TY - JOUR AU - Shea, B J; Reeves, B C; Wells, G TI - AMSTAR 2: a critical appraisal tool for systematic reviews that include randomised or non-randomised studies of healthcare interventions, or both JO - BMJ PY - 2017 DO - 10.1136/bmj.j358 L3 - PubMed-ID: 28115341 SP - 358 ER -