Visiting the sick with a telephone call

Igros Moshe (YD I #223) Question Can the mitzva of visiting the sick be accomplished with a phone call? Answer While a phone call can accomplish the mitzva of visiting the sick, it is clearly not the best way of doing the mitzva fully.  Thus it should only be done if it is impossible to go in person. If he can go in person he is obligated to do so. So even though a major component of the mitzva is to pray for the sick and that can be done anywhere, the prayer is more likely to be better if he first sees the condition of the sick person.