you seem to have missed “but we hope to follow people up for longer in the future”. it’s pretty standard for initially funding of a study to be for a limited period of time. Typically additional funding would have to be secured through another grant application at a later date. There are a number of reasons for this. One is that it would obviously cost a lot more to do a long-term study and thus an application is more likely to be sucessful if the initial request is for a shorter period. The second is that this study will be contingent on being able to recruit enough participants and retain them over 2 years, which is challenging enough given the population we are talking about. Only after successful recruitment and retention over 2 years is known would you be able to do a meaningful long-term follow up. And sadly, 2 years is actually considered a long time in medicine because of the challenges and disincentives to conducting longer term studies.