title: Validation of a Smartphone Application Measuring Motor Function in Parkinson's Disease.
abstract: Measurement of motor function is critical to the assessment and management of Parkinson's disease. Ambulatory motor assessment has the potential to provide a glimpse of the patient's clinical state beyond the consultation. We custom-designed a smartphone application that quantitatively measures hand dexterity and hypothesized that this can give an indication of a patient's overall motor function.
  
  
  
  The aims of this study were to (i) validate this smartphone application against MDS-UPDRS motor assessment (MDS-UPDRS-III) and the two-target tapping test; (ii) generate a prediction model for MDS-UPDRS-III; (iii) assess repeatability of our smartphone application and (iv) examine compliance and user-satisfaction of this application.
  
  
  
  103 patients with Parkinson's disease were recruited from two movement disorders clinics. After initial assessment, a group of patients underwent repeat assessment within two weeks. Patients were invited to use the smartphone application at home over three days, followed by a survey to assess their experience.
  
  
  
  Significant correlation between key smartphone application test parameters and MDS-UPDRS-III (r = 0.281-0.608, p < 0.0001) was demonstrated. A prediction model based on these parameters accounted for 52.3% of variation in MDS-UPDRS-III (R2 = 0.523, F(4,93) = 25.48, p < 0.0001). Forty-eight patients underwent repeat assessment under identical clinical conditions. Repeatability of key smartphone application tests parameters and predicted MDS-UPDRS-III was moderate to strong (intraclass correlation coefficient 0.584-0.763, p < 0.0001). The follow-up survey identified that our patients were very comfortable with the smartphone application and mobile technology.
  
  
  
  Our smartphone application demonstrated satisfactory repeatability and validity when measured against MDS-UPDRS-III. Its performance is acceptable considering our smartphone application measures hand dexterity only.
authors.affiliation: Neuroscience Department, The Alfred Hospital, Melbourne, VIC, Australia.|Van Cleef Roet Centre for Nervous Diseases, Monash University, The Alfred Hospital, Melbourne, VIC, Australia.
authors.forename: Will
authors.initials: W
authors.lastname: Lee
authors.affiliation: Neurology Department, The Royal Melbourne Hospital, Parkville, VIC, Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Evans
authors.affiliation: Neuroscience Department, The Alfred Hospital, Melbourne, VIC, Australia.|Van Cleef Roet Centre for Nervous Diseases, Monash University, The Alfred Hospital, Melbourne, VIC, Australia.
authors.forename: David R
authors.initials: DR
authors.lastname: Williams
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006225:Hand / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D063731:Mobile Applications; D009043:Motor Activity; D010300:Parkinson Disease / Q000175:diagnosis* / Q000503:physiopathology* / Q000523:psychology; D015203:Reproducibility of Results; D000068997:Smartphone
keywords: Parkinson’s disease; bradykinesia; measurement; motor; validation