Diagnostic Validation for Participants in the Washington State Parkinson Disease Registry

Abstract

Background The Washington State Parkinson Disease Registry (WPDR) was created to facilitate recruitment for Parkinson's disease (PD) research studies conducted in the Pacific Northwest. The success of registries that rely on self-report is dependent on the accuracy of the information provided by participants, particularly diagnosis. Objective and Methods Our goal was to assess diagnostic accuracy within the WPDR cohort. We randomly selected and attempted to contact 168 of the 1,278 actively enrolled WPDR participants. Those who responded were invited to undergo an interview and neurological examination performed by a PD specialist. If an in-person assessment was not possible, we sought information collected during participation in prior research studies or from review of medical records. A diagnosis was considered “validated” if the individual met UK Parkinson's Disease Society Brain Bank (UKBB) clinical diagnostic criteria for PD. Results Data were ascertained for 106 participants; 77 underwent an in-person assessment, 21 had data available from a prior research study, and 8 provided access to medical records. Diagnostic accuracy within the overall sample was 93.4% (95% confidence interval (86.4%, 97.1%)). Seven patients did not fulfill UKBB criteria for the following reasons: early severe autonomic involvement (n=3), history of neuroleptic treatment (n=1), presence of the Babinski sign (n=1), or insufficient supportive criteria (n=2). Conclusions Our results indicate that studies which use the WPDR for recruitment will rarely encounter patients who are misdiagnosed. This further supports the utility of the WPDR as an effective recruitment tool for PD research in the Pacific Northwest.

Parkinson’s disease case ascertainment in a large prospective cohort

“…Overall, in our study, self-report of physician diagnosis of PD alone, while agreeing reasonably well with diagnostic criteria, did not perform as well, as reported in some prior studies [9][10][11]. Lower performance of PD self-report in our current effort than in FAME may be because FAME used in-person clinical assessment while we relied on self-reports of symptoms for diagnosis and included symptoms information provided by proxies which themselves could be subject to misclassification.…”

“…Likewise, in the Women’s Health and Aging Study I, the agreement between self-report of physician diagnosis of PD and medical record was also very high (sensitivity: 89%; specificity, positive predictive value, and negative predictive value:100%) [ 9 ]. Another study, that employed in-person examination, medical records, or data from prior research to validate PD in participants (recruited based on self-report of physician diagnosis of PD) in the Washington State Parkinson Disease Registry, found that 93.4% of the registry participants met the UK Biobank criteria for PD [ 10 ]. Lastly, in the FAME study, 84% of self-reports were confirmed by clinical diagnostic criteria [ 14 ].…”

“…Although secondary data sources such as medication inventories, medical records, and administrative data, have been used for PD ascertainment in epidemiological studies [2][3][4][5][6][7][8], in large population-based cohorts, researchers often must rely on self-reported physician-made diagnosis, with or without additional clinical information. Few studies have evaluated strategies to optimize self-report for PD case ascertainment in large cohorts [6,[9][10][11], and none specifically in the context of rural farming populations.…”

Prevalence and Risk Factors for Double Vision in Parkinson Disease

“…However, studies have shown that the accuracy of self-reported PD in this context is high. 12 The NMS-Quest assesses the presence of diplopia but not its frequency or severity, which limits our ability to determine the extent to which diplopia is clinically significant and contributes directly to reduced quality of life. Finally, we were unable to distinguish between monocular and binocular diplopia, and while self-reported diplopia has been shown to correlate highly with quantitative examination-based measures of ocular misalignment, 13,14 this has not been validated in the context of the NMS-Quest in PD, so it is possible for blurry vision or other visual symptoms to be confused for diplopia.…”

“…Additionally, participants are not assessed in person to confirm the diagnosis of PD, as this is a large‐scale electronic survey. However, studies have shown that the accuracy of self‐reported PD in this context is high 12 . The NMS‐Quest assesses the presence of diplopia but not its frequency or severity, which limits our ability to determine the extent to which diplopia is clinically significant and contributes directly to reduced quality of life.…”