Intraclass Correlation Coefficient Results Research Articles

Calidad de la información que proporciona el paciente quirúrgico sobre eventos adversos

ObjectiveTo determine whether patients are a good information source on the occurrence of adverse events (AE). DesignAnalytical retrospective study using in-depth interviews in a double-blind protocol, and in parallel, to ensure whether the patient had actually suffered an AE. The Harvard method was also applied to review the medical records using a screening guide. Agreement between the physician and patient point of view of the surgery outcome was also estimated. ParticipantsA total of 28 randomly selected surgical patients discharged from a general hospital were interviewed. Ten patients (28% of the total suffering an AE yearly) who had experienced an AE, confirmed after a medical record review, and 18 patients who did not suffer an AE. ResultsIntraclass correlation coefficient for the agreement between the medical criterion and the patient point of view was 0.35 (95% CI; 0.2-0.6), and the number of correct classifications was 20/28 (71%, 95% CI; 51-86). Reporting an error reduces the likelihood of the hospital being considered as safe (Fisher's exact p=0.012).Errors were attributed to workload and to the intrinsic randomness of human activity. ConclusionsPatients can contribute in identifying an AE affecting them in a reasonable manner, providing us with additional information for enhancing patient safety and the quality of medical records.

Test–retest reliability, smallest real difference and concurrent validity of six different balance tests on young people with mild to moderate intellectual disability

ObjectivesSome studies have reported that people with intellectual disability may have reduced balance ability compared with the population in general. However, none of these studies involved adolescents, and the reliability and validity of balance tests in this population are not known. The purpose of this study was to examine the reliability of six different balance tests and to investigate their concurrent validity. DesignTest–retest reliability assessment. SettingsAll subjects were recruited from a special school for people with intellectual disability in Bollnäs, Sweden. ParticipantsEighty-nine adolescents (35 females and 54 males) with mild to moderate intellectual disability with a mean age of 18 years (range 16 to 20 years). InterventionsAll subjects followed the same test protocol on two occasions within an 11-day period. Main outcomesBalance test performances. ResultsIntraclass correlation coefficients greater than 0.80 were achieved for four of the balance tests: Extended Timed Up and Go Test, Modified Functional Reach Test, One-leg Stance Test and Force Platform Test. The smallest real differences ranged from 12% to 40%; less than 20% is considered to be low. Concurrent validity among these balance tests varied between no and low correlation. ConclusionThe results indicate that these tests could be used to evaluate changes in balance ability over time in people with mild to moderate intellectual disability. The low concurrent validity illustrates the importance of knowing more about the influence of various sensory subsystems that are significant for balance among adolescents with intellectual disability.

Reliability and reproducibility of a morpho-textural image analysis method over a patellar ligament ultrasonography

ObjectiveImage analysis techniques over ultrasonograms may be useful to extract quantitative information. Because ecography and the selection of the area of interest are technician-dependent, the objective of this work was to calculate the reliability and the reproducibility of the analysis method. Material and methodsTest-retest reliability study on 60 cross-sectional patellar ligament ultrasonograms on 1cm of patella were carried out. Sonosite Titan L-38 (5–10 MHz) and the Image analysis software J v1.40 were used. Morphometric variables were: perimeter, area, width, thickness, and mean echogenity; textural variables were: uniformity, homogeneity and entropy. The intraclass correlation coefficient (ICC) was calculated with a confidence interval of 95%. ResultsIntraclass correlation coefficients over 0,70 were found, with an agreement ranging from good to very good in all of the variables both for the intra ecography and inter ecography studies. ConclusionVery good levels of reliability and internal consistency were seen, demonstrating that from the statistical point of view, the variability introduced by the technician is not significant. This method can be taken as a reference to analyze the reliability between several ultrasonographers.

FMRI changes over time and reproducibility in unmedicated subjects at high genetic risk of schizophrenia

Functional brain abnormalities have been repeatedly demonstrated in schizophrenia but there is little data concerning their progression. For such studies to have credibility it is first important to establish the reproducibility of functional imaging techniques. The current study aimed to examine these factors in healthy controls and in unmedicated subjects at high genetic risk of the disorder: (i) to examine the reproducibility of task-related activation patterns, (ii) to determine if there were any progressive functional changes in high-risk subjects versus controls reflecting inheritance of the schizophrenic trait, and (iii) to examine changes over time in relation to fluctuating positive psychotic symptoms (i.e. state effects). Subjects were scanned performing the Hayling sentence completion test on two occasions 18 months apart. Changes in activation were examined in controls and high-risk subjects (n=16, n=63). Reproducibility was assessed for controls and high-risk subjects who remained asymptomatic at both time points (n=16, n=32). Intra-class correlation values indicated good agreement between scanning sessions. No significant differences over time were seen between the high-risk and control group; however, comparison of high-risk subjects who developed symptoms versus those who remained asymptomatic revealed activation increases in the left middle temporal gyrus (p=0.026). The current results suggest that functional changes over time occur in the lateral temporal cortex as high genetic risk subjects become symptomatic, further, they indicate the usefulness of functional imaging tools for investigating progressive changes associated with state and trait effects in schizophrenia.

Reliability of voluntary step execution behavior under single and dual task conditions

BackgroundThe current study investigated the repeatability (test-retest reliability) of ground reaction force parameters recorded during a voluntary step execution under single (motor task) and dual task (motor and cognitive task) conditions for healthy adults and elderly individuals as well as the number of trials required to produce repeatable results.MethodsTwenty-four healthy adults (21–63 years old) and 16 elderly adults (66–87 years) performed a voluntary rapid step execution following a tap on their heel while standing on a force platform under single and dual task conditions on three separate occasions. The first two tests were performed 30–60 minutes apart and the third test was performed a week later. Variables analyzed from the ground reaction force data included onset latency of step initiation (initiation phase), preparation and swing phases, foot-off and foot-contact times.ResultsIntraclass correlation coefficients (ICC(2,1)) were good to excellent across all parameters and test conditions for the pooled population and for elderly (0.74–0.92 and 0.62–0.88, respectively) except for the swing phase duration where lower values were seen (0.54–0.60 and 0.32–0.64 respectively). Values were similar under single and dual task conditions.ConclusionA voluntary step execution test, performed under single and dual task conditions especially foot-off and foot-contact times, is a reliable outcome measure that may be a useful tool to asses dynamic balance function for diagnostic purposes as well as clinical intervention trials.

Hop Testing Provides a Reliable and Valid Outcome Measure During Rehabilitation After Anterior Cruciate Ligament Reconstruction

Although various hop tests have been proposed as performance-based outcome measures following anterior cruciate ligament (ACL) reconstruction, limited reports of their measurement properties exist. The purpose of this study was to investigate the reliability and longitudinal validity of data obtained from hop tests during rehabilitation after ACL reconstruction. Forty-two patients, 15 to 45 years of age, who had undergone ACL reconstruction participated in the study. The study design was prospective and observational with repeated measures. The subjects performed a series of 4 hop tests on 3 separate occasions within the 16th week following surgery and on a fourth occasion 6 weeks later. The tests were a single hop for distance, a 6-m timed hop, a triple hop for distance, and crossover hops for distance. Performance on the ACL-reconstructed limb was expressed as a percentage of the performance on the nonoperative limb, termed the "limb symmetry index." Subjects also completed the Lower Extremity Functional Scale and a global rating of change questionnaire. Intraclass correlation coefficients for limb symmetry index values ranged from .82 to .93. Standard errors of measurement were 3.04% to 5.59%. Minimal detectable changes, at the 90% confidence level, were 7.05% to 12.96%. Changes in hop test scores on the operative limb were statistically greater than changes on the nonoperative limb. Pearson correlations (r) between change in hop performances and self-reported measures ranged from .26 to .58. The results show that the described series of hop tests provide a reliable and valid performance-based outcome measure for patients undergoing rehabilitation following ACL reconstruction. These findings support the use and facilitate the interpretation of hop tests for research and clinical practice.

Within- and between-examiner repeatability of distraction indices of the hip joints in dogs

Abstract Objective To evaluate in vivo repeatability of the distraction index method of evaluating hip joint laxity in dogs. Animals 31 two-year-old Labrador Retrievers. Procedure Each dog was anesthetized and radiographically evaluated for hip joint laxity 4 times: twice by an experienced examiner and twice by an examiner who had no previous knowledge of or training in the technique prior to the first day of testing. Distraction indices (DI) were determined from the radiographs and intraclass correlation coefficients were calculated to evaluate the repeatability of DI measurements between and within examiners. Results Intraclass correlation coefficients were high (range, 0.85 to 0.94). Lower limits of the 95% confidence intervals for the intraclass correlation coefficients ranged from 0.75 to 0.89. Conclusions Between- and within-examiner repeatabilities of DI measurements were high, suggesting that the technique is clinically reliable. Clinical Relevance Distraction index is a reliable measure of hip joint laxity and a good predictor of the risk of development of degenerative joint disease associated with hip dysplasia in dogs. Establishment of high repeatability of DI measurements suggests that the stress-radiographic method may be used by multiple examiners with the expectation of comparable and consistent results. (Am J Vet Res 1997;58:1076–1077)