Construct validity and reliability of the Brazilian version of the Falls Efficacy Scale in patients with COPD.

INTRODUCTION AND OBJECTIVE: The Brazilian version of Falls Efficacy Scale (FES-BR) used to assess the fear of falling, has not yet been validated in patients with Chronic Obstructive Pulmonary Disease (COPD). The aim of the present study was to investigate the construct validity and reliability of the (FES-BR) in patients with COPD. METHODS: A cross-sectional study involving subjects with COPD, aged between 48 and 83 years. Data were collected by two independent and blind assessors. Construct validity was assessed using the Spearman's rank correlation coefficient between FES-BR and Berg Balance Scale, Downton fall risk index, Timed Up and Go Test (TUG), hand-grip strength (HGS), Five Times Sit to Stand Test (FTSST) and 6-Minute Walk Test (6MWT). Reliability was measured by the Cronbach's alpha coefficient, Intraclass Correlation Coefficient (ICC), and Bland-Altman plot. RESULTS: The study included 60 subjects aged 68.3 ±â€¯9.9 years and FEV1 56.0 ±â€¯19.3. The correlations were significantly strong between FES-BR and the Berg Balance Scale (r = -0.66), TUG (r = 0.64), HGS (r = 0.61) and FTSST (r = 0.62); and moderate between FES-BR and the Downton fall risk index (r = 0.38) and the 6MWT (r = -0.48). All correlations had p < 0.001. Intra-rater [ICC = 0.94, (95% CI = 0.91-0.96)] and inter-rater [0.97, (95% CI = 0.97-0.98)] reliability were considered excellent. CONCLUSIONS: The Brazilian version of FES was valid and reliable in assess fear of falling in subjects with COPD.

Visual system evolution and the nature of the ancestral snake.

The dominant hypothesis for the evolutionary origin of snakes from 'lizards' (non-snake squamates) is that stem snakes acquired many snake features while passing through a profound burrowing (fossorial) phase. To investigate this, we examined the visual pigments and their encoding opsin genes in a range of squamate reptiles, focusing on fossorial lizards and snakes. We sequenced opsin transcripts isolated from retinal cDNA and used microspectrophotometry to measure directly the spectral absorbance of the photoreceptor visual pigments in a subset of samples. In snakes, but not lizards, dedicated fossoriality (as in Scolecophidia and the alethinophidian Anilius scytale) corresponds with loss of all visual opsins other than RH1 (λmax 490-497 nm); all other snakes (including less dedicated burrowers) also have functional sws1 and lws opsin genes. In contrast, the retinas of all lizards sampled, even highly fossorial amphisbaenians with reduced eyes, express functional lws, sws1, sws2 and rh1 genes, and most also express rh2 (i.e. they express all five of the visual opsin genes present in the ancestral vertebrate). Our evidence of visual pigment complements suggests that the visual system of stem snakes was partly reduced, with two (RH2 and SWS2) of the ancestral vertebrate visual pigments being eliminated, but that this did not extend to the extreme additional loss of SWS1 and LWS that subsequently occurred (probably independently) in highly fossorial extant scolecophidians and A. scytale. We therefore consider it unlikely that the ancestral snake was as fossorial as extant scolecophidians, whether or not the latter are para- or monophyletic.