Pharmacoeconomics: putting a price on health benefit

Pharmacoeconomics is the study of how the cost of a medicine relates to the health benefit it produces. When a new treatment arrives on the market, it may offer clinical advantages over existing options, but it usually comes at a higher price. Pharmacoeconomics provides a structured way to ask whether the extra benefit justifies the extra cost — and whether a health system can realistically afford to provide the medicine to everyone who needs it.

These analyses form a key part of health technology assessment (HTA), which evaluates the clinical, economic, ethical, and social implications of health interventions. Around the world, bodies such as the National Institute for Health and Care Excellence (NICE) in the United Kingdom, the Canadian Agency for Drugs and Technologies in Health (CADTH), and the World Health Organization use pharmacoeconomic methods to guide decisions about which medicines should be publicly funded or added to essential medicines lists.

Cost-effectiveness analysis

Cost-effectiveness analysis compares the costs and health outcomes of two or more treatment options. The result is typically expressed as a ratio: the additional cost per additional unit of health outcome achieved. For example, if a new medicine costs more than the standard treatment but extends life by several months, the analysis calculates how much each extra month of life costs.

The outcome measure can vary. Some studies use clinical endpoints such as years of life gained, heart attacks prevented, or infections averted. Others use intermediate measures like blood pressure reduction. The key point is that the health outcome is expressed in natural units, which makes the results relatively easy to interpret for clinicians and policymakers alike.

A threshold approach is commonly used to judge whether a treatment represents good value. If the cost per unit of health benefit falls below a predetermined ceiling, the medicine is generally considered cost-effective. These thresholds vary between countries and reflect what each health system is willing and able to pay for a given health gain.

Cost-utility analysis and the QALY

Cost-utility analysis is a specialised form of cost-effectiveness analysis that uses a standardised health outcome measure, allowing comparisons across very different types of treatments. The most widely used measure is the quality-adjusted life-year, or QALY.

A QALY combines two dimensions: length of life and quality of life. One QALY represents one year of life in perfect health. A year of life in less-than-perfect health is worth less than one QALY, with the exact value derived from population-based quality-of-life surveys. This means a treatment that improves quality of life — such as reducing pain or restoring mobility — can generate QALYs even if it does not extend life, while a treatment that extends life but with significant side effects is credited accordingly.

Because QALYs are a universal currency for health benefit, they allow a health system to compare a cancer drug, a depression treatment, and a surgical procedure on the same scale. The incremental cost-effectiveness ratio, or ICER — the extra cost per extra QALY gained — is the central metric in this type of analysis. Many HTA agencies use ICER thresholds to decide whether a medicine offers acceptable value for money.

Budget impact analysis

While cost-effectiveness asks whether a medicine provides good value, budget impact analysis asks a more immediate question: can the health system afford it? This analysis estimates the total financial effect of adopting a new medicine over a defined period, typically three to five years, taking into account the size of the eligible patient population, the expected uptake rate, and the displacement of existing treatments.

A medicine can be highly cost-effective in principle yet still be unaffordable if the patient population is large. For example, a new medicine that costs slightly more than the current standard but would be prescribed to millions of people could impose a substantial burden on a national drug budget. Budget impact analysis helps planners anticipate these costs and negotiate prices, phase in adoption, or prioritise certain patient groups.

This type of analysis is particularly important in lower- and middle-income countries, where health budgets are constrained and even modest per-patient price increases can have large aggregate effects.

How these analyses inform coverage decisions

Pharmacoeconomic evidence rarely drives decisions on its own. Instead, it is considered alongside clinical effectiveness, safety, equity, and practical considerations such as supply reliability. Coverage decisions typically involve a committee of experts who weigh the evidence and issue a recommendation — for instance, to list a medicine on a formulary, reimburse it conditionally, or decline public funding.

The process varies by country. In the United Kingdom, NICE issues technology appraisals that the National Health Service is legally required to fund. In Canada, CADTH recommendations inform provincial drug plan decisions. The WHO Essential Medicines List, which many countries use as a basis for their own formularies, considers cost-effectiveness alongside public health relevance and comparative effectiveness when selecting medicines.

In South Africa, pharmacoeconomic principles are increasingly relevant as the country moves toward National Health Insurance and seeks to allocate limited resources efficiently. Medicines registered with SAHPRA and priced under the Single Exit Price framework can be explored through HealthSA, which allows users to search by active ingredient and compare prices — a practical starting point for understanding the cost side of the pharmacoeconomic equation.