Parkinson’s disease: A scoping review of the quantitative and qualitative evidence of its diagnostic accuracy in primary care

Abstract

Background: Parkinson’s disease (PD) is a multisystem condition which usually presents as a movement disorder in clinical practice. There is no objective method for its diagnosis and current diagnostic process is based on characteristic clinical signs and symptoms. As the presenting symptoms can be vague and non-specific, there is often a delay in diagnosis leading to mismanagement and delayed treatment initiation. In the UK, General Practitioners (GPs) identify and initially assess individuals with PD and refer them to specialists for formal diagnosis and treatment initiation. Aim: We performed a scoping review to examine available evidence on the diagnostic accuracy of PD in primary care with an aim to assess the potential for GPs to make a diagnosis and initiate treatment and hence avoid harmful delays. Designs and Setting: We followed the scoping methodology as proposed by Westphaln which is a modified version of Arksey and O’Malley’ original framework. All findings were reported according to PRISMA guidelines for scoping reviews. Methods: Four databases (EMBASE, PUBMED CENTRAL, COCHRANE and CINAHL) and references lists of relevant published literature were systematically searched for all types of literature available in English on the diagnostic accuracy of Parkinsonism or Parkinson’s disease in primary care. There were no search restrictions placed on countries, type of studies or age. Two reviewers independently screened titles and abstracts followed by full text screening. Results: Out of 1844 studies identified, only six studies met the inclusion criteria. Five were from high income and one from a middle-income nation. Of these, three studies identified significant knowledge gaps of GPs in diagnosing PD using a pre and post knowledge base intervention assessment. Delay in appropriate referral due to delayed symptom identification was reported in one study. Only one study compared the accuracy of primary care PD diagnosis and reported that although specialists’ diagnosis showed more sensitivity, GPs had higher specificity in diagnosing PD. However, this study was found to have methodological issues leading to bias in the findings. Conclusion Our scoping review shows that there are no well conducted studies assessing the diagnostic accuracy of PD diagnosis by GPs. This calls for more focussed research in this area as diagnostic delays and errors may lead to potentially harmful but preventable delays in treatment initiation resulting in decreased quality of life for individuals suffering from Parkinson’s disease.