Lai 2005.

Study characteristics
Methods	Study type: RCT Design: 2‐arm, parallel group design Blinding: not blinded
Participants	Sample: older adults with sleep problems documented by PSQI scores > 5 n: 60 randomised, 60 completed and included in analyses Age: mean 67 (SD 5, range 60 to 83) years Sex: not reported Setting: participants' homes Country: Taiwan
Interventions	Intervention (n = 30): music group. Participants could choose among 6 types of researcher‐selected sedative music. Participants administered the music themselves. The music was recorded to an audiotape and participants could use earphones or not as preferred. Music characteristics: the choices of music included 5 types of Western music (new age, eclectic, popular oldies, classical, and slow jazz), and 1 type of Chinese music (folk music). Tempos ranged from 60 to 80 bpm without accented beats, percussive characteristics or syncopation. The music was expected to be familiar to the participants. Length of sessions: 45 minutes Frequency of sessions: daily at bedtime Duration of intervention period: 3 weeks Control (n = 30): no intervention
Outcomes	Sleep quality (assessed with PSQI) mean (SD) at baseline and post‐intervention
Notes	Trial start and end date: trial conducted in 2000 Funding sources: no information provided Protocol registration: none found
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Comment: permuted block randomisation with sealed envelopes stratified on gender
Allocation concealment (selection bias)	Low risk	Quote: "The envelopes were prepared by a different person so that the investigator (first author) was blind to block size and order of assignment" (Lai 2005, p 235)
Blinding of participants and personnel (performance bias) All outcomes	High risk	Comment: due to the nature of the intervention, blinding of participants was not possible. It is likely that this affected the subjective outcome measures. The intervention was used at home with no personnel involved.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Comment: no blinding of outcome assessment
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Comment: unclear information on attrition. 1 man was withdrawn due to hospitalisation. No information on completeness of data
Selective reporting (reporting bias)	Low risk	Comment: we found no published protocol on this study, but there was no indication of selective reporting.
Other bias	High risk	Comment: baseline differences in 2 sleep component scores, with the music group experiencing shorter sleep duration and more daytime dysfunction