But at what cost?
8 Apr, 08 | by Bob Phillips
It’s uncommon for us, as paediatricians, to be asked about how cost-effective our treatments are. Glancing at the media shows health stories about the new wonder drugs in adult cancer, or in Alzheimer’s disease, and how they are being restricted by a heartless and miserly health system. Where do these statements about ‘cost-effectiveness’ come from?
In examining a diagnostic test, we make the assumption that the characteristics of the test - its sensitivity and specificity (or likelihood ratios, the way I prefer to think) - will stay constant across different populations, although the positive and negative predictive values will change * . This is sort of true, and sort of false.
It’s a great sport of journalists and commentators to look back at predictions of the future from decades past, and see just how badly they have gone astray. We do this as clinicians too, but with a sense of guilt … looking back to an unexpected relapse of a low-risk tumour, or a fulminant hepatitis that presented with mild nausea, and ask ‘Why didn’t we predict that?”.
The days of a meta-analysis being the simple adding up of lots of studies, pretending that they are all just tiny pieces of the One Big Trial that was performed before the world was made are on their way out. Newer ways of using synthesised evidence - like meta-regression and individual patient data analysis - are coming up quickly.