Then and now and when.

Since the 1970s, it has been clear that the health community needs to develop a health care system that matches a person's needs with the expertise and technology to address those needs. The logical solution is a multi-tiered system. In such a system, physicians would provide second- and third-tier services and other health professionals would provide first- and second-tier services. Medical informatics should take on the challenge of supporting the decision to triage patients from one tier of service to another. Triage decisions are different from other decisions in health sciences because they take place early in the life of a problem, when little information is available, and can be made safely if adjusted to tolerate erring on the side of referral.