Medical Adherence: the extent to which patients take medications as prescribed by  health care providers.

• Up to 40% of the population fail to adhere to medical advice.
• 125,000 people die every year due to failure to comply.

Types and extent of non-adherence

Clarke (2013) noted there are four types of adherence, which were turned into non-adherence types:

1. Not following short-term advice
2. Failing to attend a follow-up interview // referral appointment
3. Refusing to make a life-style change.
4. Failing to take preventative health measures.

Rational non-adherence

Some patients do not adhere to medical advice after making a rational judgement, and find that there are more costs/risks than benefits of the treatment.

Lada, brien and Jan (2012) studied a community of sample patients in Australia and measured the importance of 8 medication factors through an online survey. The factors were put in order of the most important (1) to least important (8):

1. Immediate medication harm
2. Immediate medication benefit
3. Long-term medication harm
4. Long-term medication benefit
5. Cost of treatment
6. Regimen of treatment
7. Symptom severity
8. Alcohol restrictions

It was concluded that adherence was affected by the way the treatment was sold to patients. E.g. using words like ‘therapeutic benefits’ rather than ‘side effects’ would increase compliance.

BULPITT AND FLETCHER (1988) found out that when the costs of taking medication outweigh the benefits of treating the problem, mainly asymptomatic ones, patients are less likely to adhere.

It was discovered that the main side effects of medication for hypertension were:

• Sleepiness
• Laziness
• Impotence
• Weakened cognitive functioning.

For more detailed information – Bulpitt and Fletcher (1988)

Customizing Treatment 

Patients modify treatments to suit their individual needs and preferences.

JOHNSON AND BYTHEWAY (2000) carried out research and concluded that older people are more likely to buy over the counter medication without prescription.

4 categories of medication was found to be more frequent:

1. Prevention and maintenance – vitamins
2. Doctor’s alternatives for issues like headache/indigestion.
3. Replacements for prescriptions medicines – painkillers.
4. Medicine to counteract the side effects of prescribed medicines.

Subjective – Self-reports

RIEKART AND DROTER (1999) developed a technique used to ask questions related to how much patients are adhering to their treatment. It is good for detecting those, who admit to adherence difficulties, but will miss-classify abut 50% of patients, who deny problems or are unaware.

Strengths:

• High Validity – it is asking patients directly about their compliance.
• Way to gather data quickly and cheaply.
• Kaplan & Simon (1990)  – noted that if the questions are direct and simple to answer, this techniques can be used successfully to measure rates of adherence.

Weaknesses:

• Social desirability bias – patients may answer questions in a certain way to appear more socially desirable, which may alter the results and make them less reliable.
• Fixed choices on questions leave little space for explanation from the patient, which make it less valid.

Objective

CHUN AND NAYA (2000) developed a medication dispenser called Tracap, which recorded the date and time a pill left the the bottle. 59 patients took part in the study and were told what the device did but were not told that the research was being conducted. It was found that the adherence rate over 12 weeks was of 71%.

Strengths:

• Reliable – the method has been consistent over time and produces high rates of adherence.
• Good way of measuring without demand characteristics or social desirability affecting the results.

Weaknesses:

• Low validity – the researchers cannot be sure that the medicine was taken even if it left the bottle.
• Ethical problems – participants did not give full informed consent since they did not know they were being studied.

ROTH (1978) developed blood and urine tests to detect the levels of the drug that the patient should have consumed. It is considered one of the best measure for adherence and intake of drugs/substances.

Strengths:

• Reliable –  the method is scientific based, therefore it can replicated easily and the same results will be found. Also, demand characteristics or social desirability bias cannot affect the findings.
• Scientific – the results cannot be affected by the subjectivity of doctors as they provide quantitative data, which does not need to be analyzed. This makes the results more valid.

Weaknesses:

• Expensive – compared to other methods available, biochemical tests are quite costly because they involve elaborate scientific material.
• The tests do not show total adherence to a regime because it only suggests that enough drug has been ingested to be detectable. Therefore, there is no guarantee if the patient took the right dose and respected the regime.

SHERMAN ET AL (2000) developed repeat prescriptions for patients who are on longer-term treatment and have the option to ask for their medicines repeatedly without having to see a doctor and asking for a prescription. The belief is that patients have the motivation to pick up their medicines, then they must be adhering to the regime. However, care takers may pick up the drugs and these may not be consumed by the patient.