Showing papers on "Intraclass correlation published in 2003"

The reliability and concurrent validity of the scoliosis research society-22 patient questionnaire for idiopathic scoliosis.

Abstract: STUDY DESIGN Outcome study to determine response distribution, internal consistency, reproducibility, and concurrent validity of the Scoliosis Research Society-22 (SRS-22) health-related quality-of-life (HRQL) questionnaire. OBJECTIVES Further refinement of an HRQL questionnaire specific for idiopathic scoliosis. SUMMARY OF BACKGROUND DATA Previous experience with the original and modified SRS HRQL questionnaires suggested a need for further refinement and more complete validation. METHODS The SRS-22 and Short Form 36 (SF-36) HRQL questionnaires were mailed to 83 previously surveyed postoperative idiopathic scoliosis patients. RESULTS Fifty-eight (70%) patients returned the first set of questionnaires. Their average age at surgery was 14.6 years, and their average follow-up interval since surgery was 10.8 years. Fifty-one (88%) of the 58 returned the second set of questionnaires an average of 28 days later. The psychometric attributes of the instruments were comparable: score distribution, SRS-22 56.9% ceiling and 1.7% floor, SF-36 79.3% ceiling and 1.7% floor; internal consistency (Cronbach alpha), SRS-22 0.92 to 0.75, SF-36 0.91 to 0.36; and reproducibility (intraclass correlation coefficient), SRS-22 0.96 to 0.85, SF-36 0.92 to 0.61. Concurrent validity, determined by Pearson Correlation Coefficients between SRS-22 and SF-36 domains, was 0.70 or greater ( < 0.0001) for 17 relevant comparisons. CONCLUSION The SRS-22 HRQL questionnaire is reliable with internal consistency and reproducibility comparable to SF-36. In addition, it demonstrated concurrent validity when compared to SF-36. It is shorter and more focused on the health issues related to idiopathic scoliosis than SF-36.

Shared decision making: developing the OPTION scale for measuring patient involvement.

Abstract: Background: A systematic review has shown that no measures of the extent to which healthcare professionals involve patients in decisions within clinical consultations exist, despite the increasing interest in the benefits or otherwise of patient participation in these decisions. Aims: To describe the development of a new instrument designed to assess the extent to which practitioners involve patients in decision making processes. Design: The OPTION (observing patient involvement) scale was developed and used by two independent raters to assess primary care consultations in order to evaluate its psychometric qualities, validity, and reliability. Study sample: 186 audiotaped consultations collected from the routine clinics of 21 general practitioners in the UK. Method: Item response rates, Cronbach’s alpha, and summed and scaled OPTION scores were calculated. Inter-item and item-total correlations were calculated and inter-rater agreements were calculated using Cohen’s kappa. Classical inter-rater intraclass correlation coefficients and generalisability theory statistics were used to calculate inter-rater reliability coefficients. Basing the tool development on literature reviews, qualitative studies and consultations with practitioner and patients ensured content validity. Construct validity hypothesis testing was conducted by assessing score variation with respect to patient age, clinical topic “equipoise”, sex of practitioner, and success of practitioners at a professional examination. Results: The OPTION scale provided reliable scores for detecting differences between groups of consultations in the extent to which patients are involved in decision making processes in consultations. The results justify the use of the scale in further empirical studies. The inter-rater intraclass correlation coefficient (0.62), kappa scores for inter-rater agreement (0.71), and Cronbach’s alpha (0.79) were all above acceptable thresholds. Based on a balanced design of five consultations per clinician, the inter-rater reliability generalisability coefficient was 0.68 (two raters) and the intra-rater reliability generalisability coefficient was 0.66. On average, mean practitioner scores were very similar (and low on the overall scale of possible involvement); some practitioner scores had more variation around the mean, indicating that they varied their communication styles to a greater extent than others. Conclusions: Involvement in decision making is a key facet of patient participation in health care and the OPTION scale provides a validated outcome measure for future empirical studies.

Statistical approaches for assessing the relative validity of a food-frequency questionnaire: use of correlation coefficients and the kappa statistic

Abstract: Objective To compare different statistical methods for assessing the relative validity of a self-administered, 150-item, semi-quantitative food-frequency questionnaire (FFQ) with 4-day weighed diet records (WR). Design Subjects completed the Scottish Collaborative Group FFQ and carried out a 4-day WR. Relative agreement between the FFQ and WR for energy-adjusted nutrient intakes was assessed by Pearson and Spearman rank correlation coefficients, the percentages of subjects classified into the same and opposite thirds of intake, and Cohen's weighted kappa. Subjects Forty-one men, mean age 36 (range 21-56) years, and 40 women, mean age 33 (range 19-58) years, recruited from different locations in Aberdeen, Scotland. Results Spearman correlation coefficients tended to be lower than Pearson correlation coefficients, and were above 0.5 for 10 of the 27 nutrients in men and 17 of the 27 nutrients in women. For nutrients with Spearman correlation coefficients above 0.5, the percentage of subjects correctly classified into thirds ranged from 39 to 78%, and weighted kappa values ranged from 0.23 to 0.66. Conclusions Both Spearman correlation coefficients and weighted kappa values are useful in assessing the relative validity of estimates of nutrient intake by FFQs. Spearman correlation coefficients above 0.5, more than 50% of subjects correctly classified and less than 10% of subjects grossly misclassified into thirds, and weighted kappa values above 0.4 are recommended for nutrients of interest in epidemiological studies.

Assessment of cognition in Parkinson’s disease

Abstract: Objective: To develop a short, practical instrument that is sensitive to the specific cognitive deficits in Parkinson’s disease (PD) for comparing groups in research situations and for assessing change in cognitive functioning over time Methods: A literature search was conducted to identify the most frequently affected cognitive domains in PD and to select candidate items for the initial scale This scale was tested in 85 patients and 75 age-, education-, and sex-matched control subjects Items that met predefined criteria for data quality, reproducibility, and discriminative properties were included in the final scale Results: The final scale, the SCOPA-COG (SCales for Outcomes of PArkinson’s disease–cognition), consists of 10 items with a maximum score of 43, with higher scores reflecting better performance The test–retest reliability of the total score was 078 (intraclass correlation coefficient) and ranged from 040 to 075 for individual items (weighted κ) Cronbach’s α was 083 Construct validity of the scale was supported by the expected correlations with the CAMCOG (Cambridge Cognitive Examination) and the Mini-Mental State Examination (MMSE) and by differences found between groups of participants classified by dementia status and between patients grouped by disease severity The scale showed a clear trend toward lower cognition scores for patients with more advanced PD The coefficient of variation of the SCOPA-COG was higher than that of the CAMCOG or the MMSE, indicating a better ability to detect differences between individuals Conclusion: The SCOPA-COG is a short, reliable, and valid instrument that is sensitive to the specific cognitive deficits in PD

Rating scales for dystonia: A multicenter assessment

Abstract: The evaluation of dystonia requires a reliable rating scale. The widely used Fahn-Marsden Scale (F-M) has not been sufficiently tested across multiple centers and investigators. The Dystonia Study Group developed the Unified Dystonia Rating Scale (UDRS) and a Global Dystonia Rating Scale (GDS) to serve as instruments to assess dystonia severity. In this study, 25 dystonia experts evaluated the UDRS, F-M, and GDS for internal consistency and reliability. One hundred dystonia patients were videotaped using a standardized videotape protocol. Each examiner rated 20 patients using the UDRS, F-M, and GDS in random order. The examiner then assessed each scale for ease of use. Statistical analysis used Cronbach's alpha, intraclass correlation coefficients (ICC), generalized weighted kappa statistic, and Kendall's coefficient of concordance. The UDRS, F-M, and GDS showed excellent internal consistency (Cronbach's alpha 0.89-0.93) and good to excellent correlation among the raters (ICC range from 0.71-0.78). Inter-rater agreement was fair to excellent (Kendall's 0.54-0.87; kappa 0.37-0.91) being lowest for eyes, jaw, face, and larynx. The modifying ratings (Duration in the UDRS and Provoking Factor in the F-M) showed less agreement than the motor severity ratings. Among scales, the total scores correlated (Pearson's r, 0.977-0.983). Overall, 74% of raters found the GDS the easiest to apply. The GDS with its simplicity and ease of application may be the most useful dystonia rating scale.

Methods to reduce the impact of intraclass correlation in group-randomized trials

Abstract: This study reports intraclass correlation (ICC) for dependent variables used in group-randomized trials (GRTs). The authors also document the effect of two methods suggested to reduce the impact of ICC in GRTs; these two methods are modeling time and regression adjustment for covariates. They coded and analyzed 1,188 ICC estimates from 17 published, in press, and unpublished articles representing 21 studies. Findings confirm that both methods can improve the efficiency of analyses shown to be valid across conditions common in GRTs. Investigators planning GRTs should obtain ICC estimates matched to their planned analysis so that they can size their studies properly.

Intra-class correlation in random-effects models for binary data

Abstract: W e review the concept of intra-class correlation in random-effects mod- els for binary outcomes as estimated by Statas xtprobit, xtlogit ,a ndxtclog. We consider the usual measures of correlation based on a latent variable formu- lation of these models and note corrections to the last two procedures. We also discuss alternative measures of association based on manifest variables or actual outcomes and introduce a new command xtrho for computing these measures for all three type so fm odels. We also consider alternative measures of intra-class correlation based on manifest rather than latent variables. The possible outcomes for two observations on the same group or individual may be viewed as a two by two contingency table, and we consider measures of association based on Pearsons correlation coefficient and measures based on the odds-ratio such as Yules Q coefficient. We describe the calculation of these mea- sures for probit, logit, and complementary log-log models, using numerical integration procedures for the last two. Finally, we introduce a new command, xtrho ,t hatc anb e used to compute these measures.

Measures of muscle and joint performance in the lower limb of children with cerebral palsy.

Abstract: The aim of this study was to determine the reliability and magnitude of error of three lower-limb clinical measures for children with cerebral palsy (CP): the Modified Ashworth Scale of Spasticity (MAS), passive range of movement (PROM) and the modified Tardieu scale (MTS). Six physiotherapists measured 11 females and seven males (mean age 6 years 4 months, SD 2 years 4 months; age range 2 years 4 months to 10 years) on two occasions using a repeated measures design, collecting all data over 6 days. The severity of CP spanned all five levels of the Gross Motor Function Classification System and all children demonstrated varying degrees of spasticity. Exclusion criteria included botulinum toxin injections, inhibitory plasters, and orthopaedic surgery within the 6 months before study entry. For PROM and the MTS interrater reliability was acceptable with an intraclass correlation coefficient of 0.7, but results for MAS were lower. Standard error of measurement for repeated measures of PROM and MTS was about five degrees, but 95% confidence interval ranges were considerably higher. Test-retest results varied widely, particularly for the MAS. These measurement tools should be used with caution when evaluating changes in young children with CP.

Reliability of Joint Position Sense and Force-Reproduction Measures During Internal and External Rotation of the Shoulder.

Abstract: OBJECTIVE: To determine the reliability of 2 common measures of proprioception. DESIGN AND SETTING: Joint position sense (JPS) and force reproduction (FR) were measured in the dominant shoulder using internal-rotation (IR) and external-rotation (ER) target angles on 2 consecutive days. SUBJECTS: Thirty-one healthy subjects (age = 22.0 +/- 2.8 years, height = 171.8 +/- 9.2 cm, mass = 69.5 +/- 15.9 kg) who did not regularly compete in overhand sports volunteered to participate in the study. MEASUREMENTS: Error scores were calculated at 2 target angles by averaging the absolute difference of 3 trials of JPS and FR. Reliability was determined by comparing the error scores obtained on 2 consecutive days. RESULTS: The inclinometer was found to be a reliable instrument as both intertester (.999) and intratester (.999) intraclass correlation coefficients were high. The JPS and FR measurements were also found to be reliable, with intraclass correlation coefficients ranging from.978 to.984. No differences were observed between trials for either measure. CONCLUSIONS: The inclinometer was a reliable instrument and can provide an affordable and accurate measure of range of motion and JPS. Both JPS and FR were also reliable measures of proprioception in the shoulder. Further research is needed to identify the specific mechanism of proprioception during these tasks.

Validation and reliability of the Baecke questionnaire for the evaluation of habitual physical activity in adult men

Abstract: The aim of this study was to verify validity and reliability of the scores for physical exercise in leisure (PEL), leisure and locomotion activities (LLA), and total score (TS) of the Baecke habitual physical activity questionnaire in adult males. Twenty-one students of Physical Education were evaluated. For validation, the maximum oxygen uptake (O2max) and the decrease of the heart rate in percentile (%DHR) were measured through the Cooper's 12-minute walk or run test, and an annual index of physical exercise (IPE), and a week index of locomotion activities (ILA). The reliability was verified through test-retest with interval of 45 days. The Pearson correlation coefficient, and partial correlation adjusted for age and body mass index were used for validation. The intraclass correlation and paired t-test were used for reliability. The results indicated that %DHR was correlated with LLA and TS (r = 0.47 and p = 0.030; r = 0.48 and p = 0.027, respectively). IPE was correlated with PEL and TS (r = 0.56 and p = 0.008; r = 0.46 and p = 0.036, respectively). ILA was correlated with LLA and TS (r = 0.64 and p = 0.002 and r = 0.51 and p = 0.017, respectively). There was no significant difference in PEL, LLA and TS means in test-retest. The intraclass correlations were r = 0.69; r = 0.80 and r = 0.77, respectively for PEL, LLA and TS. In conclusion, the Baecke questionnaire is valid and reliable to measure habitual physical activity in Brazilian adult men.

Resident self-assessment of operative performance.

Abstract: Background In medicine, the development of expertise requires the recognition of one's capabilities and limitations. This study aimed to verify the accuracy of self-assessment for the performance of a surgical task, and to determine whether self-assessment may be improved through self-observation or exposure to relevant standards of performance. Methods Twenty-six senior surgical residents were videotaped performing a laparoscopic Nissen fundoplication in a pig. Experts rated the videos using two scoring systems. Subjects evaluated their performances after performance of the Nissen, after self-observation of their videotaped performance, and after review of four videotaped "benchmark" performances. Results Expert interrater reliability was 0.66 (intraclass correlation coefficient). The correlation between experts' and residents' self-evaluations was initially moderate ( r = 0.50, P r = 0.63 (Δ r = 0.13, P Conclusions Self-observation of videotaped performance improved the residents' ability to self-evaluate.

Can the Expanded Disability Status Scale be assessed by telephone

Abstract: Information from patients who are unable to continue their visits to a study centre may be of major importance for the interpretation of results in multiple sclerosis (MS) clinical trials. To validate a questionnaire based on the Expanded Disability Status Scale (EDSS), patients in five different European centres were assessed independently by pairs of trained EDSS raters, first by telephone interview and a few days later by standardized neurological examination. Seventy women and 40 men with an average age of 43.7 years (range 19-74 years) were included in the study. Mean EDSS score at the last visit was 4.5 (0-9). EDSS assessment by telephone was highly correlated with the EDSS determined by physical examination (Pearson's correlation coefficient = 0.95). An intraclass correlation coefficient (ICC) of 94.8% was found for the total sample; 77.6% and 86%, respectively, for patients with EDSS 4.5 (n = 64). Kappa values for full agreement were 0.48; for variation by +0.5 steps and +1.0 steps, 0.79 and 0.90, respectively. Best agreement could be found in higher EDSS scores, where assessment by telephone interview might be needed most. The telephone questionnaire is a valid tool to assess EDSS score in cases where the patient is unable to continue visiting a study centre or in long-term follow-up of trial participants.

Translation and cultural adaptation of quality of life questionnaires: an evaluation of methodology.

Abstract: OBJECTIVE: To evaluate the methodological steps currently proposed in translation and cultural adaptation of quality of life questionnaires. METHODS: Fifty patients with rheumatoid arthritis were invited to participate. Two versions each of the Stanford Health Assessment Questionnaire (HAQ), the MOS 36 Item Short-Form Health Survey (SF-36), and the Arthritis Impact Measurement Scales 2 (AIMS-2) were administered: version 1 was a literal translation of the questionnaire; version 2 resulted from a process of translation and cultural adaptation following internationally accepted guidelines. For each patient we applied 2 questionnaires before and after consultation. The questionnaire, the order of administration, and the version were randomly assigned. The interviews were performed by a single interviewer. Several clinical and laboratory outcome measures were assessed simultaneously. Descriptive statistical analysis was used to characterize the data. Spearman and intraclass correlation coefficients were used to evaluate reliability and validity of each version of each questionnaire. RESULTS: Patients9 mean (SD) age was 47 (12) years and mean (SD) disease duration was 10 (7) years. The differences of the mean in the physical and affective AIMS-2 components between the literal and adapted versions (0.21 and 0.11, respectively) were similar to the differences in the intraobserver application of the same version of culturally adapted AIMS-2 components (0.03 and 0.20) (the component scores range from 0 to 10). The same results were observed when considering other components of AIMS and SF-36, as well as HAQ scores. Version 1 and 2 presented a similar clinically and statistically significant correlation with clinical and laboratory measures used in the validation process of the questionnaires. CONCLUSION: The complex methodologies proposed in the translation and validation of the questionnaires should be carefully reevaluated. The simplification of this methodology should be studied.

Validation of a short cognitive tool for the screening of dementia in elderly people with low educational level.

Abstract: Aim To validate the ‘Prueba Cognitiva de Leganes’ (PCL) as a screening tool for cognitive impairment in elderly people with little formal education. Methods The PCL is a simple cognitive test with 32 items that includes two scores of orientation and memory and a global score of 0–32 points. It was applied to a population sample of 527 elderly people over 70 with low educational level, who were independently diagnosed by consensus between two neurologists as having normal cognitive function, age associated cognitive decline (AACD, IPA-OMS criteria) or dementia (DSM-IV criteria). Individuals with severe visual or hearing defects and those who rejected the exam were excluded from the study. The PCL was validated in a sample of 375 individuals: 300 normal, 42 with AACD and 33 with dementia. The sensitivity, specificity, accuracy and likelihood ratios, as well as the ROC curves for dementia and for AACD-dementia, were calculated. The confounding effect of sociodemographic variables was assessed by logistic regression analysis and convergent validity by partial correlations of the PCL with other cognitive tests. Inter-rater reliability was evaluated with the intraclass correlation coefficient. Results The PCL identified dementia (cut-off ≤22) and AACD-dementia (cut-off ≤26), with the following diagnostic parameters, respectively: sensitivity 93.9%–80%, specificity 94.7%–84.3%, positive likelihood ratio 17.8–5.1, negative likelihood ratio 0.06–0.24, and accuracy 94.6%–83.4%. The areas under the ROC curve were 0.985 (95% Confidence Intervals (CI) 0.967–0.995) and 0.904 (95% CI: 0.870–0.932) respectively. The intraclass correlation coefficient was 0.79 (0.74–0.83). Conclusion The PCL is a simple instrument, which is both valid and reliable, for the screening of dementia in population samples of individuals with low educational level. This instrument could be useful in primary health care. Copyright © 2003 John Wiley & Sons, Ltd.

The SIGAM mobility grades: a new population-specific measure for lower limb amputees

Abstract: Purpose : To develop a valid measure of lower limb amputee mobility suitable for routine clinical use, including monitoring change. Methods : The Special Interest Group in Amputee Medicine (SIGAM) described a single-item scale comprising six clinical grades (A-F) of amputee mobility. A self-report questionnaire was developed and algorithm designed to facilitate grade assignment. Reproducibility of the questionnaire and grades were assessed in 62 amputees. Concurrent validity and sensitivity to change were investigated using the timed walking test (TWT). The mobility construct was examined in 200 amputees, using item response theory, by co-calibration with the Rivermead Mobility Index (RMI) on the same patients. Results : Patients included 144 males and 66 females, aged 13-90. Intraclass correlation coefficients and reproducibility kappa values were satisfactory. Observers agreed 100% in using the algorithm. TWT improved as SIGAM grade increased. Examination of psychometric properties revealed the SIGAM it...

Temporal Stability of the Intrinsic Motivation Inventory

Abstract: To examine the temporal stability of the Intrinsic Motivation Inventory a Greek version was administered to 144 undergraduate students after an endurance field test. The same procedure was repeated one week later. Factor analysis followed by varimax rotation showed that three factors (Perceived Competence, Interest/enjoyment, and Effort/importance) explained 65.26% of the total variance. Computed intraclass correlation coefficients (ICC) were .61 for the Perceived Competence subscale, .86 for the Interest/enjoyment, .60 for the Effort/importance, and .70 for the overall scale. The results, however, were modified when the sample was divided in two groups. The first represented small changes in perceived competence between the first and the second measurement, while the second one represented large changes between the two measurements. Recalculated intraclass correlation coefficients for individuals whose Perceived Competence score remained relatively stable yield a high value (.92), whereas individuals whose Perceived Competence changed yield an extremely low value (.60). It was concluded that the Intrinsic Motivation Inventory provides a temporally stable measure, given that perceived competence has not been markedly changed.

Reliability of 4 outcome measures in pediatric spinal muscular atrophy

Abstract: Background Spinal muscular atrophy is a common neurologic disorder of infants and children with a high mortality rate. Clinical trials have not been attempted in this population until recently. Objective To demonstrate that 4 outcome measures are reliable for use in clinical trials in patients with spinal muscular atrophy. Design, Setting, Patients Thirty-eight children with spinal muscular atrophy who fulfilled inclusion and exclusion criteria were enrolled at 5 pediatric centers for a reliability study. Paired samples statistics were performed comparing results of the qualifying variance visit with a fourth visit. Main Outcome Measures Quantitative muscle testing and the Gross Motor Function Measure. Results Thirty-four patients and 7 evaluators completed the study. Thirteen patients were aged 2 through 4 years and 21 were 5 through 17 years. The Gross Motor Function Measure was completed by 34 subjects. Six variables for pulmonary function tests were measured in 20 subjects. Quantitative muscle testing was performed on 21 subjects in 8 muscle groups. Thirty-three subjects completed the PedsQL Neuromuscular Module for Parents. The intraclass correlation coefficient and Bradley-Blackwood procedures indicated a very high level of agreement between measures. Conclusion The Gross Motor Function Measure, pulmonary function tests, quantitative muscle testing, and quality of life are reliable outcome measures for clinical trials in pediatric spinal muscular atrophy.

Bias in Estimation and Hypothesis Testing of Correlation

Abstract: This study examined bias in the sample correlation coefficient, r, and its correction by unbiased estimators Computer simulations revealed that the expected value of correlation coefficients in samples from a normal population is slightly less than the population correlation, ρ, and that the bias is almost eliminated by an estimator suggested by RA Fisher and is more completely eliminated by a related estimator recommended by Olkin and Pratt Transformation of initial scores to ranks and calculation of the Spearman rank correlation, rS, produces somewhat greater bias Type I error probabilities of significance tests of zero correlation based on the Student t statistic and exact tests based on critical values of rS obtained from permutations remain fairly close to the significance level for normal and several non-normal distributions However, significance tests of non-zero values of correlation based on the r to Z transformation are grossly distorted for distributions that violate bivariate normality Also, significance tests of non-zero values of rS based on the r to Z transformation are distorted even for normal distributions This paper examines some unfamiliar properties of the Pearson product-moment correlation that have implications for research in psychology, education, and various social sciences Some characteristics of the sampling distribution of the correlation coefficient, originally discovered by RA Fisher (1915), were largely ignored throughout most of the 20th century, even though correlation is routinely employed in many kinds of research in these disciplines It is known that the sample correlation coefficient is a biased estimator of the population correlation, but in practice researchers rarely recognize the bias and attempt to correct for it

Apoio social: confiabilidade teste-reteste de escala no Estudo Pró-Saúde

Abstract: This article describes the test-retest reliability of a scale comprising five dimensions of social support: material, emotional, informational, affective, and positive social interaction. In the study, a sample of 192 employees at a university in Rio de Janeiro filled out the same questionnaire on two occasions, 15 days apart. Measures of stability used were the intraclass correlation coefficient (ICC), weighted kappa statistic, and log-linear models. Internal consistency was evaluated using the Cronbach's alpha coefficient. Social support dimensions showed internal consistency ranging from 0.75 to 0.91 at test, and 0.86 to 0.93 at retest. The ICC ranged from 0.78 to 0.87 in the five dimensions of the scale, with no substantial differences by gender, age, or level of schooling. For most questions, the "agreement plus linear by linear association" and "quasi-association" log-linear models gave the best fit. According to these results, the reliability of the instrument was considered adequate, enabling it to be used in ongoing assessment of associations between social support and health-related outcomes in a cohort study (the Pro-Health Study) recently begun in Rio de Janeiro.

The intraclass correlation coefficient applied for evaluation of data correction, labeling methods, and rectal biopsy sampling in DNA microarray experiments.

Abstract: We show that the intraclass correlation coefficient (ICC) can be used as a relatively simple statistical measure to assess methodological and biological variation in DNA microarray analysis. The IC...

Accuracy and Reliability of Observational Gait Analysis Data: Judgments of Push-off in Gait After Stroke

Abstract: 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. Method. 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.

Reliability of clinical tests of foot and ankle characteristics in older people.

Abstract: Lower-extremity problems are common in older people; however, the reliability of clinical tools used to assess foot and ankle characteristics has not been rigorously evaluated. This study evaluated the test‐retest reliability of a battery of simple clinical tests of foot and ankle characteristics (tactile sensitivity of the first metatarsophalangeal joint, navicular height, foot length and width, hallux valgus severity, an overall foot problem score, ankle flexibility, ankle dorsiflexion strength, and foot pain) in 31 individuals (13 men and 18 women) aged 76 to 87 years recruited from the community. Three examiners performed the tests on two occasions approximately 2 weeks apart. Intraclass correlation coefficients and coefficients of variation were calculated for continuously scored tests, and the kappa statistic (κ) was used to determine the reliability of hallux valgus severity grading. All of the continuously scored tests had acceptable reliability (intraclass correlation coefficients of 0.64 to 0.98; coefficients of variation of 0.6% to 15.0%), as did hallux valgus severity grading (κ = 0.77; absolute percentage agreement, 84%). These simple clinical tests can now be used with confidence in clinical and research settings to provide reliable and functionally important information regarding foot and ankle characteristics in older people. (J Am Podiatr Med Assoc 93(5): 380-387, 2003)

Interrater and test-retest reliability of the Movement Assessment Battery for Chinese preschool children.

Abstract: Objective The aim of this paper was to check on the reliability of the Movement Assessment Battery for Children (Movement ABC) in preparation for its standardization in Hong Kong. Interrater and test-retest reliability are reported for Age Band One, designed for use with children ages four to six. Method Interrater reliability of the Movement ABC was estimated using two trained observers with 79 children. Test-retest reliability was assessed using 75 children who were tested twice by the same tester over a 2- to 3-week interval. RESULTS. Agreement between testers was good with a mean intraclass correlation of 0.96 across items. A value of 0.77 was obtained for test-retest reliability. Conclusion These results support the use of this component of the Movement ABC in Hong Kong.