Perhaps you should try some spelling variations:
decrease risk » decreased risk (Expand search), increase risk (Expand search), decrease in (Expand search)
risk decrease » risk decreases (Expand search), risk increase (Expand search), break decrease (Expand search)
decrease rate » decreased rate (Expand search), decreases rate (Expand search), decrease at (Expand search)
rate decrease » rats decreases (Expand search), rate increase (Expand search), to decrease (Expand search)
decrease deaf » decreases leaf (Expand search), decrease fear (Expand search), decrease fetal (Expand search)
deaf subjects » deaf subject (Expand search), of subjects (Expand search)

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "(( decrease risk decrease rate decrease ) OR ( decrease AND decrease deaf subjects ))~".
• Adding a wildcard symbol may retrieve word variants: (( decrease risk decrease rate decrease ) OR ( decrease AND decrease deaf subjects ))*.