title: The burden of non-motor symptoms in Parkinson's disease using a self-completed non-motor questionnaire: a simple grading system.
abstract: BACKGROUND
  Non-motor symptoms (NMS) of Parkinson's disease (PD) affect virtually every patient, yet they are under-recognized and under-treated. The NMS Questionnaire (NMSQuest) is a validated 30-item self-assessment instrument useful for NMS screening in clinic.
  
  
  OBJECTIVE
  Development of a straight forward grading classification of the burden of non-motor symptoms in PD based on the number of NMS as assessed by the NMS Questionnaire.
  
  
  METHODS
  In an observational, cross-sectional, international study of 383 consecutive patients distribution of the declared NMS as per NMSQuest was analyzed according to previously published levels based on the Non-Motor Symptoms Scale and also the median and interquartile range (IR, percentiles 25 and 75) of the total NMSQuest scores. After post hoc checking, these values were proposed as cut-off points for estimating NMS burden based only on the accumulation of symptoms.
  
  
  RESULTS
  Burden and number of NMS correlate closely (r ≥ 0.80). On the basis of this finding, five levels (0 = No NMS to 4 = Very severe) of NMSQuest grading were proposed after identification of their cut-offs by ordinal logistic regression and median and interquartile range distribution. These values coincided almost completely with those obtained by median and interquartile range in an independent sample. Concordance between this classification and HY staging was weak (weighted kappa = 0.30), but was substantial (weighted kappa = 0.68) with the Non-Motor Symptoms Scale grading.
  
  
  CONCLUSIONS
  Completion of NMSQuest and subsequent grading of the burden could allow the health care professional to approach the severity of NMS burden using the self completed NMSQuest in a primary care setting.
authors.affiliation: National Parkinson Foundation International Centre of Excellence, King's College London, London, UK; National Institute for Health Research (NIHR) Mental Health Biomedical Research Centre and Dementia Unit at South London and Maudsley NHS Foundation Trust and King's College London, UK; Department of Clinical Neuroscience, Institute of Psychiatry, Kings College London, London, UK.
authors.forename: K Ray
authors.initials: KR
authors.lastname: Chaudhuri
authors.affiliation: National Parkinson Foundation International Centre of Excellence, King's College London, London, UK.
authors.forename: A
authors.initials: A
authors.lastname: Sauerbier
authors.affiliation: Department of Statistics, Centre of Human and Social Sciences, Spanish Council for Scientific Research, Madrid, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Rojo
authors.affiliation: Movement Disorders Program, Medical College of Georgia, Augusta, GA, USA.
authors.forename: K
authors.initials: K
authors.lastname: Sethi
authors.affiliation: UCL Institute of Neurology, Department of Clinical Neurosciences London, London, UK.
authors.forename: A H V
authors.initials: AH
authors.lastname: Schapira
authors.affiliation: National Institute for Health Research (NIHR) Mental Health Biomedical Research Centre and Dementia Unit at South London and Maudsley NHS Foundation Trust and King's College London, UK; Department of Psychology, Institute of Psychiatry, Kings College London, London, UK.
authors.forename: R G
authors.initials: RG
authors.lastname: Brown
authors.affiliation: Department for Parkinson's Disease, IRCCS San Camillo, Venice, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Antonini
authors.affiliation: Department of Neurology, IRCCS San Raffaele, Rome, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Stocchi
authors.affiliation: University of Lund, Lund, Sweden.
authors.forename: P
authors.initials: P
authors.lastname: Odin
authors.affiliation: Bangur Institute of Neurology, Kolkata, India.
authors.forename: K
authors.initials: K
authors.lastname: Bhattacharya
authors.affiliation: Department of Neurology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Tsuboi
authors.affiliation: Department of Community Health Medicine, Hyogo College of Medicine Division of Neurology, Hyogo College of Medicine Hospital, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Abe
authors.affiliation: National Parkinson Foundation International Centre of Excellence, King's College London, London, UK.
authors.forename: A
authors.initials: A
authors.lastname: Rizos
authors.affiliation: National Centre of Epidemiology and Centre for Networked Biomedical Research on Neurodegenerative Diseases (CIBERNED), Carlos III Institute of Health, Madrid, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Rodriguez-Blazquez
authors.affiliation: National Centre of Epidemiology and Centre for Networked Biomedical Research on Neurodegenerative Diseases (CIBERNED), Carlos III Institute of Health, Madrid, Spain. Electronic address: pmartinez@isciii.es.
authors.forename: P
authors.initials: P
authors.lastname: Martinez-Martin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001007:Anxiety / Q000175:diagnosis / Q000209:etiology*; D003430:Cross-Sectional Studies; D003863:Depression / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D006801:Humans; D007391:International Cooperation; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications*; D011788:Quality of Life; D012647:Self-Assessment; D011795:Surveys and Questionnaires
keywords: Classification; Grading; NMS Questionnaire; Non-motor symptoms; Parkinson's disease; Prevalence