Determinants of Physical Activity in Patients with Chronic Obstructive Pulmonary Disease: A 5-Year Prospective Follow-Up Study

Physical activity trajectories and their determinants in patients with chronic obstructive pulmonary disease: A cohort study

AIMS AND OBJECTIVES

The aim was to identify latent trajectories in physical activity (PA) and their determinants in adults with chronic obstructive pulmonary disease (COPD) based on the socio-ecological model.

BACKGROUND

PA has been linked to poor long-term outcomes in patients with COPD. However, few studies have explored their PA trajectories and their predictors.

DESIGN

Cohort study.

METHODS

We used data from a national cohort and included 215 participants. PA was quantified using a short PA questionnaire, and group-based trajectory modelling was used to explore the PA trajectories. Multinomial logistic regression was conducted to identify the predictors of PA trajectories. Generalised linear mixed models were used to elucidate the associations between predictors and PA during follow-up. A STROBE checklist was used to guide the reporting of this study.

RESULTS

Three PA trajectory patterns were identified among 215 COPD participants with an average age of 60.51 ± 8.87: stable inactive group (66.7%), sharp decline group (25.7%) and stable active group (7.5%). The logistic regression showed that age, sex, income, peak expiratory flow, upper limb capacity, depressive symptoms, the frequency of contact with children were PA predictors. Upper limb capacity weakness and depressive symptoms were found to be associated with a sharp decline in PA during follow-up.

CONCLUSIONS

This study revealed three PA trajectories among patients with COPD. In addition to strengthening the physical functions and mental health of patients, support from the family, community and society also play a crucial role in promoting PA of patients with COPD.

RELEVANCE TO CLINICAL PRACTICE

It is essential to identify distinct PA trajectories in patients with COPD to develop future interventions that promote PA.

NO PATIENT OR PUBLIC CONTRIBUTION

A national cohort study was used and no patients or the public were involved in the design and implementation of this study.

Causal Mediation Analysis with Multiple Time-varying Mediators

In longitudinal studies with time-varying exposures and mediators, the mediational g-formula is an important method for the assessment of direct and indirect effects. However, current methodologies based on the mediational g-formula can deal with only one mediator. This limitation makes these methodologies inapplicable to many scenarios. Hence, we develop a novel methodology by extending the mediational g-formula to cover cases with multiple time-varying mediators. We formulate two variants of our approach that are each suited to a distinct set of assumptions and effect definitions and present nonparametric identification results of each variant. We further show how complex causal mechanisms (whose complexity derives from the presence of multiple time-varying mediators) can be untangled. We implemented a parametric method, along with a user-friendly algorithm, in R software. We illustrate our method by investigating the complex causal mechanism underlying the progression of chronic obstructive pulmonary disease. We found that the effects of lung function impairment mediated by dyspnea symptoms accounted for 14.6% of the total effect and that mediated by physical activity accounted for 11.9%. Our analyses thus illustrate the power of this approach, providing evidence for the mediating role of dyspnea and physical activity on the causal pathway from lung function impairment to health status. See video abstract at, http://links.lww.com/EDE/B988 .

Physical activity and chronic obstructive pulmonary disease: a scoping review

Background

Reduced physical activity (PA) was the strongest predictor of all-cause mortality in patients with chronic obstructive pulmonary disease (COPD). This scoping review aimed to map the evidence on the current landscape of physical activity, barriers and facilitators, and assessment tools across COPD patients.

Methods

Arksey and O’Malley’s scoping review methodology framework guided the conduct of this review. An electronic search was conducted on five English databases (PubMed, Cochrane Library, PsycINFO, CINAHL and Web of Science) and three Chinese databases (CNKI, CQVIP and WAN-FANG) in January 2022. Two authors independently screened the literature, extracted the studies characteristics.

Results

The initial search yielded 4389 results, of which 1954 were duplicates. Of the remaining 135 articles, 42 studies met the inclusion criteria. Among the reviewed articles, there were 14 (33.3%) cross-sectional study, 9 (21.4%) cohort study, 4 (9.5%) longitudinal study, 3 qualitative study, 12 (28.7%) randomized control trials. The main barriers identified were older age, women, lung function, comorbidities, COPD symptoms (fear of breathlessness and injury, severe fatigue, anxiety and depression), GOLD stage, frequency of exacerbation, oxygen use, lack of motivation and environment-related (e.g., season and weather). Twelve studies have evaluated the effects of physical exercise (e.g., walking training, pulmonary rehabilitation (PR), pedometer, self-efficacy enhancing intervention and behavioral modification intervention) on PA and showed significant positive effects on the prognosis of patients. However, in real life it is difficult to maintain PA in people with COPD.

Conclusions

Changing PA behavior in patients with COPD requires multidisciplinary collaboration. Future studies need to identify the best instruments to measure physical activity in clinical practice. Future studies should focus on the effects of different types, time and intensity of PA in people with COPD and conduct randomized, adequately-powered, controlled trials to evaluate the long-term effectiveness of behavioral change interventions in PA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02099-4.

A Non-Interventional, Cross-Sectional Study to Evaluate Factors Relating to Daily Step Counts and Physical Activity in Japanese Patients with Chronic Obstructive Pulmonary Disease: STEP COPD

Purpose

Patients with chronic obstructive pulmonary disease (COPD) have decreased physical activity (PA) compared with healthy adults. As lower PA is associated with increased mortality, improving PA is an important objective for COPD management. This large-scale, multicenter, non-interventional, cross-sectional study examined the activity status of COPD patients in Japan and explored factors related to PA.

Patients and Methods

Outpatients aged ≥40 years with confirmed COPD diagnosis and pulmonary function test data were enrolled. Primary study outcomes were measurement of daily steps (over 14 consecutive days, using an activity monitor), assessment of activity time by activity intensity (using metabolic equivalents [METs]), and evaluation of correlation between PA and patient characteristics. Secondary outcomes included further investigation of the influence of patient characteristics on PA.

Results

Data from 417 patients with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages I (29.5%), II (43.9%), III (23.5%), and IV (3.1%) were evaluated. Median (Q1, Q3) daily step count was 3440.8 (1831.3, 5709.3). Median (Q1, Q3) durations of PA at ≥3 (moderate-to-vigorous) and ≥2 METs (light-to-vigorous) were 18.7 (6.5, 41.3) and 186.9 (126.9, 259.2) minutes, respectively. For >30% of patients, time spent in ≥3 METs activity was ≤10 minutes. Unemployment was significantly correlated with reduced activity time (≥3 and ≥2 METs) and step count. Severe GOLD stage was significantly correlated with reduced activity time (≥3 and ≥2 METs). High modified Medical Research Council (mMRC) dyspnea score was significantly correlated with reduced activity time (≥3 METs) and step count. Patients tended to overestimate the time spent in activities requiring ≥2 METs in their subjective reports compared with activity monitor measurements.

Conclusion

Reduced PA was observed in the Japanese COPD patients with the majority of them being GOLD stage I/II. Employment status, GOLD stage, and mMRC dyspnea score could help identify patients at risk of reduced PA.

Clinical Trial Registration

NCT03642613 (ClinicalTrials.gov); UMIN000032962 (UMIN-CTR, umin.ac.jp).

Patterns and predictors of low physical activity in patients with stable COPD: a longitudinal study

BACKGROUND

Despite the frequency and negative impact of low physical activity among patients with chronic obstructive pulmonary disease (COPD), little is known about how it persists and remits over time or the factors predicting new states of low physical activity. The aim of the study was to determine the probability of a transition between states of low and nonlow physical activity in a cohort of patients with stable COPD followed for 2 years. We also investigated different potentially modifiable factors to determine whether they can predict new states of low physical activity.

METHODS

We prospectively included 137 patients with stable COPD (mean age 66.9 ± 8.3 years). Physical activity was measured at baseline and at 1 and 2 years of follow up. Low physical activity was defined according to energy expenditure by cut-off points from the Fried frailty model. The likelihood of annual transition towards new states and recovery was calculated. We evaluated demographic, frailty, nonrespiratory, and respiratory variables as potential predictors, using generalized estimating equations.

RESULTS

At baseline, 37 patients (27%) presented with low physical activity. During the study period, a total of 179 annual transitions were identified with nonlow physical activity at the beginning of the year; 17.5% transitioned to low physical activity. In contrast, 34.3% of the 67 transitions that started with low physical activity recovered. Predictors of transition to new states of low physical activity were dyspnea ⩾2 (odds ratio = 3.21; 95% confidence interval: 1.20-8.61) and poor performance on the five sit-to-stand test (odds ratio = 4.75; 95% confidence interval: 1.30-17.47).

CONCLUSIONS

The change between levels of low and nonlow physical activity is dynamic, especially for recovery. Annual transitions toward new states of low physical activity are likely among patients with dyspnea or poor performance on the five sit-to-stand test. The reviews of this paper are available via the supplemental material section.

Importance of the relationship between symptoms and self-reported physical activity level in stable COPD based on the results from the SPACE study

Background

The burden of symptoms and risk of exacerbations are the main drivers of the overall assessment of the Chronic Obstructive Pulmonary Disease (COPD) and the adequate treatment approaches per current Global Initiative for Chronic Obstructive Lung Disease (GOLD). Physical activity has emerged as both functional outcome and non-pharmacological intervention in COPD patients, despite the lack of standardized measures or guidelines in clinical practice. This study aimed to explore in more depth the 24-h respiratory symptoms, the physical activity level (PAL) and the relationship between these two determinants in stable COPD patients.

Methods

This was a multinational, multicenter, observational, cross-sectional study conducted in ten European countries and Israel. Dedicated questionnaires for each part of the day (morning, daytime, night) were used to assess respiratory symptoms. PAL was evaluated with self- and interview-reported tools [EVS (exercise as vital sign) and YPAS (Yale Physical Activity Survey)], and physician’s judgement. Patients were stratified in ABCD groups by 2013 and 2017 GOLD editions using the questionnaires currently recommended: modified Medical Research Council dyspnea scale and COPD Assessment Test.

Results

The study enrolled 2190 patients (mean age: 66.9 years; male: 70.0%; mean % predicted FEV1: 52.6; GOLD groups II-III: 84.5%; any COPD treatment: 98.9%). Most patients (> 90%) reported symptoms in any part of the 24-h day, irrespective of COPD severity. PAL evaluations showed discordant results between patients and physicians: 32.9% of patients considered themselves completely inactive, while physicians judged 11.9% patients as inactive. By YPAS, the overall study population spent an average of 21.0 h/week performing physical activity, and 68.4% of patients were identified as sedentary. In any GOLD ABCD group, the percentage of inactive patients was high. Our study found negative, weak correlations between respiratory symptoms and self-reported PAL (p < 0.001).

Conclusions

Despite regular treatment, the majority of stable COPD patients with moderate to severe disease experienced daily variable symptoms. Physical activity level was low in this COPD cohort, and yet overestimated by physicians. With evidence indicating the negative consequences of inactivity, its adequate screening, a more active promotion and regular assessment of physical activity are urgently needed in COPD patients for better outcomes.

Trial registration

NCT03031769, retrospectively registered, 23 Jan 2017.

Electronic supplementary material

The online version of this article (10.1186/s12931-019-1053-7) contains supplementary material, which is available to authorized users.

Using step counters to promote physical activity and exercise capacity in patients with chronic obstructive pulmonary disease: a meta-analysis

BACKGROUND

Although step counters are popularly employed for physical rehabilitation in chronic obstructive pulmonary disease (COPD) patients, their effectiveness is inconsistent and even questioned. This meta-analysis aimed to investigate whether step counter use increases physical activity or improves exercise capacity in COPD patients.

METHODS

Electronic databases were searched for randomized controlled trials that assessed the efficacy of step counter use in increasing physical activity or in improving exercise capacity. Data were aggregated using a random-effects model to get the overall effect sizes [standard mean difference (SMD) with 95% confidence interval (CI)], and subgroup analyses were performed.

RESULTS

A total of 15 trials enrolling 1316 patients with moderate to severe COPD were included. Step counter use increased physical activity compared with controls (SMD = 0.57, 95% CI 0.31-0.84), which is equal to a magnitude of 1026 steps/day in daily steps. It also enhanced exercise capacity with an effect size of 0.30 (95% CI 0.16-0.45), approximating to a magnitude of 11.6 m in the 6-min walking distance. Step counter use could augment physical activity (SMD = 0.64, 95% CI 0.19-1.08) and exercise capacity (SMD = 0.32, 95% CI 0.01-0.62) for patients receiving pulmonary rehabilitation. Yet it cannot enhance physical activity or exercise capacity in patients with severe COPD or among studies with intervention durations ⩾6 months (both p > 0.50).

CONCLUSIONS

Step counter use increases physical activity and improves exercise capacity in COPD patients, at least in the short term, which supports the notion of recommending step counter use in COPD management.

The association between daily exacerbation symptoms and physical activity in patients with chronic obstructive pulmonary disease

Background

Evidence from longitudinal studies on the impact of exacerbation symptoms on physical activity in chronic obstructive pulmonary disease (COPD) is lacking. The aim of this first exploratory study was to assess the association between exacerbation symptoms and physical activity, and to quantify the relative influence of specific symptoms.

Methods

We recruited COPD patients at high risk for exacerbations from 2 pulmonary rehabilitation clinics and 1 acute care clinic in Switzerland. For 3 months after discharge, patients completed a daily symptom diary on a smartphone application, the EXAcerbations of Chronic pulmonary disease Tool (EXACT), and wore a pedometer to measure daily steps. We used mixed-effects models to determine the association of daily steps with exacerbation symptoms.

Results

A total of 21 patients (Global Initiative for Chronic Obstructive Lung Disease grades 2-4) were enrolled for a mean of 94.4 days (standard deviation 4.2). The baseline median number of daily steps was 3,264.6 (interquartile range [IQR]: 1,851.3-4,784.1) and EXACT score was 37.0 (IQR: 30.9-41.4). A 12-point increase in EXACT score (indicating the start of an exacerbation) was statistically significantly associated with a decrease in daily steps of 653.3 (95% CI 969.7-336.9). Chest symptoms (tightness, discomfort and congestion) were more strongly associated with change in steps than breathlessness, and cough and sputum (z-value -4.5 vs -2.9 and -3.0).

Conclusion

This is the first study to show that, in a small cohort of COPD patients, increases in exacerbation symptoms were associated with a statistically and clinically significant reduction in daily physical activity. These results underscore the importance for symptom control and exacerbation prevention in COPD patients.

Physical activity and risk of comorbidities in patients with chronic obstructive pulmonary disease: a cohort study

Multi-morbidity is common in patients with chronic obstructive pulmonary disease and low levels of physical activity are hypothesized to be an important risk factor. The current study aimed to assess the longitudinal association between physical activity and risk of seven categories of comorbidity in chronic obstructive pulmonary disease patients. The study included 409 patients from primary care practice in the Netherlands and Switzerland. We assessed physical activity using the Longitudinal Ageing Study Amsterdam Physical Activity Questionnaire at baseline and followed patients for up to 5 years. During follow-up, patients reported their comorbidities (cardiovascular, neurological, endocrine, musculoskeletal, malignant, and infectious diseases) and completed the Hospital Anxiety and Depression Scale questionnaire for mental health assessment. We implemented multinomial logistic regression (an approximation to discrete time survival model using death as a competing risk) for our analysis. Study results did not suggest a statistically significant association of baseline physical activity with the development of seven categories of comorbidity. However, when we focused on depression and anxiety symptoms, we found that higher levels of physical activity at baseline were associated with a lower risk for depression (adjusted hazard ratio, 0.85; 0.75–0.95; p = 0.005) and anxiety (adjusted hazard ratio, 0.89; 0.79–1.00; p = 0.045). In chronic obstructive pulmonary disease patients, those with high physical activity are less likely to develop depression or anxiety symptoms over time. Increasing physical activity in chronic obstructive pulmonary disease patients may be an approach for testing to lower the burden from incident depression and anxiety.

Patients with chronic lung disease who stay physically active could reduce their chances of depression and anxiety. Milo Puhan at the University of Zurich, Switzerland, and co-workers assessed the association between physical activity and the risk of developing various co-existing diseases in 409 patients with chronic obstructive pulmonary disease (COPD). Co-morbidities such as cardiovascular diseases, diabetes and depression are prevalent in patients with COPD, but the reasons why are not clear. Puhan’s team assessed patients’ activity levels using an existing questionnaire, and administered another questionnaire to assess mental health. They followed the cohort for 5 years. Results indicated weak associations between physical activity levels and most physical illnesses, but there were significant links between higher levels of physical activity and a reduced risk of depression and anxiety. The results could inform novel COPD treatment programs.

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

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.