Statins after 75: the evidence is thinner than the prescribing suggests

Statins are among the most studied drugs in existence, and among the most argued about. Both facts have the same root: they are given to enormous numbers of people who feel well, to prevent an event that most of them would not have had anyway, and the size of the benefit for any individual is small even where the population effect is clear.

Age changes that calculation in two opposing directions at once, which is why the over-75s are the group where the argument is sharpest.

The distinction that governs everything

Secondary prevention means you have established cardiovascular disease — a previous heart attack, stroke, angina, or arterial disease. Primary prevention means you do not, and the drug is given on the basis of estimated risk.

For secondary prevention, the evidence in older adults is good and the debate is largely over. The Cholesterol Treatment Trialists' Collaboration meta-analysis, pooling individual data from 28 trials, found that the proportional reduction in major vascular events per unit of LDL lowering was broadly similar across age groups, including in those over 75 with established vascular disease. Because absolute risk rises steeply with age, a similar proportional benefit translates into a larger absolute benefit. The number needed to treat falls.

For primary prevention over 75, the same analysis found the evidence weaker and the effect estimate less certain, largely because there were far fewer such patients in the trials. Most of the landmark statin trials either excluded people over 70 or 75 outright, or enrolled small numbers.

The arguments for continuing to prescribe

Cardiovascular disease is the leading cause of death and disability in this age group, and absolute risk is high, so even a modest relative benefit produces meaningful absolute numbers. Atherosclerosis does not stop progressing at 75. And stroke prevention matters particularly here, because the disability cost of a stroke in an 80-year-old is severe.

The PROSPER trial, which enrolled adults aged 70 to 82, found pravastatin reduced coronary events, though it did not reduce stroke and there was a puzzling excess of new cancer diagnoses that has not been replicated and is generally attributed to chance.

The arguments for caution

Time to benefit is the strongest one. Statins take roughly two to five years to produce a measurable reduction in events. If a person's life expectancy is shorter than that — because of advanced frailty, dementia, cancer, or organ failure — the drug cannot deliver what it promises and can only cost.

Then there is competing risk. In a very old person, dying of something other than cardiovascular disease becomes more likely, which mathematically dilutes the benefit of preventing a cardiovascular event.

Adverse effects are more consequential too. Muscle symptoms are the most commonly reported problem, and their true attributable rate is genuinely contested — the SAMSON and StatinWISE n-of-1 trials found that most people who report statin-associated muscle symptoms report them equally on placebo, which is an uncomfortable and well-conducted finding. But in an older person with reduced muscle mass, any reduction in activity from perceived muscle symptoms carries a cost that a younger person would absorb.

And each additional drug in a list of nine has an interaction burden, an adherence cost, and a monitoring requirement.

The cholesterol paradox

One finding regularly weaponised in this debate deserves a straight explanation. In observational studies of the very old, low total cholesterol is associated with higher mortality. This is real and repeatedly found.

It is almost certainly reverse causation. Serious illness — cancer, frailty, malnutrition, chronic inflammation — lowers cholesterol. The low cholesterol is a marker of the illness, not its cause. Interpreting it as evidence that cholesterol is protective in old age misreads the direction of the arrow, and randomised evidence does not support that interpretation.

A reasonable framework

Established cardiovascular disease, reasonable health, life expectancy comfortably beyond a few years: continue. The evidence supports it and stopping is likely to cause harm.

No cardiovascular disease, aged over 75, otherwise well and active: a genuine judgement call and a legitimate shared decision. There is no correct answer available from the literature yet.

Advanced frailty, life expectancy under two years, or a drug list that has become unmanageable: primary-prevention statins are among the more reasonable things to stop. Guidance from several bodies now explicitly supports deprescribing in this situation, and a trial of statin discontinuation in people with limited life expectancy found no increase in cardiovascular events and improvements in quality of life.

What to ask

Am I taking this to prevent a first event or a second one? What is my estimated benefit over the next five years, in absolute terms — not relative risk reduction? And given everything else on my list, is this still where I want one of my slots?

A clinician who can answer those three is giving you a considered prescription rather than a default one.