[1] Northwestern Univ, Ctr Educ Hlth Sci, 633N St Clair 20th Floor 2024-L, Chicago, IL 60611 USA
[2] Natl Parkinson Fdn, Miami, FL USA
[3] Univ Texas Hlth Sci Ctr Houston, Dept Biostat, Houston, TX 77030 USA
[4] Univ Toronto, Toronto Western Hosp, Morton & Gloria Shulman Movement Disorders Ctr, Toronto, ON, Canada
[5] Univ Toronto, Toronto Western Hosp, Edmond J Safra Program Parkinsons Dis, Toronto, ON, Canada
[6] Vanderbilt Univ, Div Movement Disorders, Dept Neurol, 221 Kirkland Hall, Nashville, TN 37235 USA
[7] Univ Toronto, Dept Med, Div Neurol, Toronto, ON, Canada
[8] Northwestern Univ, Dept Neurol, Chicago, IL USA
[9] All Natl Parkinson Fdn Qual Improvement Initiat N, Chicago, IL USA