the observers repeated the assessments of the same cataracts in the absence of information from the initial observations. The chance corrected and weighted kappa statistics for observer agreement, both for inter-observer and intra-observer variability demonstrated satisfactory repeatability of the cataract grading system. The overall intra-observer mean weighted kappa was kappa w = +0.68 (range SE kappa = 0.012-0.052) and the overall inter-observer mean weighted kappa was kappa w = +0.55 (range SE kappa = 0.011-0.043).
Cataract↗
Directly observed therapy for treating tuberculosis.
BACKGROUND: Up to half the people with tuberculosis do not complete their treatment. Strategies to improve adherence to diagnostic and treatment regimens are therefore important. OBJECTIVES: To assess the effects of directly observed therapy by an appointed agent (health worker, community volunteer, or family member) on cure and treatment completion in people on treatment for tuberculosis. SEARCH STRATEGY: We searched The Cochrane Controlled Trials Register, the Cochrane Infectious Diseases Group specialized trials register, MEDLINE, EMBASE, LILACS, and reference lists of articles. We also contacted experts in the field. SELECTION CRITERIA: Randomized and quasi-randomized trials of direct observation of tablet swallowing compared with self treatment for tuberculosis. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial quality and extracted data. MAIN RESULTS: Four studies (n = 1603 participants) included. There was no difference detected between direct observation and self treatment for cure (Relative Risk [RR] 1.06, 95% confidence interval [CI] 0.98 to 1.14); and for cure plus treatment completion (RR 1.06, 95% CI 1.00 to 1.13). A stratified analysis by the appointed agent (health professional, lay health worker, or family/community member) did not reveal any important differences. One study conducted in an optimal setting in which patients were given a choice of supervisor did show modest benefit: cure (RR 1.13, 95% CI 1.04 to 1.24); cure plus treatment completion (RR 1.11, 95% CI 1.03 to 1.18). REVIEWER'S CONCLUSIONS: Randomized trials provide no evidence that directly observed therapy in low and middle income country settings improves cure or treatment completion rates in patients with tuberculosis.
Antitubercular Agents↗
[Radiographic signs of scaphoid union after bone grafting: the analysis of inter-observer agreement and intra-observer reproducibility].
INTRODUCTION: The diagnosis of radiological union of scaphoid bone after bone grafting requires clear evidence of bony trabeculae traversing the graft from the proximal to the distal pole on at least two of four standard scaphoid views. This sign is the only objective assessments of union. Radiographs of the scaphoid taken 18 weeks after operation, however, can be difficult to interpret. This fact led us to question whether radiographs of scaphoid at 18 weeks provide reliable and objective indication of union. OBJECTIVE: Our study was, therefore, designed to determine the reliability of the radiographic diagnosis of scaphoid union after bone grafting by testing the degree of inter-observer agreement and reproducibility. METHODS: Out of 30 sets of the scaphoid bone radiographs after bone grafting taken 18 weeks after operation, 15 of good quality were selected. Each set included four views: postero-anterior, lateral, semi- pronated and semi-supinated. Seven observers were tested: three orthopedic consultants, three residents and one consultant in radiology. Each was presented with 15 sets of radiographs designated from 1 to 15 and each was asked to answer the question: "Are there trabeculae crossing the fracture site?" Possible answers were 'yes' or 'no'. Eight weeks later, the same 15 sets of radiographs were marked in alphabetic order from A to K and presented to the same seven observers. Data was then analyzed and expressed in terms of interobserver agreement in pairs and intra-observer reproducibility. Calculation was done by kappa statistics so that the degree of disagreement was taken into account and allowance was made for chance agreement. Kappa values can vary from -1.0 (complete disagreement) through 1 (chance agreement) to +1 (complete agreement). RESULTS: For all 15 sets of radiographs, the degree of agreement between each pair of observers was illustrated in Table 2. It demonstrated the level of agreement between each pairs of seven observers. The overall median kappa coefficient for inter-observer agreement was 0,46. This value corresponded to "moderate" strength of agreement. Median kappa coefficient for consultant was 0.62, but median kappa coefficient for residents was 0.43. The degree of agreement between the opinions of each observer at his first and at his subsequent reviews of the same set of radiograph after 8 weeks was presented in Table 3. The overall median Kappa coefficient for the intraobserver agreement for all seven observers was 0.54. The ability of seven observers to reproduce their own opinion regarding trabeculae crossing the fracture line was poor to use it for assessment of bone union. CONCLUSION: Our conclusion is that radiographs taken 18 weeks after scaphoid grafting cannot be reliable and reproducible for assessment of bone union.
Bone Transplantation↗
Inter-observer and intra-observer variation in bone histomorphometry.
Inter-observer variation has been examined for a number of histomorphometric indices in 20 normal human iliac crest biopsies. Quantitation was performed using an eye-piece graticule and eye-piece micrometer. The same sections were examined by two observers and the methodology was identical. Intra-observer variation was also assessed. Significant inter-observer differences were found for the measurement of total trabecular bone volume, osteoid volume and surface, double plus single and double tetracycline labeled surfaces, and the mean osteoid seam width. The percentage variance due to inter-observer variation was highest for osteoid surface and volume, total resorption surface, and mean osteoid seam width. Intra-observer variation in both observers was small. We conclude that a large inter-observer variation may occur in the measurement of a number of histomorphometric indices, even when section preparation and methodology are identical. Caution should be used in basing the diagnosis of metabolic bone disease on strictly defined control data from other observers, particularly when this has been obtained from centers where the effects of inter-observer variation may be magnified by differences in methodology.
Bone Resorption↗
Imitative learning in Japanese quail (Coturnix japonica) depends on the motivational state of the observer quail at the time of observation.
The 2-action method was used to examine whether imitative learning in Japanese quail (Coturnix japonica) depends on the motivational state of the observer quail at the time of observation of the demonstrated behavior. Two groups of observers were fed before observation (satiated groups), whereas 2 other groups of observers were deprived of food before observation (hungry groups). Quail were tested either immediately following observation or after a 30-min delay. Results indicated that quail in the hungry groups imitated, whereas those in the satiated groups did not, regardless of whether their test was immediate or delayed. The results suggest that observer quail may not learn (through observation) behavior that leads to a reinforcer for which they are unmotivated at the time of test. In addition, the results show that quail are able to delay the performance of a response acquired through observation (i.e., they show deferred imitation).
Animals↗
MRI assessment of knee osteoarthritis: Knee Osteoarthritis Scoring System (KOSS)--inter-observer and intra-observer reproducibility of a compartment-based scoring system.
OBJECTIVE: To develop a scoring system for quantifying osteoarthritic changes of the knee as identified by magnetic resonance (MR) imaging, and to determine its inter- and intra-observer reproducibility, in order to monitor medical therapy in research studies. DESIGN AND PATIENTS: Two independent observers evaluated 25 consecutive MR examinations of the knee in patients with previously defined clinical symptoms and radiological signs of osteoarthritis. We acquired on a 1.5 T system: coronal and sagittal proton density- and T2-weighted dual spin echo (SE) images, sagittal three-dimensional T1-weighted gradient echo (GE) images with fat suppression, and axial dual turbo SE images with fat suppression. Images were scored for the presence of cartilaginous lesions, osteophytes, subchondral cysts, bone marrow edema, and for meniscal abnormalities. Presence and size of effusion, synovitis and Baker's cyst were recorded. All parameters were ranked on a previously defined, semiquantitative scale, reflecting increasing severity of findings. Kappa, weighted kappa and intraclass correlation coefficient (ICC) were used to determine inter- and intra-observer variability. RESULTS: Inter-observer reproducibility was good (ICC value 0.77). Inter- and intra-observer reproducibility for individual parameters was good to very good (inter-observer ICC value 0.63-0.91; intra-observer ICC value 0.76-0.96). CONCLUSION: The presented comprehensive MR scoring system for osteoarthritic changes of the knee has a good to very good inter-observer and intra-observer reproducibility. Thus the score form with its definitions can be used for standardized assessment of osteoarthritic changes to monitor medical therapy in research studies.
Aged↗
Kappa statistics in the assessment of observer variation: the significance of multiple observers classifying ankle fractures.
Studies using kappa statistics have been conducted with a varied but limited number of observers. The aim of this study was to evaluate the significance of multiple observers on kappa as a measure of observer variation. One hundred orthopedic specialists were asked to assess a random sample of ten sets of standard radiographs of 94 consecutive patients with ankle fractures. The observers were randomly allocated into four groups, which again were divided into subgroups with an increasing number of observers. Random subgroups of three observers revealed kappa values from 0.20 to 0.64 in the Lauge-Hansen and 0.27 to 0.90 in the Weber classification system. With an increasing number of observers in the subgroups, kappa stabilizes around a mean value, indicating that the sampling variation and standard error decrease. The standard error found in this study makes kappa questionable as a measure for agreement among a small number of observers. Thus, kappa values obtained for a given diagnostic tool at one department are not directly comparable with results from other departments. We conclude that kappa cannot stand alone as a simple measure of observer variation.
Ankle Injuries↗
Methodological issues in the direct observation of parent-child interaction: do observational findings reflect the natural behavior of participants?
This review examines evidence for the utility and validity of direct observational techniques for answering particular research and clinical questions. Observational techniques often involve recording behavior in settings that are relatively unnatural for families. However, it is argued that construct validity of observational methods depends partly on whether the findings are representative of participants' typical everyday behavior. Evidence is reviewed concerning whether observational findings are affected by the presence of the observer, and by two factors which have been neglected in the literature, namely the type of task imposed by the observer (e.g., directing parent and child to play rather than observing spontaneous interaction) and the location of the observations (e.g., clinic or laboratory rather than home). The review suggests that the presence of an observer does not necessarily distort the nature of interactions. However, the small number of studies in this area suggest that interactions in structured or artificial settings are not necessarily representative of those normally taking place at home.
Child↗
Inter-observer and intra-observer agreement in the interpretation of visual fields in glaucoma.
Visual field changes are one of the main parameters used to monitor progression of glaucoma. This study assesses the degree of intra-observer and inter-observer agreement among nine observers in grading visual fields in glaucoma patients using a visual field system previously described by Jay. The results show a median inter-observer agreement of 61% (median kappa = 0.52) and a median intra-observer agreement of 72% (median kappa = 0.65). This system for grading fields in glaucoma has a high degree of intra-observer agreement, suggesting it is a useful system for longitudinal follow-up of patients by a single observer. The higher degree of disagreement between observers points to the need for careful pretraining of observers in clinical management and research where the results from visual field examinations are to be graded by more than one clinician.
Cohort Studies↗
Intra-observer and inter-observer reliability of the pulsatility index calculated from pulsed Doppler flow velocity waveforms in three fetal vessels.
OBJECTIVE: Study of the intra observer and inter observer reliability of the pulsatility index, calculated from pulsed Doppler recordings of three fetal vessels. DESIGN: Flow velocity waveforms (FVW) were recorded from the umbilical artery, the fetal descending aorta and the fetal internal carotid artery. Intra-observer reliability was assessed in six fetuses; ten repeated measurements were performed by one observer. Inter-observer reliability was studied in 14 fetuses; two observers performed two repeated measurements in each fetus. SETTING: A tertiary referral hospital. SUBJECTS: High risk pregnancies with a gestational age ranging from 29 to 42 weeks. MAIN OUTCOME MEASURES: Analysis of variance with repeated measurements and a graphical method were used for data analysis. Intra-observer repeatability was expressed as Intraclass Correlation Coefficient (IntraCC). Inter-observer agreement was expressed as Interclass Correlation Coefficient (InterCC). RESULTS: IntraCC for umbilical artery, descending aorta and internal carotid artery were 0.91, 0.78, and 0.54, respectively. InterCC values for these vessels were 0.39, 0.45 and 0.34, respectively. No systematic differences between the two observers except for the fetal descending aorta, were apparent. IntraCC decreased remarkable when fetuses with absent end diastolic velocities were excluded from the analysis. CONCLUSION: The pulsatility index (PI) used for fetal measurements has a poor reliability. This is of serious concern when clinical use of FVW measurements is considered as a diagnostic tool.
Aorta, Thoracic↗
Practice of directly observed treatment (DOT) for tuberculosis in southern Thailand: comparison between different types of DOT observers.
SETTING: A government health system in southern Thailand where the directly observed treatment, short-course (DOTS) strategy has been implemented. OBJECTIVE: To compare the practice of actual directly observed treatment (DOT) and the observer sustainability for different types of observer. METHODS: During 1999-2000, 411 patients with new smear-positive pulmonary tuberculosis were followed up. The patients and/or their observers were interviewed about the presence of any person with the patient during drug intake and the practice of watching the patient swallowing the medicine (actual DOT). Data were recorded monthly and analysed by Cox and logistic regression models. RESULTS: For health personnel (HP), community member (CM), and family member (FM) observers, the proportions who did not practise actual DOT were respectively 11%, 23%, and 35%, and the proportions who changed to no observer or self administration were respectively 11%, 1%, and 2%, during the first 9 months of treatment. Health personnel had the lowest risk of not practising actual DOT (odds ratio HP/FM 0.1, 95%CI 0.1-0.2; CM/FM 0.9, 95%CI 0.5-1.6) but the highest risk for change to self administration. CONCLUSION: To increase the coverage of actual DOT, strategies are needed to maintain health personnel as the DOT observers and to promote actual DOT among family member observers.
Adolescent↗
[Tennis elbow--the observed depends on the observer by whom the observation was done].
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Humans↗
Direct observations of nursing home care quality: Does care change when observed?
OBJECTIVES: Recent research demonstrates that care recorded by nursing home (NH) staff is often inaccurate. Direct observations of care may therefore be of critical importance in assessing and improving care in this setting. Unfortunately, despite their apparent use in several types of quality assurance activities, there is little written information about the reliability or accuracy of observational procedures in NHs. This paper provides information about one important measurement issue (reactivity) that is often cited as a limitation of observational procedures in measuring usual care practices accurately. DESIGN: Descriptive. SETTING: Seven nursing homes. PARTICIPANTS: Staff and residents. MEASUREMENTS: Direct observational time in bed; repositioning and feeding assistance. RESULTS: Observational measures of care quality were stable over multiple observation periods and consistently detected quality problems even on the first and last days of observation. CONCLUSION: Direct observations of care provided to residents do not appear to change provider behavior.
Attitude of Health Personnel↗
Are health personnel the best choice for directly observed treatment in southern Thailand? A comparison of treatment outcomes among different types of observers.
A prospective study was conducted in 24 districts in southern Thailand in 1999 with directly observed treatment, short-course strategy (DOTS) implemented to determine treatment outcomes in relation to the practical observer among 455 enrolled patients with tuberculosis. Health personnel (HP), community members (CM), family members (FM) and self-administration (SA) were initially assigned to be DOT observers in 43%, 5%, 44% and 8% of 411 analysed patients, respectively. In practice, 56% of the 379 patients with assigned observers changed their observers. The practical observer was the assigned observer among 17% of patients assigned to HP, 57% to CM, 75% to FM, and 34% to SA, respectively. There were no significant differences in treatment success between different types of main observers. Adjusted odds ratios (95% confidence interval) of treatment non-success were 1.1 (0.3-4.7), 0.7 (0.2-3.3), and 0.5 (0.2-1.1) for HP, CM, and FM, over SA groups, respectively. HP may not be the best choice in our setting due to poor sustainability and the availability of another promising choice (CM).
Adult↗