The Latin word cliens is formed of the earlier cluens, "hearing", in the sense that such an individual is at the call of his patron.
There is a discussion going on at NHS Blog Doctor about the use of client versus patient in the health care setting.
I thought this summed up the relationship I have with the workers insurance company that I have dealt with. We have been at their beck and call for a lot of years.
Went to the last medical evaluation. It was interesting to note that even though this was touted as an independant exam, the doctor making observations and supplying info to the company worked at their auxillary centre. This information was available on the College of Physicians and Surgeons site. I was wondering why nobody medically connected had heard of him through the hospital grapevine. I now know... I am very curious as to why he did not want an extra person there at first, even though our letter said that an acompanying person was allowed.
It was even more telling that there were so many levels of security going in and out of the building. They must be doing more Kama Sutra magic to their clientele, methinks.