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. 2022 Sep 21;11(19):5535.
doi: 10.3390/jcm11195535.

Validation of Simple Prediction Equations for Step Count in Japanese Patients with Chronic Obstructive Pulmonary Disease

Yuichiro Azuma  1 , Yoshiaki Minakata  1 , Mai Kato  1 , Masanori Tanaka  2 , Yusuke Murakami  1 , Seigo Sasaki  1 , Kazumi Kawabe  1 , Hideya Ono  1
Affiliations

Validation of Simple Prediction Equations for Step Count in Japanese Patients with Chronic Obstructive Pulmonary Disease

Yuichiro Azuma et al. J Clin Med. .

Abstract

Physical activity is decreased in patients with chronic obstructive pulmonary disease, and decreased physical activity leads to a poor prognosis. To determine an individual’s target step count from the measured step counts and predicted step counts, simple and detailed prediction equations for step count were developed. To verify the validity of the simple prediction equation, the validity of the simple equation was evaluated in a different cohort and the correlation between the step counts calculated by the simple equation and those by the detailed prediction equation were evaluated. When the step counts calculated by the simple prediction equation for all participants were compared with the measured step counts, a significant correlation was obtained among them, and the calculated values were found to be reproducible with the measured values in patients with a measured step count of <6500 by Bland−Altman plots. Furthermore, the values calculated by the simple prediction equation and those calculated by the detailed prediction equation showed a significant correlation. In conclusion, the simple prediction equation was considered reasonable.

Keywords: COPD; chronic obstructive pulmonary disease; physical activity; prediction equation; step count.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
CONSORT diagram. Abbreviations: FEV1, forced expiratory volume in one second; FVC, forced vital capacity; BD, bronchodilator.
Figure 2
Figure 2
Histograms of the indicators. Abbreviations: 6MWD, 6 min walking distance; HADS, Hospital Anxiety and Depression Scale; IC, inspiratory capacity; mMRC, modified British Medical Research Council; FEV1 %pred, forced expiratory volume in one second % of predicted.
Figure 3
Figure 3
Correlations between the measured values and calculated values by the simple equation. (A) Scatter plot and (B) Bland–Altman plot.
Figure 4
Figure 4
Correlations between the measured values and calculated values by the simple equation in patients with <6500 measured step. (A) Scatter plot and (B) Bland–Altman plot.
Figure 5
Figure 5
Correlation between the step count calculated by the simple prediction equation and that calculated by the detailed prediction equation.
See this image and copyright information in PMC

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