Original article
Evaluation of a New Motion Sensor in Patients With Chronic Obstructive Pulmonary Disease

https://doi.org/10.1016/j.apmr.2012.05.027Get rights and content

Abstract

Sant'Anna T, Escobar VC, Fontana AD, Camillo CA, Hernandes NA, Pitta F. Evaluation of a new motion sensor in patients with chronic obstructive pulmonary disease.

Objective

To assess the criterion validity and reproducibility of a new pedometer in patients with chronic obstructive pulmonary disease (COPD).

Design

Cross-sectional study.

Setting

Outpatient physiotherapy clinic from a university hospital.

Participants

Patients with COPD (N=30; 17 men; forced expiratory volume in the first second, 44±17% predicted) were videotaped while performing 2 protocols: one including 2 slow and 2 fast 5-minute walks, and another including a circuit of activities of daily living (ADLs). Concomitantly, patients wore 2 motion sensors: the new pedometer and a multisensor accelerometer.

Interventions

None.

Main Outcome Measures

Step counting (SC), energy expenditure (EE), walking distance (WD), activity time (AT), and walking intensity (WI) registered by the pedometer were compared with video and the multisensor as criterion methods.

Results

Correlations between the pedometer and the criterion method were high for SC during slow and fast walking (r=.79 and r=.95) and for EE during fast walking (r=.83). Correlation was more modest for EE during slow walking (r=.65) and for WD and WI during both speeds (.47<r<.68). The agreement between methods was also good, according to Bland-Altman plots. The device was reproducible for registering SC, WD, and EE during slow walking and for all variables during fast walking (intraclass correlation coefficient >.79 for all). During the ADLs circuit, the pedometer underestimated AT by an average of 55% but provided an acceptable EE estimation in a group basis (average difference of 6% with the multisensor).

Conclusions

In patients with COPD, the new pedometer analyzed in the present study is reproducible for most outcomes and highly valid for SC during slow and fast walking and EE during fast walking. The device's validity is more limited for EE during slow walking, and WD and WI at both speeds. Furthermore, during the performance of ADLs, it significantly underestimates activity time but provides an acceptable estimation of EE in a group basis.

Section snippets

Study Design and Participants

Thirty patients with COPD (17 men) with no exacerbation episodes for at least 3 months were recruited to take part in this cross-sectional study. All participants had taken part recently or were currently enrolled in programs of respiratory physiotherapy at the University Hospital of the State University of Londrina, Brazil. The patient's latest assessment of lung function (<6mo) performed by hospital staff was used to confirm COPD diagnosis and classify degree of obstruction according to

Results

All of the 30 recruited patients successfully completed the protocols. Because there was no difference between first and second walk in both speeds concerning almost all variables of interest (P>.170), we standardized to use only the first walk of each speed in the analysis. Regarding the number of steps, walking distance, and walking intensity, there was a statistical difference between the first and second slow walking (P<.002), although not of a clinically important difference (1.5%, 2%, and

Discussion

The present study showed that, in patients with COPD, although the PW had a somewhat limited validity to estimate walking distance, walking intensity, and energy expenditure during the slow walk, it was highly valid to register the number of steps. Additionally, it was reproducible not only for step counting, but also in the estimation of walking distance and energy expenditure in the slow walk. During the fast walk, the PW was reproducible concerning all variables and highly valid to estimate

Conclusions

In patients with COPD, the PW is reproducible for most outcomes and highly valid for step counting during slow and fast walking and energy expenditure estimation during fast walking. The device's validity is more limited for energy expenditure estimation during slow walking and walking distance and intensity at both speeds. Furthermore, during the performance of a circuit of ADLs, the device significantly underestimates activity time but provides an acceptable estimation of energy expenditure

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  • Cited by (0)

    Supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)/Brazil (grant no. 302061/2010-0); Coordenação de Aperfeiçoamento de Pessoal de Nivel Superior (CAPES)/Brazil (grant nos. 05768419942 and 00847546993); and Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)/Brazil (grant no. 2010/03223-2).

    No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the authors or on any organization with which the authors are associated.

    Reprints are not available from the author.

    In-press corrected proof published online on Jul 31, 2012, at www.archives-pmr.org.

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