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. 2022 Aug 24;2022(8):CD010459. doi: 10.1002/14651858.CD010459.pub3

Chang 2012.

Study characteristics
Methods Study type: RCT
Design: 2‐arm, parallel group design
Blinding: single blinded; technician scoring PSG and researchers responsible for statistical analysis unaware of group allocation
Participants Sample: adults who experienced insomnia for ≥ 1 month documented by a PSQI score > 5
n: 50 randomised, 50 completed and included in analyses
Age: mean 32 (SD 11, range 22–58) years
Sex: 3 men, 47 women
Setting: sleep laboratory
Country: Taiwan
Interventions Intervention (n = 25): music group. Participants were encouraged to bring their own preferred music to listen to (n = 10) and those who did not bring their own music, listened to researcher‐selected music (n = 15). The music was administered by the researchers using a CD player (AZ‐1836, Philips, the Netherlands)
Music characteristics: Rural Spring Field, Woman under the Moon (Chinese music), Going Home (Czech music), Destiny, Heart Lotus (Taiwanese music), and Memory (composed by the authors). Tempos were 60–85 bpm, minor tonalities, smooth melodies and no dramatic changes in volume or rhythm. The music was expected to be familiar to participants.
Length of sessions: 45 minutes
Frequency of sessions: daily at bedtime
Duration of intervention period: 3 consecutive days
Control (n = 25): no intervention
Outcomes

  1. Sleep‐onset latency, minutes (assessed with PSG and morning questionnaire)

    1. mean (SD) at baseline

    2. GEE analysis estimating group differences post‐intervention

  2. TST, minutes (assessed with PSG and morning questionnaire)

    1. mean (SD) at baseline

    2. GEE analysis estimating group differences postintervention

  3. Sleep interruption, minutes (assessed with PSG, wake after sleep onset)

    1. mean (SD) at baseline

    2. GEE analysis estimating group differences postintervention

  4. Sleep interruption (assessed with PSG and morning questionnaire, number of awakenings)

    1. mean (SD) at baseline

    2. GEE analysis estimating group differences postintervention

  5. Sleep efficiency, % (assessed with PSG)

    1. mean (SD) at baseline

    2. GEE analysis estimating group differences postintervention

  6. Stage 1, % of TST (assessed with PSG)a

    1. mean (SD) at baseline

    2. GEE analysis estimating group differences post‐intervention

  7. Stage 2, % of TST (assessed with PSG)a

    1. mean (SD) at baseline

    2. GEE analysis estimating group differences postintervention

  8. Stage 3 and 4, % of TST (assessed with PSG)a

    1. mean (SD) at baseline

    2. GEE analysis estimating group differences postintervention

  9. Stage REM, % of TST (assessed with PSG)a

    1. mean (SD) at baseline

    2. GEE analysis estimating group differences postintervention

  10. Rested rating (assessed with morning questionnaire)a


We contacted the author 16 December 2014 to obtain data on the raw postintervention scores, but we have not yet received a reply.
aOutcome not included in this review
Notes Trial start and end dates: May 2010 to June 2011
Funding sources: National Science Council, Taiwan
Protocol registration: none found
Risk of bias
Bias Authors' judgement Support for judgement
Random sequence generation (selection bias) Low risk Quote: "Participants were randomly assigned …, using the drawing of lots" (Chang 2012, p 924).
Allocation concealment (selection bias) Low risk Quote: "All lots (labels) are packed in a jar that was prepared by another person. Researchers therefore did not know beforehand which group each participant would be assigned to" (Chang 2012, p 924).
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 unclear if this affected the objective sleep measures, but likely that it affected the subjective measures of sleep. Blinding of personnel at the sleep laboratory was not reported. Since the intervention was music, it is likely that they were not blinded.
Blinding of outcome assessment (detection bias)
All outcomes Low risk Comment: the technician scoring the PSG and the researchers doing the statistical analyses were not aware of which group the data belonged to.
Incomplete outcome data (attrition bias)
All outcomes Low risk Comment: no dropouts and no missing data.
Selective reporting (reporting bias) Unclear risk Comment: we found no published protocol on this study. Sleep efficiency, based on a self‐report questionnaire, was not reported. All other measures of interest were included in the analysis.
Other bias High risk Comment: there were baseline differences in measures of depression and self‐reported number of awakenings, with the music group experiencing significantly more depression and arousals than the control group.