Data extraction and managementTwo review authors (CS, MAC) will develop a standard data extraction form and independently extract data from the included studies. A third review author (GDR) will resolve any disagreements regarding data collection and extraction. We will collect information on study design, participants, setting, interventions, outcomes, follow-up, methods employed to control for confounders and biases, sources of funding, and notable conflicts of interest of trial authors, amongst other items. For observational studies where we extract adjusted estimates, we will select the most fully adjusted model. Should we identify multiple papers that report results from the same study during the data extraction process, we will select a single paper as the primary Interventions for reducing the use of opioids in breast reconstruction (Protocol)