In general, specifying a good research question is difficult, but crucial. Imagine an important research question for your own field of interest. Further imagine that this question is possible to answer and that knowing the answer would lead to a large positive impact on the world. Almost certainly, academic researchers, policy practitioners, implementers, and funding organisations would all agree that trying to answer this question is a top priority. 

Prioritising crucial health-related research questions is especially important. For each area of health, from heart disease to schizophrenia, it is vital to systematically identify the most pressing and potentially impactful set of priority research questions to improve health outcomes. Identifying the most crucial questions can't just be the purview of one constituency. Research translation to improve health usually relies on the confluence of policy makers, funders/doners as well as researchers.

And since context matters, a geographical spread of this expertise is also important. Hence, setting research priorities is usually done by conducting a research project collating the views of a comprehensive range of researchers and practitioners in the particular health field and distilling from the data a rank-ordered list of priority questions.A funding organisation may valuably peruse a priority list when specifying a research call. The list may form part of the objective evidence base enabling the funder to confidently defend its decisions to fund certain research themes (and sub-themes) rather than others.

Source: https://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=11444