Interest in patient adherence has increased in recent years, with a growing literature that shows the pervasiveness of poor adherence to appropriately prescribed medications. However, four decades of adherence research has not resulted in uniformity in the terminology used to describe deviations from prescribed therapies. The aim of this review was to propose a new taxonomy, in which adherence to medications is conceptualized, based on behavioural and pharmacological science, and which will support quantifiable parameters. A systematic literature review was performed using MEDLINE, EMBASE, CINAHL, the Cochrane Library and PsycINFO from database inception to 1 April 2009. The objective was to identify the different conceptual approaches to adherence research. Definitions were analyzed according to time and methodological perspectives. A taxonomic approach was subsequently derived, evaluated and discussed with international experts. More than 10 different terms describing medication-taking behaviour were identified through the literature review, often with differing meanings. The conceptual foundation for a new, transparent taxonomy relies on three elements, which make a clear distinction between processes that describe actions through established routines ('Adherence to medications' , 'Management of adherence') and the discipline that studies those processes ('Adherence-related sciences'). 'Adherence to medications' is the process by which patients take their medication as prescribed, further divided into three quantifiable phases: 'Initiation' , 'Implementation' and 'Discontinuation' . In response to the proliferation of ambiguous or unquantifiable terms in the literature on medication adherence, this research has resulted in a new conceptual foundation for a transparent taxonomy. The terms and definitions are focused on promoting consistency and quantification in terminology and methods to aid in the conduct, analysis and interpretation of scientific studies of medication adherence.

BackgroundNon-adherence to medications is prevalent across all medical conditions that include ambulatory pharmacotherapy and is thus a major barrier to achieving the benefits of otherwise effective medicines.ObjectiveThe objective of this systematic review was to identify and to compare the efficacy of strategies and components thereof that improve implementation of the prescribed drug dosing regimen and maintain long-term persistence, based on quantitative evaluation of effect sizes across the aggregated trials.Data sourcesMEDLINE, EMBASE, CINAHL, the Cochrane Library, and PsycINFO were systematically searched for randomized controlled trials that tested the efficacy of adherence-enhancing strategies with self-administered medications. The searches were limited to papers in the English language and were included from database inception to 31 December 2011.Study selectionOur review included randomized controlled trials in which adherence was assessed by electronically compiled drug dosing histories. Five thousand four hundred studies were screened. Eligibility assessment was performed independently by two reviewers. A structured data collection sheet was developed to extract data from each study.Study appraisal and synthesis methodsThe adherence-enhancing components were classified in eight categories. Quality of the papers was assessed using the criteria of the Cochrane Handbook for Systematic Reviews of Interventions guidelines to assess potential bias. A combined adherence outcome was derived from the different adherence variables available in the studies by extracting from each paper the available adherence summary variables in a pre-defined order (correct dosing, taking adherence, timing adherence, percentage of adherent patients). To study the association between the adherence-enhancing components and their effect on adherence, a linear meta-regression model, based on mean adherence point estimates, and a meta-analysis were conducted.ResultsSeventy-nine clinical trials published between 1995 and December 2011 were included in the review. Patients randomized to an intervention group had an average combined adherence outcome of 74.3 %, which was 14.1 % higher than in patients randomized to the control group (60.2 %). The linear meta-regression analysis with stepwise variable selection estimated an 8.8 % increase in adherence when the intervention included feedback to the patients of their recent dosing history (EM-feedback) (p < 0.01) and a 5.0 % increase in adherence when the intervention included a cognitive-educational component (p = 0.02). In addition, the effect of interventions on adherence decreased by 1.1 % each month. Sensitivity analysis by selecting only high-quality papers confirmed the robustness of the model. The random effects model in the meta-analysis, conducted on 48 studies, confirmed the above findings and showed that the improvement in adherence was 19.8 % (95 % CI 10.7–28.9 %) among patients receiving EM-feedback, almost double the improvement in adherence for studies that did not inclu...

Different methods are available for measuring medication adherence. In this paper, we conducted a scoping review to identify and summarize evidence of all studies comparing the Medication Event Monitoring System (MEMS) with alternative methods for measuring medication adherence. A literature search was performed using the open database www.iAdherence.org that includes all original studies reporting findings from the MEMS. Papers comparing methods for measuring adherence to solid oral formulations were included. Data was extracted using a standardized extraction table. A total of 117 articles fulfilled the inclusion criteria, including 251 comparisons. Most frequent comparisons were against self-report (n = 119) and pill count (n = 59). Similar outcome measures were used in 210 comparisons (84%), among which 78 used dichotomous variables (adherent or not) and 132 used continuous measures (adherence expressed as percentage). Furthermore, 32% of all comparisons did not estimate adherence over the same coverage period and 44% of all comparisons did not use a statistical method or used a suboptimal one. Only eighty-seven (35%) comparisons had similar coverage periods, similar outcome measures and optimal statistical methods. Compared to MEMS, median adherence was grossly overestimated by 17% using self-report, by 8% using pill count and by 6% using rating. In conclusion, among all comparisons of MEMS versus alternative methods for measuring adherence, only a few used adequate comparisons in terms of outcome measures, coverage periods and statistical method. Researchers should therefore use stronger methodological frameworks when comparing measurement methods and be aware that non-electronic measures could lead to overestimation of medication adherence.

Ambulatory pharmacotherapy is marked by many deviations, mostly downward, in drug dosing from prescribed instructions. Soundly compiled dosing histories date from 1977, based on electronic time-stamping of medication 'events': package entry times, done first with eyedrop dispensers for glaucoma drugs. Electronically monitored packages for oral dosage forms date from 1988. Since then, expanding data have brought many surprises, as evidence has replaced eminence in clinical views regarding discrepancies between prescription and reality. Key features of electronic monitoring are: automaticity of time-stamping, inviolable data, and high rates of data-sampling (60/hr vs 2 - 12/yr with older methods), revealing time-of-day, day-of-week, and white coat effects that facilitate medication management, opening new ways to improve care.

Purpose: Gout is an inflammatory process initiated by tissue deposition of urate crystals. Heart failure patients have a 20-fold increased risk of gout and more than 15% of them will develop gout. It is not known which patients with heart failure are at risk of gout. Known risk factors for gout are the use of diuretics, renal impairment, overweight and obesity. We investigated the relationship between the development of gout and severity of heart failure. Methods: We collected by standard questionnaires the clinical characteristics of heart failure patients, the functional class based upon the New York Heart Association (NYHA class) and related risk factors for gout. LVEF was determined using 2D echocardiography. In addition renal function, uric acid and NT-pro BNP were determined. NT-ProBNP samples were collected in a stable phase of heart failure. Results: In total 187 patients (118 men, 69 women), median age 72 yrs, (range 37 to 92 yrs), NYHA I and II 118 patients. NYHA III and IV 69 patients, mean disease duration 3 yrs (range 0 to 24 yrs) were included. Gout was diagnosed in 57 (31%) patients. All except for two patients were treated with loop diuretics (98%) and 84.6.% had elevated serum uric acid levels. In respectively 31% patients with NYHA class I and II and 51% patients with NYHA class III and IV gout was diagnosed (p = 0.010). In patients with gout mean NT-ProBNP was 578 pmol/l (median 548 pmol/l) compared to a mean of 300 pmol/l (median 371 pmol/l) in the group without gout (p < 0.0001). Mean LVEF in patients with gout was 26% (22−30%) compared to 30% (28−33%) for patients without gout (p = 0.63). Conclusion: In heart failure patients, the presence of gout was strongly associated with elevated serum uric acid level, impaired renal function, decreased fractional urate excretion, elevated NT-proBNP and high NYHA class. Almost all patients (with and without gout) were treated with diuretics, which could be a confounding factor. This study provides further evidence that the development of gout is associated with more severe heart failure and impaired renal function.