OBJECTIVES: Orphan diseases (OD) are chronic and degenerative pathologies with a low global prevalence that affect quality of life due to their late and difficult diagnosis, and require timely initiation and continuous treatment according to the prescription. The compliance and adherence to the treatment is critical to achieve health outcomes. We aim to evaluate the state of art related to adherence scales in OD for intravenous treatment (IVT) administered at home or at specialized centers.

METHODS: A scoping literature review of published research articles of adherence scales in OD was carried out in MEDLINE, Cochrane, LILACS, PubMed, Ovid, Embase, SciELO and Redalyc. The search strategy included the keywords: adherence, compliance to treatment, rare diseases, home infusion therapy, surveys, and questionnaires.

RESULTS: 510 articles were found, only 1 accomplished the inclusion criteria. The VERITAS-PRO scale for hemophilia meets the characteristics to evaluate OD adherence, however, the publication did not describe the questionnaire components.

Additional instruments with potential to be adapted and used for IVT in OD were identified and chosen according to the disease used to test them and the inclusion of therapeutic adherence. These used indirect measurement methods and/or a patient-reported outcomes approach.

The MMAS-8, BMQ, ARMS, and MAS instruments, amongst others, were described in different studies for high-prevalence of chronic diseases, outpatients, daily dosage interval medications and/or an oral administration route.

CONCLUSIONS: There are several methods available to measure adherence without a standardized application for chronic infusion therapies. In this literature review, an optimal method for OD was not found.

There are opportunities to develop alternatives that evaluate objectively the IVT adherence in OD. Such instrument could allow improved treatment effectiveness and would have a positive impact on the patient’s quality of life, reduced disease complications, and healthcare cost reduction.