Assertion: pericarditis's cause | /r/HasProperty | hard to determine
Facets:
value: often
type: TEMPORAL
Source sentences:
text: The cause of pericarditis is often hard to determine.
text: The cause of pericarditis is often hard to determine.
text: The cause of pericarditis is hard to determine.
text: The exact cause is often hard to determine, but viral infections are thought to be responsible for 80 to 90 percent of the cases.
text: The exact cause of pericarditis is often hard to determine.