• Cystic Fibrosis
• Exercise Physiology
• Epidemiology

‘I'm not going to do nothing anymore. Never again? Well not so much...’ Eeyore (from When We Were Very Young (1924), by AA Milne)

From the Oracle at Delphi through Nostradamus to modern day astrologers, the desire to predict the future has been pervasive. Paediatric patients and their carers are no exception because they want to know what is going to happen to them. Clinicians are pushed with varying degrees of enthusiasm to provide them with outcome data and we need to tread carefully, because by definition, probability is bedevilled by uncertainty and so there are two dreaded questions: ‘How long will my child live?’ and ‘My child is bad, when does he/she need a (lung) transplant?’ The first produces an answer so hedged around by caveats and with boundaries of certainty so wide that no party is satisfied. The second has similar problems but lends itself well to decision analysis.

Paediatric oncology had a certain advantage, particularly with leukaemia, because in the past, nearly every UK patient was in a trial of current best practice versus a modification thereof, as UKALL trials I to XI and beyond will testify. Five-year survival was the outcome, and so the endpoint was both certain and not too far into the future. As a result, prognostication was both reasonably accurate, and the limits of certainty, given the number of patients involved, reasonably tight.

Cystic fibrosis, the commonest inherited disease of white Caucasians produces no less a desire for prognosis but suffers from several extra problems.

1. Life expectancy in cystic fibrosis (CF) has increased so rapidly1 that death in childhood is now most unusual, and median life expectancy, currently about 40 years, will probably for recent births be at least 55 years. This is now so far into the future that it is no surprise …