Fig. 3From: Prognostic risk factors for moderate-to-severe exacerbations in patients with chronic obstructive pulmonary disease: a systematic literature reviewSummary of risk factors for exacerbation events. aTreatment impact studies removed. BDR bronchodilator reversibility, BMI body mass index, COPD chronic obstructive pulmonary disease, EOS eosinophil, QoL quality of lifeBack to article page