Development of the physical therapy outpatient satisfaction survey (PTOPS).
BACKGROUND AND PURPOSE: The purposes of this 3-phase study were (1) to identify the underlying components of outpatient satisfaction in physical therapy and (2) to develop a test that would yield reliable and valid measurements of these components. SUBJECTS: Three samples, consisting of 177, 257, and 173 outpatients from 21 facilities, were used in phases 1, 2, and 3, respectively. METHODS AND RESULTS: In phase 1, principal component analyses (PCAs), reliability checks, and correlations with social desirability scales were used to reduce a pool of 98 items to 32 items. These analyses identified a 5-component model of outpatient satisfaction in physical therapy. The phase 2 PCA, with a revised pool of 48 items, indicated that 4 components rather than 5 components represented the best model and resulted in the 34-item Physical Therapy Outpatient Satisfaction Survey (PTOPS). Factor analyses conducted with phase 2 and phase 3 data supported this conclusion and provided evidence for the internal validity of the PTOPS scores. The 4-component scales were labeled "Enhancers," "Detractors," "Location," and "Cost." Responses from subsamples of phase 3 subjects provided evidence for validity of scores in that the PTOPS components of "Enhancers," "Detractors," and "Cost" appeared to differentiate overtly satisfied patients from overtly dissatisfied patients. "Location" and "Enhancer" scores discriminated subjects with excellent attendance at scheduled physical therapy sessions from those with poor attendance. CONCLUSION AND DISCUSSION: In this study, we identified components of outpatient satisfaction in physical therapy and used them to develop a test that would yield valid and reliable measurements of these components. (+info)
The psychometric properties of clinical rating scales used in multiple sclerosis.
OullII;l y Many clinical rating scales have been proposed to assess the impact of multiple sclerosis on patients, but only few have been evaluated formally for reliability, validity and responsiveness. We assessed the psychometric properties of five commonly used scales in multiple sclerosis, the Expanded Disability Status Scale (EDSS), the Scripps Neurological Rating Scale (SNRS), the Functional Independence Measure (FIM), the Ambulation Index (AI) and the Cambridge Multiple Sclerosis Basic Score (CAMBS). The score frequency distributions of all five scales were either bimodal (EDSS and AI) or severely skewed (SNRS, FIM and CAMBS). The reliability of each scale depended on the definition of 'agreement'. Inter-and intra-rater reliabilities were high when 'agreement' was considered to exist despite a difference of up to 1.0 EDSS point (two 0.5 steps), 13 SNRS points, 9 FIM points, 1 AI point and 1 point on the various CAMBS domains. The FIM, AI, and the relapse and progression domains of the CAMBS were sensitive to clinical change, but the EDSS and the SNRS were unresponsive. The validity of these scales as impairment (SNRS and EDSS) and disability (EDSS, FIM, AI and the disability domain of the CAMBS) measures was established. All scales correlated closely with other measures of handicap and quality of life. None of these scales satisfied the psychometric requirements of outcome measures completely, but each had some desirable properties. The SNRS and the EDSS were reliable and valid measures of impairment and disability, but they were unresponsive. The FIM was a reliable, valid and responsive measure of disability, but it is cumbersome to administer and has a limited content validity. The AI was a reliable and valid ambulation-related disability scale, but it was weakly responsive. The CAMBS was a reliable (all four domains) and responsive (relapse and progression domains) outcome measure, but had a limited validity (handicap domain). These psychometric properties should be considered when designing further clinical trials in multiple sclerosis. (+info)
A principal-components approach based on heritability for combining phenotype information.
For many traits, genetically relevant disease definition is unclear. For this reason, researchers applying linkage analysis often obtain information on a variety of items. With a large number of items, however, the test statistic from a multivariate analysis may require a prohibitively expensive correction for the multiple comparisons. The researcher is faced, therefore, with the issue of choosing which variables or combinations of variables to use in the linkage analysis. One approach to combining items is to first subject the data to a principal components analysis, and then perform the linkage analysis of the first few principal components. However, principal-components analyses do not take family structure into account. Here, an approach is developed in which family structure is taken into account when combining the data. The essence of the approach is to define principal components of heritability as the scores with maximum heritability in the data set, subject to being uncorrelated with each other. The principal components of heritability may be calculated as the solutions to a generalized eigensystem problem. Four simulation experiments are used to compare the power of linkage analyses based on the principal components of heritability and the usual principal components. The first of the experiments corresponds to the null hypothesis of no linkage. The second corresponds to a setting where the two kinds of principal components coincide. The third corresponds to a setting in which they are quite different and where the first of the usual principal components is not expected to have any power beyond the type I error rate. The fourth set of experiments corresponds to a setting where the usual principal components and the principal components of heritability differ, but where the first of the usual principal components is not without power. The results of the simulation experiments indicate that the principal components of heritability can be substantially different from the standard principal components and that when they are different, substantial gains in power can result by using the principal components of heritability in place of the standard principal components in linkage analyses. (+info)
Towards measurement of outcome for patients with varicose veins.
OBJECTIVE: To develop a valid and reliable outcome measure for patients with varicose veins. DESIGN: Postal questionnaire survey of patients with varicose veins. SETTING: Surgical outpatient departments and training general practices in Grampian region. SUBJECTS: 373 patients, 287 of whom had just been referred to hospital for their varicose veins and 86 who had just consulted a general practitioner for this condition and, for comparison, a random sample of 900 members of the general population. MAIN MEASURES: Content validity, internal consistency, and criterion validity. RESULTS: 281(76%) patients (mean age 45.8; 76% female) and 542(60%) of the general population (mean age 47.9; 54% female) responded. The questionnaire had good internal consistency as measured by item-total correlations. Factor analysis identified four important health factors: pain and dysfunction, cosmetic appearance, extent of varicosity and complications. The validity of the questionnaire was demonstrated by a high correlation with the SF-36 health profile, which is a general measure of patients' health. The perceived health of patients with varicose veins, as measured by the SF-36, was significantly lower than that of the sample of the general population adjusted for age and a lower proportion of women. CONCLUSION: A clinically derived questionnaire can provide a valid and reliable tool to assess the perceived health of patients with varicose veins. IMPLICATIONS: The questionnaire may be used to justify surgical treatment of varicose veins. (+info)
Measuring intermediate outcomes of violence prevention programs targeting African-American male youth: an exploratory assessment of the psychometric properties of six psychosocial measures.
This study examined the psychometric properties of six psychosocial measures that may be useful indicators of intermediate outcomes of violence prevention programs targeting African-American male youth. Baseline and 6 month follow-up survey data are used from 223 African-American male 12-16 year olds participating in a violence prevention program evaluation study. The constructs of interest are beliefs supporting aggression, aggressive conflict-resolution style, hostility, ethnic identity, self-esteem and hopelessness. Each construct is measured as a multi-item scale. Exploratory factor analysis results provided limited support for the unidimensionality of these scales, thus suggesting that further scale development is warranted. Reliability coefficients for the scales ranged from 0.55 to 0.80. Bivariate analyses with baseline data indicate that all six measures have construct and criterion-related validity, as they are associated with each other and with four behavioral criteria in the expected directions. Predictive validity was also demonstrated for beliefs supporting aggression, aggressive conflict-resolution style, hostility and hopelessness which were associated with weapon-carrying behaviors measured in the 6 month follow-up survey both before and after controlling for corresponding behaviors measured in the baseline survey. (+info)
Measuring attitudes towards smoking in the Community Intervention Trial for Smoking Cessation (COMMIT).
We present the development of indices using baseline data from the Evaluation Survey for the Community Intervention Trial for Smoking Cessation (COMMIT). The indices are designed to measure two primary attitude constructs that relate to smoking behavior: beliefs about smoking as a public health problem (SPHP); and norms and values concerning smoking (NVS). Two general approaches to index construction, the rational method and the factor analytic method, were used. Item analysis suggested good internal consistency for both indices (alpha > 0.75). Seven subconstructs emerged from the factor analysis accounting for 55.0% of the total variance. The SPHP and NVS items uniquely identify with four factors and three factors, respectively, confirming the validity of the two indices. Confirmatory factor analyses of a different data set provided further validation. Validity was also assessed by an examination of the relationships between index scores and smoking status. Smokers reported significantly higher scores than non-smokers on the two measures indicating, as anticipated, that smokers have more favorable attitudes towards smoking than non-smokers. These findings suggest that the two a priori constructs of SPHP and NVS are empirically distinguishable components of attitudes towards smoking, and that the indices developed here are reliable and valid measures of those constructs. (+info)
Interpretations of healthy and unhealthy eating, and implications for dietary change.
Central to many considerations of health-related dietary change is the interpretation given to 'healthy' and 'unhealthy' eating. Results are reported from two studies which investigated people's understanding of these concepts. The first study involved structured interviews with 48 respondents: a wide range of interpretations of healthy and unhealthy eating was found using content analysis techniques. The second study (n = 242) used questionnaires to assess the extent to which different interpretations were endorsed. The extent to which different eating behaviours were perceived as healthy or unhealthy varied greatly. A principal components analysis of perceptions of healthy and unhealthy eating produced five separate factors. Some differences in perceptions were found for people of different age, gender and educational level. Objectively assessed dietary intake and perceived intake were found to be two distinct quantities. 'Healthy' eaters were found to perceive 'healthy eating' slightly differently to 'unhealthy' eaters. The results suggest that lay understanding of healthy eating does generally conform with dietary guidelines, and therefore health promotion priorities should focus on physical and psychological constraints to healthy eating, rather than attempting to increase the public's knowledge as a whole. (+info)
Computerized tailored feedback to change cognitive determinants of smoking: a Dutch field experiment.
In the last decade, attempts have been made to improve the efficacy of minimal interventions by tailoring them to individual features. In the development of these tailored interventions, it is important to know which information in interventions is essential. Most smoking cessation interventions contain information on the outcomes of quitting and skills to be used in a quit attempt. The present study was designed to assess the cognitive changes caused by both sorts of information. Therefore, 246 smokers who were planning to quit within 6 months were randomly assigned to three different conditions. In the first condition, the respondents received a computer-generated tailored letter on the outcomes of smoking cessation. In the second condition, the respondents received a computer-generated tailored letter containing self-efficacy enhancing information, mainly on skills. In both conditions, the contents of the letters were based on the pre-test scores of the participants. Participants in the control condition did not receive any cessation information. The results show that information on the outcomes of quitting changed expected outcomes while information on coping skills changed self-efficacy expectations, in comparison with the control condition. Comparing both experimental conditions, information on the outcomes led to changes in expected outcomes, whereas information on coping skills did not lead to higher self-efficacy expectations than information on the outcomes of quitting. It is concluded that the hypothesized effects were partly verified. (+info)