Over the Christmas period the UK had its snowiest, iciest winter in years. It brought with it the obvious medical problems: deaths from hypothermia, breaks and strains and other injuries from falls and accidents, and the disruption caused by hospital closures. It will also have caused countless patients to miss their appointments for starting chemotherapy or radiotherapy or for receiving treatments as part of courses already established. 

Clinical trials are designed to discover whether or not a new therapy offers any advantage over conventional ‘best’ therapy, and for the results of any trial to provide credible results its conduct must be run according to a detailed, pre-determined, protocol. While in any one trial the protocol will set out what to do, and how to analyse the ultimate results, when patients miss sessions, there is almost certainly nothing in the protocols about how to analyse the effects of simultaneous disruption across tens of trials due to some external force. Accordingly, and interestingly, since the lapses would have been the result of the inclement weather rather than as a result of some specified contraindication (low blood count, fever) listed in the protocol, they introduce an otherwise new dimension.

Assuming others feel such an observation would be worthwhile, and knowing that the outcome of such lapses will take years to discover, the cancer community needs to work fast and in a coordinated way. The least they can do is to identify the names etc of all those who missed sessions no matter the study. Then, through ingenuity, they need to develop statistical approaches to follow such a diverse cohort over time. Such a study will be a challenge, not least because a new outcome will be written into the trial design which was not originally contemplated. However, I am sure it will be worth while. It could certainly help inform us as to what to do, and how to counsel patients, when other equivalent calamities arise in the future, and they certainly will. 

Joe Collier is emeritus professor of medicines policy at St George’s, University of London