Cutshall 2011.

Study characteristics
Methods	RCT 2‐arm parallel group
Participants	Adults undergoing first‐time CABG or cardiac valve surgery Total N randomized: 173 N randomized to music group: 86 N randomized to control group: 87 N analyzed in music group: 49 N analyzed in control group: 51 Mean age: 62.9 (SD 12.65) years Sex: 23 (23%) women, 77 (77%) men Ethnicity: not reported Setting: inpatient Country: USA
Interventions	Two study groups: 1. Music group: listening to prerecorded music combined with nature sounds 2. Control group: 20 minutes of bed rest Music provided: participants were given the choice of four selections of music and nature sounds Number of sessions: 6 Duration of each session: 20 minutes Categorized as music medicine
Outcomes	Pain (VAS): change scores Anxiety (VAS): change scores Satisfaction (VAS): change scores Relaxation (VAS): change scores HR, SBP, DBP: change scores
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Stratification for randomization was based on a pain level of 4 or less (the institutional pain level goal) or greater than 4. The randomization was blocked to ensure balanced allocation throughout the course of the study. There were 25 randomized blocks of 4 patients and 25 randomized blocks of 2 patients. Each set of 50 blocks was changed into a random order as well." (p.17)
Allocation concealment (selection bias)	Low risk	Quote: "The use of cards in sealed envelopes prevented the study coordinator who was enrolling patients from knowing to which group each patient was randomly assigned." (p.17)
Blinding of participants and personnel (performance bias) All outcomes	High risk	Blinding of participants was not possible. Personnel were not blinded.
Blinding of outcome assessment (detection bias) Subjective outcomes	High risk	Quote: "The study coordinator read to the patient a printed script and obtained measurements of pain, anxiety, satisfaction, and relaxation orally with a visual analog scale (VAS)." (p.18)
Blinding of outcome assessment (detection bias) Objective outcomes	High risk	Study coordinator obtained the measurements
Incomplete outcome data (attrition bias) All outcomes	High risk	Attrition rate = 73 (42%). Reasons for withdrawal were not reported. The report states that recruitment continued until 100 participants had completed all six sessions
Selective reporting (reporting bias)	Unclear risk	Not sufficient information available to make judgment
Other bias	Low risk	The prerecorded music used in this study was donated by Ambience Medical and the study was funded in part by Richer J and Sharon M Mrocek.