The gold standard for testing a drug is to trial it on hundreds or thousands of people — then compare the results to an equal number given a placebo.
Such randomised controlled trials find out how a drug works overall, but there will be some people for whom the drug works well and others for whom it didn’t work at all.
But another type of trial, that tests the effects of a drug on just one patient, has hit the headlines recently.
Called an N-of-1, the aim is to give an individual result about whether a drug works for them, which is the best dose, or if there are side-effects.
The ‘N’ stands for the number of people in the trial and the ‘1’ means there is just one.
Up to eight million Britons take statins, but a fifth stop, or refuse to start, over worries about side-effects such as aches and fatigue
‘N-of-1 are the ultimate form of personalised care,’ says Nicky Britten, an emeritus professor of applied healthcare research at Exeter University.
‘If you’re prescribed a drug that has been through a randomised controlled trial, all your doctor can tell you is that on average, say, 70 per cent of people get better when taking it. They can’t tell you if it will work for you.’
Another reason why conventional trial results will not apply to everyone is that older people and women have traditionally been excluded from studies — over concerns that women’s hormones could affect the results; and that existing health conditions in older people, or other medication they are taking, could skew the findings. N-of-1 trials address this by focusing on just one patient.
John Chapple, 77, a retired engineer from West London, is among a handful to benefit from an N-of-1 trial. He had been prescribed statins after heart surgery in 2010, but stopped taking them five months later due to side-effects.
‘My muscles ached all over,’ says John. ‘It was like constantly having the flu. My consultant suggested I try two other statins, but that didn’t make a difference.’
Up to eight million Britons take statins, but a fifth stop, or refuse to start, over worries about side-effects such as aches and fatigue.
In 2016, John had a heart attack. When he told his consultant why he’d stopped taking statins, he was put on an N-of-1
