Methods: We performed a systematic review (Medline-OVID, EMBASE, LILACS) to identify observational studies reporting the effect of past exacerbations in COPD prognosis. Two of the authors independently selected studies that met the inclusion criteria and assessed methodological quality using the GRADE approach. Exacerbations were defined by an increased use of health care (event-based) or an increase of symptoms, and severe exacerbations defined by a hospitalization. Results: Eleven relevant studies were included