title: Progression of Parkinson's disease as evaluated by Hoehn and Yahr stage transition times.
abstract: This study was carried out to evaluate progression in Parkinson's disease (PD) by analyzing time taken to transit from one Hoehn and Yahr (H&Y) stage to the next stage and to investigate the variables that would be associated with H&Y transition times using a large PD database that contained prospectively collected information. Data were obtained from the movement disorder database of the National Neuroscience Institute in Singapore. Kaplan-Meier (KM) survival analysis was adopted to investigate the time taken to progress through various H&Y stages. Cox regression analysis was used to examine the association between the baseline variables at the entry point of each H&Y stage and the progression to the next stage. A total of 695 patients (mean age: 65.2, male: 57.3%) were studied. Using KM analysis, the median time taken to transit from H&Y stage 1 to 2, 2 to 2.5, 2.5 to 3 were 20, 62, and 25 months, respectively; whereas the median time taken to progress from stage 3 to 4 and 4 to 5 were 24 and 26 months, respectively. Cox regression analysis revealed that older age-at-diagnosis, longer PD duration, and higher Unified Parkinson's Disease Rating Scale (UPDRS) motor scores at baseline were associated with a significantly faster progression through various H&Y stages. Gender and ethnicity were not associated with disease progression. In conclusion, H&Y transition time is a useful measure of disease progression in PD and may be utilized in clinical studies evaluating therapeutic interventions and prognostic factors in PD.
authors.affiliation: Department of Pharmacy, National University of Singapore, Republic of Singapore.
authors.forename: Ying Jiao
authors.initials: YJ
authors.lastname: Zhao
authors.forename: Hwee Lin
authors.initials: HL
authors.lastname: Wee
authors.forename: Yiong-Huak
authors.initials: YH
authors.lastname: Chan
authors.forename: Soo Hoon
authors.initials: SH
authors.lastname: Seah
authors.forename: Wing Lok
authors.initials: WL
authors.lastname: Au
authors.forename: Puay Ngoh
authors.initials: PN
authors.lastname: Lau
authors.forename: Emmanuel Camara
authors.initials: EC
authors.lastname: Pica
authors.forename: Shu Chuen
authors.initials: SC
authors.lastname: Li
authors.forename: Nan
authors.initials: N
authors.lastname: Luo
authors.forename: Louis C S
authors.initials: LC
authors.lastname: Tan
mesh_terms: D000368:Aged; D004185:Disability Evaluation; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000175:diagnosis / Q000473:pathology*; D011446:Prospective Studies; D012044:Regression Analysis; D012720:Severity of Illness Index