Mini best test

J Rehabil Med 2010; 42: 323–331

ORIGINAL REPORT

USING PSYCHOMETRIC TECHNIQUES TO IMPROVE THE BALANCE EVALUATION SYSTEMS TEST: THE MINI-BESTEST
Franco Franchignoni, MD1, Fay Horak, PT, PhD2, Marco Godi, PT3, Antonio Nardone, MD3,4 and Andrea Giordano, PhD5
From the 1Unit of Occupational Rehabilitation and Ergonomics, Salvatore Maugeri Foundation, Clinica del Lavoro e della Riabilitazione,IRCCS, Veruno, Italy, 2Department of Neurology, Oregon Health and Science University, Portland, OR, USA, 3Department of Physical Medicine and Rehabilitation, Salvatore Maugeri Foundation, Clinica del Lavoro e della Riabilitazione, IRCCS, Veruno, 4Department of Clinical and Experimental Medicine, University of Eastern Piedmont, Novara and 5Unit of Bioengineering – Salvatore Maugeri Foundation,Clinica del Lavoro e della Riabilitazione, IRCCS, Veruno, Italy

Objective: To improve, with the aid of psychometric analysis, the Balance Evaluation Systems Test (BESTest), a tool designed to analyse several postural control systems that may contribute to poor functional balance in adults. Methods: Performance of the BESTest was examined in a convenience sample of 115 consecutive adult patientswith diverse neurological diagnoses and disease severity, referred to rehabilitation for balance disorders. Factor (both explorative and confirmatory) and Rasch analysis were used to process the data in order to produce a new, reduced and coherent balance measurement tool. Results: Factor analysis selected 24 out of the 36 original BESTest items likely to represent the unidimensional construct of“dynamic balance”. Rasch analysis was then used to: (i) improve the rating categories, and (ii) delete 10 items (misfitting or showing local dependency). The model consisting of the remaining 14 tasks was verified with confirmatory factor analysis to meet the stringent requirements of modern measurement. Conclusion: The new 14-item scale (dubbed mini-BESTest) focuses on dynamic balance, can beconducted in 10–15 min, and contains items belonging evenly to 4 of the 6 sections from the original BESTest. Further studies are needed to confirm the usefulness of the mini-BESTest in clinical settings. Key words: postural balance, outcome assessment, psychometrics. J Rehabil Med 2010; 42: 323–331 Correspondence address: Franco Franchignoni, Fondazione Salvatore Maugeri, Clinica del Lavoro e dellaRiabilitazione, IRCCS, Via Revislate 13, IT-28010 Veruno, Italy. E-mail: franco.franchignoni@fsm.it Submitted August 25, 2009; accepted January 5, 2010 INTRODUCTION Assessment of balance and mobility in clinical settings can help to determine both risk of falling (1) and the most suitable measures to reduce postural instability (2–3). Laboratory studies have shown that postural control embracesdifferent subdomains, including stability during quiet stance, postural

reactions to external disturbances, anticipatory postural adjustments to perturbations caused by self-initiated movements (e.g. lifting an object), and dynamic balance during gait (4). However, until recently clinical balance tests did not systematically evaluate all these subdomains (5–6). Recently, a new clinical tool forassessing subdomains underlying balance deficits has been presented: the Balance Evaluation Systems Test (BESTest) (7). The BESTest is a comprehensive balance assessment tool developed to identify the postural control systems underlying poor functional balance, so that treatments can be targeted to the specific balance deficit. Since the BESTest encompasses 4–6 items for each of 6 different balancedomains, it takes approximately 35 min to administer, compared with only approximately 15 min for other balance scales (e.g. the Berg Balance Scale; BBS) (8). This is an important shortcoming of the BESTest, limiting its routine use. On the other hand, the main disadvantage of other popular balance scales, including the BBS, is that they do not include important aspects of dynamic balance control,...