It was a single paragraph in a Financial Times opinion piece by Sally Gainsbury that crystallised something we had been observing for years through our analytical work with NHS systems:
While technological advance elsewhere tends to reduce costs, in healthcare it increases them by expanding what treatments are possible. It also expands what the public expects to receive. Healthcare consumption tends to grow at more than twice the rate of population growth.
From that observation came something we now treat as a law. Because, like the laws of physics, it appears baked in.
Gainsbury's Law: Advances in procedures, and drug, device, and digital technologies, plus shifts in demographics and demand, collectively and inexorably increase the cost of healthcare.
One prescription, £250,000
One late evening in 2013, I added £250,000 to the annual cost of care of one patient with one prescription.
The patient was a boy diagnosed with atypical haemolytic uraemic syndrome, a very rare genetic abnormality of the immune system. We had been keeping him from kidney failure through fortnightly blood filtering at about £20,000 a year. Then his catheter got infected, triggering the immune attack that was heading for irreversible renal failure.
NICE had not yet approved eculizumab for this condition. There were only anecdotal case reports. No trial data, because the disease is too rare. I called the medical director that evening. He said yes. We infused the drug. It worked. The kidneys were saved.
We moved from £20,000 a year in blood products and machine time to £250,000 a year in drug costs. The unit did not decommission a machine or remove staff. We added a cost to healthcare. The boy will be an adult now, probably still receiving the drug. Career cost to the state: approximately £4.1 million in drug costs alone.
All thanks to Niels Jerne, Georges Köhler, and César Milstein, who invented the monoclonal antibody technique in 1975, earning the 1984 Nobel Prize. Saving lives. Costing millions. Gainsbury's Law in action.
Prevention does not break the law
The King's Fund recently published a long read on cardiovascular disease prevention. The summary: if 80% of diagnosed hypertension patients had their blood pressure reduced to optimal levels, over three years it would prevent 7,000 heart attacks, prevent 5,600 deaths, and save the NHS £200 million.
Nobody would argue against those outcomes. But the £200 million does not come with an appendix laying out the cost to do the prevention work: the time and resources to measure blood pressure, prescribe, and monitor across 8,039 GP practices. There is no detail on which assets would be decommissioned or which staff made redundant. The saving shortens waits and frees capacity. That is real. But freed capacity gets filled by the next queue. There is no cash pile in the bank.
Finance purists would say the freed capacity gets filled by the next queue of patients waiting for care that was previously inaccessible. Gainsbury's Law does not get broken by prevention. It just redistributes the spend.
What the law means for how we measure value
At STRASYS, the Decision Intelligence engine for healthcare, we accept Gainsbury's Law as a structural reality. The question is not how to bend or break it. The question is how to prove the value of healthcare while containing budgets so healthcare does not consume the entire treasury at the cost of education, security, and social needs.
The Strasys Value Index was built to answer that question. It measures how effectively trusts deliver high-quality, timely healthcare relative to cost, accounting for population need. Lower mortality and readmission is better. Shorter waits improve outcomes. Shifting care to appropriate settings is good, if quality is maintained.
Gainsbury's Law means every NHS system must find and release trapped value just to stay level. Not as a one-off efficiency programme, but as a permanent capability. The Consultant Workforce Optimisation System targets the single largest controllable cost: how senior clinical time is deployed. Since 2018/19, consultant headcount grew by 28.5% while productivity declined by 12.1%. More people inside an unchanged model does not improve value. It accelerates Gainsbury's Law.
Naeem Younis, STRASYS CEO, argues that NHS boards need to stop treating financial sustainability as a cost-cutting exercise and start treating it as a value question. The Naci et al. Lancet paper showed that during 2000-2020, NHS coverage of new drugs displaced more population health than it generated, with a net loss of approximately 1.25 million QALYs. The trade-offs are real. The only way through them is to measure value, not just cost.
How to have our cake without devouring it all. That is the challenge Gainsbury's Law sets for every health system in the world.