Is the Berg Balance Scale an effective tool for the measurement of early postural control impairments in patients with Parkinson's disease? Evidence from Rasch analysis.

BACKGROUND: It is unclear whether the BBS is an effective tool for the measurement of early postural control impairments in patients with Parkinson's disease (PD). AIM: The aim of this paper was to evaluate BBS' content validity, internal construct validity, reliability and targeting in patients with PD within the Rasch analysis framework. DESIGN: Observational, cross-sectional study. SETTING: Outpatient Rehabilitation Unit. POPULATION: A sample of 285 outpatients with PD. METHODS: The content validity of the BBS was assessed using standard linking techniques. The BBS was administered by trained physiotherapists. The data collected then underwent Rasch analysis. RESULTS: Content validity analysis showed a lack of items assessing postural responses to tripping and slips and stability during walking. On Rasch analysis, the BBS failed the requirements of monotonicity, local independence, unidimensionality and invariance. After rescoring 7 items, grouping of locally dependent items into testlets, and deletion of the static sitting balance item because mistargeted and underdiscriminating, the Rasch-modified BBS for PD (BBS-PD) showed adequate internal construct validity (χ(2)24=39.693; P=0.023), including absence of differential item functioning (DIF) across gender and age, and was, as a whole, sufficiently precise for individual person measurement (PSI=0.894). However, the scale was not well targeted to the sample in view of the prevalence of higher scores. CONCLUSION: This study demonstrated the internal construct validity and reliability of the BBS-PD as a measurement tool for patients with PD within the Rasch analysis framework. However, the lack of items critical to the assessment of postural control impairments typical of PD, affected negatively the targeting, so that a significant percentage of patients was located in the higher ability range of the measurement continuum, where precision of measurement is reduced. CLINICAL REHABILITATION IMPACT: These findings suggest that the BBS, even if modified, may not be an effective tool for the measurement of early postural control in patients with PD.

Predicting the need for institutional care shortly after admission to rehabilitation: Rasch analysis and predictive validity of the BRASS Index.

BACKGROUND: Effective discharge planning is increasingly recognised as a critical component of hospital-based Rehabilitation. The BRASS index is a risk screening tool for identification, shortly after hospital admission, of patients who are at risk of post-discharge problems. AIM: To evaluate the internal construct validity and reliability of the Blaylock Risk Assessment Screening Score (BRASS) within the rehabilitation setting. DESIGN: Observational prospective study. SETTING: Rehabilitation ward of an Italian district hospital. POPULATION: One hundred and four consecutively admitted patients. METHODS: Using classical psychometric methods and Rasch analysis (RA), the internal construct validity and reliability of the BRASS were examined. Also, external and predictive validity of the Rasch-modified BRASS (RMB) score were determined. RESULTS: Reliability of the original BRASS was low (Cronbach's alpha=0.595) and factor analyses showed that it was clearly multidimensional. A RA, based on a reduced 7-BRASS item set (RMB), satisfied model's expectations. Reliability was 0.777. The RMB scores strongly correlated with the original BRASS (rho=0.952; P<0.000) and with FIM™ admission scores (rho=-0.853; P<0.000). A RMB score of 12 was associated with an increased risk of nursing home admission (RR=2.1, 95%CI=1.7-2.5), whereas a score of 17 was associated to a higher risk of length of stay >28 days (RR=7.6, 95%CI=1.8-31.9). CONCLUSION: This study demonstrated that the original BRASS was multidimensional and unreliable. However, the RMB holds adequate internal construct validity and is sufficiently reliable as a predictor of discharge problems for group, but not individual use. CLINICAL REHABILITATION IMPACT: The application of tools and methods (such as the BRASS Index) developed under the biomedical paradigm in a Physical and Rehabilitation Medicine setting may have limitations. Further research is needed to develop, within the rehabilitation setting, a valid measuring tool of risk of post-discharge problems at the individual level.

1,2,3-Triazole derivatives of salicylic acid.

This paper describes the preparation of 1,2,3-triazole derivatives of salicylic acid from the methyl 4-azidosalicylate, by 1,3-dipolar cycloaddition reactions to beta-ketoesters, beta-ketoamides, beta-diketones and to symmetrical or asymmetrical alkynes. Other derivatives were obtained by hydrolysis and decarboxylation reactions. Some compounds were evaluated for antiinflammatory activity by an in vitro test based upon the inhibition of the cyclooxygenase enzyme, but they generally showed a weak activity.