Martínez-Martín P, Rojo-Abuin JM, Rodríguez-Violante M, Serrano-Dueñas M, Garretto N, Martínez-Castrillo JC, Arillo VC, Fernández W, Chaná-Cuevas P, Arakaki T, Alvarez M, Ibañez IP, Rodríguez-Blázquez C, Chaudhuri KR, and Merello M
Global evaluations of Parkinson's disease (PD) severity are available, but their concordance and accuracy have not been previously tested. The present international, cross-sectional study was aimed at determining the agreement level among four global scales for PD (Hoehn and Yahr, HY; Clinical Global Impression of Severity, CGIS; Clinical Impression of Severity Index, CISI-PD; and Patient Global Impression of Severity, PGIS) and identifying which of them better correlates with itemized PD assessments. Assessments included additional scales for evaluation of the movement impairment, disability, affective disorders, and quality of life. Spearman correlation coefficients, weighted and generalized kappa, and Kendall's concordance coefficient were used. Four hundred thirty three PD patients, 66% in HY stages 2 or 3, mean disease duration 8.8 years, were analyzed. Correlation between the global scales ranged from 0.60 (HY with PGIS) to 0.91 (CGIS with CISI-PD). Kendall's coefficient of concordance resulted 0.76 ( P <0.0001). HY and CISI-PD showed the highest association with age, disease duration, and levodopa-equivalent daily dose, and CISI-PD with measures of PD manifestations, disability, and quality of life. PGIS and CISI-PD correlated similarly with anxiety and depression scores. The lowest agreement in classifying patients as mild, moderate, or severe was observed between PGIS and HY or CISI-PD (58%) and the highest between CGIS and CISI-PD (84.3%). The four PD global severity scales agree moderately to strongly among them; clinician-based ratings estimate PD severity, as established by other measures, better than PGIS; and the CISI-PD showed the highest association with measures of impairment, disability, and quality of life., Competing Interests: P.M.-M. has received honorarium from AbbVie as speaker for a symposium, Editorial Viguera for a master course, UCB for lecturing in a summer course of the International University Menendez Pelayo, and honorarium from AbbVie for participating in the Advisory Board (epidemiological study). He has received Research grants from Parkinson’s UK, Parkinson’s Disease Non-Motor Group. M.R-V. has received honoraria from Boehringer-Ingelheim, Ever Neuro Pharma, UCB, Vanquish and MedLearning, and has participated in Advisory Boards for UCB Latin America. He has received grant from Boehringer Ingelheim for a workshop. J.C.M.-C. has received research support from Allergan, Lundbeck, and Abbvie, and speaking honoraria from Abbvie, Italfarmaco, Lundbeck, UCB, Allergan, Ipsen and Merz. N.G. has received honorarium from Allergan and Bago as speaker and director of a workshop. V.C.A. has received honorarium for speaking engagements at scientific meetings of Abbvie, and UCB Pharma, Allergan and Merz. W.F. is an associated editor of the IPMDS Website, Financial Committe, and Public Relationships Committee. He has received honoraria from Novartis for organizing Continued Medical Education Courses and has received research grants from Colciencias and the Universidad Nacional de Colombia. K.R.C. has received honorarium from UCB, Abbvie, Britannia, US Worldmeds, Mundipharma, Medtronic, Napp, Otsuka pharmaceuticals in the last 3 years and acted as a consultant for UCB, Abbvie, Britannia, Medtronic and Mundipharma. He has received funding from Parkinson’s UK, NIHR, European Commission, as well as educational grants from UCB, Britannia, Abbvie and Medtronic. M.M. received honoraria from speaking engagements at scientific meetings of Lundbeck and GSK. He has received grant support from Allergan and Pfizer and honoraria as consultant for Medtronic. The remaining authors declare no conflict of interest.