Assertion: passive surveillance | /r/HasProperty | difficult
Facets:
value: to ensure timeliness
type: PURPOSE
Source sentences:
text: Passive surveillance is less expensive than other surveillance strategies and covers wide areas (whole countries or provinces); however, because it relies on an extensive network of health workers, it can be difficult to ensure completeness and timeliness of data.
text: Passive surveillance is the most common method used to detect VPDs, the least expensive, and covers the widest geographical areas; however it can be difficult to ensure completeness and timeliness of data collection.