P: Prevent deterioration

P: Prevent deterioration

Evidence level

Strength of recommendation*

Smoking cessation is the most important intervention to prevent worsening of COPD.IIStrong
Preventing exacerbations has a key role in preventing deterioration.III-2Strong
Vaccination reduces the risks associated with influenza and pneumococcal infection.IStrong
Mucolytics may benefit certain patients with COPD.IStrong
Long-term oxygen therapy has survival benefits for COPD patients with hypoxaemia.IStrong
Preventing exacerbations has a key role in preventing deterioration [evidence level III-2, strong recommendation]

REDUCING RISK FACTORS for COPD is a priority, and smoking is the most important of these. A systematic review of 47 studies with an average follow-up of 11 years found a significantly higher decline in FEV1 in people who continued to smoke compared to those who ceased (Lee 2010) [evidence level 1]. The annual decline in FEV1 for those who stopped at the beginning of follow-up was 12.4 ml/year (95% CI 10.1 to 14.7) and for those who stopped during the period of follow-up 8.5 ml/year (95% CI 5.6 to 11.4), both less than people who continued to smoke. While there were limitations to the data, the review clearly found that in people who continue to smoke the annual decline in FEV1 is >10 ml/year greater than in people who have never smoked or stopped smoking. Reduction of exposure to occupational dust, fumes and gases and to indoor and outdoor air pollutants is also recommended. Influenza immunisation reduces the risk of exacerbations and death [evidence level I], while long term oxygen therapy reduces mortality [evidence level I].

Avoidance of passive smoking is also recommended to prevent deterioration. In a cohort study exposure to second hand smoke (SHS) was found to be associated with worse clinical outcomes for people with COPD. Living with a smoker was associated with poorer health-related quality of life (on both St George’s Respiratory Questionnaire (SGRQ) and COPD Assessment Test (CAT) scores) and increased risk of severe exacerbations (OR 1.51, 95% CI 1.04 to 2.17), while SHS exposure in the last week was associated with worse SGRQ and more symptoms (Putcha 2016) [evidence level III-2].