"studied issues" is correct and can be used in written English.
You can use it when discussing topics or problems that have been researched or examined in depth. Example: The panel of experts presented their findings on the studied issues of climate change and its impact on the environment at the conference.
She also studied issues like altruism and political ideology, and wrote psychobiographical works on historical figures including Nathaniel Hawthorne and Karl Marx's daughter Eleanor.
Mr. Stone used a monthly newsletter to turn the federation into a policy research organization that studied issues like nuclear proliferation, energy and government secrecy.
Though the wine vinegar process is being considered, many of the studied issues could be applied to other fermentations.
He has also requested documents and information from the banks, examined material given to his predecessor, Andrew Cuomo, and studied issues raised in lawsuits against the banks.
But three experts who have studied issues related to politicians and their health said yesterday that as far as they could determine, the mayor appeared to be justified in declining to answer questions about his treatment.
The Pentagon and the State Department have studied issues arising from dependence on foreign sources of energy for years but are only now considering the effects of global warming in their long-term planning documents.
But some panel members argue that the heavily studied issue deserves further scrutiny.
The center will study issues such as shareholder rights, executive pay and auditing.
Early in his career he began studying issues related to the insanity defense.
She has pledged to study issues that will help her better represent all New Yorkers.
He said that he has been studying issues "for a month".
