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PubMed1991

The Reliability of Computer-Processed EEG in the Determination of ECT Seizure Duration.

The reliability of single-channel analog EEG and two-channel, computer-processed EEG (cEEG) in determining seizure duration during electroconvulsive therapy (ECT) was studied in 144 consecutive individual treatment sessions of 14 hospitalized patients. Seizure durations determined by post hoc, blind readings of data generated by each method were compared. These estimates of seizure duration were also compared to those determined by the "cuff" method. We found that under our study conditions, the cEEG method was more reliable than the EEG method in two tests of reliability: the cEEG method had fewer readings with a discrepancy of 10 s or more between readers, and had a higher degree of correlation between readers. There was no difference, however, between the cEEG and EEG methods when comparing mean differences and the mean absolute difference between readers within the methods. We also found that the EEG and cEEG methods detected seizure durations that were substantially longer than those detected by the "cuff" method. We conclude that under our study conditions, cEEG was more reliable than analog EEG in certain measures of reliability.

Journal Article↗
PubMedDate not supplied

Assessment of motoneuron excitability using recurrent inhibition and paired reflex depression protocols: a test of reliability.

Motor output may be regulated by both pre- and post-synaptic mechanisms. The purpose of this study was to investigate the reliability of two measurement protocols, which purport to examine spinal mechanisms responsible for gating motoneuron excitability. Nine subjects (aged 29 +/- 5 years) were tested using two soleus H-reflex protocols; 1) recurrent inhibition (RI) and 2) paired reflex depression (PRD). The dependent variable for each protocol was the peak-to-peak amplitude of the conditioned Hoffmann reflex (H-reflex). Seven trials were obtained for each subject under each condition as well as control values to assess test-retest reliability. After all trials were collected the subjects rested for at least five minutes after which the process was repeated. Each subject returned to the lab after a period of no less than 24 hours at which time the process was repeated. Protocol #1: Control reflexes (20% of maximal motor response) were obtained during quiet stance. After obtaining control trials two reflex responses were elicited which were separated by 10 ms on each trial to assess recurrent inhibition (Pierrot-Deseilligny et al., 1976; Bussel and Pierrot-Deseilligny, 1977). Protocol #2: Again a double-pulse technique was used to assess reflex activation history on motoneuron pool output (Trimble et al., 2000). This protocol utilized two reflex stimuli of the same intensity separated by 80 ms. The peak-to-peak amplitude of the control, RI conditioned and PRD conditioned H-reflexes exhibited intraclass reliability estimates of .97, .97 and .93 respectively. To achieve a reliability of rI > or = .80, it is recommended that a minimum of 2 trials be used for the RI protocol and that 4 trials be used for the PRD protocol. The results indicate that both techniques provide a means to objectively and reliably measure spinal mechanisms for gating motoneuron pool output.

Adult↗
PubMed2002

[Reliability of a positron emission tomography system (CTI:PT931/04-12)].

PURPOSE: The maintenance data of a PET system (PT931/04-12 CTI Inc.) was analyzed to evaluate its reliability. METHOD: We examined whether the initial performance for the system resolution and efficiency is kept. The reliability of the PET system was evaluated from the value of MTTF (mean time to failure) and MTBF (mean time between failures) for each part of the system obtained from the maintenance data for 13 years. RESULTS: The initial performance was kept for the resolution, but the efficiency decreased to 72% of the initial value. The 83% of the troubles of the system was for detector block (DB) and DB control module (BC). The MTTF of DB and BC were 2,733 and 3,314 days, and the MTBF of DB and BC per detector ring were 38 and 114 days. The MTBF of the system was 23 days. We found seasonal dependence for the number of troubles of DB and BC. This means that the trouble may be related the humidity. CONCLUSION: The reliability of the PET system strongly depends on the MTBF of DB and BC. The improvement in quality of these parts and optimization of the environment in operation may increase the reliability of the PET system. For the popularization of PET, it is effective to evaluate the reliability of the system and to show it to the users.

Equipment Failure Analysis↗
PubMed2002

[Reliability of volumetric measures of mesial temporal structures].

RATIONALE: The development of reliable techniques for volumetric measurement of mesial temporal structures (amygdala, hippocampus and parahippocampal gyrus) on magnetic resonance imaging (MRI) can provide data for the study of neuropsychiatric disorders, mainly temporal lobe epilepsy, Alzheimer's disease and schizophrenia. METHOD: We investigated these techniques performing intraobserver and interobserver reliability study concerning normal controls, epilepsy and Alzheimer's disease patients using the intra-class correlation coefficient. RESULTS: Intra-observer reliability of evaluated structures ranged from 0.93 to 0.99 (p<0.001). Inter-observer reliability ranged from 0.70 to 0.95 (p < or = 0.001). CONCLUSION: The results suggest that the technique of MRI morphometry of mesial temporal regions can be considered a reliable tool which may help in the investigation of neuropsychiatric disorders, since used by adequately trained clinicians and researchers.

Alzheimer Disease↗
PubMed2001

Reliability of the Demand-Control Questionnaire for sewing machine operators.

The Demand-Control Questionnaire (DCQ), a 20-item scale that measures psychological work demands, job control and workplace social support, has frequently been used to assess occupational stress. The purpose of this study was to determine the test-retest reliability and internal consistency of the DCQ with sewing machine operators. Forty-six sewing machine operators completed the DCQ on two occasions with an 11-week time interval. A repeated measures analysis of variance model and subsequent application of generalizability theory were used to calculate the test-retest reliability of the subjects' ratings on the DCQ. Cronbach's alpha was used to determine the internal consistency of the scale. The test-retest reliability was 0.33 (95% confidence interval = 0.05-0.61), indicating fair reliability. Good internal consistency (Cronbach's alpha = 0.70) was found. The DCQ appears to be a reliable measure for assessing occupational stress in sewing machine operators. Workplaces need to place greater emphasis on the role of occupational stress in the prevention and treatment of musculoskeletal injuries among sewing machine operators.

Journal Article↗
PubMed2002

Reliability and reactivity of three new functional assessment measures.

This study of the reliability of three new tests of work performance considered the effect of test reactivity on measured performance. The tests are components of an employment screening battery designed for placement of applicants in automotive assembly jobs. Statistical measures of reliability were compared with a simple measure of test reactivity in a sample of 51 healthy adults. The effect of test reactivity on employment selection decisions using various cut scores was studied. Test reactivity is found to be a significant threat to reliability that must be considered when skill-based performance tests are used on a serial basis. When intended for use on a serial basis, such tests should be studied for both reliability and reactivity. In addition to reporting traditional statistical indices of reliability, an index of the reactivity should be reported.

Adult↗
PubMed2003

Accuracy and reliability of observational gait analysis data: judgments of push-off in gait after stroke.

BACKGROUND AND PURPOSE: Physical therapists routinely observe gait in clinical practice. The purpose of this study was to determine the accuracy and reliability of observational assessments of push-off in gait after stroke. SUBJECTS: Eighteen physical therapists and 11 subjects with hemiplegia following a stroke participated in the study. METHODS: Measurements of ankle power generation were obtained from subjects following stroke using a gait analysis system. Concurrent videotaped gait performances were observed by the physical therapists on 2 occasions. Ankle power generation at push-off was scored as either normal or abnormal using two 11-point rating scales. These observational ratings were correlated with the measurements of peak ankle power generation. RESULTS: A high correlation was obtained between the observational ratings and the measurements of ankle power generation (mean Pearson r=.84). Interobserver reliability was moderately high (mean intraclass correlation coefficient [ICC (2,1)]=.76). Intraobserver reliability also was high, with a mean ICC (2,1) of.89 obtained. DISCUSSION AND CONCLUSION: Physical therapists were able to make accurate and reliable judgments of push-off in videotaped gait of subjects following stroke using observational assessment. Further research is indicated to explore the accuracy and reliability of data obtained with observational gait analysis as it occurs in clinical practice.

Adult↗
PubMed2003

The reliability of frequency-doubling technology (FDT) perimetry in a pediatric population.

PURPOSE: Frequency-doubling Technology IFDT) Perimetry was introduced as a rapid, easy method for detection of visual-field defects in adults. Its reliability, howev, has never been tested among pediatric patients. The purpose of this study was to determine if children could complete a screening program of FDT Perimetry reliably and to define the age range over which it might be most applicable. METHODS: Two hundred fifty-nine normal children (mean age, 10.7 years; range, 4 to 17 years) were asked to complete the FDT C-20-1 screening test as part of their general eye examination. The visual-field results were analyzed for reliability using the number of false-positive errors, fixation losses, and visual-field defects. For the purposes of this analysis, field results were considered unreliable with false-positives > or = 1 or fixation errors > or = 1. The visual-field test was also considered unreliable if > 2 sectors were flagged. RESULTS: Data from 254 children were included in the analysis. Five children were excluded because of suspected malingering or ocular health diagnosis that may have produced a visual-field defect. False-positives were less than one for all but the youngest age group 14 years old). Fixation errors decreed with increasing age and fell below one (became reliable) at approximately 9 years of age, and remained less than one through 17 year. Visual-field loss for purposes of this study when present in more than two sectors was considered unreliable in this normal population. CONCLUSIONS: Children ages 10 years of age and older can reliably complete the FDT C-20-1 screening field test using the strictest criteria, combining false-positives, fixation losses, and visual-field losses. These data are derived from normal subjects, who on complete eye examination, had no ocular disease or reason to suspect visual-field defects.

Adolescent↗
PubMed2003

Measuring self-reported functional status and pain in patients with chronic low back pain by postal questionnaires: a reliability study.

STUDY DESIGN: A reliability study was performed. OBJECTIVES: To evaluate the test-retest reliability of self-reported functional status and pain in chronic low back pain patients by postal questionnaires. SUMMARY OF BACKGROUND DATA: Evaluation tools focusing on the patients' self-reported physical function are recommended in studies on low back pain. Postal questionnaires are inexpensive and should be considered to assess long-term results. The reliability of a postal questionnaire has not been assessed in patients with chronic low back pain. METHODS: Forty-two patients with chronic low back pain (15 men, 27 women; mean age, 40 years; range, 20-61 years) agreed to participate in the study. The mean duration of symptoms was 8.9 years (range, 1-40 years). A postal questionnaire was sent to the patients twice within a 2-week interval. The questionnaire included the following items: work, back satisfaction, General Function Score (GFS), Oswestry Disability Index (ODI), pain, fear-avoidance beliefs, life satisfaction and pain medication. RESULTS: Thirty-seven patients (88%) returned both questionnaires. Except for lumbar pain, there were no statistical differences between the answers from the two questionnaires. The intraclass coefficient values ranged from 0.70 (lumbar pain) to 0.94 (ODI). The repeatability or absolute size of measurement error was 11.9 for the ODI and 28.6 and 34.2 for lumbar and leg pain, respectively. The kappa values for work, back satisfaction, and pain medication were 0.94 and 0.61, 0.62, and 0.64, respectively. The kappa values for the separate items in the GFS ranged from 0.41 to 0.79. The correlations between ODI and the GFS, lumbar pain, life satisfaction, and back satisfaction were 0.35, -0.72, -0.76, and 0.76, respectively. CONCLUSION: The ODI was highly reliable. The questions about work, back satisfaction, and pain medication showed good agreement. The GFS, pain intensity, fear-avoidance beliefs, and life satisfaction appeared to lack sufficient reliability to be recommended in postal questionnaires.

Activities of Daily Living↗
PubMed2003

Assessing reliability and validity measures in managed care studies.

BACKGROUND: To review the reliability and validity literature and develop an understanding of these concepts as applied to managed care studies. RESULTS: Reliability is a test of how well an instrument measures the same input at varying times and under varying conditions. Validity is a test of how accurately an instrument measures what one believes is being measured. METHODS: A review of reliability and validity instructional material was conducted. CONCLUSIONS: Studies of managed care practices and programs abound. However, many of these studies utilize measurement instruments that were developed for other purposes or for a population other than the one being sampled. In other cases, instruments have been developed without any testing of the instrument's performance. The lack of reliability and validity information may limit the value of these studies. This is particularly true when data are collected for one purpose and used for another. The usefulness of certain studies without reliability and validity measures is questionable, especially in cases where the literature contradicts itself

Data Interpretation, Statistical↗
PubMed2003

[Integrated evaluation on system reliability of a space metabolism simulation device].

OBJECTIVE: To define the lower confidence limit of the system reliability of the space metabolism simulation device by using the test data of the comprising units in their development phases. METHOD: A new method for defining the environmental conversion factors of failure times has been given basing on the AMSAA model, and the MTBF point evaluated values and lower confidence limits of the units were defined, at last, the lower confidence limit of the system reliability was obtained using L-M method. RESULT: The lower confidence limit of the system reliability under confidence level of 0.8 is 0.9281, which is consistent with the result obtained by the classic system reliability evaluation method. CONCLUSION: Integrated system reliability evaluation using the proposed method can well satisfy the need in engineering.

Equipment Design↗
PubMedDate not supplied

Clinical measures of shoulder subluxation: their reliability.

The purpose of this report is to describe the reliability of three clinical measures used to evaluate changes in shoulder subluxation. The three methods include measuring the subacromial space in fingers breadth, using calipers, or a plexiglass jig. Thirty-six patients with shoulder subluxation who had experienced a cerebrovascular accident were the subjects. Four occupational therapists with experience in stroke rehabilitation were divided into two teams of two therapists and rated the subjects independently. Each rater repeated her assessments on nine subjects to test intrarater agreement. Inter-rater agreement was assessed both between members of the same team (27 subjects per rater pair) and members of different teams (18 subjects per rater pair). The measure of reliability was the intraclass correlation coefficient (ICC2, 1) as derived from two-way analysis of variance. The highest intra-rater reliability was displayed by the finger breadth method, the second highest by the caliper method and the lowest by the plexiglass jig. The coefficients in the former two cases were always above .8. Using the jig only one rater achieved this level. Agreement between the two members of the same team were above .75 for the fingers and caliper methods, but less than this for the jig. Between members of different teams however, only the finger breadth method attained reliabilities above .7, and the plexiglass jig, in particular, showed very low reliability. These results demonstrate the difficulty of achieving consistent clinical measurement for a condition like shoulder subluxation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2004

Reliability and validity of opiate use self-report in a population at high risk for esophageal cancer in Golestan, Iran.

OBJECTIVE: To assess the reliability and validity of self-reported opium use in a rural Iranian population at high risk for esophageal cancer in preparation for a large cohort study. METHOD: 1,057 subjects ages 33 to 84 years were recruited from Gonbad city and three surrounding villages in Golestan province of Iran and completed a questionnaire and provided biological samples. The history and duration of using opium, smoking tobacco, chewing nass, and drinking alcohol were measured by questionnaire in the entire cohort. A subgroup of 130 people was reinterviewed after 2 months to assess reliability. Validity of the opium question was assessed by comparing the questionnaire responses with the presence of codeine and morphine in the urine of 150 selected subjects. RESULTS: Self-reported opiate use is reliable and valid in this population. The reliability of ever opium use and duration of opium use had kappa's of 0.96 and 0.74, respectively. The validity of self-reported opium use was also high. Using urine codeine or morphine as the gold standard for use of opium, self-report had a sensitivity of 0.93 and a specificity of 0.89. CONCLUSIONS: The self-reported use of opium can provide a reliable and valid measurement in this population and will be useful for studying associations between opium use and occurrence of esophageal cancer and other diseases.

Adult↗
PubMed2005

Retest reliability of self-reported function, self-care, and disease history.

BACKGROUND: Exposures and outcomes frequently are measured by self-reports in epidemiologic studies. However, compared with objective data based on physiologic or laboratory tests, self-reports may suffer from lower accuracy and reliability. In addition, few reports examine reliability in population subgroups, such as black adults. METHODS: The authors examined the retest reliability of common self-reports concerning self-care, function, and chronic conditions in a random subsample of 92 middle-aged black subjects from a larger cohort of 998 subjects in St. Louis, Missouri. Subjects completed in-home interviews between September 2000 and July 2001. MEASURES: Function and self-care measures included 7 basic activities of daily living, 8 instrumental activities of daily living, and 9 items based on the Nagi physical performance scale. Chronic conditions included a list of 11 common diseases and conditions and the 7 items of the Rose Angina protocol. Item level agreement was measured by kappa and scale level agreement was measured by intraclass correlation coefficients. RESULTS: Function and self-care items demonstrated highly variable agreement with 7 items failing to reach even moderate (kappa = 0.40) levels of agreement. Scale reliability was better, and intraclass correlation coefficients ranged from 0.75 to 0.95. Self-reported chronic conditions all achieved at least moderate agreement, except for angina based on the Rose protocol. CONCLUSIONS: This study provides evidence that summary measures of function and a number of chronic conditions and diseases are reliable based on self-reports from urban black adults.

Activities of Daily Living↗
PubMed2005

[A reliability study of the Turkish version of the mornings-evenings questionnaire].

PURPOSE: To investigate the reliability of the Turkish version of the self-assessment mornings-evenings questionnaire (MEQ). METHODS: A Turkish version of the MEQ, which was originally designed by Horne and Ostberg (1976), was given to 618 (291 women and 327 men) volunteers, aged 18 to 57 (23.0+/-5.4 years). Participants were recruited from the university student population and staff who were not night-shift workers. Exclusion criteria included sleep disorders and a history of medical and psychiatric diagnoses. The participants completed the questionnaire twice, 15-20 days apart. The reliability was assessed by Cronbach's and Pearson's r coefficient. RESULTS: MEQ scores were 51.9+/-9.0 (range 22-73) and 52.4+/-9.5 (range 21-72) for the 1st and 2nd applications, respectively, and did not differ significantly between the two applications. Of the 618 subjects interviewed, 149 were self-reported as morning types at the 1st application and 169 as morning types at the 2nd application; 79 as evening types at the 1st application and 87 as evening types at the 2nd application; and 390 as intermediate types at the 1st application and 362 as intermediate types at the 2nd application. Cronbach's a was 0.785 and 0.812 for the 1st and 2nd applications, respectively, and the test-retest reliability coefficient was 0.84 (p< 0.0001). DISCUSSION: The Turkish version of the MEQ shows high reliability. Nevertheless, further evaluation using different subject groups such as the elderly, athletes and shift workers is required to confirm the reliability and validity of the Turkish version.

Adolescent↗
PubMed2005

[Methodology of retrospective chart review to detect adverse events: the reliability of physician judgment].

PURPOSE: To establish a scientific basis for promoting patient safety, basic information related to the incidence of adverse events (AEs) is needed. In studies in several other countries, trained nurses screened for potential AEs using explicit criteria in the first stage, and physicians reviewed selected charts in the second stage. To assure the accuracy of retrospective chart review, it is important to verify the reliability of AE judgments by physician reviewers. The purpose of this study was to test this reliability of judgment of AEs (their presence, causation of healthcare management and preventability) by three physician reviewers. METHODS: This study used 100 selected charts of non-psychiatric inpatients in an acute care hospital. Three physicians independently assessed AEs and discussed their judgments with the physician who created the manual for judging AEs. We considered judgments of the AEs agreed on by the four physicians to be final AE judgments and compared the reliability of each measure related to AE judgments among the physician reviewers using the kappa statistic. RESULTS: The number of AE cases each physician reviewer judged ranged from 18 to 27. Agreement on the presence of an AE ranged from 83.0% to 90.0% (kappa=0.52-0.70). Ultimately, AEs were judged to have occurred in 16 cases while 7 cases were deferred. The agreement on the presence of an AE between the physician's and the final judgment ranged from 86.0% to 96.8% (kappa = 0.56-0.88). However, agreement on the causation of healthcare management and preventability between the physician's and the final judgment was not in the acceptable range. CONCLUSION: The reliability of each physician's judgments regarding the presence of an AE was satisfactory. However, the reliability of judgments related to the causation of health care management and preventability was not necessarily satisfactory. Therefore, it is considered important to judge causation and preventability based on discussion with clinical experts in the relevant field.

Adolescent↗
PubMed2005

Clinical quality indicators of venous leg ulcers: development, feasibility, and reliability.

In the clinical setting, diagnosis and treatment of venous leg ulcers can vary considerably from patient to patient. The first step to reducing this variation is to document venous leg ulcer care through use of quantitative scientific documentation principles. This requires the development of valid and reliable evidence-based quality indicators of venous leg ulcer care. A Scandinavian multidisciplinary, cross-sectional panel of wound healing experts developed clinical quality indicators on the basis of scientific evidence from the literature and subsequent group nominal consensus of the panel; an independent medical doctor tested the feasibility and reliability of these clinical indicators, assessing the quality of medical technical care on 100 consecutive venous leg ulcer patients. Main outcome measures were healing, recurrence, pain, venous disease diagnosis, differential diagnosis and treatment, and inter- and intra-rater reliability. The indicators proved feasible and reliable to measure (inter-rater kappa = 0.79, P < 0.01 and intra-rater kappa = 0.89, P < 0.1). Within 3 months of initial examination, venous etiology was verified by duplex in 61 of the 98 participating patients (62%) and 31 (32%) were assessed for venous surgery. Distal arterial pressure was measured following initial examination in 33 of the patients (34%). All patients (100%) were prescribed compression therapy. Of the 98 patients, 11 (11%) had ulcers recur in 3 months and 72 (73%) healed in 12 months, which is in line with the literature. It is feasible to reliably measure the quality of medical technical venous leg ulcer care in the clinical setting using a few strategic clinically relevant indicators of quality.

Aged↗
PubMedDate not supplied

Measuring functional disability in early rheumatoid arthritis: the validity, reliability and responsiveness of the Recent-Onset Arthritis Disability (ROAD) index.

OBJECTIVE: Disability has been identified as a core outcome measure in rheumatoid arthritis (RA). The aim of this study was to test the Recent-Onset Arthritis Disability (ROAD) questionnaire for validity, reliability and responsiveness in Italian patients with early RA. METHODS: The psychometric properties of ROAD were tested in 159 patients with early RA, mean age 54.7 (+/- 8.8), 74.3% women, mean disease duration 14.5 months (+/- 1.9 months). All completed the ROAD, the Medical Outcomes Study SF-36 Health Survey (SF-36), the Health Assessment Questionnaire (HAQ) and the patient global assessment (PGA) of functional disability twice, in order to test for validity and responsiveness. Of the 159 patients who completed the health status instruments on two occasions, 121 were included in the responsiveness analyses. The test-retest reliability of the ROAD questionnaire was calculated using intraclass correlation coefficients (ICCs) and the Bland and Altman method on 77 patients who completed the questionnaire twice over an interval of one week. Construct validity was assessed using Spearman's correlations, while responsiveness was evaluated by 3 different methods: (1) effect size (the mean difference between the baseline scores and thefollow-up scores divided by the standard deviation of the baseline scores); (2) standardized response mean (the mean change in scores divided by the standard deviation of the change in scores); (3) receiver operating characteristics (ROC) curve analysis. RESULTS: ROAD fulfilled the established criteria for validity, reliability and responsiveness. In comparison with the SF-36, the expected correlations were found when comparing items measuring similar constructs, thus supporting the convergent construct validity. Significant correlations were seen between ROAD scores and HAQ scores (rho = 0.372), SF-36 physical component summary (PCS) (rho = -0.413), PGA functional disability (rho = 0.417), pain (rho = 0.639), Ritchie index (rho = 0.357), number of swollen joints (rho = 0.387), patient and physician assessment of disease activity (rho = 0.467 and 0.323, respectively), and Disease Activity Score (rho = 0.476). Test-retest reliability was satisfactory, with ICCs of 0.927 (upper extremity function), 0.892 (lower extremity function), and 0.851 (activity of daily living/work). Bland-Altman plots confirmed this finding. The results of responsiveness analysis indicate that the ROAD subscales were slightly more sensitive to perceived change in functional disability than those of HAQ, SF-36 PCS, and PGA offunctional disability. CONCLUSION: Our data suggest that the ROAD index is a reliable, valid and responsive tool for measuring physical functioning in patients with early RA, and is suitable for use in clinical trials and daily clinical practice. Its generalizability and utility for assessing aggressive treatment and functional outcomes must now be evaluated in broader settings.

Arthritis, Rheumatoid↗