Surgical patients who listen to music — even while they are under general anesthesia — have less anxiety and need less pain medication during recovery than those who do not, a large review of studies has found.

The analysis, in Lancet, includes data from 72 randomized controlled trials. The studies covered various music genres, timing and delivery methods (speakers versus headphones), and procedures ranging from routine colonoscopy to open heart surgery. Researchers recorded length of stay in the hospital, measured pain using numerical rating scales, and estimated anxiety and satisfaction by self-report.

Compared with regular care, music was associated with a 20 percent reduction in postoperative pain, a 10 percent reduction in anxiety and a significant reduction in the use of pain medication. It increased patient satisfaction slightly, but did not affect length of hospital stay.

Pain was reduced most when music was played before the operation, slightly less when played during the procedure, and least when played afterward, but the difference in timing was not clinically significant.

“If you like music and find it calming, it might help a lot,” said the senior author, Catherine Meads, a reader in health technology assessment at Brunel University in London. “It might be that hospitals would want to tell patients that they can listen to music before the operation.”