Principle: An intervention outside its response window means the outcomes hierarchy will fail to meet is necessary completion point - Interventions need to be undertaken within the intervention response window of the relevant outcomes hierarchy if high-level outcomes are to be achieved within the necessary time. This can occur for at least two reasons. The first is if the intervention duration is longer than the intervention response window. The second is if the intervention actual start point is too late in the case where the length of the intervention duration will cause it to not be completed before the intervention terminal point and therefore the high-level outcomes in the outcomes hierarchy will not be achieved.
Discussion: The time in which it is necessary for the high-level outcomes within an outcomes hierarchy to be achieved is known as the outcomes hierarchy response time. It is illustrated in the diagram below.
However the full length of the outcomes hierarchy response time may not all be available for an intervention. The time available for an intervention is that between the intervention potential start point and the intervention terminal point - the point at which the intervention needs to be completed if higher-level outcomes are to be achieved. The intervention response window is shown in the diagram below.
Interventions have different durations and in two cases the intervention terminal point can be overshot. The first is where there is an excessive intervention duration which means that even if commenced right at the intervention potential start point, due to its length, it can not be completed until past the intervention terminal point. This is illustrated in the diagram below.
The second case is where the intervention is commenced after the intervention potential start point, but too late for it to be completed before the intervention terminal point. This is illustrated in the diagram below.
