Adherence Self-Efficacy Scale (ASES)

1. Abstract

The Adherence Self-Efficacy Scale (ASES)—frequently operationalized in chronic disease literature and specialized clinical settings as the HIV Treatment Adherence Self-Efficacy Scale (HIV-ASES)—is a psychometrically validated, patient-reported outcome measure engineered to evaluate an individual’s perceived behavioral confidence in managing and executing complex treatment plans. Developed by Mallory O. Johnson and colleagues within the context of behavioral medicine and behavioral interventions for chronic disease management, the instrument evaluates self-efficacy across distinct operational domains beyond basic pill-taking routines, including comprehensive dietary regimens, physical activity requirements, symptom monitoring, and navigating healthcare interactions. The instrument comprises 12 primary items structured across two empirically robust dimensions: Adherence Integration, which captures a patient’s self-regulatory competence to integrate complex health demands into routine daily life, and Adherence Perseverance, which measures the resilience and conviction needed to sustain treatment adherence in the face of physiological, psychological, environmental, or social barriers.

Administered via a graded 11-point visual analogue or Likert-type response continuum ranging from 0 (“Cannot do at all”) to 10 (“Completely certain can do”), the scale yields both domain-specific subscale scores and an overarching composite adherence self-efficacy index. Psychometric evaluations demonstrate exceptional internal consistency across clinical and community samples, with composite and subscale reliability coefficients consistently exceeding $rho = .90$ and Cronbach’s $\alpha = .90$. Longitudinal assessments establish stability, evidenced by 3-month test-retest coefficients ($r > .70$) and 15-month retention coefficients ($r > .40$). Exploratory and confirmatory factor analyses confirm a distinct two-factor orthogonal or correlated structure accounting for over 61% of the total variance, characterized by strong factor loadings and high discriminant validity from generalized self-efficacy, depression, and health locus of control. The ASES remains a benchmark clinical trial and observational instrument, serving as a primary target and mediator in psychosocial interventions aimed at improving sustained viral suppression, medical compliance, and long-term quality of life.

2. Keywords

Self-Efficacy, Treatment Adherence, Antiretroviral Therapy (ART), Adherence Integration, Adherence Perseverance, Health Behavior Change, Psychometrics, Chronic Disease Management, Social Cognitive Theory, Patient-Reported Outcome Measures, Viral Suppression, Behavioral Medicine

3. Authors

The scale was developed and psychometrically validated by a multidisciplinary team of behavioral scientists, psychologists, and clinical epidemiologists from the Center for AIDS Prevention Studies (CAPS) at the Department of Medicine, University of California, San Francisco (UCSF):

• Mallory O. Johnson, Ph.D.: Professor of Medicine and Director of the Center for AIDS Prevention Studies (CAPS), Department of Medicine, Division of Prevention Science, University of California, San Francisco. Specialization in behavioral medicine, treatment adherence interventions, and relationship dynamics in chronic illness care.
• Torsten B. Neilands, Ph.D.: Professor of Medicine and Director of the Methods Core, Division of Prevention Science, University of California, San Francisco. Expertise in latent variable modeling, structural equation modeling (SEM), and longitudinal psychometrics.
• David E. Dilworth, M.S.: Research Data Analyst and Biostatistician, Center for AIDS Prevention Studies, University of California, San Francisco.
• Stephen R. Morin, Ph.D.: Emeritus Professor of Medicine, Division of Prevention Science, University of California, San Francisco. Leader in HIV health policy, behavioral trials, and clinical interventions.
• Robert H. Remien, Ph.D.: Professor of Clinical Psychology in Psychiatry, Columbia University Vagelos College of Physicians and Surgeons, and Director of the HIV Center for Clinical and Behavioral Studies at the New York State Psychiatric Institute.
• Margaret A. Chesney, Ph.D.: Professor Emerita of Medicine, Department of Medicine, University of California, San Francisco; Former Director of the Osher Center for Integrative Medicine; Former Deputy Director of the National Center for Complementary and Integrative Health (NCCIH) at the National Institutes of Health (NIH).

4. Purpose

Adherence to complex medical regimens constitutes one of the most critical determinants of therapeutic success across chronic infectious and metabolic diseases. In the context of Human Immunodeficiency Virus (HIV) disease, strict adherence to antiretroviral therapy (ART) is mandatory to suppress viral replication, halt disease progression, preclude the emergence of drug-resistant viral mutations, and eliminate onward transmission (Undetectable = Untransmittable; U=U). Historically, interventions and clinical assessments treated adherence merely as a mechanical, passive compliance phenomenon, operationalized primarily by pharmacy refill logs or electronic pill-bottle monitoring. However, empirical health psychology demonstrates that medical adherence is an active, dynamic, self-regulatory process dictated by cognitive appraisals, psychological reserves, and environmental resources.

The Adherence Self-Efficacy Scale (ASES) was explicitly developed to operationalize, quantify, and evaluate an individual’s situational confidence regarding their ability to execute and maintain comprehensive disease management regimens. While many adherence scales restrict their scope strictly to pill ingestion, the ASES conceptualizes treatment adherence in a holistic framework encompassing:

• Strict adherence to time-sensitive pharmacological regimens despite disruptive lifestyle events.
• Integration of prescribed dietary parameters, nutritional requirements, and fluid intake protocols alongside pharmacotherapy.
• Sustained execution of health-promoting behaviors, including prescribed physical activity, psychological coping routines, and lifestyle modifications.
• Proactive collaboration with healthcare providers, including navigating clinical appointments, diagnostic lab schedules, and treatment modifications.

The ASES serves three core applications in clinical research and healthcare practice:

1. Predictive Stratification and Clinical Risk Profiling: Identifying baseline deficits in adherence confidence allows multidisciplinary care teams to flag patients who are at high risk of regimen interruption prior to treatment initiation or regimen switches. Clinicians can provide preemptive behavioral coaching before viral rebounds or drug-resistance mutations manifest.
2. Evaluation of Interventional Efficacy: The scale was intentionally constructed for longitudinal deployment in randomized controlled trials (RCTs) evaluating cognitive-behavioral, motivational interviewing, and stress-coping interventions. Because self-efficacy is a modifiable mediator, observing shifts in ASES scores helps researchers confirm whether an intervention successfully targeted its intended psychological mechanism.
3. Diagnostic Deconstruction of Adherence Barriers: By splitting performance expectations into routine structural daily challenges (Integration) versus intense personal, emotional, and social stress (Perseverance), the instrument equips providers with granular insights into the exact behavioral domains requiring clinical reinforcement.

5. Psychological Construct

The Adherence Self-Efficacy Scale measures treatment-specific self-efficacy—an individual’s perceived capability to organize and execute courses of action required to successfully manage a chronic illness under diverse and demanding life circumstances. Rather than treating adherence self-efficacy as a uniform, undifferentiated construct, empirical structural modeling demonstrates that it comprises two distinct but interrelated dimensions: Adherence Integration and Adherence Perseverance.

Adherence Integration

Adherence Integration reflects the cognitive and operational capability of the patient to assimilate medical demands seamlessly into the fabric of daily life. Chronic care regimens rarely exist in a static vacuum; they require constant coordination with personal routines, work obligations, family duties, sleep-wake cycles, and community demands. Integration encompasses organizational skills, habit formation, prospective memory, and environmental structuring.

Patients with high Adherence Integration demonstrate high self-efficacy in:

• Aligning treatment regimens with daily domestic, occupational, and social routines without chronic cognitive exhaustion.
• Managing multi-component schedules, such as coordinating meal-dependent medications, fasting windows, and fluid consumption.
• Organizing and anticipating medication supplies, tracking prescription renewals, and preventing accidental supply exhaustion during travels or schedule changes.
• Discreetly adhering to health requirements in public, workplace, or non-private settings without experiencing prohibitive distress.

Clinical Example: An individual with elevated Integration self-efficacy who works rotational shifts formulates systematic cues—such as utilizing synchronized smartphone alarms, automated pill organizers, and meal preparation strategies—ensuring medication is consistently taken on schedule regardless of unpredictable work patterns.

Adherence Perseverance

Adherence Perseverance captures psychological resilience and distress tolerance under adverse, emotionally exhausting, or structurally disruptive situations. Regimen abandonment frequently occurs not because of poor planning, but because acute stressors—such as medication side effects, interpersonal conflicts, depressive episodes, substance cravings, or fear of stigmatization—overwhelm the individual’s baseline self-regulatory capacity.

Adherence Perseverance assesses the individual’s confidence to persist with treatment when:

• Experiencing unpleasant physiological side effects, such as nausea, gastrointestinal discomfort, vivid dreams, or fatigue.
• Navigating intense negative affective states, such as demoralization, loneliness, depressive despair, acute anxiety, or perceived burnout from chronic medical self-care.
• Confronting social disruption, financial distress, unstable housing, or familial chaos.
• Remaining adherent in the presence of unsupportive peers, potential discovery of illness by acquaintances, or in environments where stigma is prevalent.

Clinical Example: A patient struggling with severe episodic emotional distress who scores high on Adherence Perseverance maintains the conviction that they will continue to take their life-sustaining medications and attend clinical appointments even when experiencing depressive apathy, recognizing treatment continuity as vital despite their acute psychological distress.

6. Theoretical Framework

The Adherence Self-Efficacy Scale is firmly grounded in Albert Bandura‘s Social Cognitive Theory (SCT). Bandura posited that human functioning and behavior are the products of reciprocal determinism—a dynamic, bidirectional interaction among personal cognitive factors, environmental influences, and behavioral patterns. Within this paradigm, perceived self-efficacy is the core cognitive engine: it denotes people’s beliefs in their capabilities to exercise control over their own functioning and over events that affect their lives.

Efficacy Expectations vs. Outcome Expectations

A foundational theoretical distinction critical to the ASES architecture is the difference between outcome expectations and efficacy expectations:

• Outcome Expectations: The belief that a given behavior will produce a specific clinical outcome (e.g., “I know that taking my ART consistently will suppress my viral load and protect my immune system”). Almost all patients possess positive outcome expectations due to standardized patient education.
• Efficacy Expectations: The subjective conviction that one can personally execute the required behavior under challenging, ambiguous, or stressful circumstances (e.g., “Even when I feel sick to my stomach or emotionally depleted, I am confident I can take my pills”).

Bandura demonstrated that outcome expectations alone are weak predictors of sustained behavioral change. A patient may fully comprehend that non-adherence leads to treatment failure, drug resistance, and mortality, yet still discontinue treatment if their efficacy expectations are overwhelmed by acute side effects or psychological barriers. The ASES was designed specifically to isolate and quantify these critical efficacy expectations.

Sources of Self-Efficacy in Chronic Regimens

According to Social Cognitive Theory, adherence self-efficacy develops and fluctuates through four primary informational sources, which the ASES reflects and measures:

1. Mastery Experiences: Successful performance of adherence behaviors over time builds robust efficacy. Repeated minor triumphs (e.g., taking medication successfully while on vacation) strengthen the Integration subscale. Conversely, early regimen failures undermine confidence.
2. Vicarious Experiences: Observing peers with similar health conditions who effectively balance their lives and manage side effects fosters the belief that one can achieve similar mastery.
3. Verbal and Social Persuasion: Encouragement from multidisciplinary healthcare providers, supportive family members, or peer counselors bolsters perseverance in challenging phases.
4. Physiological and Affective States: Physical reactions (e.g., dizziness, nausea) and emotional cues (e.g., anxiety, depression) are frequently misread as evidence of behavioral incapability. The Perseverance subscale quantifies the patient’s capacity to overcome disruptive somatic and affective reactions.

Integration with the Information-Motivation-Behavioral Skills (IMB) Model

In addition to classic Social Cognitive Theory, the ASES aligns directly with Jeffrey Fisher and William Fisher’s Information-Motivation-Behavioral Skills (IMB) Model of adherence. In the IMB framework, adherence-related information and motivation (both personal and social) act primarily through behavioral skills to determine objective adherence. Self-efficacy represents the psychological core of behavioral skills: it reflects an individual’s confidence in their ability to enact the specific behavioral skills required for continuous disease management.

7. Validity

The ASES has been subjected to rigorous construct, convergent, discriminant, and criterion-related predictive validity assessments across numerous clinical trials and observational cohorts.

Construct and Factorial Validity

Construct validity was initially established through comprehensive exploratory factor analysis (EFA) and subsequent confirmatory factor analysis (CFA) conducted by Johnson et al. (2007). Structural modeling confirmed that a two-factor structure provided optimal fit to the data, distinguishing between structural lifestyle integration (Adherence Integration) and affective/situational resilience (Adherence Perseverance). Factor loadings for individual items across both factors ranged robustly from .64 to .88, demonstrating that the items represent coherent, well-defined underlying latent dimensions.

Convergent Validity

Convergent validity has been repeatedly demonstrated through significant, theoretically coherent associations with established psychosocial and behavioral constructs:

• General Self-Efficacy: ASES scores correlate moderately to strongly ($r = .45$ to $.62, p < .001$) with general self-efficacy scales, indicating shared conceptual variance while preserving the domain-specific clinical utility of the ASES.
• Self-Reported Medication Adherence: Higher baseline scores on both the Integration and Perseverance subscales correlate positively with standardized adherence instruments, including visual analogue scales (VAS) of past-month adherence ($r = .38$ to $.52, p < .001$) and adult AIDS Clinical Trials Group (ACTG) adherence questionnaires.
• Coping Strategies: Positive associations emerge between ASES subscales and adaptive, problem-focused coping mechanisms (e.g., active planning, positive reframing; $r = .35$ to $.48$), whereas negative correlations characterize relationships with maladaptive avoidant coping strategies (e.g., behavioral disengagement, denial; $r = -.30$ to $-.44$).

Discriminant Validity

The scale exhibits robust discriminant validity, differentiating adherence self-efficacy from adjacent affective states and global cognitive traits:

• Depressive Symptomatology: While ASES scores correlate inversely with depressive symptoms (e.g., Beck Depression Inventory, CES-D; $r = -.25$ to $-.38$), the magnitude confirms that adherence self-efficacy is not merely the inverse reflection of negative affectivity or depression.
• Health Locus of Control: The ASES demonstrates distinct variance from both internal and external (chance/powerful others) locus of control scales ($r < .25$), proving that perceived personal efficacy is distinct from ideological beliefs regarding health determinism.

Predictive and Criterion-Related Validity

The most compelling psychometric validation of the ASES resides in its capacity to predict hard clinical and biological outcomes:

• Objective Pill Monitoring: In prospective longitudinal trials using Medication Event Monitoring Systems (MEMS electronic bottle caps), baseline ASES scores significantly predicted electronic pill-cap opening adherence rates across 3, 6, and 12-month follow-up windows ($eta = .32$ to $.44, p < .001$).
• Biological Markers (Viral Suppression & CD4 Counts): Logistic regression analyses demonstrate that for every one-point increment on the 10-point ASES composite score, the odds of achieving complete plasma HIV viral suppression ($< 50$ copies/mL) increase significantly ($OR = 1.35$ to $1.52, p < .01$). Conversely, low baseline Perseverance prospectively predicts viral rebound and regimen failure.
• Healthcare Utilization: Longitudinal tracking indicates that individuals with higher adherence self-efficacy exhibit significantly fewer emergency department presentations and avoidable hospital admissions, alongside improved routine clinic visit retention.

8. Reliability

The psychometric evaluation of the ASES reveals exceptional internal consistency and longitudinal stability across diverse clinical settings, socioeconomic strata, and demographic groups.

Internal Consistency Reliability

Across the development and validation cohorts ($N > 400$), the HIV-ASES demonstrated internal consistency values that exceed standard psychometric benchmarks for both research and clinical decision-making:

• Overall Composite Scale: Raykov’s rho ($rho$) and Cronbach’s alpha ($\alpha$) coefficients consistently exceed $.90$ (typically falling between $.91$ and $.94$).
• Adherence Integration Subscale: Internal consistency estimates consistently range from $\alpha = .86$ to $.91$.
• Adherence Perseverance Subscale: Internal consistency estimates consistently range from $\alpha = .88$ to $.93$.

Subsequent validation studies among diverse cohorts—including women of color, individuals with dual diagnoses (substance use and severe mental illness), and multinational cohorts across sub-Saharan Africa and Latin America—have mirrored these findings, reporting composite alpha coefficients consistently above $.88$.

Test-Retest Reliability and Stability

Longitudinal evaluation demonstrates that while self-efficacy is sensitive to targeted psychological interventions, it remains structurally stable in the absence of exogenous intervention:

• 3-Month Test-Retest Reliability: Among stable outpatients undergoing routine clinical observation without psychological intervention, 3-month test-retest correlation coefficients remained robust ($r > .70, p < .001$).
• 15-Month Stability: Extended prospective follow-up revealed stability coefficients exceeding $r = .40$ ($p < .001$), reflecting long-term cognitive continuity while capturing natural life course adjustments and regimen adaptations.

Standard error of measurement (SEM) calculations confirm minimal measurement error, ensuring that clinicians can confidently distinguish true psychological changes from random response variance.

9. Factor Analysis

The structural dimensionality of the Adherence Self-Efficacy Scale was delineated using sequential Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA) by Johnson and colleagues (2007).

Exploratory Factor Analysis (EFA)

Initial principal components and principal axis factoring with both orthogonal (Varimax) and oblique (Promax) rotations revealed a robust two-factor structure:

• Factor 1: Adherence Integration: Yielded an initial eigenvalue of 6.12, accounting for approximately 51.0% of the total item variance. The items loading primarily on this factor capture organizational, behavioral, and logistical integration of treatment protocols into daily life.
• Factor 2: Adherence Perseverance: Yielded an eigenvalue of 1.16, capturing an additional 10.0% of the item variance. The items loading primarily on this factor reflect self-regulatory confidence to maintain adherence in the presence of physical side effects, emotional distress, and interpersonal obstacles.
• Total Explained Variance: Together, these two primary factors account for 61.0% of the total variance across scale items.

Confirmatory Factor Analysis (CFA) Fit Indices

Subsequent CFA supported this structural model over alternative single-factor or multi-factor solutions. Representative model fit indices across independent validation cohorts consistently meet or exceed contemporary psychometric standards:

• Comparative Fit Index (CFI): Values consistently range from $.95$ to $.98$, exceeding the conventional $.95$ threshold for excellent model fit.
• Tucker-Lewis Index (TLI): Values range between $.94$ and $.97$.
• Root Mean Square Error of Approximation (RMSEA): Estimates range from $.048$ to $.062$ (with $90%$ confidence intervals bounded below $.08$), indicating close to acceptable approximation fit.
• Standardized Root Mean Square Residual (SRMR): Values remain below $.05$, confirming minimal residual correlation.

Standardized factor loadings across both latent factors remain uniformly high (predominantly between $.65$ and $.88$), with zero item cross-loadings exceeding $.30$. In oblique models, the two latent factors display a moderate-to-high inter-factor correlation ($r \approx .60$ to $.70$), confirming that while Integration and Perseverance represent distinct clinical targets, they operate as complementary facets of a unified adherence self-efficacy system.

10. Instrument / Measurement Tool

The Adherence Self-Efficacy Scale (ASES) is formatted as a patient-reported psychometric instrument designed for self-administration or interviewer-assisted administration across clinical and field environments.

• Construct Assessed: Perceived behavioral self-efficacy for comprehensive chronic disease treatment adherence.
• Administration Format: Paper-and-pencil questionnaire, digital patient portal (computerized/tablet administration), or trained interviewer-administered assessment.
• Target Population: Adolescents and adults managing chronic medical regimens, originally validated in individuals receiving antiretroviral therapy (ART) for HIV disease.
• Estimated Completion Time: Approximately 3 to 5 minutes.
• Number of Items: 12 core items (divided into Integration and Perseverance domains).
• Response Continuum: An 11-point visual analogue/Likert-type rating scale ranging from 0 (“Cannot do at all”) to 10 (“Completely certain can do”). Intermediate anchors typically highlight 5 (“Moderately certain can do”).
• Scoring Methodology:
  • Subscale Scores: Calculated by computing the mean of the items comprising each subscale (Adherence Integration Mean; Adherence Perseverance Mean). Subscale scores range from 0 to 10.
  • Overall Composite Score: Derived by calculating the arithmetic mean across all 12 items (sum of all item responses divided by 12). Overall scores range from 0 to 10.
  • Interpretation: Higher scores reflect greater perceived self-efficacy. Composite scores below 7.0 or 8.0 frequently serve as clinical screening indicators denoting heightened vulnerability to regimen disruption and non-adherence.

11. Permissions & Fee and Test Year

The Adherence Self-Efficacy Scale was formally published and validated in 2007 by Mallory O. Johnson and co-investigators. Developed under research grants funded by the National Institutes of Health (NIH)—specifically the National Institute of Mental Health (NIMH)—the instrument is generally made accessible for academic research, non-commercial clinical trials, and non-profit educational evaluation.

• Publication Year: 2007.
• Copyright Status: The original psychometric development article is published under standard academic copyright agreements (Springer Science+Business Media). However, the scale itself is widely disseminated by the authors for research and clinical use without commercial licensing fees.
• Permissions & Usage: Clinicians and academic investigators intending to utilize, translate, or digitize the ASES for non-commercial research protocols typically do not require paid licensing, provided appropriate formal citation of the seminal validation paper is maintained. For commercial licensing, large-scale commercial pharmaceutical trials, or systematic health system adaptations, direct contact with the corresponding author (Dr. Mallory O. Johnson, Center for AIDS Prevention Studies, University of California, San Francisco) or the UCSF Innovation Ventures office is recommended.

12. References

• Bandura, A. (1977). Self-efficacy: Toward a unifying theory of behavioral change. Psychological Review, 84(2), 191–215. https://doi.org/10.1037/0033-295X.84.2.191
• Bandura, A. (1997). Self-efficacy: The exercise of control. W. H. Freeman and Company.
• Chesney, M. A., Ickovics, J. R., Chambers, D. B., Gifford, A. L., Neidig, J., Zwickl, B., & Wu, A. W. (2000). Self-reported adherence to antiretroviral medications among participants in HIV clinical trials: The AACTG adherence instruments. AIDS Care, 12(3), 255–266. https://doi.org/10.1080/09540120050042917
• Fisher, J. D., Fisher, W. A., Amico, K. R., & Harman, J. J. (2006). An Information-Motivation-Behavioral Skills model of adherence to antiretroviral therapy. Health Psychology, 25(4), 462–473. https://doi.org/10.1037/0278-6133.25.4.462
• Johnson, M. O., Neilands, T. B., Dilworth, S. E., Morin, S. F., Remien, R. H., & Chesney, M. A. (2007). The role of self-efficacy in HIV treatment adherence: Validation of the HIV Treatment Adherence Self-Efficacy Scale (HIV-ASES). Journal of Behavioral Medicine, 30(5), 359–370. https://doi.org/10.1007/s10865-007-9118-3
• Remien, R. H., Bastos, F. I., Berkman, A., Terto, V. G., Raxach, J. C., Parker, R. G., & Chesney, M. A. (2003). Universal access to antiretroviral therapy: Challenges to delivery and adherence in developing countries. Journal of Acquired Immune Deficiency Syndromes, 32(Suppl 1), S1–S7.

13. Items of the Scale