We included 26 trials (2051 participants). All studies used listening to pre-recorded music. The results suggested that music listening
may have a beneficial effect on preoperative anxiety. Specifically, music listening resulted, on average, in an anxiety reduction that was
5.72 units greater (95% CI -7.27 to -4.17, P < 0.00001) than that in the standard care group as measured by the Stait-Trait Anxiety
Inventory (STAI-S), and -0.60 standardized units (95% CI -0.90 to -0.31, P < 0.0001) on other anxiety scales. The results also suggested
a small effect on heart rate and diastolic blood pressure, but no support was found for reductions in systolic blood pressure, respiratory
rate, and skin temperature. Most trials were assessed to be at high risk of bias because of lack of blinding. Blinding of outcome assessors
is often impossible in music therapy and music medicine studies that use subjective outcomes, unless in studies in which the music
intervention is compared to another treatment intervention. Because of the high risk of bias, these results need to be interpreted with
caution.
None of the studies included wound healing, infection rate, time to discharge, or patient satisfaction as outcome variables. One large
study found that music listening was more effective than the sedative midazolam in reducing preoperative anxiety and equally effective
in reducing physiological responses. No adverse effects were identified.