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Accelerometer- versus questionnaire-based assessment of physical activity and their changes over time in patients with COPD

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ABSTRACT

Background and objective: Physical activity (PA) is an important outcome parameter in patients with COPD regarding hospitalizations and mortality. Both objective assessment by accelerometers and self-evaluation by questionnaires were used in studies investigating PA in COPD. Whether self-reported questionnaires can adequately reflect PA and its changes over time compared to objective assessments has not been thoroughly investigated in COPD. In this COPD cohort study, we evaluated whether PA measured by accelerometer and its annual changes can also be assessed by self-reported questionnaires.

Methods: In 178 COPD patients with at least two assessments of PA, the agreement between objectively measured and self-reported activity was analyzed by Bland–Altman plots. Daily PA was assessed by a triaxial activity monitor over 1 week and by the self-reported German PA questionnaire 50+.

Results: Comparison between the two methods of measurement revealed no convincing agreement with a mean difference and limits of agreement (±1.96 standard deviation [SD]) of time spent in at least moderate PA (>3 metabolic equivalent of task [MET]) of −77.6 (−340.3/185.2) min/day, indicating a self-reported overestimation of PA by the questionnaire. The mean difference and limits of agreement (±1.96SD) in the annual change of PA was 1.2 min/day (−208.2/282.6 min/day), showing also a poor agreement on an individual level.

Conclusion: Evaluation of objectively measured and self-reported PA and their annual changes revealed no agreement in patients with COPD. Therefore, the evaluated questionnaire seems not helpful for measurement of PA and its changes over time.

No MeSH data available.


Study flow.Abbreviations: FU, follow-up; LTPL, lung transplantation.
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f1-copd-12-1113: Study flow.Abbreviations: FU, follow-up; LTPL, lung transplantation.

Mentions: A total of 178 COPD patients (59 females) were analyzed (Figure 1) and had at least two assessments of PA. Three study visits were performed by 103 patients; four or more visits by 38 patients. In total, 513 assessments of self-reported and objective PA were investigated. Of the COPD patients included, 46% had a spirometric GOLD stage 1/2, 37% stage 3 and 17% stage 4. The median (quartiles) age of this cohort was 64 (60–69) years, body mass index (BMI) was 26 (23–28) kg/m2 and 23% of the COPD patients were current smokers. The detailed patient characteristics are shown in Table 1.


Accelerometer- versus questionnaire-based assessment of physical activity and their changes over time in patients with COPD
Study flow.Abbreviations: FU, follow-up; LTPL, lung transplantation.
© Copyright Policy
Related In: Results  -  Collection

License 1 - License 2
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getmorefigures.php?uid=PMC5391993&req=5

f1-copd-12-1113: Study flow.Abbreviations: FU, follow-up; LTPL, lung transplantation.
Mentions: A total of 178 COPD patients (59 females) were analyzed (Figure 1) and had at least two assessments of PA. Three study visits were performed by 103 patients; four or more visits by 38 patients. In total, 513 assessments of self-reported and objective PA were investigated. Of the COPD patients included, 46% had a spirometric GOLD stage 1/2, 37% stage 3 and 17% stage 4. The median (quartiles) age of this cohort was 64 (60–69) years, body mass index (BMI) was 26 (23–28) kg/m2 and 23% of the COPD patients were current smokers. The detailed patient characteristics are shown in Table 1.

View Article: PubMed Central - PubMed

ABSTRACT

Background and objective: Physical activity (PA) is an important outcome parameter in patients with COPD regarding hospitalizations and mortality. Both objective assessment by accelerometers and self-evaluation by questionnaires were used in studies investigating PA in COPD. Whether self-reported questionnaires can adequately reflect PA and its changes over time compared to objective assessments has not been thoroughly investigated in COPD. In this COPD cohort study, we evaluated whether PA measured by accelerometer and its annual changes can also be assessed by self-reported questionnaires.

Methods: In 178 COPD patients with at least two assessments of PA, the agreement between objectively measured and self-reported activity was analyzed by Bland–Altman plots. Daily PA was assessed by a triaxial activity monitor over 1 week and by the self-reported German PA questionnaire 50+.

Results: Comparison between the two methods of measurement revealed no convincing agreement with a mean difference and limits of agreement (±1.96 standard deviation [SD]) of time spent in at least moderate PA (>3 metabolic equivalent of task [MET]) of −77.6 (−340.3/185.2) min/day, indicating a self-reported overestimation of PA by the questionnaire. The mean difference and limits of agreement (±1.96SD) in the annual change of PA was 1.2 min/day (−208.2/282.6 min/day), showing also a poor agreement on an individual level.

Conclusion: Evaluation of objectively measured and self-reported PA and their annual changes revealed no agreement in patients with COPD. Therefore, the evaluated questionnaire seems not helpful for measurement of PA and its changes over time.

No MeSH data available.