title: Accuracy of clinical diagnosis of Parkinson disease: A systematic review and meta-analysis.
abstract: OBJECTIVE
  To evaluate the diagnostic accuracy of clinical diagnosis of Parkinson disease (PD) reported in the last 25 years by a systematic review and meta-analysis.
  
  
  METHODS
  We searched for articles published between 1988 and August 2014. Studies were included if reporting diagnostic parameters regarding clinical diagnosis of PD or crude data. The selected studies were subclassified based on different study setting, type of test diagnosis, and gold standard. Bayesian meta-analyses of available data were performed.
  
  
  RESULTS
  We selected 20 studies, including 11 using pathologic examination as gold standard. Considering only these 11 studies, the pooled diagnostic accuracy was 80.6% (95% credible interval [CrI] 75.2%-85.3%). Accuracy was 73.8% (95% CrI 67.8%-79.6%) for clinical diagnosis performed mainly by nonexperts. Accuracy of clinical diagnosis performed by movement disorders experts rose from 79.6% (95% CrI 46%-95.1%) of initial assessment to 83.9% (95% CrI 69.7%-92.6%) of refined diagnosis after follow-up. Using UK Parkinson's Disease Society Brain Bank Research Center criteria, the pooled diagnostic accuracy was 82.7% (95% CrI 62.6%-93%).
  
  
  CONCLUSIONS
  The overall validity of clinical diagnosis of PD is not satisfying. The accuracy did not significantly improve in the last 25 years, particularly in the early stages of disease, where response to dopaminergic treatment is less defined and hallmarks of alternative diagnoses such as atypical parkinsonism may not have emerged. Misclassification rate should be considered to calculate the sample size both in observational studies and randomized controlled trials. Imaging and biomarkers are urgently needed to improve the accuracy of clinical diagnosis in vivo.
authors.affiliation: From the Department of Clinical Research in Neurology (G.R., S.A., G.L.), University of Bari, Tricase; Department of Biomedical and Neuromotor Sciences (G.R.), University of Bologna; Unit of Biostatistics (M.C., A.F.), IRCCS "Casa Sollievo della Sofferenza," San Giovanni Rotondo, Italy; Department of Neurology (D.M.), King's College NHS Foundation Trust; Department of Neurology (D.M.), Queen Elizabeth Hospital, Lewisham and Greenwich NHS Trust, London, UK; and Department of Basic Medical Science (G.L.), Neuroscience and Sense Organs, University of Bari, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Rizzo
authors.affiliation: From the Department of Clinical Research in Neurology (G.R., S.A., G.L.), University of Bari, Tricase; Department of Biomedical and Neuromotor Sciences (G.R.), University of Bologna; Unit of Biostatistics (M.C., A.F.), IRCCS "Casa Sollievo della Sofferenza," San Giovanni Rotondo, Italy; Department of Neurology (D.M.), King's College NHS Foundation Trust; Department of Neurology (D.M.), Queen Elizabeth Hospital, Lewisham and Greenwich NHS Trust, London, UK; and Department of Basic Medical Science (G.L.), Neuroscience and Sense Organs, University of Bari, Italy.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Copetti
authors.affiliation: From the Department of Clinical Research in Neurology (G.R., S.A., G.L.), University of Bari, Tricase; Department of Biomedical and Neuromotor Sciences (G.R.), University of Bologna; Unit of Biostatistics (M.C., A.F.), IRCCS "Casa Sollievo della Sofferenza," San Giovanni Rotondo, Italy; Department of Neurology (D.M.), King's College NHS Foundation Trust; Department of Neurology (D.M.), Queen Elizabeth Hospital, Lewisham and Greenwich NHS Trust, London, UK; and Department of Basic Medical Science (G.L.), Neuroscience and Sense Organs, University of Bari, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Arcuti
authors.affiliation: From the Department of Clinical Research in Neurology (G.R., S.A., G.L.), University of Bari, Tricase; Department of Biomedical and Neuromotor Sciences (G.R.), University of Bologna; Unit of Biostatistics (M.C., A.F.), IRCCS "Casa Sollievo della Sofferenza," San Giovanni Rotondo, Italy; Department of Neurology (D.M.), King's College NHS Foundation Trust; Department of Neurology (D.M.), Queen Elizabeth Hospital, Lewisham and Greenwich NHS Trust, London, UK; and Department of Basic Medical Science (G.L.), Neuroscience and Sense Organs, University of Bari, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Martino
authors.affiliation: From the Department of Clinical Research in Neurology (G.R., S.A., G.L.), University of Bari, Tricase; Department of Biomedical and Neuromotor Sciences (G.R.), University of Bologna; Unit of Biostatistics (M.C., A.F.), IRCCS "Casa Sollievo della Sofferenza," San Giovanni Rotondo, Italy; Department of Neurology (D.M.), King's College NHS Foundation Trust; Department of Neurology (D.M.), Queen Elizabeth Hospital, Lewisham and Greenwich NHS Trust, London, UK; and Department of Basic Medical Science (G.L.), Neuroscience and Sense Organs, University of Bari, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Fontana
authors.affiliation: From the Department of Clinical Research in Neurology (G.R., S.A., G.L.), University of Bari, Tricase; Department of Biomedical and Neuromotor Sciences (G.R.), University of Bologna; Unit of Biostatistics (M.C., A.F.), IRCCS "Casa Sollievo della Sofferenza," San Giovanni Rotondo, Italy; Department of Neurology (D.M.), King's College NHS Foundation Trust; Department of Neurology (D.M.), Queen Elizabeth Hospital, Lewisham and Greenwich NHS Trust, London, UK; and Department of Basic Medical Science (G.L.), Neuroscience and Sense Organs, University of Bari, Italy. giancarlo.logroscino@uniba.it.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Logroscino
mesh_terms: D001499:Bayes Theorem; D015415:Biomarkers / Q000032:analysis; D001921:Brain / Q000503:physiopathology; D042241:Early Diagnosis; D006801:Humans; D010300:Parkinson Disease / Q000175:diagnosis*
chemical_list: D015415:Biomarkers