Self-report instruments for assessing adherence to warfarin therapy: a systematic review.

BACKGROUND: The assessment of adherence to warfarin therapy is useful in clinical practice due to its wide variability in dose-response and risks of complications. The aim of this study was to investigate validated instruments used to assess adherence to warfarin therapy. METHODS: Information was collected from the MEDLINE (PubMed), LILACS, EMBASE, and Cochrane Library databases. Search strategies were applied for each database, with no time limit or language restriction. Inclusion criteria consisted of study participants of ≥ 18 years of age, from both sexes, on chronic anticoagulation with warfarin for any indication and the use of validated instruments to assess adherence to warfarin therapy. Exclusion criteria consisted of duplicate articles, narrative or systematic reviews, and meta-analyses, as well as case reports/series and experimental studies involving animals. Two independent reviewers performed the following steps: evaluation of titles/abstracts, selection of studies after full reading, data extraction, and evaluation of potential bias. Discrepancies were resolved by a third reviewer. RESULTS: Overall, 19 articles were selected for this systematic review, including 17 cross-sectional studies, one cohort study, and one quasi-experimental study, published from 2009 to 2019. The validated instruments identified in this review were Morisky Medication Adherence Scale (MMAS), the eight-item Morisky Medication Adherence Scale (MMAS-8), Measurement of Treatment Adherence (MTA), and Brief Medication Questionnaire (BMQ). Only MMAS-8 was tested for reliability, using the internal consistency assessment, with Cronbach's α range 0.56-0.71. CONCLUSIONS: This review highlighted a gap in knowledge regarding the scarcity of validated instruments to assess adherence to warfarin therapy. Limitations were found in instruments that comprised the assessment of the isolated use of medication and the lack of analysis of other relevant therapeutic aspects. Future studies are needed to develop and validate more comprehensive instruments in an attempt to assess adherence to warfarin therapy. PROSPERO: Registration number CRD42019128324.

Relationship of health literacy and adherence to oral anticoagulation therapy in patients with atrial fibrillation: a cross-sectional study.

Oral anticoagulant therapy (OAT) has increased substantially due to the aging population and prevalence rise of atrial fibrillation (AF). Medication adherence is important to achieve effectiveness and safety of OAT. The study aim was to investigate the relationship between health literary (HL) and the adherence to OAT in patients with atrial fibrillation (AF). This is a cross-sectional study conducted in a public cardiology clinic in Brazil, 2019. Sociodemographic and clinical data were collected by the review of medical records and interviews with patients. The relation between health literacy (HL) and adherence to OAT was investigated by a multiple logistic regression model. Overall, 100 AF patients were included in this study, with average age of 68.8 ± 13.8 years and predominance of women (54 %). Inadequate HL was found in 79 % of the patients and non-adherence was identified in 66 % of the participants. Sex was the only variable with a statistically significant association with non-adherence to OAT. Men presented a 2.54-fold greater chance of non-adherence to OAT, when compared to the women (Odds ratio (OR) = 2.54; 95 % confidence interval (CI): 1.03-6.62; p = 0.047). No statistically significant relationship was found between inadequate HL and non-adherence to OAT (OR 1.48; 95 % CI, 0.47-4.61; p = 0.49). High rates of inadequate HL and non-adherence to OAT were identified in this study; however, this relationship did not prove to be statistically significant. Further studies are needed to investigate factors associated with non-adherence to OAT in large samples of vulnerable populations and strategies for its improvement in public health.

Influence of sex-based differences on oral anticoagulation control in patients taking coumarin derivatives: a systematic review protocol.

OBJECTIVE: This review will aim to assess the influence of sex-based differences on oral anticoagulation control in patients taking coumarin derivatives. INTRODUCTION: Coumarin derivatives, such as warfarin, have a narrow therapeutic index, requiring frequent monitoring to achieve adequate anticoagulation control, which can be assessed by the time in therapeutic range. Differences in the quality of oral anticoagulation control between men and women have been reported, although the current evidence is controversial. A systematic review on this topic would provide results that could be incorporated into clinical practice to enhance oral anticoagulation control and treatment outcomes. INCLUSION CRITERIA: Observational and experimental studies were assessed for eligibility, with participants aged ≥18 years of either sex taking oral anticoagulation or other coumarin derivatives for ≥3 months, for any indication of chronic use, who had oral anticoagulation control evaluated by time in therapeutic range. METHODS: Electronic databases to be searched include MEDLINE, BVS, CINAHL, Embase, Cochrane CENTRAL, and Web of Science. Two reviewers will independently perform title/abstract selection and screening, and then full text retrieval and screening of articles that meet the inclusion criteria. The evaluation of methodological quality and data extraction will also be performed by two independent reviewers. Data will be synthesized in tables and then the compiled results will be meta-analyzed. In the presence of subgroup differences, meta-regression methods will be used to investigate the effects of categorical or continuous covariates. If statistical pooling is not possible, a narrative synthesis will be presented. SYSTEMATIC REVIEW REGISTRATION NUMBER: PROSPERO (CRD42019128329).

Assessment of the complexity of drug therapy and psychosocial and behavioral aspects in people living with type 2 diabetes mellitus.

Background Type 2 diabetes mellitus is a public health problem worldwide. The complexity of drug therapy and behavioral aspects are important factors in its management. Objective To characterize the complexity of drug therapy, attitudes, empowerment and self-care in people with type 2 diabetes mellitus. Methods Observational descriptive study involving people with type 2 diabetes mellitus recruited in eight public primary care settings in Brazil, 2018. We used validated instruments to determine the complexity of drug therapy employing the Medication Regimen Complexity Index, and to describe the behavioral aspects, encompassing Diabetes Attitudes Questionnaires, Diabetes Empowerment Scale-Short Form and Diabetes Mellitus Care Self-Management. Results The 119 participants showed median age of 64 years (Quartile 1 57.0; Quartile 3 71.0) with predominance of women (68.1%). We found high percentages of participants with low scores on attitudes (87.9%) and self-care (84.8%) questionnaires, but with high scores on empowerment questionnaire (81.8%) in groups with high complexity of drug therapy. Conclusion High complexity of drug therapy concentrated low scores for attitudes and self-care, even though presenting elevated empowerment scores. Further studies are needed to investigate the effect of these aspects on the behavior of people with type 2 diabetes mellitus on drug therapies of high complexity.