Tese
Desenvolvimento de um instrumento para avaliação da adesão à farmacoterapia com varfarina.
Fecha
2022-08-04Autor
Mayara Sousa Vianna
Institución
Resumen
The warfarin is recommended for primary and secondary thromboprophylaxis in
different clinical conditions. It's a drug with narrow therapeutic index and predisposition
to adverse events, which may be a consequence of medication non-adherence.
Adherence can encompass health-related behaviors in addition to medication
administration. Its assessment is relevant in the pursuit of treatment goals and
prevention of complications. Adherence assessment can be performed properly using
validated and treatment-appropriate measurement scales. The objective of the present
study was to develop an instrument to assess adherence to warfarin therapy. This estudy
was divided into three stages, namely: 1) Elaboration of a protocol to carry out a
systematic review of the literature; registered in the International prospective register of
systematic (PROSPERO), under code CRD42019128324, 2) Systematic review to
investigate validated instruments used to assess adherence to warfarin therapy; 3)
Development of the instrument "Tool to assess adherence to warfarin therapy".
Observational and experimental studies were searched in the MEDLINE (PubMed),
LILACS, EMBASE and Cochrane Library databases. Inclusion criteria: participants of
≥18 years of age, from both sexes, on chronic anticoagulation with warfarin and the use
of validated instruments to assess adherence to warfarin therapy. Two reviewers
performed the independent search and discrepancies were resolved by a third reviewer.
The tool was designed considering the medication administration and treatment-related
dimensions. The development of the instrument comprised: i) construction of a
conceptual map; ii) proposal of a preliminary version of the tool; iii) content analysis by
experts; and iv) semantic analysis through a pre-test. Nineteen articles were selected for
the review, including 17 cross-sectional studies, a cohort study and a quasi-experimental
study, published in 2009-2019. Of the 35 items developed for the tool, 14 were
discarded and 19 were modified, resulting in 21 items covering the following
dimensions: intake of warfarin pills (n=10), self-care associated with the use of warfarin
(n=7) and health monitoring (n=4). The tool showed adequate content validity, as well
as good acceptance and understanding of the items by patients. The theoretical
framework resulting from the systematic review was useful for the different stages of
instrument development. Furthermore, the systematic review highlighted a gap in
knowledge, the scarcity of validated instruments to assess adherence to warfarin
therapy. Limitations were found in instruments as the assessment of the isolated use of
medication and the lack of analysis of other relevant therapeutic aspects. More
psychometric tests are needed to ensure the construct validity, reliability and stability of
the instrument, which could be useful for a global assessment of adherence to warfarin
therapy and planning strategies to improve safety and adherence to therapy.