This review was based on broadly defined inclusion criteria for participants, interventions and outcomes. A range of sources were searched but search dates were not reported. Publication bias was assessed. It was unclear whether more than one reviewer was involved in the processes of data extraction and quality assessment, which could help to minimise bias and error.
Trial quality was assessed but results were not presented in full. It was unclear if statistical pooling was appropriate given the variation in the populations, nature of sleep disorders and outcome measures. The authors conducted subgroup analyses to investigate heterogeneity, but the influence of other variables not investigated cannot be excluded. The authors' conclusion on cumulative dose of music therapy could not be verified from the data provided. The authors acknowledged the heterogeneity, small sample sizes, relatively low trial quality, and short term results.
Although the authors observed that music showed positive results for sleep disorders, this was only evident when subjective measures were used. Given these limitations, the authors' conclusions may not be reliable and long-term effects remain unknown.