英语长难句分析.请问括号部分是主语从句还是定语从句呢?

英语长难句分析.请问括号部分是主语从句还是定语从句呢?
The second set of more specific changes （that have led to the present concern about the distribution of health-care resources ）stems from the dramatic rise in health costs in most OECD countries,accompanied by large-scale demographic and social changes which have meant,to take one example,that elderly people are now major and relatively very expensive)consumers of health-care resources.请问括号部分是主语从句还是定语从句呢?