Figure 1From: Association of current smoking with airway inflammation in chronic obstructive pulmonary disease and asymptomatic smokersSpearman's rank correlation: Cigarettes smoked per day and macrophages in induced sputum. COPD (â– , ): rho = 0.44 p = 0.03 and asymptomatic smokers(â–¡, ): rho = 0.35 p = 0.1.Back to article page