Comprehensive Geriatric Assessment (CGA):Medication history and review

A thorough medication history is essential before any review of medicines, during acute health events and after transfer between care settings. This should follow best practice guidance for medicines reconciliation,¹ and include immunisation status, alcohol, smoking and recreational drug use. It is important that these latter sections are not omitted in the older adult due to preconceptions about age and lifestyle, which may preclude an accurate history.

Current guidance for prescribing is based predominantly on clinical trials that did not include older adults, those with frailty or those with comorbidities. This makes ascertaining whether a medication is safe for an older person incredibly difficult, as the evidence often does not exist.

We know that the more medicines a person takes, the greater their risk of adverse effects from these medicines, including falls, cognitive impairment and hospitalisations². These risks increase as polypharmacy increases; a person taking 10 or more medicines is 300 times more likely to be admitted to hospital because of medicines-related issues,³ and 1 in 5 unplanned hospital admissions in over 65s have been found to be due to adverse drug reactions (ADRs) and polypharmacy.⁴ 

Frailty and polypharmacy are inextricably linked; comorbidities common in older adults with frailty increase prescribing for multiple disease states, and polypharmacy itself has been associated with an increased prevalence of frailty.⁵ It is common for prescribing cascades to be established in older people with more medicines being added in to counteract the, often misdiagnosed, side-effects of others. This can lead to unnecessary polypharmacy, increased risk of adverse drug effects and reduces quality of life.⁶

The dangerous consequences of polypharmacy are stark, with the prevalence significant and growing. In England in January 2025, there were over 1.1 million people who received 10 or more medicines.⁷

• 457,285 were aged 75 or older
• 153,507 were aged 85 or older

In addition to the catastrophic effects on our older adults, the Department of Health and Social Care (DHSC) National Overprescribing Review report⁸ determined that 10% of the prescription items dispensed through primary care in England were inappropriate for patients circumstances and wishes, highlighting a significant waste of NHS resources in addition to clinical ineffectiveness.

Structured medication review

A Structured Medication Review (SMR) is defined by NICE as a critical, person-centred examination of a person's medicines to reach an agreement about treatment, optimise medication impact, minimise problems, and reduce waste, all while considering individual needs and preferences.⁹ They should be carried out with all older adults with frailty as part of CGA, regardless of the number of medicines prescribed. Evidence has shown that two thirds of unplanned admissions due to ADRs were preventable,¹⁰ so proactive medication optimisation is key.

Review of all medicines is key for an effective SMR, and medication alterations may need to be completed over several consultations if a person has complex polypharmacy. Certain classes of medicines should be prioritised due to their significant adverse effects in older adults. For example, a high anticholinergic burden score (ACB), resulting from taking multiple medications with anticholinergic effects, is linked to an increased risk of cognitive impairment, dementia, falls, and mortality, so reviewing a person’s ACB should be a priority action for an SMR.¹¹

The Scottish Polypharmacy Guidance: Realistic Prescribing resource details 7 steps to consider during medication review.¹²

1. What matters to the patient
2. Identify essential drug therapy
3. Does the patient take unnecessary drug therapy?
4. Are therapeutic objectives being achieved?
5. Is the patient at risk of ADRs or suffers actual ADRs?
6. Is drug therapy cost-effective?
7. Is the patient willing and able to take drug therapy as intended?

A successful structured medication review will carefully balance the values, wishes and preferences of the older person involved with the potential benefits and risks of the medicines they are prescribed.

For a list of further valuable resources to aid your medication reviews see our Older adult pharmacy resources.