Uniforms in a healthcare environment

If you supply them, then they should wear them.  Actually, you might supply them with 5 shirts (as I did w/ scrubs in a medical practice).  The wearing of the uniform should be presented as a privilege, not a requirement.  They should be sold on this idea from the moment of hire.  It is a privilege to work here, therefore it is a privilege to wear our shirts, which, unlike scrubs are much more comfortable, and still allow you the choice of type of pant (or color --- unless you supply those also). 

Another thing I did was show "rank" (longevity w/the company) or supervisory status by way of color:  New hires were always furnished white; one year or more, royal blue (true blue ideology); supervisory, bright red and Outstanding person of the year, Black (always the most popular choice).  

Once, when we were in the process of changing the focus of the practice from family to a more "carriage" clientèle, (read, more money and more cash services such as Swedish massage w/ aromatherapy, hydrotherapy, spider vein therapy, psychotherapy, esthetitherapy (spa treatment) and podiatry, we all wore scrubs made from camouflage material in order to bring everyone's attention to our intended changes.  We wore them for one month until all the changes were completed.

Our scrubs purchases are a complete business expense, and we just asked everyone to bring them back when they quit our employ.  (I never had to let anyone go in 5 years because we had such a great time at work!).