Journal of Rehabilitation Medicine 51-9 | Page 65

Comparison of 3 short-form BESTests in stroke Fig. 1. Receiver operating characteristic (ROC) plot of the S-BESTest, the Brief-BESTest, the Mini-BESTest, and the BESTest scores using the Berg Balance Scale (BBS) as reference, measured at (a) 0–2 weeks (b) 2–4 weeks, in people with subacute stroke. Arrow depicts cut-off score (minimal clinically important difference; MCID). DISCUSSION This study compared the reliability, validity and responsiveness of 3 different short versions of the BESTest (S-BESTest, the Brief-BESTest and the Mini- BESTest) with the original BESTest in patients with subacute stroke. Our findings showed that all short forms of the BESTest were reliable and valid in this group of the population, but only the S-BESTest de- monstrated no significant floor-ceiling effect with high external responsiveness in accurately identification of balance improvement similar to the original BESTest, 689 suggesting that the S-BESTest was more appropriate as a short version of the BESTest for assessing postural control in patients with subacute stroke. Excellent intra-rater and inter-rater reliability of the S-BESTest, the Brief-BESTest, and the Mini-BESTest in patients with subacute stroke were consistent with a previous study in people with balance disorders, in- cluding patients with subacute stroke (12). In patients with subacute stroke, excellent concurrent validity of the S-BESTest, Brief-BESTest, Mini-BESTest and original BESTest with the BBS, the clinical gold standard of balance tests, suggest that all versions of the BESTest assess the same balance constructs as the BBS. Our finding of a strong correlation between the BESTest and the BBS (r = 0.96) was also in agreement with previous findings (12). This study confirmed that the original BESTest had no floor and ceiling effect similar to those reported in the previous studies (12). Although the S-BESTest did not reach significant floor effect (<20%), the magnitude of floor effect at baseline of the S-BESTest was still high (18.6%) compared with the original BESTest (5.7%), suggesting that the original BESTest outperformed other shortened versions, including S-BESTest, Brief- BESTest and Mini-BESTest. We recommended the use of original BESTest in assessing balance impairment in patients with subacute stroke when there is no time constraint. However, when there is the need for redu- cing assessment time or the need to identify patients with balance improvement, the S-BESTest is the most appropriate choice for balance assessment in patients with subacute stroke. In contrast, the Brief-BESTest and the Mini-BESTest may be more suitable for asses- sing postural control in patients with chronic stroke, as previous studies found no floor effect in patients with chronic stroke using the Brief-BESTest and the Mini-BESTest (15, 17). The floor effect of the Brief- BESTest and Mini-BESTest in subacute stage may be due to the fact that these 2 scales contain items that are more difficult for patients with subacute stroke to perform. For example, the items of compensatory step- ping correction in a backward direction, standing with eyes closed on a foam surface and walking with pivot turn showed no change in score when measured at 0–2 weeks. A previous study showed that protective steps in a backward direction require more supraspinal control than protective steps in a forward direction; thus, this backward protective mechanism could be more impaired in patients with stroke (35). In the same way, patients with stroke showed larger postural sway velocity while standing on foam with eyes closed, compared with other conditions of sensory orientation testing (36). The S-BESTest, the Mini-BESTest, the Brief- BESTest, and the BESTest demonstrated good internal J Rehabil Med 51, 2019