“Can do, don’t do” are not the lazy ones: a longitudinal study on physical functioning in patients with COPD

Abstract

Background and objective: Reduced physical capacity (PC) and physical activity (PA) are common in COPD patients and associated with poor outcome. However, they represent different aspects of physical functioning and interventions do not affect them in the same manner. To address this, a new PC-PA quadrant concept was recently generated to identify clinical characteristics of subgroups of physical functioning. The objective of this study was to I) proof the new concept and to verify their differentiating clinical characteristics, II) evaluate the consistency of the concept over time, III) assess whether patients changed their quadrant affiliation over time, IV) and to test if changes in quadrant affiliations are associated with changes in clinical characteristics. Methods: In a longitudinal, prospective, non-interventional cohort with mild to very severe COPD patients, PC and PA as well as respiratory variables, COPD-specific health status, comorbidities, survival, and exacerbations were yearly assessed. Results: Data from 283 patients were analysed at baseline. Mean (min/max) follow-up time was 2.4 (0.5/6.8) years. The PC-PA quadrants could be characterized as follows: I) "can't do, don't do": most severe and symptomatic, several comorbidities II) "can do, don't do": severe but less symptomatic, several comorbidities III) "can't do, do do": few patients, severe and symptomatic, less comorbidities IV) "can do, do do": mildest and less symptomatic, less comorbidities, lowest exacerbation frequency. Of the 172 patients with at least one follow-up, 58% patients never changed their quadrant affiliation, while 17% declined either PC, PA or both, 11% improved their PC, PA or both, and 14% showed improvement and decline in PC, PA or both during study period. None of the clinical characteristics or their annual changes showed consistent significant and relevant differences between all individual subgroups. Conclusion: Our findings suggest that there are no clinical characteristics allowing to distinguish between the PC-PA quadrants and the concept seems not able to illustrate disease process. However, the already low PA but preserved PC in the "can do, don't do" quadrant raises the question if regularly assessment of PA in clinical practice would be more sensitive to detect progressive deterioration of COPD compared to the commonly used PC. Clinical trial registration: www.ClinicalTrials.gov, NCT01527773.

The “can do, do do” concept in individuals with chronic obstructive pulmonary disease: an exploration of psychological mechanisms

“…Despite applying the same operationalization to calculate relative PC, our study included more participants (60.5%) in the “can do” categories (Quadrants 2 and 4) than the original study (45%) [ 7 ]. Accordingly, the average number of daily steps found in the present study (5.850) was slightly higher than in the two other quadrant studies (4.421 [ 12 ] vs. 5.521 [ 7 ]) and in most other COPD studies with an objective PA assessment (4.579) [ 47 ]. Notably, we identified these values and quadrant distributions despite the fact that the research took place in the setting of inpatient rehabilitation and that the individuals of the present sample exhibited more severely impaired lung function (FEV 1 %pred: 40) than the individuals in the other quadrant studies coming from usual outpatient care (FEV 1 %pred: 44 [ 12 ] vs. 56 [ 7 ]).…”

“…Accordingly, the average number of daily steps found in the present study (5.850) was slightly higher than in the two other quadrant studies (4.421 [ 12 ] vs. 5.521 [ 7 ]) and in most other COPD studies with an objective PA assessment (4.579) [ 47 ]. Notably, we identified these values and quadrant distributions despite the fact that the research took place in the setting of inpatient rehabilitation and that the individuals of the present sample exhibited more severely impaired lung function (FEV 1 %pred: 40) than the individuals in the other quadrant studies coming from usual outpatient care (FEV 1 %pred: 44 [ 12 ] vs. 56 [ 7 ]). However, a considerable portion of participants were still involved in working life (76.6%); hence, the sample was significantly younger (mean age: 58 years) than those in other studies using the concept (mean age: 63 years [ 12 ] and 63 years [ 7 ]).…”

“…Koolen et al [ 7 ] stated that the PC–PA based quadrants differ considerably in multiple clinical characteristics, such as forced expiratory volume in one second (FEV 1 ), the COPD Assessment Test (CAT), and GOLD indicators. On the contrary, on the basis of longitudinal analyses, Sievi et al [ 12 ] concluded that “there are no clinical characteristics allowing to distinguish between the PC–PA quadrants” (p. 1) and that scientific evidence regarding long-term health outcomes is scarce. Nevertheless, both groups of researchers congruently highlighted the urgency of shedding more light on the quadrants of the “can do, do do” concept.…”

Exacerbations and Changes in Physical Activity and Sedentary Behaviour in Patients with Bronchiectasis after 1 Year

“…Likewise, Bradley et al [ 21 ] reported that neither lung function (FEV 1 % predicted) nor disease severity (BSI score) was correlated with sedentary behaviour in patients with bronchiectasis. Data collected from patients with COPD have shown that physical activity decliners vary from 35% to 59% over time [ 41 , 42 ], but the clinical characteristics could not predict or explain the subsequent patterns of decline, included the number of exacerbations [ 42 , 43 , 44 , 45 ]. This indicates that the common clinical and functional assessments are unsuitable for use as indicators of risk of physical activity decline and/or increase in sedentary behaviour, which further highlights the need for further longitudinal and objective assessment in clinical settings.…”

Telemonitoring of daily activities compared to the six-minute walk test further completes the puzzle of oximetry-guided interventions

“…Recent research identified inactive, active improvers and active decliners as 3 distinct patterns on patients with COPD physical activity natural progression over 1-year 49 . Not only efficiently targeted intervention on PADL is needed to promote long sustainable healthy habits, as there is growing evidence that its systematic assessment might be more sensitive detecting progressive disease deterioration 50 . Because of this, we recommend a comprehensive regular assessment with oximetry and accelerometery, as it provides combined perspectives about PADL: quantity (duration), intensity (METs), modality (type) and quality (SpO 2 and HR).…”