Comparison of manual and automated measures of walking speed: Distance and pace matter.

BACKGROUND: Walking speed (WS) represents a global marker of individual health and provides a simple and objective measure of motor performances for use in clinical and research settings. WS is most often measured over relatively short distances at usual (UWS) or fast (FWS) pace, using manual (e.g., stopwatch) or automated methods (e.g., photoelectric cells). As the time needed to walk over these distances is very short, we hypothesized that measurement error related to manual compared to automated WS measures is more pronounced for shorter distances and FWS and investigated the reliability and agreement of WS in a subsample of the Constances cohort at two paces and over two distances. METHODS: We recruited 100 community-dwelling participants (50 % women) aged 45-70y (mean = 56.1y). WS was measured manually (stopwatches) and using photoelectric cells, at two paces (UWS/FWS) and over two distances (3 m/5 m). Agreement was examined using Bland and Altman plots and intraclass correlation coefficients (ICC). RESULTS: Participants were on average 169.8 cm tall, and their mean body mass index was 25.4 kg/m2. Agreement between manual stopwatches and photoelectric cells was excellent (ICCs between 0.92 and 0.97), but it was lower for smaller distances, with significantly lower ICCs over 3 m compared to 5 m both for UWS (differenceICC = -0.04) and FWS (differenceICC = -0.05). Bias of manual measures was constant for UWS and increased with increasing FWS. There were inter-rater effects, with better agreement for UWS and 5 m compared to FWS and 3 m. CONCLUSIONS: Both distance and pace have an influence on the reliability of WS measures using manual timing methods. Our findings also suggest the presence of rater effects and better agreement for 5 m and UWS. These findings are helpful for the design of studies that include manual measures of WS, especially FWS, in order to reduce measurement error and suggest that longer distances are preferable.

The relationship between social deprivation and a frailty index of cumulative deficits in French middle-aged caregivers.

BACKGROUND: The Institut Pasteur de Lille, in the north of France, has implemented a large, multidisciplinary health check, which aims to identify frailty in middle-aged caregivers. We aimed to construct an adapted frailty index of cumulative deficit (FI-CD) and study the associated factors, in particular socioeconomic factors. METHODS: The cross-sectional study included caregivers aged 45 to 65. A 34-item FI-CD including deficits adapted to a middle-aged population (related to cognition and autonomy, dietetics, physical activity, comorbidities, functional signs, lab values and paraclinical examinations) was constructed in accordance with standard procedures. It was calculated as a ratio of deficits present out of the total number of possible deficits, giving a continuous score between 0 and 1. Scores > 0.25 and >  0.4 were classified as frailty and severe frailty, respectively. Univariate and multivariate associations were studied using linear regressions. RESULTS: One hundred and seventeen caregivers were included; among them, 111 were analyzed due to missing values. The mean FI-CD was 0.22 ± 0.08. Forty (36%) individuals were classified as frailty and three (2.7%) as severe frailty. In multivariate analysis, FI-CD was significantly associated with age (beta [95% confidence interval] = 0.005 [0.002; 0.009] per 1-year increase, p = 0.005) and social deprivation (beta = 0.054 [0.007; 0.102], p = 0.025). A significant interaction was observed between and age and social deprivation (p = 0.036). The adjusted relationship between FI-CD and age was beta = 0.010 [0.002; 0.019], p = 0.017 in precarious caregivers, and beta = 0.003 [- 0.001; 0.007], p = 0.19 in non-precarious caregivers. CONCLUSIONS: The study suggested that the 34-item FI-CD could have clinical utility in the management of middle-aged caregivers. Social deprivation appeared as an important factor associated with frailty, highlighting the importance of early care and social support for precarious caregivers.