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Medication adherence assessment in a clinical trial with centralized follow-up and direct-to-patient drug shipments.

ABSTRACT: BACKGROUND:Assessment of adherence to study medications is a common challenge in clinical research. Counting unused study medication is the predominant method by which adherence is assessed in outpatient clinical trials but it has limitations that include questionable validity and burdens on research personnel. PURPOSE:To compare capsule counts, patient questionnaire responses, and plasma drug levels as methods of determining adherence in a clinical trial that had 2056 participants and used centralized drug distribution and patient follow-up. METHODS:Capsule counts from study medication bottles returned by participants and responses to questions regarding adherence during quarterly telephone interviews were averaged and compared. Both measures were compared to plasma drug levels obtained at the 3-month study visit of patients in the treatment group. Counts and questionnaire responses were converted to adherence rates (doses taken divided by days elapsed) and were categorized by stringent (?85.7%) and liberal (?71.4%) definitions. We calculated the prevalence-adjusted bias-adjusted kappa to assess agreement between the two measures. RESULTS:Using a pre-paid mailer, participants returned 76.0% of study medication bottles to the central pharmacy. Both capsule counts and questionnaire responses were available for 65.8% of participants and were used to assess adherence. Capsule counts identified more patients who were under-adherent (18.8% by the stringent definition and 7.5% by the liberal definition) than self-reports did (10.4% by the stringent definition and 2.1% by the liberal definition). The prevalence-adjusted bias-adjusted kappa was 0.58 (stringent) and 0.83 (liberal), indicating fair and very good agreement, respectively. Both measures were also in agreement with plasma drug levels determined at the 3-month visit (capsule counts: p?=?0.005 for the stringent and p?=?0.003 for the liberal definition; questionnaire: p?=?0.002 for both adherence definitions). LIMITATIONS:Inconsistent bottle returns and incomplete notations of medication start and stop dates resulted in missing data but exploratory missing data analyses showed no reason to believe that the missing data resulted in systematic bias. CONCLUSIONS:Depending upon the definition of adherence, there was fair to very good agreement between questionnaire results and capsule counts among returned study bottles, confirmed by plasma drug levels. We conclude that a self-report of medication adherence is potentially comparable to capsule counts as a method of assessing adherence in a clinical trial, if a relatively low adherence threshold is acceptable, but adherence should be confirmed by other measures if a high adherence threshold is required.

SUBMITTER: Warren SR

PROVIDER: S-EPMC6178218 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature

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Medication adherence assessment in a clinical trial with centralized follow-up and direct-to-patient drug shipments.

Warren Stuart R SR Raisch Dennis W DW Campbell Heather M HM Guarino Peter D PD Kaufman James S JS Petrokaitis Elizabeth E Goldfarb David S DS Gaziano J Michael JM Jamison Rex L RL

Clinical trials (London, England) 20110803 3

<h4>Background</h4>Assessment of adherence to study medications is a common challenge in clinical research. Counting unused study medication is the predominant method by which adherence is assessed in outpatient clinical trials but it has limitations that include questionable validity and burdens on research personnel.<h4>Purpose</h4>To compare capsule counts, patient questionnaire responses, and plasma drug levels as methods of determining adherence in a clinical trial that had 2056 participant ...[more]

PMID: 21813583

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Project description:PurposeTo assess longer-term patterns of glaucoma medication adherence and identify whether patterns established during the first year of medication use persist during 3 subsequent years of follow-up.DesignRetrospective, longitudinal cohort analysis.ParticipantsBeneficiaries aged ≥40 years who were enrolled in a United States (US)-managed care plan for ≥7 years between 2001 and 2012 and newly diagnosed and treated for open-angle glaucoma.MethodsFor each enrollee, we quantified medication adherence using the medication possession ratio. Group-based trajectory modeling (GBTM) was applied to identify patterns of adherence for 1 and 4 years of follow-up. The percent of beneficiaries who remained in the same trajectory group in the 1- and 4-year models was tabulated to evaluate group stability. Factors impacting adherence at 1 and 4 years were identified using regression analyses.Main outcome measuresPatterns of glaucoma medication adherence.ResultsOf the 1234 eligible beneficiaries, GBTM identified 5 distinct glaucoma medication adherence patterns in both the 1-year and 4-year follow-up periods. These groups were as follows: (1) never adherent after their index prescription fill (7.5% and 15.6% of persons in the 1- and 4-year models, respectively); (2) persistently very poor adherence (14.9% and 23.4% of persons in the 1- and 4-year models, respectively); (3) declining adherence (9.5% and 9.1% of persons in the 1- and 4-year models, respectively); (4) persistently moderate adherence (48.1% and 37.0% of persons in the 1- and 4-year models, respectively); and (5) persistently good adherence (20.0% and 15.0% of persons in the 1- and 4-year models, respectively). More than 90% of beneficiaries in the 4 groups with the worst and best adherence patterns (groups 1, 2, 3, 5) maintained their patterns from their first year throughout their 4 years of follow-up. Those with persistently moderate adherence (group 4), the largest group, were most likely to change groups from 1 to 4 years of follow-up. Persons with the best adherence over 4 years were more likely to be white, to be older, to earn >$60 000/year, and to have more eye care visits (P < 0.05 for all comparisons). Those with a higher initial copayment cost had lower adherence rates (β = -0.06/dollar, P = 0.03).ConclusionsFor most patients who were newly prescribed glaucoma medications, adherence patterns observed in the first year of treatment reflect adherence patterns over the subsequent 3 years. Investing resources in both identifying and helping patients with suboptimal adherence patterns over the first year may have a large impact on longer-term adherence.

Project description:BACKGROUND:Patients with diabetes are at high risk of drug therapy problems (DTPs), as they are receiving multiple medications. To date, studies regarding DTPs in patients with diabetes in Ethiopia are limited. The aim of this study was to assess prevalence of DTPs, medication adherence and treatment satisfaction of patients with diabetes at Tikur Anbessa Specialized Hospital (TASH). METHOD:A cross-sectional study was conducted on randomly selected 418 participants who fulfilled the inclusion criteria. Data were collected using structured questionnaire and patients' chart review. Cipolle's classification system was used to determine DTPs. Modified Morisky's Adherence Scale (MMAS-8) was used to measure patients' adherence to their medication. Treatment Satisfaction with Medicines Questionnaire (SATMED-Q) patient satisfaction assessment questionnaire was used to assess patients' treatment satisfaction. RESULTS:A total of 207 DTPs in 177 (42.3%) of participants were identified. Commonly identified DTPs were dosage too low (58, 28.0%), ineffective drug therapy (54, 26.1%), and need additional drug therapy (52, 25.1%). Factors associated with DTPs were female gender (Adjusted Odds Ratio [AOR] = 2.31,95% CI:1.30-4.12); ?3comorbidities (AOR = 3.61, 95% CI:1.19-10.96); ever married (AOR = 2.58,95% CI:1.23-5.48); type 2 diabetes (AOR = 5.62, 95% CI:1.21-26.04); non-adherence (AOR = 5.26,95% CI:2.51-11.04) and residence out of Addis Ababa (AOR = 0.30, 95% CI:0.12-0.73). Twenty four percent of participants were non-adherent to their drug therapies. Factors associated with non-adherence were diabetes complications (AOR = 2.00, 95% CI: 1.2-3.32), the female gender (AOR = 1.67, 95%CI: 1.01-2.8) and level of education (AOR = 0.42, 95%CI: 0.18-0.96). Eighty one percent of participants were satisfied with the current treatment. CONCLUSION:A significant proportion of patients were satisfied with their treatment and a quarter of the study participants were non-adherent to their medications at TASH diabetic clinic. However, DTPs were considerably higher among the study participants. Hence, future interventions targeting prevention and resolution of DTPs deemed to be necessary.

Project description:Patient misunderstanding of prescription drug label instructions is a common cause of unintentional misuse of medication and adverse health outcomes. Those with limited literacy and English proficiency are at greater risk.To test the effectiveness of a patient-centered drug label strategy, including a Universal Medication Schedule (UMS), to improve proper regimen use and adherence compared to a current standard.Two-arm, multi-site patient-randomized pragmatic trial.English- and Spanish-speaking patients from eight community health centers in northern Virginia who received prescriptions from a central-fill pharmacy and who were 1) ?30 years of age, 2) diagnosed with type 2 diabetes and/or hypertension, and 3) taking ?2 oral medications.A patient-centered label (PCL) strategy that incorporated evidence-based practices for format and content, including prioritized information, larger font size, and increased white space. Most notably, instructions were conveyed with the UMS, which uses standard intervals for expressing when to take medicine (morning, noon, evening, bedtime).Demonstrated proper use of a multi-drug regimen; medication adherence measured by self-report and pill count at 3 and 9 months.A total of 845 patients participated in the study (85.6 % cooperation rate). Patients receiving the PCL demonstrated slightly better proper use of their drug regimens at first exposure (76.9 % vs. 70.1 %, p?=?0.06) and at 9 months (85.9 % vs. 77.4 %, p?=?0.03). The effect of the PCL was significant for English-speaking patients (OR 2.21, 95 % CI 1.13-4.31) but not for Spanish speakers (OR 1.19, 95 % CI 0.63-2.24). Overall, the intervention did not improve medication adherence. However, significant benefits from the PCL were found among patients with limited literacy (OR 5.08, 95 % CI 1.15-22.37) and for those with medications to be taken ?2 times a day (OR 2.77, 95 % CI 1.17-6.53).A simple modification to pharmacy-generated labeling, with minimal investment required, can offer modest improvements to regimen use and adherence, mostly among patients with limited literacy and more complex regimens. Trial Registration (ClinicalTrials.gov): NCT00973180, NCT01200849.

Project description:BACKGROUND:Control of vascular risk factors is essential for secondary stroke prevention. However, adherence to secondary prevention medications is often suboptimal, and may be affected by cognitive impairment. Few studies to date have examined associations between cognitive impairment and medication adherence post-stroke, and none have considered whether adherence to secondary prevention medications might affect subsequent cognitive function. The aim of this study was to explore prospective associations between cognitive impairment and medication non-adherence post-stroke. METHODS:A five-year follow-up of 108 stroke survivors from the Action on Secondary Prevention Interventions and Rehabilitation in Stroke (ASPIRE-S) prospective observational cohort study. Cognitive function was assessed using the Montreal Cognitive Assessment at 6 months, and a neuropsychological test battery at 5 years. Adherence to antihypertensive, antithrombotic and lipid-lowering medications was assessed using prescription refill data. RESULTS:The prevalence of cognitive impairment at five years was 35.6%. The prevalence of non-adherence ranged from 15.1% for lipid-lowering agents to 30.2% for antithrombotics. There were no statistically significant associations between medication non-adherence in the first year post-stroke and cognitive impairment at 5 years, nor between cognitive impairment at 6 months and non-adherence at 5 years. Stroke survivors with cognitive impairment were significantly more likely to report receiving help with taking medications [OR (95% CI): 4.84 (1.17, 20.07)]. CONCLUSIONS:This is the first study to explore the potential impact of non-adherence to secondary prevention medications on cognitive impairment in stroke survivors. Findings highlight the role of family members and caregivers in assisting stroke survivors with medication administration, particularly in the context of deficits in cognitive function. Involving family members and caregivers may be a legitimate and cost-effective strategy to improve medication adherence in stroke survivors.

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Medication adherence assessment in a clinical trial with centralized follow-up and direct-to-patient drug shipments.

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Medication adherence assessment in a clinical trial with centralized follow-up and direct-to-patient drug shipments.

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