Many of the articles you find will also cite statistics. If you want more information you can try to track down the primary source of that citation yourself, or ask a librarian for help.
The websites of many health related government offices and NGO's will have information, research, and policy documents about issues related to social determinants of health.
A few general resources are listed below, but a web search focusing on your specific topic along with .gov and .org resources will help you find many smaller organizations or specialized resources.
If a resource is new to you, take a few minutes to evaluate it using the NIH's Guide to Evaluating Health Information