Reasons For Medication Nonadherence Research Articles

Tensions in caring for chronic patients' medication adherence: A qualitative study in Cyprus.

Medication adherence (MA) to recommended treatment is a multi-faceted problem and an ongoing challenge for healthcare providers (HCPs) to monitor. This qualitative study with 10 HCPs in Cyprus aims to explore HCPs' perceptions and strategies used on addressing medication non-adherence (MNA) in patients with chronic conditions. Two main themes emerged from the analysis reflecting the ways that HCPs described their reactions to MNA of their patients: (1) "Relying on information provision to improve MA" and (2) "Trying to understand patients' perspective." HCPs reported empathizing with patients and engaging in discussions to understand patients' perspective and reasons for MNA, so as to explore alternative solutions. Simultaneously, some HCPs reflected that the techniques used to improve MA are solely centered around information on medication and side-effects. HCPs experienced an internal conflict between providing patient-centered care versus using directive approaches to improve MA. Findings suggest how HCPs could thoroughly address patients' individual barriers.

Development and Initial Validation of a Systemic Lupus Erythematosus-Specific Measure of the Extent of and Reasons for Medication Nonadherence.

Development and Initial Validation of a Systemic Lupus Erythematosus-Specific Measure of the Extent of and Reasons for Medication Nonadherence.

Effectiveness of Caregiver Intervention for Improving Medication Adherence on Level of Medication Adherence and Attitude toward Medications among Nonadherent Patients with Mental Illness

Abstract Background: Nonadherence to medication is the major challenge in treating mental illness, resulting in worsening symptoms and prolonging the course of the illness. Caregivers spend a considerable amount of time with the patients. Therefore, proper training and education for caregivers help to improve treatment outcomes. Aim: This study aims to evaluate the effectiveness of caregiver intervention for improving medication adherence (CIIMA) on level of medication adherence and attitude toward medications among nonadherent patients with mental illness. Methods: This study was an experimental study using a randomized pretest posttest control group design. The study was conducted in the psychiatric outpatient department of tertiary care hospital in the eastern India. Eighty nonadherent patients with mental illness and their primary caregivers were randomly allocated to the experimental and control group using the concealment allocation method. Patients were assessed for their level of medication adherence using medication adherence rating scale, their attitude toward medication were assessed using drug attitude inventory and reasons for medication nonadherence were assessed using the Rating of Medication Influence. CIIMA consisted of individual psycho-education, pill card monitoring, weekly telephonic and text reminders provided to the experimental group, and routine treatment was provided to the control group. The level of medication adherence and attitude toward medication were reassessed for both groups after 1 month of the initial assessment. Results: After 1 month of CIIMA, 87.2% of patients in the experimental group were adherent to medication as compared 18.4% in the control group (P < 0.001), significant improvement in their attitude toward medication and treatment in the experimental group as compared to the control group (P = 0.001). Conclusion: CIIMA is an effective, low-cost, nurse-led intervention can be delivered in the inpatient and outpatient units for improving medication adherence thereby preventing future relapse of their mental illness.

Dealing With Failure.

Dealing With Failure.

Development and Initial Validation of a Systemic Lupus Erythematosus-Specific Measure of the Extent of and Reasons for Medication Nonadherence.

Medication nonadherence is common in patients with systemic lupus erythematosus (SLE) and negatively affects outcomes. To better recognize and address nonadherence in this population, there is a need for an easily implementable tool with interpretable scores. Domains of Subjective Extent of Nonadherence (DOSE-Nonadherence) is a measure that captures both extent of and reasons for nonadherence. We refined and evaluated DOSE-Nonadherence for patients with SLE. We refined the reasons for the nonadherence domain of DOSE-Nonadherence through rheumatologist feedback and patient cognitive interviewing. We then administered the refined instrument to patients prescribed oral SLE medications and compared the results to the Beliefs About Medicines Questionnaire (BMQ), the Medication Adherence Self-Report Inventory (MASRI), medication possession ratios (MPRs), and hydroxychloroquine (HCQ) blood levels using Pearson correlations. Five rheumatologists provided feedback; 16 patients (median age 43 yrs, 100% female, 50% Black) participated in cognitive interviews and 128 (median age 49 yrs, 95% female, 49% Black, 88% on antimalarials, and 59% on immunosuppressants) completed the refined instrument. Items assessing extent of nonadherence produced reliable scores (α 0.89) and identified 47% as nonadherent. They showed convergent validity with MASRI (r = -0.57), HCQ blood levels (r = -0.55), to a lesser extent MPRs (r = -0.34 to -0.40), and discriminant validity with BMQ domains (r = -0.27 to 0.32). Nonadherent patients reported on average 3.5 adherence barriers, the most common being busyness/forgetting (62%), physical fatigue (38%), and pill fatigue (33%). Our results support the reliability and validity of DOSE-Nonadherence for SLE medications. This refined instrument, DOSE-Nonadherence-SLE, can be used to identify, rigorously study, and guide adherence intervention development in SLE.

Hesitancy Regarding Medical Advice on COVID-19: An Emergency Department Perspective.

The rejection of or non-compliance with treatment arises for different reasons by patients who receive treatment recommendations for various diseases. These states are described by various concepts, such as discharge against medical advice (DAMA) and medication nonadherence (MNA). The basis of the study is to determine how these states have arisen during the coronavirus disease (COVID-19) pandemic. The data of this study were collected through standardized interviews with 103 volunteer participants who were diagnosed with COVID-19 at different times and who did not use their prescribed medicine during the pandemic in Turkey. The data obtained in the research were analyzed through the MAXQDA qualitative analysis program. As a result of the analysis of the data, 4 main themes and sub-codes have been reached: (1) prescribed medicine, (2) an information source for the COVID-19 period/treatment, (3) the reason for medication nonadherence, and (4) treatment of choice. When the approach toward treatment of patients who were diagnosed with COVID-19 and had started treatment by a physician was evaluated, it was revealed that the nonadherence state emerged as a cycle. In the initial period, nonadherence due to the medication itself was observed. The second period is when the patients recognize their disease and collect information from their environment. Although this period begins before the disease, the search for informative sources intensifies, especially once the diagnosis has been received. In the third period, with their diagnosis and the information they had obtained, patients consider the reasons to use the medication and then decide whether or not to use it. In the fourth period, the patients who will not use antivirals consider other medications, such as anti-flu, anticoagulant, supplements, and nutrition. Since a specific treatment protocol has not yet been revealed for COVID-19, a new conceptual framework is required. In the current condition, the state of "hesitation for medical advice" arises for non-hospitalized patients.

Reasons for antihypertensive medication nonadherence influence physician preferences for hypertension management

Abstract Background/Introduction Patient nonadherence to prescribed antihypertensive medications is a major contributor to low global hypertension control rates. Attitudes toward renal denervation vary between physicians and patients, with recent data showing that side effects from medications is a key factor influencing both patient nonadherence to prescribed medications and preferences for interventional treatment. The influence of patient nonadherence on physician recommendations for renal denervation is not well understood. Purpose To examine whether specific reasons for patient nonadherence influence physician preferences for renal denervation as a treatment option for hypertension. Methods Online surveys were fielded to general and interventional cardiologists in Europe and the United States. Physicians were asked to position their willingness to recommend renal denervation in the hypertension management pathway based on three factors of nonadherence: patients' preference not to take antihypertensive medications, medication side effects, and nonspecific nonadherence to medication. The surveys followed the highest industry standards ISO 20252. Results were compared using two-tailed Z tests. Results Over two-thirds of 501 physicians surveyed stated that they would recommend renal denervation for uncontrolled hypertension irrespective of the reason for nonadherence. This recommendation was significantly more common in the scenario of patient reported medication side effects as compared with desire not to take medications or other nonspecific reasons for nonadherence (p<0.001 for both; Figure) Conclusions Surveyed physicians were more likely to recommend renal denervation to patients reporting side effects with their antihypertensive medications than for other reasons of nonadherence. These findings underscore the influence of patient-specific reasons for medication nonadherence on provider recommendations as part of a shared decision-making process when evaluating different options for hypertension management. Funding Acknowledgement Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Medtronic

Assessment of Knowledge and reasons for Medication non-Adherence in Ambulatory Elderly Patients with Hypertension and Diabetes Mellitus in a Geriatric Centre in Nigeria

Abstract Introduction Hypertension and type 2 Diabetes mellitus are global health disorders afflicting millions of elderly patients worldwide with an ever-increasing incidence and prevalence. Non-adherence to medications affects the quality and length of life, and has been associated with negative health outcomes and increasing healthcare costs especially in the elderly [1]. Few empirical data exist on the knowledge and medication adherence among elderly patients in sub-Saharan Africa countries. Aim This study aimed to assess the knowledge, medication adherence, and the factors associated with patient’s knowledge on diabetes mellitus and hypertension. Methods A cross-sectional study of 423 elderly patients aged ≥60 years diagnosed with hypertension and diabetes mellitus, selected consecutively at the Geriatric centre in the University College Teaching Hospital, Ibadan was carried out between October 2019 and January 2020. Socio-demographic information, knowledge of the indication of the medications, possible side effects, and details of medication adherence level with reasons for non-adherence were obtained using interviewer-administered semi-structured questionnaire. Bivariate and multivariate analyses were carried out using SPSS 23. Alpha was set at 0.05. Results The mean age (±SD) of the older patients was 69.6 ± 6.4 years and 253 (59.8%) were females. About three-quarter of participants (320; 75.7%) were retired. Majority of the elderly (381; 90.1%) were hypertensive, while 270 (63.8 %) were diabetic, and 85 (20.1%) had multimorbidity of both hypertension and diabetes mellitus. Patients that were non-adherent with their medication were 138 (32.6%). The most common reasons reported for non-adherence included patient slept off (41; 56.6%), pre-occupation (24; 33.1%) and unavailability of medications (12; 16.6%). Thirty-seven (8.7%) participants intentionally missed doses, out of which 22 (59.5%) reported pill burden as its reason for medication non-adherence. All patients 423 (100.0%) knew the indication for their medications and 20 (4.7%) experienced medication-related side effects. Overall, 299 (70.6%) and 309 (73.0%) of patients with hypertension and diabetes mellitus showed good knowledge about their conditions. Adherence to medication was associated with good knowledge in hypertensive patients (p=0.002), while being male (p=0.002), age-group of 60–69 (p=0.001) and poor adherence (p=0.001) were associated with good knowledge in diabetes mellitus patients. Conclusion We found non-adherence was mainly as a result of patients’ behaviors, attitude, and unavailability of medications which could be the cause of low medication adherence among the elderly patients. A systematic review on factors associated with medication adherence in older patients reported medication review aimed at simplifying regimens and educating patients about their treatment as intervention to improve adherence [2]. Thus, we recommend educational intervention among the elderly patients. The elderly patients demonstrated good knowledge about their conditions and medication. However, the relatively good knowledge did not appear to have significant impact on patient’s adherence to medication. Improvement in medication adherence through interdisciplinary approach may improve clinical outcomes.

Assessment of Medication Adherence in Patients with Chronic Diseases in Tabuk, Kingdom of Saudi Arabia.

Objective:Uncontrolled chronic diseases such as hypertension and diabetes mellitus can lead to severe complications. Poor adherence to medication is one of the important reasons, leading to complications for chronically diseased patients. We aimed to assess the trend toward medication adherence and the reasons for medication nonadherence in chronic disease patients in Tabuk city in Saudi Arabia.Methods:A cross-sectional study was conducted at a tertiary care hospital in Tabuk, Saudi Arabia. Participants were selected and interviewed for information regarding their medication adherence. A medication adherence rating scale questionnaire was used to measure the level of adherence in study participants. The data were analyzed by the statistical package for the social sciences (SPSS) database 24.Findings:Overall, 208 participants were involved in this study. Among these, 134 (64.4%) were female, and 74 (35.6%) were male. This study showed that 159 (76.44%) participants were adherent to their medications and nearly one-quarter of patients were nonadherent to their medications. No statistically significant differences were found between male and female patients toward their medication adherence. The primary intentional and nonintentional reason for nonadherence was side effects and forgetfulness, respectively.Conclusion:Tailoring the therapy according to the individual need of the patients will maximize the patient's adherence toward medications.

Abstract 17004: Using mHealth to Capture Patient-Reported Sexual Satisfaction in Heart Failure

Introduction: Over 60% of heart failure (HF) patients have reported problems with sexual satisfaction, which is a major reason for medication non-adherence. While many patients are reticent to verbally self-report impaired sexual satisfaction, mobile health (mHealth) technology may improve patient comfort in reporting these symptoms. We aimed to evaluate the feasibility of HF patients using mHealth to self-report sexual satisfaction by comparing responders to non-responders and evaluating symptom burden. Methods: We prospectively recruited HF patients from inpatient and outpatient cardiology clinics at an urban academic medical center from October 2016 to January 2017. Patients completed Patient Reported Outcomes Measurement Information System (PROMIS ® ) questionnaires via an mHealth application, mi.Symptoms . The specific outcomes of interest were fatigue- and pain-related impairment of sexual satisfaction, due to the prevalence of those symptoms in HF. Data were analyzed using descriptive statistics and Chi-square tests to evaluate differences between responders and non-responders. Results: The mean age of participants (n=168) was 59 years (±12.5); 37% were female; 37% were Latino; 32% were Black, 32% White, and 36% Other Race . Few significant differences in demographic characteristics of responders and non-responders were noted ( Table ). Of the 117 participants (69.6%) who responded regarding fatigue, 59 (50.4%) indicated that fatigue affected sexual satisfaction “quite a bit” or “very much.” Of the 114 participants (67.9%) who responded regarding pain, 44 (38.6%) indicated that pain affected sexual satisfaction “quite a bit” or “very much.” Conclusion: This study showed that mHealth can be a feasible way to collect sexual satisfaction data with fairly high response rates and few differences between responders and non-responders. Participants’ reported high burden of impairment underscores the importance of measuring this symptom.

A cultural adaptation and validation study of a self-report measure of the extent of and reasons for medication nonadherence among patients with diabetes in Singapore.

BackgroundThis self-report measure is a new instrument to measure the extent of and reasons for medication adherence separately. However, few studies have assessed its psychometric properties in diabetic patients and also in Asian populations.ObjectivesTo validate this self-report measure in diabetic patients in Singapore.MethodsWe collected data prospectively using a questionnaire among 393 diabetic patients from hospitals in Singapore from July 2018 to January 2019. Using the COnsensus-based Standards for the selection of health Measurement INstruments framework, we assessed face validity, internal consistency, test–retest reliability, structural validity, and measurement error. We tested four a priori hypotheses on correlation of extent score with patient-reported outcome measures to assess construct validity. We examined cross-cultural validity via measurement invariance across gender, age groups, and languages.ResultsWe performed cognitive interviews with 30 consenting English-literate, Chinese-literate, and Malay-literate (10 patients per language) diabetic patients (age range 48–76 years, 53% male, disease duration range 1–30 years) and face validity was supported. Among 393 patients (mean age: 59.4±12.2 years, 50.9% female, 52.4% Chinese), we showed moderate internal consistency (Cronbach’s alpha =0.67) and test–retest reliability (intra-class coefficient=0.56 [95% CI 0.37–0.70]). We calculated smallest detectable change as 0.80. We established construct validity by meeting all four hypotheses. We showed structural validity as confirmatory factor analysis confirmed a one-factor model, with excellent fit statistics (Comparative Fit Index=1.0; Tucker-Lewis Index=1.0; Root Mean Square Error of Approximation<0.001; Standardized Root Mean Residuals<0.001). Analysis of cross-cultural validity supported configural invariance model but not metric invariance and scalar invariance model. Caution must be taken against directly comparing extent scores across gender, age groups, and languages.ConclusionThis self-report measure is valid and reliable in measuring medication adherence in diabetic patients in Singapore.

Medication non-adherence related to patients’ attitudes and knowledge rather than socio-cultural factors: a study of cardiac clinic attendees at a public healthcare institute

Background: Medication non-adherence contributes significantly to sub-optimum care, for reasons that could be unique to specific localities. The study sought to identify reasons for non-adherence and associated factors in cardiac clinic attendees at a leading tertiary health institution in Trinidad and Tobago.Methods: This cross-sectional study included a convenience sample of cardiac clinic attendees. The data collection instrument was a questionnaire comprising items regarding socio-demographic characteristics, medical history, social support and reasons for medication non-adherence. Data were collected between March and July, 2016. Non-adherence was identified with total scores of &gt;1 using selected similar questions to that used in the Morisky four-item adherence instrument. Data analyses involved both descriptive and inferential methods.Results: Non-adherent patients represented the largest proportion of participants (n=270, 78.3%). Participants were predominantly women, aged &gt;50 years, of Indo-Trinidadian descent, married, and unemployed. Carelessness (n=251, 93.0%), ceasing medication use when feeling well (n=217, 80.4%), forgetfulness (n=187, 69.3%), and ceasing medication use when feeling worse (n=151, 50.6%) were the leading reasons for non-adherence, followed by unpleasant effects of medication and cost (n=144, 53.3%). Associated factors included feeling that one would become more ill upon ceasing medication use (p=0.003), the importance of understanding the reasons for taking medication (p=0.017), the importance of following physicians’ instructions (p=0.023), and educational level (p=0.040).Conclusions: Effective communication regarding patients’ concerns and potential adverse medication effects between patients and healthcare providers could promote greater adherence.

Comparison of Student and Patient Perceptions for Medication Non-adherence

Objective. To compare pharmacy students' perceptions with patients' reasons for medication non-adherence. Methods. Pharmacy students completing an experiential rotation recruited patients exhibiting medication non-adherence from community pharmacies and asked them to respond to statements about reasons for their medication non-adherence. Patient responses were ranked in order of prevalence and compared to self-reported student perceptions on reasons for non-adherence. Results. There was a significant difference between patients' and students' rankings of reasons for medication non-adherence. Significant factors for patients included medications that interfere with lifestyle, sexual health and drinking alcohol; whereas, students believed that cognitive-related issues were patients' primary reasons for non-adherence to their medications. Conclusion. Educational opportunities to reflect on and discuss differing perspectives should be provided in the pharmacy curriculum to better equip students to address medication adherence issues and improve patient care.

Management Practice, and Adherence and Its Contributing Factors among Patients with Chronic Kidney Disease at Tikur Anbessa Specialized Hospital: A Hospital Based Cross-Sectional Study.

The objective of this study was to assess the management practice, medication adherence, and factors affecting medication adherence in CKD patients at Tikur Anbessa Specialized Hospital (TASH). Methods. A cross-sectional study was conducted at the nephrology clinic of TASH. A total of 256 CKD (stages 1 and 2=50, stage 3=88, stage 4=55, and stage 5=63) patients were recruited through systematic random sampling. Data were collected from medical records and interviewing patients. The rate of adherence was determined using 8-item Morisky medication adherence scale. The data were analyzed using SPSS version 20.0 statistical software. Univariate and multivariate binary logistic regression were used to investigate the potential predictors of medication nonadherence. Results. About 57.3% of diabetes mellitus with hypertension were treated with combination of insulin and ACEI based regimens. Other cardiovascular comorbidities were predominantly treated with Acetyl Salicylic Acid in combination with β-blocker. Only 61.3% (stages 1 and 2=70%, stage 3=73.9%, stage 4=54.5%, and stage 5=43%) of the study population were adherent to their treatment regimens. Forgetfulness (79.8%) was the major reason for medication nonadherence. Patients who had an average and high monthly income were 4.14 (AOR=4.14, 95% CI: 1.45-11.84, p=0.008) and 6.17 times (AOR=6.17, 95% CI: 1.02-37.46, p=0.048) more likely to adhere as compared to those who had very low income. Patients who were prescribed with ≥5 drugs were 0.46 times (AOR= 0.54, 95% CI: 0.27-1.10, p=0.049) less likely to adhere compared to their counterpart. Patients who were students, drivers, or teachers working in private school were about 7.46 times (AOR=7.46, 95% CI: 1.49-37.26, p=0.014) more likely to adhere compared with patients who were farmers. Conclusion. Insulin and ACEIs based regimens were the most frequently used regimens in the treatment of diabetes mellitus and hypertension comorbidities. Very low income, increased number of prescribed medications, and being a farmer were the predictors of medication nonadherence.

PHP159 - Comparing Rates and Reasons for Medication Non-Adherence Across Seventeen Disease Conditions, Three Modes of Administration, And two Frequencies of Administration, Using the Medication Adherence Reasons Scale (MAR-SCALE)

PHP159 - Comparing Rates and Reasons for Medication Non-Adherence Across Seventeen Disease Conditions, Three Modes of Administration, And two Frequencies of Administration, Using the Medication Adherence Reasons Scale (MAR-SCALE)

A theoretical model of how neighborhood factors contribute to medication nonadherence among disadvantaged chronically ill adults.

In addition to individual-level socioeconomic and psychological factors, the neighborhood environment has been found to be related to medication nonadherence, particularly among low-income, minority populations managing a chronic disease. In this article, we synthesize the relevant literature on how neighborhood factors contribute to engagement in health behaviors and reasons for medication nonadherence among this population. We propose a theoretical framework for understanding the mediating and moderating mechanisms whereby the neighborhood environment may impact medication nonadherence among individuals most at risk for adverse disease outcomes. Guided by this model, we provide recommendations for future research, practice, and policy.

Impact of a web-based intervention on the awareness of medication adherence.

Medication nonadherence is a widely recognized problem that leads to adverse outcomes and increased health care costs. Reasons for medication nonadherence are multifactorial, and patient awareness of the salience of medication adherence is critical. The purpose of this research was to assess the impact of a pharmacist-led, web-based video presentation in increasing patients' awareness of the importance of medication adherence. Patients aged 35 years and above, taking at least 1 chronic prescription medication were included in the study (n=166). Patients completed a pre-survey, watched a pharmacist-led web-based video presentation educating them on the importance of medication adherence, then completed a 1-month follow-up survey. The primary outcome was measurement of change in patients' awareness of the importance of medication adherence. Results indicated a statistically significant increase in the primary outcome of increasing awareness of the importance of medication adherence. More patients in the follow-up survey indicated that it was important for their health to take their medications around the same time daily (P=0.002), and more patients identified that their family will be impacted as a result of their medication nonadherence (P=0.001) as compared to the pre-survey. More patients in the follow-up survey reported that they expected to experience fewer emergency room visits (P=0.0001) and anticipated that they would get more time to spend with friends and family (P=0.0039) as benefits of taking medications as prescribed. A pharmacist-led web-based video presentation may be a low-cost intervention to increase patients' awareness of the importance of medication adherence.

Teaching Wisely.

Teaching Wisely.

The Effect of Rheumatoid Arthritis Disease Education on Adherence to Medications and Followup in Kerala, India

To the Editor: We read with interest the study by Harrold, et al exploring cost-related medication nonadherence (CRN) in elderly American patients with rheumatoid arthritis (RA)1. In their study of a population covered by insurance, Harrold, et al have identified cost as the reason for medication nonadherence. However, nonadherence to medication and followup in RA is a complex issue, with several patient-specific and disease-specific domains. Factors such as beliefs about medication, which have social and psychological roots, have an important influence on adherence2. The traditional paternalistic view that the patient is a passive party who should take their prescribed medications and adhere to the recommended followup is also a major barrier3. In contrast to industrialized nations, in a developing and populous country such as India an additional barrier could be the lack of awareness regarding RA and the benefits of managing it, which go beyond mere symptom alleviation. It is noteworthy that healthcare in India is by … Address correspondence to Dr. V. Ravindran, MES Medical College, Perinthalmanna-679338, Kerala, India. E-mail: drvinod12{at}gmail.com

Initial Validation of a Self-Report Measure of the Extent of and Reasons for Medication Nonadherence

Self-report measures of medication nonadherence confound the extent of and reasons for medication nonadherence. Each construct is assessed with a different type of psychometric model, which dictates how to establish reliability and validity. To evaluate the psychometric properties of a self-report measure of medication nonadherence that assesses separately the extent of nonadherence and reasons for nonadherence. Cross-sectional survey involving the new measure and comparison measures to establish convergent, discriminant, and predictive validity. The new measure was readministered 2-21 days later. A total of 202 veterans with treated hypertension were recruited from the Durham Veterans Affairs Medical Center. A new self-report measure assessed the extent of nonadherence and reasons for nonadherence. Comparison measures included self-reported medication self-efficacy, beliefs about medications, impression management, conscientiousness, habit strength, and an existing nonadherence measure. Three items assessing the extent of nonadherence produced reliable scores for this sample, α = 0.84 (95% confidence interval, 0.80-0.87). Correlations with comparison measures provided evidence of convergent and discriminant validity. Correlations with systolic ( r = 0.27, P < 0.0001) and diastolic (r = 0.27, P < 0.0001) blood pressure provided evidence of predictive validity. Reasons for nonadherence were assessed with 21 independent items. Intraclass correlations were 0.58 for the extent score and ranged from 0.07 to 0.64 for the reasons. The dual conceptualization of medication nonadherence allowed a stronger evaluation of the reliability and validity than was previously possible with measures that confounded these 2 constructs. Measurement of self-reported nonadherence consistent with psychometric principles will enable reliable, valid evaluation of interventions to reduce nonadherence.