Integration is the key term because it reflects ongoing structural changes in the health care system (Physician Payment Review Commission, 1995). However, this term has multiple meanings. It can connote the integration of primary care and specialty care, the merger of inpatient and outpatient treatment, or a combination of organizational structures and financial incentives such as group practice with capitation (Shortell and Hull, 1995; Shortell, Gillies, and Anderson, 1994). Economists typically view integration in efficiency terms: how do we organize the health workforce in an efficient way without sacrificing quality of care? This is an ambitious goal, but one for which governments, employers, and the public are striving.
It is useful to classify relationships among workforce components in terms that turn on the notion of skills: (1) What is the set of skills unique to each type of clinician? (2) What set of skills can more than one clinician use? (3) What sets of skills are interdependent (i.e., skills that require more than one health care worker)? The first set contains specific skills, the second contains substitutional skills, and the third contains complementary skills. Skill, as defined here, involves clinical, interpersonal, and organization or management competencies.
The relative economic returns to each type of skill since the 1980s after managed care (AMC) are likely to be much different than those prior to the 1980s before managed care (BMC). BMC, the health care workforce functioned in a fee for service (FFS), patient self-referral, and physician-specialty-dominated system. AMC, the health care workforce copes with capitated payment and managed-patient referrals, and strives to integrate primary care and specialty care.
BMC, the health system was characterized by few payer restrictions on patient choice of providers, independent provider billing units, and open-ended FFS payment. Patients freely chose the providers whom they believed would provide the best care; freestanding physicians, hospitals, and other providers did the billing; and insurance plans paid virtually all provider bills (Enthoven, 1987; Pauly, 1970). Because insurance payment schedules favored highly specialized, procedure-based skills, this system rewarded specialty over primary care (Delbanco, Meyers, and Segal, 1979; Roe, 1981).
The health system BMC supported nonphysician clinicians to a limited degree. In the 1970s it began to train and license significant numbers of nurse practitioners (NPs) and physician assistants (PAs).4 However, because of physician resistance, legal restrictions, and other barriers, NPs and PAs were delegated