COPD Outcomes: Sedentary Lifestyle Significantly Increases Risk for ED Visits, Hospitalization

Individuals with chronic obstructive pulmonary disease (COPD) are at great risk for all-cause and respiratory emergency department (ED) visits or hospitalizations than persons without COPD, with the risk being highest among those who are sedentary, according to a recent study published in BMJ Open Respiratory Research.¹

Diminished physical activity (PA) is characteristic of COPD and those lower levels are associated with both decreased lung function and accelerated deterioration of lung function, investigators wrote. PA levels in individuals with COPD are in fact the strongest predictor of all-cause mortality and an independent predictor of acute exacerbation hospitalization risk and premature death.

Even so, there is little information on the association between PA levels as specifically assessed by metabolic equivalents (METs) and risk for hospitalization in persons with COPD. In the current study, investigators aimed to quantify levels of PA using METs and to evaluate their effects on all-cause and respiratory ED visits or hospitalizations in individuals with and without COPD.

The study tapped Health Screening Examination data from the National Health Insurance Service-National Sample Cohort, a population-based retrospective cohort that includes a 2.2% representative sample of Korean citizens. This database collects health data regarding major and minor diagnoses using the ICD-10 codes, health examination findings, and drug prescriptions.

The study’s primary exposure was PA, and PA intensity was measured using self-reported questionnaires; the survey included 3 questions on PA frequency and duration during the prior 7 days. The researchers calculated PA levels by assigning ratings of 2.9, 4.0, and 7.0 METs for light-intensity, moderate-intensity, and vigorous-intensity PAs, respectively.

The primary outcomes of interest were all-cause and respiratory ED visits or hospitalizations, according to the study. The researchers calculated the respective incidence of ED visits or hospitalizations by dividing the number of ED visits or hospitalizations by the sum of the follow-up duration, presented as the rate per 1000 person-years (PY). Lastly, the covariates considered included body mass index (BMI), smoking status, alcohol consumption, and COPD-related comorbidities.

From the database, the researchers created 2 cohorts: the COPD cohort and the non-COPD cohort. The COPD cohort consisted of 3308 participants with at least 1 ICD-10 code for COPD and COPD-related medications within 1 year of health examination. Conversely, the non-COPD cohort consisted of 293 358 participants without ICD-10 codes for COPD. They noted that those with COPD were of older age, underweight, ex-smokers, of lower income, and had comorbidities such as diabetes, asthma, and hypertension (P < .001 for all variables).

FINDINGS

Among all participants, the researchers found the median PA level to be 414 METS-min/week (IQR, 87-728). More specifically, they reported that the PA level was significantly lower in the COPD cohort (280 METS-min/week; IQR, 0-609) than in the non-COPD cohort (414 METS-min/week; IQR, 87-728) (P < .001), highlighting the more significant level of sedentary activity in the COPD cohort than in the non-COPD cohort (35.4% vs 24.1%; P < .001).

When they analyzed the all-cause ED visit or hospitalization rate (/1000 PY) the investigators found it was significantly higher in the COPD cohort than in the control cohort (P < .01 for all PA groups). Compared with the non-COPD group with PA greater than or equal to 1500 METs-min/week, the researchers reported that the COPD group had a higher risk of all-cause ED visit and hospitalization across all PA levels; the highest risk was found in the sedentary group (adjusted hazard ratio [aHR], 1.70; 95% CI, 1.59-1.81). Conversely, the continuous PA model showed that a 500 METs-min/week increase in PA was associated with reduced all-cause ED visits or hospitalizations by 10% (aHR, 0.92; 95% CI, 0.88-0.96) in the COPD cohort and 3% (aHR, 0.98; 95% CI, 0.97-0.98) in the non-COPD cohort.

Similarly, researchers found the respiratory ED visit or hospitalization rate per 1000 PY was significantly greater in the COPD cohort across all PA levels (P < .01 for all PA groups). Compared with the non-COPD cohort with PA greater than or equal to 1500 METs-min/week, the COPD cohort had a higher risk of all-cause ED visits and hospitalizations, the highest risk being in the sedentary group (aHR, 5.45; 95% CI, 4.86-6.12). Lastly, the continuous PA model showed that a 500 METs-min/week increase in PA was associated with reduced respiratory ED visits or hospitalizations by 14% in the COPD cohort (aHR, 0.87; 95 CI, 0.82-0.93) and 7% in the non-COPD cohort (aHR, 0.94; 95% CI, 0.92-0.95).

Among the study's limitations, the researchers noted the use of questionnaires to evaluate PA levels, which may have introduced recall bias and participants were queried about aerobic exercise only. Also, despite statistical adjustments for potential confounding variables, personal habits including smoking and alcohol may have had residual effects. Despite these limitations, the researchers made suggestions for future improvements and research based on their findings.

“Increasing PA would be important for improving long-term outcomes in patients with COPD in Korea,” the authors concluded. “Confirmative future prospective studies are needed on whether assessing and modifying PA levels could reduce ED visit or hospitalization in COPD.”

This article originally appeared on the American Journal of Managed Care.

Source: Yang B, Lee H, Ryu J, et al. Impacts of regular physical activity on hospitalisation in chronic obstructive pulmonary disease: a nationwide population-based study. BMJ Open Respir Res. 2024;11(1):e001789. doi:10.1136/bmjresp-2023-001789