Perhaps you should try some spelling variations:
decrease risk » decreased risk (Expand search), increase risk (Expand search), decrease hiv (Expand search)
risk decrease » risk decreases (Expand search), risk increase (Expand search), break decrease (Expand search)
decrease toc » decrease of (Expand search), decrease the (Expand search), decreased to (Expand search)
toc decrease » to decrease (Expand search), the decrease (Expand search), not decrease (Expand search)
in effective » an effective (Expand search), and effective (Expand search), _ effective (Expand search)
decrease il » decreased il (Expand search), decrease hiv (Expand search), decrease of (Expand search)
il decrease » l decrease (Expand search), will decrease (Expand search), oil decreases (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 il decrease toc decrease ) OR ( decrease risk decrease in effective ))~".
• Adding a wildcard symbol may retrieve word variants: (( decrease il decrease toc decrease ) OR ( decrease risk decrease in effective ))*.