Getting some exercise — either a lot or a little — appears to lower the risk of dying among patients with chronic obstructive pulmonary disease (COPD) following a disease-related hospitalization, according to findings from a retrospective, cohort study.
Patients who reported engaging in 150 minutes or more per week of moderate to vigorous physical activity (MVPA) following hospitalization for COPD had a 47% lower risk of death in the year following their hospitalization than patients who were inactive.
Those who reported engaging in some, but not as much, moderate to vigorous activity (1 to 149 minutes per week) had a 28% lower risk of dying, compared with inactive patients, researcher Huong Q. Nguyen, PhD, of Kaiser Permanente Southern California, and colleagues, wrote in a study published online March 16 in ERJ Open Research.
“Clinicians should routinely assess physical activity level and if patients are inactive, advise and assist them to become more active,” Nguyen told MedPage Today. “Those patients who are inactive and unable to exercise due to the severity of their disease may need closer monitoring and support for their COPD.”
She added that while clinicians are doing a better job educating their COPD patients about the importance of exercise, there is still room for improvement, especially in assessing physical activity as a first-line vital sign.
Being hospitalized for symptom exacerbation is a major risk factor for COPD mortality, with re-hospitalization and death rates as high as 25% and 21% in the year following a COPD hospitalization.
“Physical activity has emerged as a modifiable behavior that is associated with COPD outcomes,” the researchers wrote. “Higher levels of physical activity are associated with shorter hospital length of stay and decreased risk of acute exacerbations, hospitalizations, and death, independent of airflow obstruction.”
The Global Initiative for Chronic Obstructive Lung Disease guidelines recommend regular physical activity for patients with stable COPD, but there has been little research examining the impact of physical activity on mortality risk in high-risk patients following a COPD hospitalization.
The newly published retrospective analysis included COPD patients with disease-related hospitalizations treated at the 14 hospitals that make up the Kaiser Permanente Southern California health system. The primary study outcome was death from all causes in the 12 months after a COPD hospitalization, and all-cause rehospitalization was a secondary outcome.
Patients hospitalized for COPD between Jan. 1, 2011 and Dec. 31, 2011 were included in the analysis. Self-reported physical activity — expressed as minutes of moderate to vigorous physical activity — was routinely assessed at outpatient visits before hospitalization occurred.
Specifically, patients were asked how many days per week they engaged in moderate to vigorous exercise, such as brisk walking, and how many minutes they exercised at this level per week.
“We categorized patients as inactive (0 minutes of MVPA per week), insufficiently active (1-149 minutes of MVPA per week) or active (≥150 minutes of MVPA per week) according to national physical activity recommendations,” the researchers wrote.
Of the 2,370 patients included in the analysis (55% female, mean age 73±11 years), 1,727 (73%) were classified as inactive, 412 (17%) were insufficiently active, and 231 (10%) were active. A total of 464 deaths (20%) occurred during the year-long follow-up, and three out of four deaths (75%) were preceded by a hospitalization for COPD or other causes.
The analysis revealed that:
- Patients who were insufficiently active or active had a 28% (adjusted HR 0.72 (95% CI, 0.54–0.97), P=0.03) and 47% (adjusted HR 0.53 (95% CI, 0.34–0.84), P<0.01) lower risk of death, respectively, in the 12 months following an index COPD hospitalization, compared with inactive patients.
- Inactive patients had an almost fourfold higher adjusted risk for dying of COPD-related causes compared with active patients (HR 3.8, 95% CI, 1.41-10.42).
- Patients who were insufficiently active had a threefold higher risk for dying due to COPD compared with very active patients (HR 3.0, 95% CI, 1.02-8.64).
- Any level of MVPA was found to be associated with a lower risk of all-cause mortality after a COPD hospitalization.
Other lifestyle factors, such as active cigarette smoking, failure to participate in pulmonary rehabilitation, and poor nutritional status, were also identified as independent predictors of death.
“Our findings demonstrate the importance of routinely assessing physical activity in clinical care to identify high-risk patients, as well as the need to conduct prospective controlled studies to determine if interventions to increase MVPA can improve survival in patients who have been hospitalized for a COPD exacerbation,” the researchers wrote.