High adherence and concordance within a clinical trial of antihypertensives

Centre for Behavioural Medicine, The School of Pharmacy, University of London, Mezzanine Floor, BMA House, Tavistock Square, London WC1H 9JP, UK.
Chronic Illness 12/2010; 6(4):243-51. DOI: 10.1177/1742395310369018
Source: PubMed


To explore hypertensive patients' beliefs about their condition and its treatment and their adherence within the context of a clinical trial. To assess the degree of concordance between patients' beliefs about hypertension and the medical model of the condition.
This was a questionnaire-based study, involving 230 patients participating in the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT), a randomized controlled trial comparing two pharmaceutical approaches to the management of hypertension. A comparison group of 106 hypertensive patients who were screened for ASCOT but did not meet the entry criteria was also recruited. Outcome measures were beliefs about hypertension and antihypertensive medication, and adherence to medication (self-report and tablet count).
Adherence to medication was higher than anticipated, with 45% participants reporting complete adherence over the 18-month study and a further 40% only rare non-adherence. Patients' beliefs about their condition and treatment were generally concordant with the medical model of hypertension. High concordance was associated with high medication adherence (p<0.001).
Clinical trial volunteers may have beliefs that are unusually concordant with the medical model of hypertension and may demonstrate atypically high adherence. This has implications for the transferability of trial findings to the general hypertensive population.

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Available from: Rob Horne, Apr 20, 2015
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    • "Concordance is characterised as a negotiation-like health communication approach based on an equal partnership between patients and health professionals, collaborative attitude in therapeutic decision-making, and sufficient consideration of the patients' preferences234. Concordant health communication seeks to improve the trust between patients and health professionals involved and the acceptability and feasibility of the treatment regimens , which are then likely to contribute to the level of adherence to treatment regimens[5,6][7], patients[8], medical students[9], and pharma- cists[10]. Knapp et al.,[11]subsequently modified the LATCon and developed a 20-item (Leeds Attitudes to Concordance scale II (LATCon II). "
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    ABSTRACT: Background: Concordance is characterised as a negotiation-like health communication approach based on an equal and collaborative partnership between patients and health professionals. The Leeds Attitudes to Concordance II (LATCon II) scale was developed to measure the attitudes towards concordance. The purpose of this study was to translate the LATCon II into Chinese and psychometrically test the Chinese version of LATCon II (C-LATCon II). Methods: The study involved three phases: i) translation and cross-cultural adaptation; ii) pilot study; and iii) a cross-sectional survey (n = 366). Systematic random sampling was used to recruit hypertensive patients from nine communities covering around 78,000 residents in China. Tests of psychometric properties included content validity, construct validity, criteria-related validity (correlation between the C-LATCon II and the Therapeutic Adherence Scale for Hypertensive Patients (TASHP)), internal reliability, and test-retest reliability (n = 30). Results: The study found that the C-LATCon II had a satisfactory content validity (item-level Content Validity Index (CVI) = 0.83-1, scale-level CVI/universal agreement = 0.89, and scale-level CVI/averaging calculation = 0.98), construct validity (four components extracted explained 56.66 % of the total variance), internal reliability (Cronbach's alpha of overall scale and four components was 0.78 and 0.66-0.84, respectively), and test-retest reliability (Pearson's correlation coefficient = 0.82, p < 0.001; interclass correlation coefficient = 0.82, p < 0.001; linear weighted kappa statistic for each item = 0.40-0.65, p < 0.05). Criteria-related validity showed a weak association (Pearson's correlation coefficient = 0.11, p < 0.05) between patients' attitudes towards concordance during health communication and their health behaviours for hypertension management. Conclusions: The C-LATCon II is a validated and reliable instrument which can be used to evaluate the attitudes to concordance in Chinese populations. Four components (health professionals' attitudes, partnership between two parties, therapeutic decision making, and patients' involvement) describe the attitudes towards concordance during health communication.
    Full-text · Article · Aug 2015 · BMC Medical Informatics and Decision Making
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    • "Medication non-adherence has also been noted to be particularly problematic in individuals with chronic kidney disease, such as Mr. P (Magacho et al., 2011). Consistent with the theoretical models described above, health beliefs about the relative benefit and potential adverse outcomes of medications have been linked to non-adherence across different diseases (Horne et al., 1999, 2010), as has self-efficacy (Littlefield et al., 1992). Also of interest to health psychologists in particular may be the relationship between non-adherence and psychological traits. "
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    ABSTRACT: Background: Medication non-adherence continues to be a major challenge facing the healthcare system. A case is presented of a 48-year-old man with myocardial infarction who was found to be non-adherent to multiple medications. Conceptual models are reviewed along with current approaches for assessment and treatment of medication non-adherence. Design: Case report and literature review. Discussion: A theoretical model for medication non-adherence built on the Theory of Planned Behavior is presented. Empirical evidence is reviewed for determinants of non-adherent behavior such as health beliefs and self-efficacy. Current methods to assess medication non-adherence, including self-report, pill count, biological drug levels, pharmacy refill, and electronic bottles are summarized along with their limitations. Finally, an individualized approach for assessment is described using the case presented and the conceptual framework outlined above. Follow-up for the patient and potential interventions to improve medication adherence are discussed. Conclusion: Despite the challenges, a conceptual framework for medication non-adherence can guide assessment and treatment. Further research for innovative and effective methods to detect and treat medication non-adherence is urgently needed to aid clinicians in treating this pervasive behavioral problem.
    Full-text · Article · Aug 2012 · Frontiers in Psychology
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    ABSTRACT: A systematic review was performed from published articles on compliance (PubMed), between 1975 and first of June 2011. Specifically those which measured medication adherence using indirect methods (RCS and/or MEMS-Medication Event Monitoring System) were searched. Descriptors used were: hypertension AND patient compliance AND medication adherence. The main objective is to update the topic of therapeutic compliance in arterial hypertension worldwide, with special attention to Spain, as well as a critical evaluation of the evolution of therapeutic compliance over the period 1975-2011. After analysing 37 research studies published worldwide, the results were: total number of 8623 hypertensive patients, of whom 25.62% were non-compliers (n=2209; 95% CI; 23.82-27.42), and 74.38% were compliers (n=6414; 95% CI; 73.32-75.44). The weighted average of non-compliance was 37.60%. We conclude that the default rate in the pharmacological treatment of hypertension worldwide is high.
    Full-text · Article · Jan 2012 · SEMERGEN - Medicina de Familia
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