Examining the Relationship Between Exacerbations and Decline in Physical Activity in Patients With COPD

There is no significant evidence to suggest that acute exacerbations (AEs) of chronic obstructive pulmonary disease (COPD) cause an overall decline in patients’ physical activity (PA) over time, according to a new longitudinal study in the International Journal of COPD. Data on frequency and severity of exacerbations analyzed over a period of 7 years found that any drop in PA due to AEs did not result in a permanent change to patient behavior.

Patients with COPD had their total number of steps recorded during the span of a single week to calculate daily PA. AEs were characterized as incidents which led to patients being prescribed antibiotics or corticosteroids, and data on frequency and severity of AE were compiled from examinations a year prior to the study from medical reports and patient accounts. Results were clarified by physicians and external pulmonologists when records were not consistent. The severity of AE was categorized as moderate if treatment was administered in an ambulatory setting or severe if a hospitalization was required.

Both univariate and multivariate mixed-effect models were utilized to examine associations between changes in number of steps per day and exacerbations. Analyses were performed with parameters from the corresponding follow-up period and from the year prior to examination, in order to determine the lasting effects of exacerbations.

Pulmonary function testing was performed to measure forced expiratory volume and forced vital capacity. Data recorded after bronchodilation were evaluated. Disease severity was categorized by individual spirometric Global Initiative for Chronic Obstructive Lung Disease stages from 1 to 4 and COPD risk groups ranging from low to high. The authors used the modified Medical Research Council scale to evaluate dyspnea and the COPD Assessment Test to observe disease-related symptoms.

A total of 181 patients with COPD (65% male; mean age, 64 years) were included in the study. At baseline, 37% of patients experienced at least 1 exacerbation in the year prior to participating, whereas 14% had 2 or more AEs and were categorized as frequent exacerbators. A total of 273 exacerbations were recorded throughout the observation period, and 20% resulted in hospitalizations.

Patients were requested to participate in the study during outpatient visits or hospital stays for a minimum of 3 annual follow-ups. Although patient backgrounds varied, it was determined that their demographics had no effect on observed PA. As a result, creation of patient subcategories was determined unnecessary. During follow-up visits, data on 127 patients were evaluated during the third year and 48 during the fourth.

COPD-associated AEs are defined as events that intensify patients’ symptoms to a greater degree than expected variation. AEs serve as crucial predictors of negative outcomes in patients with COPD; they have been known to reduce respiratory function, lower overall quality of life, and decrease survival rates. Severe exacerbations observed in both ambulatory settings and hospitals have been found to limit patients’ daily physical activity. The question of whether patients could resume prior levels of PA following an exacerbation could be important for encouraging greater activity.

The authors conclude, “This study shows that although a considerable drop of PA has been attributed to the phase of an AE in previous studies, this decline seems not to be a lasting phenomenon leading to a fundamental change in activity behavior.”

Reference

Sievi NA, Kohler M, Thurnheer R, et al. No impact of exacerbation frequency and severity on the physical activity decline in COPD: a long-term observation. Int J Chron Obstruct Pulmon Dis. 2019;14:431-437. doi: 10.2147/COPD.S188710.