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What is medication adherence?
• degree to which patient’s medicine use coincides with prescription by health worker
• Has different dimensions, including doses missed, adequate timing of medication use, compliance to additional requirements like food-intake, non-alcohol use.
• Changes over time
Three approaches to adherence
• Descriptive: to measure non-compliance
• Analytical: define determinants of non-adherence (comparative approach)
• Intervention oriented -- defining problems in use of medications and seeking solutions
Beware: authoritative versus empathy approach
Different methods to measure adherence
• Self-report in patient interviews• Patient-kept diaries• Semi-structured interviews• Focus group discussions• Projective techniques, including visual analogue scales• Pill counts• Electronic monitoring• Prescription record reviews• Drug levels in biological fluids
Adherence methods
• Bad news: no gold standard
• Good news: many methods have acceptable sensitivity and specificity for our purpose
• Mix of methods can be used to increase validity
Self-report/diaries
PROS• Easy to use in resource
poor settings
• Inexpensive
• Can be used to identify high and low adherers
• Can be used to explore why non-adherence occurs and possible solutions
CONS• Time-intensive• Influenced by question
construction and interviewer skill
• Patient likely to report desirable behavior
• Over-estimates use
Semi-structured interviews
PROS
• Depth of understanding
• Unexpected issues can come up
• Less ‘authoritative’ style, more empathy possible
• Generates understanding of reasons for non-adherence and possible solutions
CONS• Time consuming• skilled interviewer
required• Analysis is demanding
Focus group discussions
PROs
• Inexpensive
• Participants encourage each other to talk
• Less authoritative
• Provides information on general patterns of use, reasons for non-use and possible solutions
CONS• Cannot be used to
measure individual adherence
• Does not quantify adherence levels
• Requires skilled moderator
• Analysis challenging
Projective techniques
PROS• Good to encourage
discussion• Visual analogues can
indicate adherence levels
• Inexpensive
CONS• Underdeveloped• Difficult to interpret
Pill counts
PROS• Easy to use• Inexpensive• Non-invasive
CONS• Does not reflect actual
ingestion of drugs• Participants have to
remember to bring the pill bottles
• Patients can dump pills to appear to be good adherers
• Patients may share pills• Does not measure actual
use patterns on a daily basis.
Medical/pharmacy records review
PROS• Rapid• Inexpensive• Large populations
possible• Non-invasive
CONS• Often records missing• No data on patients
who don’t come back for check-up or refill
• Need permission from facility
• Limited set of data collected routinely
Electronic monitoring
PROS• Can increase validity
of data• More resistant to
desirability effect• Provides details on
daily use
CONS• Does not confirm
ingestion• Expensive• Vulnerable to
mechanical problems• Does not provide data
on medicine sharing
Drugs levels in biological fluids
PROS• Objective measure• Recent use verified
• No details on timing of use
• Data limited to recent use
• Expensive• Difficult to manage –
fluids have to be collected/transported/aanalysed
Mix of methods
• Combine qualitative and quantitative
- Qualitative: measures dimensions and ways of and reasons for non-adherence, and can be used
to identify possible solutions
- Quantitative measure how often non-adherence occurs
• Tri-angulate• Phase methods• Validate by correlating with health outcomes
Measures of adherence
• Many different ones used in literature
• Definition often not explicit
• Need to be clear about which dimensions of adherence are being measured, which not
• Should relate to health outcomes
• Be appropriate to the situation
Kinds of adherence measures
• Numerical: 95% or 80% of prescribed in- 24 hours- 3 days- 1 week- 1 month
• Five point scale: always/mostly used in accordance with prescription
• Binary: Adherent – Not• Composite: adding up different dimensions of
adherence
Usually more than one measure
• Analyzed separately
• Analyzed together to increase validity of measure (includes more dimensions of validity, relates better to health outcomes)
• But, no analysis of divergences qualitatively– why do they occur?
Validity
• Relevant dimensions of adherence measured
• The measures make sense to respondents
• The measures predict relevant outcomes (viral load/CD4 counts/health outcomes)
Ways to increase validity….
Be non-adherer friendly:
Most people with HIV have many pills to take at different times during the day. Many people find it hard to always remember their pills...
What influences Adherence?
• Treatment related• Disease state• Patient ideas, practices• Social environment• Health facility• National policy Usually focus is on patient factors – blame the victim! Very few exploratory studies to define which factors
are relevant in specific situations
Treatment related
• Number of pills• Number of times per day• Dosage level • Adverse effects (of each pill)• Characteristics of drug (branded, colour,
administration form)• Additional requirements, such as food
intake, non-alcohol use
Disease related
• Health state at initiation of therapy
• Seriousness of disease over time
• Concurrent Depression/fatigue
• Concurrent opportunistic infections requiring additional medication (TB)
• Individual response to therapy (can vary)
Patient ideas
• Trust in health services• Changes in identity related to using ART• Ideas about HIV-causation• Ideas about disease progression• Ideas about efficacy of HIV medications• Ideas about risks of missed doses• Ideas about toxicity of medicines• Tolerance to side/effects• Lack of knowledge on HIV/Medicine use
Patient practices
• Disciplined life-style
• Disclosure of HIV/AIDS status
• Way medicines are used in every-day life, including at school/work/when traveling
• Forgetfulness, taking drugs and medical appointments
• Substance abuse
Patient background variables
• Socio-economic status
• Gender
• Age
• Religion
• Employment status
• Marital status
• Number and age of children
Social environment
• Level of community preparedness for treatment• Adherence support mechanisms, if any• Stigma/fear for HIV/AIDS• Discrimination of particular sub-groups of AIDS
patients (drug-users, prostitutes)• Gender-differentials in support to people on HAART• Levels of employer support• Levels of privacy• Communication channels on HIV/AIDS and treatment
Health facility structural
• Accessibility• Regularity of supply• Cost of medicines• Range of medicines available• Spatial dimensions, and cleanliness• Workload of staff• Diagnostic facilities• Guidelines• Records present
Health facility processes
• Quality of patient-provider interactions
• Treatment eligibility and choice
• Constellation of care provided
• Monitoring/response treatment outcome
• Adherence support and follow-up
• Respect for privacy and informed consent
• Over and under the counter payment
• Motivation and training of staff
Counseling: information
Info (oral/written) provided on-How ARVs work- How to use them- The need to continue treatment - What to do if a pill is forgotten- Which side effects can occur and what to do if they occur- (breast) feeding requirements- when and where to get re-supply
Info understood?
Counseling: interpersonal
• Client treated with respect, and in privacy?
• Clients feel listened to and do they get a chance to ask questions about the treatments and the effects on their bodies and their lives?
National level
• Political commitment to ART scale-up
• Implementation, kinds of ARVs distributed, supply chain, training, guidelines
• Specifics for adherence support program
• Monitoring and Evaluation
• Health policy maker views on adherence problems
Challenges
• Be cost-effective• Describe and understand adherence• Allow for comparison• Select appropriate adherence measure• Select appropriate mix of methods• Define feasible sampling strategy• Overcoming sensitivities• Avoid authoritative approach• Conduct good analysis• And identify solutions with stakeholders