Best Interests Decisions Explained | Mental Capacity Act 2005
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In healthcare, patients normally make their own decisions about treatment and care. They listen to the information provided by professionals and decide what they want to happen. But there are many situations where a person cannot make those decisions for themselves. Someone may be unconscious, experiencing severe confusion, living with dementia or affected by a condition that makes it difficult to understand information. When this happens, decisions about treatment, care or living arrangements still need to be made. The law provides a framework to guide how those decisions should be approached.
In England and Wales, this framework comes from the Mental Capacity Act 2005, which requires decisions to be made in the best interests of the person who lacks capacity.
What “Best Interests” Means
A best interests decision is a decision made for someone who cannot make that decision themselves.
Importantly, this does not simply mean choosing what professionals believe is medically best. The decision should reflect what is best for the individual person, taking into account their values, beliefs and previously expressed wishes. The aim is to reach a decision that respects the person as much as possible, even when they cannot actively participate in the decision-making process.
When Best Interests Decisions Are Used
Best interests decisions are used whenever a person lacks capacity for a specific decision. This may involve decisions about:
- medical treatment
- investigations and procedures
- care arrangements
- discharge planning
- accommodation and support needs
In most healthcare situations in England and Wales, these decisions are made using the best interests framework rather than through court orders.
The Best Interests Checklist
The Mental Capacity Act sets out several factors that decision-makers must consider when determining what is in a person’s best interests. These include:
- the person’s past wishes and preferences
- their beliefs and values
- any written statements made when they had capacity
- whether the person might regain capacity in the future
- the views of family members, carers or others close to the person
Decision-makers must also consider the least restrictive option, meaning the option that interferes least with the person’s rights and freedoms.
The “Balance Sheet” Approach
In practice, many healthcare teams use what is often called the “balance sheet” approach when making best interests decisions. This involves listing the benefits and burdens of each possible option. For example, a clinical team might consider:
- Potential benefits
- improved health or comfort
- prevention of deterioration
- improved quality of life
- Potential burdens
- pain or distress
- invasive procedures
- prolonged hospitalisation
By weighing these factors carefully, teams can reach a reasoned decision about which option best reflects the individual’s overall interests.
Involving Family and Others
Best interests decisions should rarely be made by a single professional acting alone. Healthcare professionals are encouraged to involve people who know the patient well. This may include:
- family members
- carers
- close friends
- individuals with legal authority such as a Power of Attorney or Deputy
Their input helps ensure that the decision reflects what the person would likely have wanted.
Best Interests Meetings
For complex situations, healthcare teams may hold best interests meetings. These meetings bring together professionals involved in the person’s care along with family members or others who can provide insight into the patient’s preferences. Best interests meetings commonly occur when decisions involve:
- major medical treatment
- long-term care placement
- disagreements about care plans
- discharge planning
The goal is to reach a decision that balances clinical judgement with the individual’s wishes and wellbeing.
When an IMCA Is Required
If a person has no family or friends available to represent them, the law requires the involvement of an Independent Mental Capacity Advocate (IMCA). IMCAs support individuals who lack capacity during important decisions, particularly those involving:
- serious medical treatment
- long-term accommodation decisions
Their role is to ensure that the individual’s rights and interests are properly considered during the decision-making process.
Capacity is not always permanent. Some patients temporarily lose the ability to make decisions due to conditions such as delirium, infection, medication effects, or acute illness.
If a person is likely to regain capacity in the near future, the decision should be delayed where possible so that the individual can participate in the decision themselves.
Recent legal clarification, including Townsend v Epsom & Helier [2026], has reinforced that even decisions once considered purely clinical must still follow the statutory best interests process when a patient lacks capacity.
Life-Sustaining Treatment and Disputes
Most best interests decisions are made collaboratively between healthcare teams and families. However, disagreements can occasionally arise. If there is a fundamental disagreement between the clinical team and family members about life-sustaining treatment, the case must be referred to the Court of Protection.
Recent Court of Appeal rulings have reaffirmed that hospitals cannot unilaterally withdraw life-sustaining treatment when there is a serious dispute. In such cases, the court must decide what is in the person’s best interests.
Why This Matters in Healthcare
The best interests framework ensures that decisions for people who lack capacity are made in a structured, ethical, and legally protected way. Rather than leaving decisions solely to professional judgement, the law requires decision-makers to consider the person’s values, consult those who know them well and carefully weigh the benefits and burdens of different options.
For healthcare professionals and students, understanding this framework helps explain how treatment decisions are made when patients are unable to decide for themselves.
The "Best Interests" Decision Hierarchy
If a patient lacks capacity, the clinician usually follow this order to see who holds the "pen":
Advance Decision (ADRT): If valid and applicable, it is legally binding, even over "best interests."
LPA or Court-Appointed Deputy: They make the decision using the best interests framework.
The Clinician (Decision-Maker): If no proxy exists, the lead clinician is the "Decision Maker" but must follow the statutory checklist.
References
Mental Capacity Act Code of Practice (UK Government).
Townsend v Epsom & Helier University Hospitals NHS Trust [2026].
Disclaimer: This resource is designed for educational purposes for UK student nurses and healthcare professionals. While we strive for clinical accuracy, it does not constitute medical advice. Always refer to your specific Trust’s local policies, NICE guidelines and the NMC Code in clinical practice. Clinical scenarios can change rapidly; when in doubt, escalate to your mentor or senior clinician.