Figure 1From: Long-term smoking increases the need for acute care among asthma patients: a case control study Cumulative emergency visits free time among asthma patients who were current smokers (solid line), ex-smokers (dotted line) and never smokers (dashed line) using the Cox regression model adjusted for age, gender, duration of disease, FEV1, chronic sinusitis, and number of co-morbidities. Back to article page