Perhaps you should try some spelling variations:
significantly better » significantly greater (Expand Search), significantly higher (Expand Search), significantly lower (Expand Search)
better decrease » greater decrease (Expand Search), teer decrease (Expand Search), between decreased (Expand Search)
level decrease » levels decreased (Expand Search), level increased (Expand Search), teer decrease (Expand Search)
level disease » severe disease (Expand Search), vessel disease (Expand Search), lethal disease (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: "\"((\\"significantly better decrease\\") OR (\\"significant ((level decrease) OR (level disease))\\"))\"".
• Removing quotes may allow a broader search: (( significantly better decrease ) OR ( significant ((level decrease) OR (level disease)) )).