Do metronomes improve the quality of life in people with Parkinson's disease? A pragmatic, single-blind, randomized cross-over trial

Objective: To evaluate the effect of acoustic cueing using metronomes on the quality of life of people with moderate to severe Parkinson's disease. Study design: Pragmatic, single-blind, randomized cross-over trial. Participants: Forty-two people aged 50-85 years, in Hoehn and Yahr stage II-IV and on stable medication. Eight were lost to follow-up. Intervention: Participants were randomized using concealed allocation to either an early group (n = 21) to receive an electronic metronome without therapy but limited support (5-10 minutes instruction and on-demand telephone assistance) for four weeks, or a late group (n = 21) to receive the same intervention at 10 weeks. In both groups the beat frequency was initially set to be comfortable for walking. Outcomes measures: Primary and secondary outcomes were measured at baseline, 4, 10 and 14 weeks using the Parkinson's Disease Questionnaire 39 (PDQ-39), the Short Form 36 version 2 (SF-36 version 2) and a falls diary. Results: There were positive effects in six domains of the SF-36 version 2 and eight domains of the PDQ-39, although only one mean difference was clinically important: the role limitation (emotional) domain of SF-36 version 2 (a mean difference of 3.77, 95% confidence interval (CI), -2.68 to 10.22), a secondary outcome. None of these changes were statistically significant. There were no statistically significant differences in falls rates over the study period. Ten participants (24%) wanted to continue with their metronomes at the end of the study. Conclusion: To demonstrate metronomes are beneficial on the role limitation domain of the SF-36 version 2 in people with moderate to severe Parkinson's disease a sample size of 600 would be required.