Affiliations: [a] Department of Physical Therapy, University of Utah, Salt Lake City, UT, USA | [b] The George Institute for Global Health, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia | [c] Department of Physical Therapy and Athletic Training, Boston University, Boston, MA, USA | [d] Program in Physical Therapy, Department of Neuroscience, Department of Neurology, Washington University in St. Louis-School of Medicine, St Louis, MO, USA | [e] Department of Physical Therapy, Samford University, Birmingham, AL, USA | [f] Department of Physical Therapy, University of New England, Portland, ME, USA
Correspondence to: A/Prof James T. Cavanaugh, Department of Physical Therapy, University of New England,716 Stevens Ave, Portland, ME 04103, USA. Tel.: +1 207 221 4595, Fax: +1 207 523 1910; E-mail: firstname.lastname@example.org.
Abstract: We determined the number of days required, and whether to include weekdays and/or weekends, to obtain reliable measures of ambulatory physical activity in people with Parkinson’s disease (PD). Ninety-two persons with PD wore a step activity monitor for seven days. The number of days required to obtain a reliable estimate of daily activity was determined from the mean intraclass correlation (ICC2,1) for all possible combinations of 1–6 consecutive days of monitoring. Two days of monitoring were sufficient to obtain reliable daily activity estimates (ICC2,1 > 0.9). Amount (p = 0.03) but not intensity (p = 0.13) of ambulatory activity was greater on weekdays than weekends. Activity prescription based on amount rather than intensity may be more appropriate for people with PD.
Keywords: Exercise, physical fitness, Parkinson disease, reproducibility of results