Risk Factors and Precipitating Triggers

Several factors can increase an individual’s risk for COPD exacerbations. Additionally, identifiable triggers often precipitate an acute exacerbation episode. Understanding both risk factors and common triggers provides insight into exacerbation susceptibility and prevention.

Risk Factors

• Severe airflow obstruction – Patients with an FEV1 <50% predicted have a higher exacerbation frequency.
• Frequent prior exacerbations – The single best predictor of future exacerbations is a history of past events.
• Chronic bronchitis phenotype – Chronic mucus hypersecretion is associated with more frequent exacerbations.
• Older age – Advanced age increases exacerbation risk.
• Comorbidities – Coexisting heart disease, lung cancer, GERD, depression, and metabolic disease increase exacerbation frequency.
• Chronic airway bacterial colonization – Colonization with H. influenzae, S. pneumoniae, or M. catarrhalis is linked to more frequent exacerbations.

Triggers

• Respiratory infections – The most common precipitating factors. Both viral (rhinovirus, influenza) and bacterial (S. pneumoniae, H. influenzae) infections can trigger exacerbations.
• Air pollution – Higher ambient levels of particulate matter, ozone, and nitrogen dioxide are associated with increased COPD exacerbations.
• Cigarette smoke – Both active smoking and secondhand smoke exposure can worsen symptoms.
• Weather changes – Temperature inversions and drops in barometric pressure may precipitate exacerbations.
• Medication nonadherence – Poor adherence to maintenance COPD therapies is an important reversible trigger.

Identifying patients at high risk for exacerbations allows providers to optimize preventative strategies. Likewise, advising patients regarding modifiable triggers such as smoking cessation and medication adherence enables self-management. Awareness of risk factors and triggers provides opportunities to reduce exacerbation susceptibility.