Whatever facility you work for should have a policy & procedure that define what a fall is, and how to treat situations where you find someone on the floor without having actually witnessed them falling. Most facilities do
consider that to be a fall (erring on the side of caution ...
The facility should also have a policy & procedure for a fall risk protocol (or whatever they choose to call it), which would identify the process by which the facility identifies patients at higher risk of falls and interventions to be used with those patients to attempt to keep them safe. All of the suggestions may by the other posters are good ones that you often see in these protocols. Another common intervention is to place the fall risk people in rooms as close to the nursing station as possible, and communicate to all nursing staff which patients are at high risk for falls so that all can work together to keep an eye on them and keep them safe.
If you are working for a facility which does not have specific policies and procedures that address these issues, you may want to bring that up with administration as something that needs to be addressed. I work as a surveyor/inspector of hospitals for my state and for the feds, and we often investigate complaints that involve patient falls. The facility may not get in trouble if they took reasonable steps to keep the patient safe but the patient fell anyway
, but it will definitely
get in trouble if it does not have an established policy/procedure for identifying patients at higher risk of falls and taking steps to reduce the risk of falls (or if it has such a policy/procedure but staff failed to implement it).