Educational and certification requirements for registered nurses and nurse practitioners are not uniform. As our paper indicated, nurse practitioners are licensed registered nurses with advanced education ranging from 9 to 24 months of supervised clinical training, generally leading to a Master's degree. However, as Maffie-Lee and colleagues indicate, many nurses obtain advanced training to become nurse practitioners after already having completed educational and licensure requirements as registered nurses. The American Nurses Association has called for a minimum requirement of a Master's degree for certification of nurse practitioners by 1998.

Certification is available from several sources, is generally voluntary, but is not required for licensure in many states. According to survey data compiled for the Division of Nursing of the U.S. Public Health Service [1], as of December 1992, an estimated 37 963 nurses held national certification or state recognition as nurse practitioners or clinical nurse specialists. Of these, 27 746 (73%) were nurse practitioners only, 7998 (21%) were clinical nurse specialists, and 2219 (6%) held dual certification or recognition in both fields. The study cautioned that there is "considerable cross-over and overlap between and among nurse practitioners and clinical nurse specialists, with respect to educational preparation, certification/recognition, and practice." Of the 27 746 nurses certified or recognized only as nurse practitioners, most (51.8%) were prepared as nurse practitioners through a certificate program; the remaining 42.4% obtained their credentials through a Master's degree program. Only 2.8% were educated as nurse practitioners in a post-Master's degree certificate program. Almost all (99.5%) of the clinical nurse specialists obtained their education in Master's degree programs. Of the nurses with dual certification, 64.1% were prepared as nurse practitioners and clinical nurse specialists at the Master's level in two different programs. The remaining nurses with dual certification received their nurse practitioner education in a certificate program and their clinical nurse specialist education in a Master's program.

In contrast, the training for physician assistants generally consists of at least 2 years at the Bachelor's level. Of the physician assistant's programs, 60% lead to a Bachelor's degree, and the remainder result in an Associate's degree or a certificate.

We agree that nurse practitioners must be accountable not only to physicians but also to patients, the profession, and themselves. We remain convinced, however, that until evidence suggests that advanced practice nurses can provide high-quality care in independent practice arrangements without accountability to physicians, they must continue to function within systems in which physicians bear ultimate responsibility for patient care.

Our paper also noted that nonphysician providers are a heterogeneous group with different educational paths. Dr. Miller reinforces this point in suggesting that we also consider the role of clinical pharmacists. The roles of these professionals and many others were beyond the scope of our paper but certainly should be considered in discussions of the primary health care work force. Dr. Miller also raises the important distinction between dispensing and prescribing authority. The sixth position of our paper was meant to address prescribing authority, not dispensing authority; it will be revised accordingly.