In promoting everything from frozen foods to cell phones, PR firms have tapped - sometimes effectively, other times not - countless actors and singers to help consumers connect with brands. In working with healthcare clients, though, the choice to include stars offers a unique set of challenges.

"Quite often, celebrities are not good spokespeople because they are not always seen as authentic and relevant unless they have a personal experience or connection with the [disease]," says Paul Lerner, founder of healthcare ...