One thing I've learned most in my 12 year role as volunteer coordinator at Duke Hospital Auxiliary is that building relationships with volunteers is your only hope of retention. In this volunteer world, many different organizations are competing to gain volunteers for their skills and time. I've noticed that the more I know and understand my volunteer's "story", you are able to communicate with them better and build on to their 'life story". Volunteers want to make connections whether it is socially or emotionally . In a hospital, there is quite a bit of turnover with the patients and staff but, one thing that can remain constant is the volunteer coordinator. The coordinators see the volunteer's weekly faithfulness efforts and acknowledge their presence in such a busy place where faces could get lost.
In conclusion, they are most likely here because they like you. Retention is focused around you so be nice and you will keep the help your hospital needs. :-)