Try to discuss with health authorities in your area and find out what health problems they like to explore. Look for "Adequacy of the financing system in one of Iran provinces. prior to that you need to be familiar with various financing systems and the parameters to use for measuring adequacy.. I wish you the best.
How about the nearness to death effect. Widely recognised by economists but has never been applied to health care capacity planning and demand forecasting. See papers at http://www.hcaf.biz/2010/Publications_Full.pdf
Additionally, you can make a mapping review to identify some health care critical themes and make research scope. In case of doubt, I can assist you about it. For a short deadline, you can search some tackled themes on program and projects available on (https://www.findamasters.com/) and (https://www.findaphd.com/). The best for you!
In my opinion, it is very important to base some of your research on a solid economic theory (for expample: austrian school of economics). Without it, it will be very difficult to interpret the changes in health systems. In addition, I would not be tempted to compare the health systems between countries. Such reflections, at first glance, seem to be interesting, but you have to ask: what is the result of them? Certainly not trends for one global health system. Each country has its own unique health insurance system. In addition, I think that it would be worth looking at how they function partly market solutions. A good topic for research could be the probelmics of transofrming public systems into market ones. There are many myths and half-truths about market relations and an interesting task would be to refute them (for example: https://mises.org/wire/healthcare-government---not-technology---driving-prices). I would also like to draw attention to the role of modern technologies in the future shape of health systems (see: https://www.economist.com/leaders/2018/02/01/a-revolution-in-health-care-is-coming).
From my point of view: What about the healthcare soulutions that are offered outside the classical "school medicine" and how to integrate them into the public healthcare system?
Late to add a response but relevant. The biggest domestic issue (at least to me) is Risk Management. The aversion to release of data is becoming more stringent and hampers the most important qualitative studies, which are QOL and personalized stories. Quantitative studies already have de-personalized requirements coming from IRBs but writing for programs like Medical Humanities becomes very difficult.