10. Medication Adherence Flashcards
Adherence
The extent to which the patient’s behaviour (e.g. taking medication) corresponds with agreed-upon recommendations from a health care provider
A critical aspect of adherence is the patient’s involvement in deciding whether or not to take medications
Compliance
The extent to which the patient’s behaviour matches the healthcare provider’s recommendations
The patient does what he or she has been told to do by the doctor/pharmacist
Persistence
Length of time the patient stays on treatment
Obtaining refills to maintain adherence over time
Forms of non-adherence: Intentional/Unintentional
Intentional non-adherence: Deliberate & largely related to denial or uncertainty of diagnosis, lack of trust in HCP’s medication fears, poor health literacy, affordability & access to therapy
Unintentional non-adherence: Non-deliberate & largely driven by a lack of capacity or resources to take medicines
Forms of non-adherence: Primary/Secondary
Primary non-adherence: Failure to fill 1st prescription
Secondary non-adherence: Failure to take medicines appropriately
Why does adherence matter?
Failure to adhere to asthma/COPD medications may result in:
- Risk of exacerbations
- Increased hospitalisation rates
- Poor health outcomes
- Increased healthcare costs
- Loss & impaired productivity
- Reduced quality of life
- Patient death
How much adherence is enough?
For most chronic medical conditions, a patient is considered adherent if they take ≥ 80% of their prescribed medicine
However for some medications e.g. most HIV/AIDS patients require ≥95% adherence to achieve full & durable viral suppression
Measures of adherence - Direct
Biochemical measures:
- Measuring drug levels in blood, urine or other body fluids
- Limited drug tests are available
Directly observed therapy:
- Direct review of patient performance with aerosol device by a healthcare provider
Pros: Most accurate & objective methods
Cons: Intrusive, expensive, & difficult to perform
Measures of adherence - Indirect
- Asking providers/patients for their subjective estimates of adherence
- Counting remaining pills or weight a MDI at clinic/pharmacy
- Medical/pharmacy records e.g. rates of prescription refills
+ Medication possession rate (MPR) as a measure, which is the number of days of medication supplied divided by the number of days between the 1st & last refill
Pros: Simple, easy, less intrusive, & cheaper
Cons: Overestimate adherence
Measures of adherence - Electronic device monitors
- Indirect measure of adherence
- Record exact time, frequency & dosage
- Accurate & objective measure
- Expensive for routine use
Idea adherence measures
- Low cost
- User friendly
- Easy to carry
- Highly reliable
- Flexible & practical
No single method that can meet all the above criteria
None of the adherence measures have the ability to differentiate between intentional & unintentional adherence
Extent of non-adherence to asthma/COPD preventers
Primary non-adherence rate:
- ~20% non-refill for asthma controllers
Secondary non-adherence:
- ~Half of medications dispensed are not taken as directed
- Adherence rates for long-acting inhaled therapies decrease over time
- Compared with other chronic conditions, asthma & COPD treatment have markedly lower rates of adherence
+ Respiratory (overall) ~54%
+ Asthma only ~55%
+ COPD only ~54%
Factors contributing to non-adherence: Socioeconomic factors
- Poverty
- Unemployment
- Low level education
- Lack of social support
- Out of pocket expense
- Social inequities
- Cultural beliefs about illness & treatment
Factors contributing to non-adherence: Patient related factors
- Forgetfulness
- Not understanding medication instructions
- Misperceptions about illness & medicines
- Fear of possible side effects
- Fear of addiction or dependence
- Altered mental status
Factors contributing to non-adherence: Treatment factors
- Regimen complexity
- Long duration of therapy
- Adverse effects of treatment
- Frequent doses
