Measuring the unmeasurable
When we look at treatments for children’s ill health, we tend to be stuck in a pleasant dilemma. We normally want to use treatments to stop kids dying, and to make them better quicker—but it is uncommon for children to die, and they will often get better anyway. So we end up using alternative outcome measures, be they called a proxy or surrogate or sometimes even a process measure. What is the difference anyway?
Using a measure which the study folk believe is intimately related to the outcome we really want to measure, because it is too rare, or takes too long to occur, is often called a ‘surrogate’ or ‘proxy’ measure. In these cases, you need to demonstrate the surrogate is strongly linked to the ‘real’ outcome—and that altering the surrogate always also alters the actual outcome.
These phrases can be used to describe approaches…