I am aware of at least one incident where a man had his medical records used without his consent and the records inadvertently revealed his identity. As a result, many people in his community discovered details of his medical history that he wished to keep private!
Forcing individuals to divulge medical information without their consent also runs afoul of the Fifth Amendment's prohibition on taking private property for public use without just compensation. After all, people do have a legitimate property interest in their private information; therefore restrictions on an individual's ability to control the dissemination of their private information represents a massive regulatory taking. The takings clause is designed to prevent this type of sacrifice of individual property rights for the "greater good." To the extent these regulations sacrifice individual rights in the name of a bureaucratically-determined "common good," they are incompatible with a free