Topic 8: adherence/non-adherence to treatment
What are two models that can help understand health behaviours?
1. Health Belief Model (Rosenstock) 1 of the most known health psych model to explain health behaviours. Similarly to SRM, includes perceptions of illness and perceived benefits or risks of illness-related action or behaviour BUT ALSO incorporates SOCIODEMOGRAPHIC VARIABLES AND PSYCHOLOGICAL CHARACTERISTICS which also influence HEALTH MOTIVATION as well as beliefs!! 2. Theory of Planned Behaviour (Azjen) Idea that beliefs and attitudes about illness or treatment, subjective and normative beliefs and norms, and perceived control --> all influence BEHAVIOURAL INTENTION --> which leads to behaviour... The way they're used to explain intention and behaviour is by looking at behaviour and then working backwards through model. Implies a causal effect between the components as arrow are one direction and also implies that intention always leads to behaviour...it doesn't...
What are some examples of non-adherent behaviour?
> overuse - not picking up prescription - missing doses - taking inconsistently and changing frequency/dose - changing time taken - non persistence
Outline notions of the HBM (health belief model) and TPB (theory of planned behaviour)?
According to HBM (rosenstock), action is likely when: - perceived threat is high - perceived benefit of behaviour outweighs barriers - cues are in place (illness, media influences - internal or external) According to TPB, action is likely when intention to behave is present and caused by: - people important to you support the behaviour - the behaviour is considered positive or beneficial - confidence/perceived ability to control bvr is high Limitation of both: assume a rational one-off decision that is not revisited. Too simple?
how are illness perceptions measured?
Based on the SRM and before proposing extended version, Weinman developed the IPQ - illness perception questionnaire which asked questions based on ICCCT However, following revisions made by HORNE & WEINMAN and MOSS-MORRIS, BROADBENT developed the BRIEF illness perception questionnaire which includes treatment beliefs as well as emotional representation and illness coherence Relevant to topic: would want to see whether beliefs about illness, and beliefs about treatment align...
What did the study conducted by Clifford et al. find when exploring beliefs in adherers, unintetional non-adhererers and intentional non-adherers?
CLIFFORD ET AL: They used the necessity concerns framework to see whether there were differences in necessity beliefs or concerns towards medications between people who are adherent, or not (intentionally and not) Cross-sectional survey Results: - Intentional non-adherers had lower perceptions of the necessity and higher levels of concern - Unintentional non-adherers and adherers did not differ significantly as unintentional non-adherents's beliefs in necessity were higher. However, more than the other two, intentional adherers were more likely to rate their CONCERNS as HIGHER relative to their NEEDS...perhaps a defence mechanism of justifying? Limitation: adherence rate was also measured through self-report over the phone!
Outline Clifford et al. telephone-based intervention:
Clifford et al. ran a pilot study on TELEPHONE BASED INTERVENTION: pharmacist giving advice over telephone 500 patients recruited and randomised to either intervention or care as usual Intervention: 10 days after new prescription, a nurse 'follows up' and gives patient a call 12 minute call --> • asking patients how there getting along with meds • what they think and then targeting and adjusting any incorrect beliefs that come up IDEA: not assuming adherence or non-adherence and not assuming beliefs but ASKING FINDINGS: - more positive beliefs about medicines - higher adherence - fewer patients reporting medication-related problems promising...
What did the cochrane review on interventions for enhancing medication adherence find?
Findings:evidence on interventions to increase adherence was mixed and inconsistent across studies - only a minority of good quality RCTs observed improved adherence and clinical outcomes - even most effective interventions did not lead to large improvements - current methods are mostly complex and not very effective
What interventions does Haynes recommend?
HAYNES ET AL. CONDUCTED ANOTHER SYSTEMATIC REVIEW: a wiiiiide range of interventions to promote adherence in patients were investigated in the studies found: A greater proportion of short-term treatments, showed an effect on both adherence and at least one clinical outcome but short term treatments were few. For long-term treatments, 36 of 81 interventions reported in 69 RCTs were associated with improvements in adherence --> less than half but only 26 interventions led to improvement in at least one treatment outcome. ISSUE: Almost all of the interventions that were effective for long-term care were complex, including combinations of more convenient care, information, reminders, self-monitoring, reinforcement, counseling, family therapy, psychological therapy, crisis intervention, manual telephone follow-up, and supportive care. The diversity, complexity, and uncertain effects of the interventions MAKE GENERALISATIONS ABOUT WHICH INTERVENTIONS WORK AND WHICH DO NOT PROBLEMATIC. Even the most effective interventions did not lead to large improvements in adherence and treatment outcomes. SO THE ISSUE IS MORE COMPLEX THAN WE THOUGHT
What are the two categories of non-adherence?
HORNE The PERCEPTION & PRACTICALITIES model argues that non-adherence is best understood as 2 separate categories: 1. intentional non-adherence 2. unintentional non-adherence Perception barriers vs practical barriers
What does NICE offer as an intervention package for patients non-adherent?
Have produced and published a MEDICINES ADHERENCE guide... overarching message: in promoting adherence, need to involve patients in decisions about prescrive medicines --> they say that non-adherence should not be seen as SOLELY PATIENT'S RESPONSIBILITY or problem...it is about the alliance between patient and doctor. Represents a flaw in the delivery of healthcare Doctor is responsible in initiating an AGREEMENT as well as IDENTIFY AND PROVIDE support if need be... Needs to be part of consultation... They provide guidelines for things to do if patients are non-adherence but idea is that they are selected APPROPRIATELY based on whether patient is intentionally or unintentionally non-adherent and patient's treatment or illness representations 1st step suggested --> involve patients in decisions: - improve communication - increase involvement - understand patient's perspective - provide information Would have consultation with patient and ask about/identify beliefs about illness and treatment...based on this might want to: - clarify use of medications - can discuss side effects - ask about expectations - address implications of not taking meds long term - NORMALISE BEHAVIOUR!! no judgment for honest conversation Also offers ways to assess adherence and can keep monitoring... Doctor should also review medicines to make sure they fit patients contexts!
What are the different terms that evolved into adherence to medication?
Horne et al. (2006) Concordance: more complex and less easy to define - related to the outcomes of prescribing consultations Persistance: time from starting treatment to complete stop Compliance: the extent to which the patient's behaviour matches the prescriber's advice (not agreed) --> evolved into --> Adherence: non-adherence occurs when adherence behaviours do not match the agreed recommendation of the prescriber so adherence is when they do! Adherence definition similar to COMPLIANCE but tries to acknowledge patient's right to decline treatment - takes blame of patient if non-adherent as the responsibility is not all on patient but a shared understanding. Though adherence and compliance are quite different in theory, they are still measured the same way.
What is the key issue driving adherence/non-adherence?
It is not a case of patients not being provided with enough information - this does not solve the problem, while it can be helpful for some. Similarly, providing reminders and being authoritative is not enough either to change adherence behaviours. AT LEAST, NOT ALONE. How well the treatment fits in with the individual patient's routine, expectations and preferences are predictors... CLAXTON ET AL.
What is the self-regulatory model?
Leventhal et al. developed a self-regulatory model, also known as the common sense model of illness perceptions Used to understand how people manage their chronic illnesses and explain management... ICCCT and eventually plus EC based on Moss-Morris extension (emotional representation, and illness coherence) According to the model: 1. people have beliefs about their illness and the revised/extended version also includes beliefs about their treatment prescribed 2. these beliefs influence behavioural management and coping of illness 3. behaviour may include: - help seeking - self-management - ADHERENCE TO TREATMENT Horne and Weinman revised the original model to include treatment beliefs and also more dynamic representation - illness beliefs and treatment beliefs can influence each other...
What negative consequences is non-adherence linked to?
Low adherence rates are linked with negative consequences, and are problematic in MOST chronic diseases... cancer, diabetes, heart disease, HIV, asthma etc. Also, found that adherence rates get worse over time. Relevant in the case of long term illnesses that require long term medication. Kramer looked at adherence to beta-blockers over the first year after myocardial infarction... 30 days after discharge, 69% of patients were adherence whereas after a year only 45% were adherent!
Outline Mann et al. study:
Mann et al. also investigated how perceptions around illness and treatment predict adherence.... 151 participants with type 2 diabetes Found that negative BELIEFS about ILLNESS CHRONICITY, lower TREATMENT NECESSITY and CONCERNS about medication predicted poor adherence... Also, patients with 'sceptical' beliefs about medication were more likely to be poorly adherent than people with AMBIVALENT (mixed) or INDIFFERENT beliefs People with high concerns and low necessity beliefs were more sceptical about the medication and less-adherent second strongest association with non-adherence is high concerns and also high necessity --> ambivalence high necessity and low concerns - best adherence
What is the COM-B model? Michie ET AL
Michie ET AL. A simplistic representation but very comprehensive as allows consideration of ALL factors that explain adherence behaviour... 1. PHYSICAL OR MENTAL CAPACITY 2. MOTIVATION - reflective (beliefs about illness and treatment) AND automatic (driven by emotions and habits) 3. Opportunity (physical and social) These are influence BEHAVIOUR...and also dynamic, CAPABILITY AND MOTIVATION will also influence MOTIVATION. e.g: might struggle to swallow pills (capability) which will cause frustration (emotion/lower automatic motivation) Critical: can't motivation also influence capability and opportunity? Also, doesn't tell us about sub-components of each category
What is non-adherence?
NICE have offered a definition of non-adherence: non-adeherence to medication occurs when a patient's medicine taking behaviour does not match the AGREED recommendations made by the prescriber --> good thing about this definition is that it implies a shared agreement between doctor and patient rather than power/authority of doctor However, treatment is not always medication...can fail to adhere to other forms of treatment
What stages of the patient journey is adherence/non-adherence relevant to?
Non-adherence can start at all different stages of the patient journey, including: - at the hospital - with the GP - at the pharmacy - at home
What factors make a person non-adherent?
Non-adherence is not linked to a specific TYPE of illness, it is seen across different types. Likewise, a 'non-adherent' person does not exist - there aren't any individual characteristics that predict or make someone susceptible: age, gender, intelligence, marital status, personality... none of these are associated with adherence... Most of us, actually, are non-adherent some time but the degree varies (Horne et al.)
outline Petrie et al's text message intervention:
PETRIE ET AL. --> a text message programme to modify illness and treatment beliefs Aim: to improve self-reported adherence to asthma preventer medication... Adherence to preventer medication is a problem for asthma patients DUE TO ILLNESS & MEDICATION BELIEFS... Participants randomised: Illness and medication beliefs assessed at baseline and after 18 weeks Intervention --> individually tailored text messages sent over 18 weeks based on illness and medication beliefs... Outcomes besides beliefs -> adherence rates self-reported through telephone calls at 6, 12 and 18 week...and then long term at 6 months! Findings: > AT 18 WEEKS, relative to control group INTERVENTION GROUP: - increased NECESSITY beliefs - increased belief about LONG-TERM/CHRONIC NATURE OF IT (timeline) - increased belief of control over asthma Also, adherence rates improved in intervention group over follow up period --> average increase of 10%. Even at 6 months, intervention group report higher adherence but this does not mean adherence was perfect. At 6 months --> just over 40% reported taking at least 80% of prescribed doses. Something else going on...not just beliefs? maybe motivation needs to be targeted beyond beliefs...Also, adherence is self-reported...
What are common beliefs about medicines?
Study by KCL suggests that people most of the time are unable to identify location of major organs! Even in renal patients themselves, just less than half were able to correctly locate kidneys! Ramstrum et al conducted a study to look at social representations of medicines and general beliefs people hold. Compared patients to pharmaceutical specialist! Asked questions based on: 1. general overuse: belief that doctors over prescribe medicines 2. General harm: belief that medicines are essentially harmful, addictive and poisoins 3. General benefit: belief that benefits outweigh risks Pharma and patients agreed on general benefits and necessity of medications... When it came to general harm, nearly half of patients were UNCERTAIN about whether natural or chemical medicines were better...while 91% of pharma strongly disagreed with natural being safer than chemical. Only a low percentage of patients disagreed with the statement "people who take medicines should stop for a while every now and then" this is quite striking...indicates issue about coherence? consequences of stopping treatment?
What is the strongest predictor of how people use medicines?
Their beliefs! Beliefs about medicine are the stronger predictor of how people use them... People engage in a risk-benefit analysis to decide whether to adhere: Weigh NECESSITY against CONCERN (side-effects) Higher the beliefs in necessity, higher the adherence and lower the concerns about medication, the lower the adherence. Examples of BELIEFS ABOUT NECESSITY: - my health depends on them - i would be very ill without them - protect me from getting worse - will prevent a flare CONCERNS include: - side effects - long-term effects - my medicines are a mystery to me - they don't work - dependence
How can adherence/non-adherence be measured objectively?
There are ways that adherence can be tracked and measured 'objectively' through - 'proportion of days covered' = proportion of days that a patient has enough pills for a given period of time. This info is collected from the pharmacy. e.g.: 3 months supply given to me - pill counts (can be manipulated?) - electronic medication monitors - blood samples These methods can be time consuming...
How common is non-adherence to medication? What is the scale of the problem?
This is an important issue because PRESCRIBING MEDICINE IS ONE OF THE MOST COMMON INTERVENTIONS IN NHS • Costs NHS over 8 billion on medication supplied by prescription If around 50% of medication isn't adhered to, wastes about 4 million a year! And the WHO published a report, reporting that 30-50% of medicines prescribed for LTCs are not taken AS DIRECTED! So there is a current cost to the healthcare system but also PATIENT --> adherence to medication is important for management and outcomes of chronic illnesses.
How can adherence/non-adherence be measured subjectively?
Through self-report questionnaires: 1. Morisky Scale - the first one developed included 4 questions...ask questions that are answered with simple yes or no...no equals 1 score for adherence. 2. A revised Morisky scale that includes questions related to MOTIVATION domain and then KNOWLEDGE domain... e.g. knowledge about prescription/when should stop etc. vs forgetfulness/carelessness to adhere 3. MEDICATION ADHERENCE REPORT SCALE (MARS). Not as simplistic as considered time/frequency of adherence/non-adherence behaviours - uses first person statements to engage and personalise - includes introductory paragraph that has instructions but also states that sometimes people find a way to use medication differently to what they were medically advised --> normalises behaviour which reduces risk of social desirability bias MARS scale developed by Horne & Weinman!
What are the different barriers to adherence leading to either unintentional or intentional non-adherence?
Unintentional non-adherence is more influenced by PRACTICAL BARRIERS - RESOURCE and FUNCTIONAL limitations: resource limitations include: - access to a pharmacy - finance (in some regions) functional limitations include: - limited comprehension of prescriptions - inability to read leaflet - memory problems Intentional non-adherence is more influenced by personal cognitive factors that are PERCEPTION BARRIERS: - motivation - illness beliefs: ICCCT - identity, cause, consequence, control/cure and timeline - treatment beliefs: about efficacy, necessity and concern People can start out as unintentionally non-adherent and then move to intentionally - might forget a few days and then see that you're ok so think don't need it Also, some people can fall in the middle - FORGETTING medication can be influenced by both practical barriers but also perception barriers. Someone might not be bothered to TRY to remember - memory correlated with motivation! Opposite is might believe they are unnecessary so won't be bothered to check instructions or go to a pharmacy...
Wald et al. conducted a RCT of another text-message intervention that looked at objective measures of adherence:
Wald et al. investigated effects of intervention on adherence to CARDIOVASCULAR PREVENTIVE TREATMENT... Intervention: reminder texts sent to patients > daily for 2 weeks > alternate days for 2 weeks > and weekly thereafter for 22 weeks! (6 months total) Patients were asked to report whether they had taken medication, whether the text reminded them, and if they didn't - why not. were asked at clinical whether they stopped taking medication and number of days medication was not taken in past 28 days Control group - highest rate of discontinuation...significantly more participants in the control group stopped completely and/or discontinued compared to intervention HOWEVER --> no differences found between cholesterol or blood measure levels between the two groups!! - experimenter expectations - social desirability bias Also perhaps selection bias involved as participants were already quite adherent - that's why looked at non-adherence not adherence
Outline Horne & Weinman's study on the role of illness perceptions and treatment beliefs in explaining non-adherence to preventer medication in asthma:
Wanted to see whether variations in treatment adherence were explained better by asthma perceptions of asthma preventer medication perceptions (necessity and concerns)... Also first time to investigate the additional to the SRM --> evidence whether treatment beliefs also influence illness management and responses... Cross-sectional design whereby participants completed questionnaires assessed illness beliefs, treatment beliefs AND reported adherence. Non-adherent behaviours --> associated with doubts about the NECESSITY of MEDICATION and CONCERNS about its potential adverse consequences...was also associated with more PERCEIVED ADVERSE CONSEQUENCES OF THE ILLNESS....avoidance? Conversely, sociodemographic and clinical factors only explained minor variance in adherence...illness perceptions and treatment perceptions were more substantial independent predictors. Also, analyses showed that illness perceptions influence adherence directly and indirectly through treatment expectations --> support for extended version of SRM