Psychology (9990) | Adherence to medical advice

🧠 Health Psychology: Adherence to Medical Advice (Syllabus 3.2)

Hello future Psychologists! This chapter is incredibly practical. You’ll learn why people often struggle to follow doctor's orders—whether it’s taking medication, changing their diet, or attending check-ups—and what health professionals can do about it. Understanding adherence (or lack thereof) is vital because treatments only work if people use them correctly!

Don't worry if this seems like common sense at first. Psychology gives us frameworks (models and theories) to explain these behaviors scientifically, which is essential for your exams.

3.2.1 Types of Non-Adherence and Reasons Why Patients Do Not Adhere

What is Non-Adherence?

Adherence is the extent to which a patient follows the recommendations of a health provider (e.g., taking medicine, lifestyle changes, attending follow-up appointments).

Non-adherence (or non-compliance) is the failure to follow these recommendations. This is a massive global issue, often leading to worse health outcomes and wasted resources.

There are two main types of non-adherence:

• Failure to follow treatments: This includes not taking medication as prescribed (e.g., stopping early, taking the wrong dose), or not following lifestyle advice (e.g., quitting smoking).
• Failure to attend appointments: Missing check-ups, follow-up consultations, or therapy sessions.

Explanations of Non-Adherence

Psychologists distinguish between two key reasons for non-adherence:

1. Unintentional Non-Adherence: This is when the patient *wants* to adhere but fails due to external factors (e.g., forgetting, complex schedule, medication confusion).
2. Intentional Non-Adherence: This is when the patient *chooses* not to adhere. This leads us to Rational Non-Adherence.

Rational Non-Adherence

This explanation suggests that patients make a conscious, logical decision to ignore or alter medical advice based on their own assessment of the costs versus the benefits of the treatment.

Think of it like this: A patient might stop taking a blood pressure tablet because they feel fine and the pill causes unpleasant side effects (like dizziness). Rationally, they decide the cost (side effect) outweighs the immediate perceived benefit (since they feel healthy anyway).

Reasons for rational non-adherence include:

• Believing the medication is not working.
• Experiencing negative side effects.
• Financial concerns (medication is expensive).
• Fears about dependency or long-term risks.

Key Study: Laba et al. (2012) – Rational Non-Adherence and Financial Barriers

Context: This study looked at adherence to lifestyle advice (like diet and exercise) for managing Cardiovascular Disease (CVD) in a low-income population.

Finding: Laba et al. found that adherence to lifestyle changes often depended on financial barriers. If the doctor recommends expensive healthy foods or gym memberships, a patient in poverty is rationally choosing non-adherence because the cost is too high.

Key Takeaway: Non-adherence isn't always stubbornness; it is often an economic or practical choice based on the individual's circumstances.

The Health Belief Model (HBM)

The HBM is a psychological model used to explain and predict health behaviors, including adherence. It assumes that a person's decision to act (or adhere) is based on several core "beliefs" or perceptions about their health condition and the proposed treatment.

To adhere, an individual must have high scores on all these components:

1. Perceived Susceptibility: How likely the person believes they are to get the illness or condition.
   (e.g., "I smoke, but lung cancer only happens to heavy smokers, not me.")
2. Perceived Severity: How serious the consequences of the illness are believed to be.
   (e.g., "A cold is unpleasant, but it’s not serious enough to warrant medication.")
3. Perceived Benefits: The positive outcomes expected from following the advice.
   (e.g., "If I take my antibiotics, I will get better faster.")
4. Perceived Barriers: The perceived obstacles or negative aspects of the treatment (these drive non-adherence). This includes cost, pain, side effects, and inconvenience.
   (e.g., "The pill makes me nauseous, so I'm stopping.")

The model also includes two modifying factors:

• Cues to Action: Internal (like pain) or external (like a poster campaign or a doctor's firm warning) triggers that motivate behavior.
• Self-Efficacy: The belief that one can successfully execute the behavior required to produce the outcomes. (This was added later to the original HBM).
  (e.g., "I know I can stick to this new diet plan.")

3.2.2 Measuring Non-Adherence

How do psychologists and doctors know if a patient is actually following their advice? They use several methods, categorized as subjective, objective, or biological.

1. Subjective Measures

These methods rely on the patient's own reporting. They are generally inexpensive but suffer from issues like social desirability bias (where patients lie to look good).

• Clinical Interviews: A practitioner asks the patient directly about their adherence.
• Semi-structured Interviews: These use a mix of fixed questions but allow the interviewer to follow up and explore detailed responses, yielding richer (qualitative) data.
• Self-Reports/Questionnaires: Patients fill out forms about their behavior.

Study: Riekert and Drotar (1999) – Subjective Measurement in Children

Procedure: Riekert and Drotar reviewed the use of self-reports and interviews to measure adherence in children and adolescents with chronic illnesses, such as Type 1 Diabetes. They focused on how to improve the validity of self-reports.

Finding: They confirmed that interviews and self-reports often overestimate adherence, but they are useful for gathering qualitative data on barriers (like family conflict or feeling embarrassed about the illness) which objective measures miss.

2. Objective Measures

These methods attempt to measure adherence directly, without relying on patient honesty.

• Pill Counting: The doctor counts the remaining pills at a follow-up appointment.
• Medication Dispensers: Electronic devices (e.g., a smart pill bottle) record the exact date and time the medication container was opened.

Study: Chung and Naya (2000) – Objective Measurement using Medication Dispensers

Procedure: Chung and Naya investigated adherence to medication using Medication Event Monitoring Systems (MEMS)—special caps that record when the bottle is opened.

Finding: They found that MEMS provided a more accurate and reliable record of medication taking compared to simple pill counts or patient self-reports. This data is quantitative and less prone to bias, confirming that objective methods reveal lower adherence rates than subjective ones.

3. Biological Measures

These are the most accurate methods, as they confirm whether the drug has entered the patient's system.

• Blood Samples: Measuring the concentration of the drug in the patient's bloodstream.
• Urine Samples: Analyzing urine for traces of the medication or its byproducts.

Limitation: Biological measures only confirm recent drug usage (e.g., in the last 24 hours), not consistent long-term adherence. They are also invasive and expensive.

3.2.3 Improving Adherence

Since non-adherence is a major problem, health psychology focuses on effective strategies to help patients stick to their plans. These interventions can be aimed at the individual or at the community level.

Individual Behavioural Techniques

These focus on changing the specific actions of the patient using learning principles (like operant conditioning).

• Customising Treatment: Simplifying the medical regimen to fit the patient’s existing routine, making it less disruptive.
  (e.g., suggesting a patient takes their pill every morning when they brush their teeth.)
• Prompts and Reminders: Using external cues to jog memory.
  (e.g., text messages, medication charts, alarms, or linking medication to a daily task.)
• Behavioural Contracts: A formal, written agreement between the patient and practitioner outlining the desired behavior and specific rewards for adherence. This uses principles of positive reinforcement.

Study: Improving Adherence in Children (Chaney et al., 2004)

Aim: To increase adherence to asthma medication (nebulizers) in children using positive reinforcement.

Procedure: Children played a computer game (Winnie the Pooh) that was activated by their correct nebulizer usage. When the child inhaled properly, the game became active for a short period.

Finding: This behavioral strategy significantly increased adherence rates compared to a control group, showing that making treatment fun and rewarding (reinforcement) is effective for improving child adherence.

Community Interventions (Key Study)

These interventions focus on influencing behavior across a wider population, often using public health campaigns or easily accessible reminders.

Key Study: Yokley and Glenwick (1984) – Improving Immunization Adherence

Context: The study focused on increasing the rate of childhood immunizations (vaccinations) in a community setting, particularly among low-income families in New York.

Aim: To compare different types of community-based interventions designed to increase attendance at pediatric immunization clinics.

Procedure: Three groups of families were contacted and compared to a control group:

1. Group 1 (Prompt): Families received a simple mailed reminder of their appointment.
2. Group 2 (Prompt + Social Enhancement): Families received the reminder plus a message emphasizing the community benefit of immunization (social pressure/responsibility).
3. Group 3 (Prompt + Specific Reward/Incentive): Families received the reminder plus a financial incentive (e.g., $5 off a future appointment or a small gift certificate).
4. Control Group: Received no intervention.

Results and Conclusion: All three intervention groups showed significantly higher rates of adherence (attendance) than the control group. The group receiving the Prompt + Specific Reward/Incentive (Group 3) showed the highest adherence rate.

Key Takeaway: Simple behavioral techniques, such as prompts and small extrinsic rewards, are highly effective when applied through community interventions to increase adherence to medical schedules.