Heterogeneity of outcomes for intraoperative music interventions: a scoping review and evidence map.

Our scoping review identifies that almost two-thirds of studies in this field used >1 outcome measure unique to that study (not also used in other studies), which hinders opportunities to aggregate data across studies and meta-analyse evidence. Future studies should provide clear documentation regarding the intervention and consider using valid and reliable outcome tools. Researchers should consider standardisation when appropriate and adopting the use of core outcome sets for conditions where these sets have been developed.