Perhaps you should try some spelling variations:
ratings risk » patients risk
wang yang » wang yan, wang liang, wang yanling
yang ying » yang yang, yang jing, huang ying
side cost » time cost, die cost, life cost
life lost » life long
diet cost » die cost, direct cost, net cost
among men » among women

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: wang yang ying ((((side cost) OR (life lost))) OR (diet cost)) ratings risk among men ;~.
• Adding a wildcard symbol may retrieve word variants: wang yang ying ((((side cost) or (life lost))) or (diet cost)) ratings risk among men ;*.