Rating scales for medication adherence in people living with Parkinson's disease: a systematic review protocol.

OBJECTIVE: The objective of the review is to evaluate the measurement properties of rating scales that have been used to assess the components of medication adherence in patients with Parkinson's disease. INTRODUCTION: Drug therapy is a central strategy in the control of Parkinson's disease symptoms. Measuring behaviors related to medication adherence in patients with Parkinson's disease is vital to understanding the therapeutic response. Consequently, it is necessary to define which instrument offers the most reliable and valid screening. INCLUSION CRITERIA: This review will consider studies in English and Portuguese using structured rating scales to assess medication adherence in people with Parkinson's disease. Studies including data from patients with different diseases in addition to Parkinson's disease will be included only if data are clearly available for each disorder covered. Study protocols, letters to the editors, reviews, and studies with clinical judgment scales but no operationally defined anchor points will be excluded. METHODS: A three-step search strategy will be utilized. Databases will include MEDLINE (PubMed), LILACS (BVS Portal), PsycINFO (APA PsycNet), CINAHL (EBSCO), Web of Science (Clarivate Analytics), Embase, and Scopus (Elsevier). The search strategy will be presented using a PRISMA flow diagram. Eligible studies will be critically appraised for methodological quality using the COSMIN Risk of Bias checklist. Criteria for good measurement properties of the selected scales will be summarized narratively using COSMIN, the Movement Disorder Society Rating Scale Program Committee methodology, the World Health Organization concepts, and the ABC taxonomy of medication adherence. The certainty of the evidence will be determined using the modified GRADE recommendations. SYSTEMATIC REVIEW REGISTRATION NUMBER: PROSPERO (CRD42021211099).