Research Proposal

My topic is 'What are the relationships between health problems and economic status?' I'm curious about the health problems of poor and rich countries and how they are related. If they're related, I want to find reasons and think about the solutions. I think that poor countries are more vulnerable to diseases due to their poor sanitary conditions and undeveloped medical system. Others may think that health problems are not related to contries' economic status but it's individual's problem.