P: Prevent deterioration

	Summary Evidence level Smoking cessation reduces the rate of decline of lung function A General practitioners and pharmacists can help smokers quit A Treatment of nicotine dependence is effective and should be offered to smokers A Pharmacotherapies double the success of quit attempts; behavioural techniques further increase the quit rate by up to 50% A Influenza vaccination reduces the risk of exacerbations, hospitalisation and death   A Long-term oxygen therapy (> 15 h/day) prolongs life in hypoxaemic patients (PaO2 < 55 mmHg, or 7.3 kPa) A Mucolytics may reduce the frequency and duration of exacerbations  A Inhaled glucocorticoids are indicated for patients with a documented response or who have severe COPD with frequent exacerbations B

Reducing risk factors for COPD is a priority, and smoking is the most important of these. Reduction of exposure to occupational dust, fumes and gases and to indoor and outdoor air pollutants is also recommended⁶ [evidence level D]. Influenza vaccination reduces the risk of exacerbations and death [evidence level I], while long term oxygen therapy reduces mortality [evidence level I].