There is not much demand for LVNs or LPNs because they have to be supervised by an RN, so it makes more sense to just hire an RN. Also, in home care for example, but depending on the setting, the reimbursement from insurance esp Medicare is not as much for LPNs, PTAs or COTAs as it is for RNs, PTs, and OTs. So from a business standpoint it may be cost effective to only hire RNs and not LVNs/LPNs.