Renal adverse effects of proton pump inhibitors (PPIs) were described in your research briefing ‘Proton pump inhibitors linked with chronic kidney disease’ (
2015;7:217). Simply telling us that there was a 10% or 50% increase among trial participants gives readers no useable information. We need to know how many events we expect, say, in 1,000 patients, so that we can see the absolute risk and how it is changed by the drugs. If there were normally two events and three events in patients taking PPIs that is a 50% increase, but only one patient in 1,000 will be adversely affected. If we know that we can make an informed decision and help patients to do the same.
We need to be able to work out the absolute levels of risk in the study population, with and without the drug in question.