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.