Medication adherence as a learning process: insights from cognitive psychology

Chemical adherence testing in the clinical management of hypertension: a scoping review

Background

Despite growing use, questions remain surrounding the utility, acceptability and feasibility of chemical adherence testing (CAT) as part of hypertension management in clinical practice.

Objectives

This scoping review aimed to (i) identify and summarise studies using CAT in hypertension management, and (ii) describe and critically evaluate how CAT is currently being used in the clinical management of hypertension.

Eligibility criteria

Peer-reviewed and published studies in English, reporting original research in any setting, with any study design, were included. Search concepts included hypertension, medication adherence, CAT, and their synonyms.

Sources of evidence

Searches were carried out using Ovid Medline, EMBASE, and PsycInfo (EBSCO), alongside manual searching of reference lists. Using Covidence software, we screened titles and abstracts, followed by full-text articles. Data from the included articles were tabulated and summarised.

Results

Of the 618 studies identified, 48 were included. The studies cover diverse clinical settings, and were mostly observational in design. 7 studies reporting adherence analyses within clinical trials for hypertension therapies. The use of theoretical frameworks to guide reporting was rare, and there was considerable variation in key terminology and definitions, most notably in the definition of adherence.

Conclusion

The current body of evidence demonstrates considerable variability in the approach to implementing CAT for hypertension management in clinical practice, and a paucity of randomised controlled trials to evaluate its impact. Future research could (i) adopt a cohesive theoretical framework including clear operational definitions to standardise the approach to this important topic; (ii) further explore the impact of CAT on clinical outcomes using RCTs.

Risk Factors for Unfavorable Glycemic Control Trajectory in Type-2 Diabetes Mellitus: A Community-based Longitudinal Study in Urbanslums of Central India

BACKGROUND

Diabetes mellitus (DM) is a chronic disease, which requires optimal glycemic control to prevent its ensuing vascular complications. Pathway to optimal glycemic control in T2DM has a complex socio-behavioral construct, especially in vulnerable populations, like slum dwellers, who have reduced health-care access and lower prioritization of health needs.

OBJECTIVE

The study aimed to map trajectories of glycemic control amongst individuals with T2DM living in urban slums and identify key determinants associated with unfavourable glycaemic trajectory.

METHODS

This study was a community-based longitudinal study conducted in an urban slum of Bhopal in Central India. Adult patients diagnosed with T2DM and on treatment for more than one year were included. All 326 eligible participants underwent a baseline interview, which captured sociodemographic, personal behavior, medication adherence, morbidity profile, treatment modality, anthropometric and biochemical measurements (HbA1c). Another 6-month follow-up interview was conducted to record anthropometric measurements, HbA1c and treatment modality. Four mixed effect logistic regression models (through theory-driven variable selections) were created with glycemic status as dependent variable and usage of insulin was considered as random effect.

RESULTS

A total of 231 (70.9%) individuals had unfavorable glycemic control trajectory (UGCT), and only 95 (29.1%) had a favorable trajectory. Individuals with UGCT were more likely to be women, with lower educational status, non-vegetarian food preference, consumed tobacco, had poor drug adherence, and were on insulin. The most parsimonious model identified female gender (2.44,1.33-4.37), tobacco use (3.80,1.92 to 7.54), and non-vegetarian food preference (2.29,1.27 to 4.13) to be associated with UGCT. Individuals with good medication adherence (0.35,0.13 to 0.95) and higher education status (0.37,0.16 to 0.86) were found to be protective in nature.

CONCLUSION

Unfavorable glycemic control trajectory seems to be an inescapable consequence in vulnerable settings. The identified predictors through this longitudinal study may offer a cue for recognizing a rational response at societal level and adopting strategy formulation thereof.

Optimization of an Information Leaflet to Influence Medication Beliefs in Women With Breast Cancer: A Randomized Factorial Experiment

BACKGROUND

Adherence to adjuvant endocrine therapy (AET) is low in women with breast cancer. Negative beliefs about the necessity of AET and high concerns are barriers to adherence.

PURPOSE

To use the multiphase optimization strategy to optimize the content of an information leaflet intervention, to change AET beliefs.

METHODS

We conducted an online screening experiment using a 25 factorial design to optimize the leaflet. The leaflet had five components, each with two levels: (i) diagrams about AET mechanisms (on/off); (ii) infographics displaying AET benefits (enhanced/basic); (iii) AET side effects (enhanced/basic); (iv) answers to AET concerns (on/off); (v) breast cancer survivor (patient) input: quotes and photographs (on/off). Healthy adult women (n = 1,604), recruited via a market research company, were randomized to 1 of 32 experimental conditions, which determined the levels of components received. Participants completed the Beliefs about Medicines Questionnaire before and after viewing the leaflet.

RESULTS

There was a significant main effect of patient input on beliefs about medication (β = 0.063, p < .001). There was one significant synergistic two-way interaction between diagrams and benefits (β = 0.047, p = .006), and one antagonistic two-way interaction between diagrams and side effects (β = -0.029, p = .093). There was a synergistic three-way interaction between diagrams, concerns, and patient input (β = 0.029, p = .085), and an antagonistic four-way interaction between diagrams, benefits, side effects, and concerns (β = -0.038, p = .024). In a stepped approach, we screened in four components and screened out the side effects component.

CONCLUSIONS

The optimized leaflet did not contain enhanced AET side effect information. Factorial experiments are efficient and effective for refining the content of information leaflet interventions.

Predicting adherence to postdischarge malaria chemoprevention in Malawian pre-school children: A prognostic multivariable analysis

Chemoprevention with antimalarials is a key strategy for malaria control in sub-Saharan Africa. Three months of postdischarge malaria chemoprevention (PDMC) reduces malaria-related mortality and morbidity in pre-school children recently discharged from hospital following recovery from severe anemia. Research on adherence to preventive antimalarials in children is scarce. We aimed to investigate the predictors for caregivers' adherence to three courses of monthly PDMC in Malawi. We used data from a cluster randomized implementation trial of PDMC in Malawi (n = 357). Modified Poisson regression for clustered data was used to obtain relative risks of predictors for full adherence to PDMC. We did not find a conclusive set of predictors for PDMC adherence. The distribution of households across a socio-economic index and caregivers' education showed mixed associations with poor adherence. Caregivers of children with four or more malaria infections in the past year were associated with reduced adherence. With these results, we cannot confirm the associations established in the literature for caregiver adherence to artemisinin-based combination therapies (ACTs). PDMC combines multiple factors that complicate adherence. Our results may indicate that prevention interventions introduce a distinct complexity to ACT adherence behavior. Until we better understand this relationship, PDMC programs should ensure high program fidelity to sustain adherence by caregivers during implementation.

Supporting adjuvant endocrine therapy adherence in women with breast cancer: the development of a complex behavioural intervention using Intervention Mapping guided by the Multiphase Optimisation Strategy

BACKGROUND

Adjuvant endocrine therapy (AET) reduces the risk of breast cancer recurrence and mortality. However, up to three-quarters of women with breast cancer do not take AET as prescribed. Existing interventions to support adherence to AET have largely been unsuccessful, and have not focused on the most salient barriers to adherence. This paper describes the process of developing four theory-based intervention components to support adherence to AET. Our aim is to provide an exemplar of intervention development using Intervention Mapping (IM) with guidance from the Multiphase Optimisation Strategy (MOST).

METHODS

Iterative development followed the six-stage IM framework with stakeholder involvement. Stage 1 involved a literature review of barriers to adherence and existing interventions, which informed the intervention objectives outlined in Stage 2. Stage 3 identified relevant theoretical considerations and practical strategies for supporting adherence. Stage 4 used information from Stages 1-3 to develop the intervention components. Stages 1-4 informed a conceptual model for the intervention package. Stages 5 and 6 detailed implementation considerations and evaluation plans for the intervention package, respectively.

RESULTS

The final intervention package comprised four individual intervention components: Short Message Service to encourage habitual behaviours surrounding medication taking; an information leaflet to target unhelpful beliefs about AET; remotely delivered Acceptance and Commitment Therapy-based guided self-help to reduce psychological distress; and a website to support self-management of AET side-effects. Considerations for implementation within the NHS, including cost, timing and mode of delivery were outlined, with explanation as to how using MOST can aid this. We detail our plans for the final stage of IM which involve feasibility testing. This involved planning an external exploratory pilot trial using a 24-1 fractional factorial design, and a process evaluation to assess acceptability and fidelity of intervention components.

CONCLUSIONS

We have described a systematic and logical approach for developing a theoretically informed intervention package to support medication adherence in women with breast cancer using AET. Further research to optimise the intervention package, guided by MOST, has the potential to lead to more effective, efficient and scalable interventions.

Using nasal sprays to prevent respiratory tract infections: a qualitative study of online consumer reviews and primary care patient interviews

OBJECTIVES

Nasal sprays could be a promising approach to preventing respiratory tract infections (RTIs). This study explored lay people's perceptions and experiences of using nasal sprays to prevent RTIs to identify barriers and facilitators to their adoption and continued use.

DESIGN

Qualitative research. Study 1 thematically analysed online consumer reviews of an RTI prevention nasal spray. Study 2 interviewed patients about their reactions to and experiences of a digital intervention that promotes and supports nasal spray use for RTI prevention (reactively: at 'first signs' of infection and preventatively: following possible/probable exposure to infection). Interview transcripts were analysed using thematic analysis.

SETTING

Primary care, UK.

PARTICIPANTS

407 online customer reviews. 13 purposively recruited primary care patients who had experienced recurrent infections and/or had risk factors for severe infections.

RESULTS

Both studies identified various factors that might influence nasal spray use including: high motivation to avoid RTIs, particularly during the COVID-19 pandemic; fatalistic views about RTIs; beliefs about alternative prevention methods; the importance of personal recommendation; perceived complexity and familiarity of nasal sprays; personal experiences of spray success or failure; tolerable and off-putting side effects; concerns about medicines; and the nose as unpleasant and unhygienic.

CONCLUSIONS

People who suffer disruptive, frequent or severe RTIs or who are vulnerable to RTIs are interested in using a nasal spray for prevention. They also have doubts and concerns and may encounter problems. Some of these may be reduced or eliminated by providing nasal spray users with information and advice that addresses these concerns or helps people overcome difficulties.

Young adult preferences for digital health interventions to support adherence to inhaled corticosteroids in asthma: a qualitative study

Objective: Adherence to inhaled corticosteroids (ICS) among young adults living with asthma is low and in need of appropriate intervention. Digital health interventions (DHIs) have demonstrated potential to improve ICS adherence; however, young adult preferences for these DHIs and how their use could support adherence in this population remain understudied. Therefore, this study aimed to explore young adult preferences for ICS adherence supports and potential DHI features to deliver these supports, in order to improve adherence behaviour throughout this critical developmental stage of the lifespan.

Methods: Qualitative, semi-structured interviews were conducted with 13 young adults living with asthma. Analysis followed an inductive, reflexive thematic approach.

Results: Participant’s age ranged from 18 to 30 years (M = 24.7; 8 female). Three themes were developed from the analysis: ‘Enabling young adults to find their ‘own way of knowing', ‘Support for making a habit of adherence’, and ‘Providing accessible information’ which included the sub-themes: ‘Education on asthma self-management and medication’, ‘Self-monitoring information’ and ‘Personal feedback on outcomes of adherence’. Suggested features to deliver these supports included a medication and prescription refill reminder, adherence charts, symptom and trigger monitoring, rewards for adherence, visual representations of lungs demonstrating the impact of adherence and lung function monitoring.

Conclusion: DHIs may offer an appropriate solution to improve suboptimal adherence to ICS in young adults. However, it is crucial that young adult preferences for adherence supports and features are integrated into these interventions in order to optimise engagement and support adherence behaviour in this population.

An Adaptable Framework for Factors Contributing to Medication Adherence: Results from a Systematic Review of 102 Conceptual Frameworks

OBJECTIVE

To summarize the available conceptual models for factors contributing to medication adherence based on the World Health Organization (WHO)'s five dimensions of medication adherence via a systematic review, identify the patient groups described in available conceptual models, and present an adaptable conceptual model that describes the factors contributing to medication adherence in the identified patient groups.

METHODS

We searched PubMed®, Embase®, CINAHL®, and PsycINFO® for English language articles published from inception until 31 March 2020. Full-text original publications in English that presented theoretical or conceptual models for factors contributing to medication adherence were included. Studies that presented statistical models were excluded. Two authors independently extracted the data.

RESULTS

We identified 102 conceptual models, and classified the factors contributing to medication adherence using the WHO's five dimensions of medication adherence, namely patient-related, medication-related, condition-related, healthcare system/healthcare provider-related, and socioeconomic factors. Eight patient groups were identified based on age and disease condition. The most universally addressed factors were patient-related factors. Medication-related, condition-related, healthcare system-related, and socioeconomic factors were represented to various extents depending on the patient group. By systematically examining how the WHO's five dimensions of medication adherence were applied differently across the eight different patient groups, we present a conceptual model that can be adapted to summarize the common factors contributing to medication adherence in different patient groups.

CONCLUSION

Our conceptual models can be utilized as a guide for clinicians and researchers in identifying the facilitators and barriers to medication adherence and developing future interventions to improve medication adherence.

PROTOCOL REGISTRATION

PROSPERO Identifier: CRD42020181316.

The placebo effect: To explore or to exploit?

How people choose between options with differing outcomes (explore-exploit) is a central question to understanding human behaviour. However, the standard explore-exploit paradigm relies on gamified tasks with low-stake outcomes. Consequently, little is known about decision making for biologically-relevant stimuli. Here, we combined placebo and explore-exploit paradigms to examine detection and selection of the most effective treatment in a pain model. During conditioning, where 'optimal' and 'suboptimal' sham-treatments were paired with a reduction in electrical pain stimulation, participants learnt which treatment most successfully reduced pain. Modelling participant responses revealed three important findings. First, participants' choices reflected both directed and random exploration. Second, expectancy modulated pain - indicative of recursive placebo effects. Third, individual differences in terms of expectancy during conditioning predicted placebo effects during a subsequent test phase. These findings reveal directed and random exploration when the outcome is biologically-relevant. Moreover, this research shows how placebo and explore-exploit literatures can be unified.

When Success Is Not Enough: The Symptom Base-Rate Can Influence Judgments of Effectiveness of a Successful Treatment

Patients’ beliefs about the effectiveness of their treatments are key to the success of any intervention. However, since these beliefs are usually formed by sequentially accumulating evidence in the form of the covariation between the treatment use and the symptoms, it is not always easy to detect when a treatment is actually working. In Experiments 1 and 2, we presented participants with a contingency learning task in which a fictitious treatment was actually effective to reduce the symptoms of fictitious patients. However, the base-rate of the symptoms was manipulated so that, for half of participants, the symptoms were very frequent before the treatment, whereas for the rest of participants, the symptoms were less frequently observed. Although the treatment was equally effective in all cases according to the objective contingency between the treatment and healings, the participants’ beliefs on the effectiveness of the treatment were influenced by the base-rate of the symptoms, so that those who observed frequent symptoms before the treatment tended to produce lower judgments of effectiveness. Experiment 3 showed that participants were probably basing their judgments on an estimate of effectiveness relative to the symptom base-rate, rather than on contingency in absolute terms. Data, materials, and R scripts to reproduce the figures are publicly available at the Open Science Framework: https://osf.io/emzbj/.

Biased Sampling and Causal Estimation of Health-Related Information: Laboratory-Based Experimental Research

Background

The internet is a relevant source of health-related information. The huge amount of information available on the internet forces users to engage in an active process of information selection. Previous research conducted in the field of experimental psychology showed that information selection itself may promote the development of erroneous beliefs, even if the information collected does not.

Objective

The aim of this study was to assess the relationship between information searching strategy (ie, which cues are used to guide information retrieval) and causal inferences about health while controlling for the effect of additional information features.

Methods

We adapted a standard laboratory task that has previously been used in research on contingency learning to mimic an information searching situation. Participants (N=193) were asked to gather information to determine whether a fictitious drug caused an allergic reaction. They collected individual pieces of evidence in order to support or reject the causal relationship between the two events by inspecting individual cases in which the drug was or was not used or in which the allergic reaction appeared or not. Thus, one group (cause group, n=105) was allowed to sample information based on the potential cause, whereas a second group (effect group, n=88) was allowed to sample information based on the effect. Although participants could select which medical records they wanted to check—cases in which the medicine was used or not (in the cause group) or cases in which the effect appeared or not (in the effect group)—they all received similar evidence that indicated the absence of a causal link between the drug and the reaction. After observing 40 cases, they estimated the drug–allergic reaction causal relationship.

Results

Participants used different strategies for collecting information. In some cases, participants displayed a biased sampling strategy compatible with positive testing, that is, they required a high proportion of evidence in which the drug was administered (in the cause group) or in which the allergic reaction appeared (in the effect group). Biased strategies produced an overrepresentation of certain pieces of evidence at the detriment of the representation of others, which was associated with the accuracy of causal inferences. Thus, how the information was collected (sampling strategy) demonstrated a significant effect on causal inferences (F_1,185=32.53, P<.001, η^2p=0.15) suggesting that inferences of the causal relationship between events are related to how the information is gathered.

Conclusions

Mistaken beliefs about health may arise from accurate pieces of information partially because of the way in which information is collected. Patient or person autonomy in gathering health information through the internet, for instance, may contribute to the development of false beliefs from accurate pieces of information because search strategies can be biased.

Diseases that resolve spontaneously can increase the belief that ineffective treatments work

RATIONALE

Self-limited diseases resolve spontaneously without treatment or intervention. From the patient's viewpoint, this means experiencing an improvement of the symptoms with increasing probability over time. Previous studies suggest that the observation of this pattern could foster illusory beliefs of effectiveness, even if the treatment is completely ineffective. Therefore, self-limited diseases could provide an opportunity for pseudotherapies to appear as if they were effective.

OBJECTIVE

In three computer-based experiments, we investigate how the beliefs of effectiveness of a pseudotherapy form and change when the disease disappears gradually regardless of the intervention.

METHODS

Participants played the role of patients suffering from a fictitious disease, who were being treated with a fictitious medicine. The medicine was completely ineffective, because symptom occurrence was uncorrelated to medicine intake. However, in one of the groups the trials were arranged so that symptoms were less likely to appear at the end of the session, mimicking the experience of a self-limited disease. Except for this difference, both groups received similar information concerning treatment effectiveness.

RESULTS

In Experiments 1 and 2, when the disease disappeared progressively during the session, the completely ineffective medicine was judged as more effective than when the same information was presented in a random fashion. Experiment 3 extended this finding to a new situation in which symptom improvement was also observed before the treatment started.

CONCLUSIONS

We conclude that self-limited diseases can produce strong overestimations of effectiveness for treatments that actually produce no effect. This has practical implications for preventative and primary health services. The data and materials that support these experiments are freely available at the Open Science Framework (https://osf.io/xt3z9/). https://bit.ly/2FMPrMi.

Knowledge of Potential Harms and Benefits of Tamoxifen among Women Considering Breast Cancer Preventive Therapy

Tamoxifen reduces breast cancer incidence in women at increased risk, but may cause side effects. We examined women's knowledge of tamoxifen's potential harms and benefits, and the extent to which knowledge reflects subjective judgments of awareness and decision quality. After a hospital appointment, 408 (55.7%) women at increased risk of breast cancer completed a survey assessing objective knowledge about the potential benefit (risk reduction) and harms (endometrial cancer, thromboembolic events, and menopausal side effects) of tamoxifen, and subjective tamoxifen knowledge and decisional quality. Two hundred fifty-eight (63.2%) completed a 3-month follow-up survey. Sixteen percent (15.7%) of participants recognized the potential benefit and three major harms of using tamoxifen. These women were more likely to have degree-level education [vs. below degree level; OR, 2.24; 95% confidence interval (CI), 1.11-4.55] and good numeracy (vs. poor numeracy; OR, 5.91; 95% CI, 1.33-26.19). Tamoxifen uptake was higher in women who recognized all harms and benefits (vs. not recognizing; OR, 2.47; 95% CI, 0.94-6.54). Sixty-six percent (65.8%) of tamoxifen users were unaware of its potential benefit and harms. Most (87.1%) women reported feeling informed about tamoxifen, and subjective decisional quality was high [Mean (SD), 17.03 (1.87), out of 18]. Knowledge regarding the potential harms and benefit of tamoxifen is low in women considering prevention therapy, and they may need additional support to make informed decisions about tamoxifen preventive therapy.

Expectancy and Utilisation of Reflexology among Women with Advanced Breast Cancer

OBJECTIVE

Little is understood about patient expectations and use of complementary therapies (CT) during cancer treatment. A secondary analysis of an 11-week reflexology trial among women with breast cancer was conducted. We examined factors that predicted women's expectations about reflexology for symptom relief, factors that predicted utilisation of reflexology, and whether by the end of the trial they believed that reflexology had helped with symptom management.

METHODS

Women (N = 256) were interviewed at baseline and week 11. Friend or family caregivers in the reflexology group were trained to deliver standardised sessions to patients at least once a week for 4 weeks. Baseline and week-11 reflexology expectations were analysed using general linear models. Reflexology utilisation was analysed with generalised linear mixed effects models.

RESULTS

Patients who expected benefits from reflexology ("higher expectancy") at baseline were younger, had lower anxiety, higher education, higher spirituality, and greater CT use. Worsening symptoms over time were associated with greater utilisation of reflexology, but only when baseline expectancy was low. At week 11, expectancy was higher for those with greater symptom improvement.

CONCLUSIONS

Assessing patterns of patient factors, expectancy, and change in symptoms can help determine who is likely to use reflexology, and when.

Long-Term Effects of Psychological Interventions to Improve Adherence to Antiretroviral Treatment in HIV-Infected Persons: A Systematic Review and Meta-Analysis

We examined the efficacy of psychological adherence-enhancing interventions (AEIs) compared with usual care in HIV-infected adults under antiretroviral treatment (ART) by focusing on adherence and clinical HIV markers as outcomes in the short term and long term. We searched relevant databases for controlled studies that compared psychological AEIs with usual care. We included 31 comparisons from 27 individual studies in our meta-analyses. Psychological AEIs were significantly superior to usual care in improving adherence [standardized mean difference (SMD) 0.30, 95% CI 0.20-0.40] and reducing HIV viral load (SMD 0.15, 0.07-0.23) at the end of treatment. At the last follow-up, we found no difference between psychological AEIs and usual care, neither on adherence (SMD 0.07, -0.11-0.24) nor on clinical markers (SMD 0.06, -0.03-0.15). After excluding outliers from the analyses, between-study heterogeneity was small, and we did not identify any relevant moderators of intervention effects. In summary, psychological AEIs may significantly improve ART adherence and HIV viral load compared with usual care in the short term, but fail to be superior in achieving long-lasting improvements on ART adherence and clinical HIV markers as compared with usual care. Owing to limited quality and the majority of studies being conducted in the United States or Europe, our results have to be interpreted with caution, and are most relevant to the United States and Europe. The consistently reported difficulties to achieve sustained ART adherence improvements in previous and the present meta-analyses highlight the need to focus on maintaining ART adherence improvements in future research.

Bridging the divide between causal illusions in the laboratory and the real world: the effects of outcome density with a variable continuous outcome

Illusory causation refers to a consistent error in human learning in which the learner develops a false belief that two unrelated events are causally associated. Laboratory studies usually demonstrate illusory causation by presenting two events-a cue (e.g., drug treatment) and a discrete outcome (e.g., patient has recovered from illness)-probabilistically across many trials such that the presence of the cue does not alter the probability of the outcome. Illusory causation in these studies is further augmented when the base rate of the outcome is high, a characteristic known as the outcome density effect. Illusory causation and the outcome density effect provide laboratory models of false beliefs that emerge in everyday life. However, unlike laboratory research, the real-world beliefs to which illusory causation is most applicable (e.g., ineffective health therapies) often involve consequences that are not readily classified in a discrete or binary manner. This study used a causal learning task framed as a medical trial to investigate whether similar outcome density effects emerged when using continuous outcomes. Across two experiments, participants observed outcomes that were either likely to be relatively low (low outcome density) or likely to be relatively high (high outcome density) along a numerical scale from 0 (no health improvement) to 100 (full recovery). In Experiment 1, a bimodal distribution of outcome magnitudes, incorporating variance around a high and low modal value, produced illusory causation and outcome density effects equivalent to a condition with two fixed outcome values. In Experiment 2, the outcome density effect was evident when using unimodal skewed distributions of outcomes that contained more ambiguous values around the midpoint of the scale. Together, these findings provide empirical support for the relevance of the outcome density bias to real-world situations in which outcomes are not binary but occur to differing degrees. This has implications for the way in which we apply our understanding of causal illusions in the laboratory to the development of false beliefs in everyday life.

Intentional and Unintentional Medication Non-Adherence in Psoriasis: The Role of Patients' Medication Beliefs and Habit Strength

Medication non-adherence is a missed opportunity for therapeutic benefit. We assessed “real-world” levels of self-reported non-adherence to conventional and biologic systemic therapies used for psoriasis and evaluated psychological and biomedical factors associated with non-adherence using multivariable analyses. Latent profile analysis was used to investigate whether patients can be categorized into groups with similar medication beliefs. Latent profile analysis categorizes individuals with similar profiles on a set of continuous variables into discrete groups represented by a categorical latent variable. Eight hundred and eleven patients enrolled in the British Association of Dermatologists Biologic Interventions Register were included. Six hundred and seventeen patients were using a self-administered systemic therapy; 22.4% were classified as “non-adherent” (12% intentionally and 10.9% unintentionally). Patients using an oral conventional systemic agent were more likely to be non-adherent compared to those using etanercept or adalimumab (29.2% vs. 16.4%; P ≤ 0.001). Latent profile analysis supported a three-group model; all groups held strong beliefs about their need for systemic therapy but differed in levels of medication concerns. Group 1 (26.4% of the sample) reported the strongest concerns, followed by Group 2 (61%), with Group 3 (12.6%) reporting the weakest concerns. Group 1 membership was associated with intentional non-adherence (odds ratio = 2.27, 95% confidence interval = 1.16−4.47) and weaker medication-taking routine or habit strength was associated with unintentional non-adherence (odds ratio = 0.92, 95% confidence interval = 0.89−0.96). Medication beliefs and habit strength are modifiable targets for strategies to improve adherence in psoriasis.