Parkinson's Disease Stigma Questionnaire (PDStigmaQuest): Development and Pilot Study of a Questionnaire for Stigma in Patients with Idiopathic Parkinson's Disease.

Background: Stigma is significant in Parkinson's disease (PD). However, no specific tool is available to assess stigma in PD comprehensively.

Objective: This pilot study aimed to develop and test a stigma questionnaire specific to PD patients (PDStigmaQuest).

Methods: Based on a literature review, clinical experience, expert consensus, and patients' feedback, we developed the preliminary, patient-completed PDStigmaQuest in German language. It included 28 items covering five stigma domains: uncomfortableness, anticipated stigma, hiding, experienced stigma, and internalized stigma. In this pilot study, 81 participants (PD patients, healthy controls, caregivers, and health professionals) were included to investigate the acceptability, feasibility, comprehensibility, and psychometric properties of the PDStigmaQuest.

Results: The PDStigmaQuest showed 0.3% missing data points for PD patients and 0.4% for controls, suggesting high data quality. Moderate floor effects, but no ceiling effects were found. In the item analysis, most items met the standard criteria of item difficulty, item variance, and item-total correlation. Cronbach's alpha was > 0.7 for four of five domains. PD patients' domain scores were significantly higher than healthy controls' for uncomfortableness, anticipated stigma, and internalized stigma. Feedback to the questionnaire was predominantly positive.

Conclusion: Our results indicate that the PDStigmaQuest is a feasible, comprehensive, and relevant tool to assess stigma in PD and helps to understand the construct of stigma in PD further. Based on our results, the preliminary version of the PDStigmaQuest was modified and is currently validated in a larger population of PD patients for use in clinical and research settings.