Musculoskeletal disorders and injuries account for a large percentage of primary care and emergency room visits in the United States. There is concern about potential shortages of orthopaedic specialists and an expectation that some portion of musculoskeletal care will be delivered by nonphysician health care providers. Physician assistants are one such group.
Grunfeld and his co-investigators express their belief that all health care providers should have a basic fund of musculoskeletal knowledge that permits them to provide appropriate, safe, and efficient care. This is reasonable, and, in fact, the public largely believes that this is so. Unfortunately, there are few cross-disciplinary studies of the knowledge base of health care providers. The authors of this multicenter study used a valid and highly reliable standardized assessment of musculoskeletal knowledge produced by the National Board of Medical Examiners (NBME) to test the hypothesis that the basal knowledge of musculoskeletal medicine is equivalent in medical students and physician assistant students nearing graduation.
Acknowledging that knowledge is but one competency required for practice, Grunfeld et al. found a significant difference. The mean examination score (and standard deviation) for medical students was higher than that for physician assistant students (73.8% ± 9.7% compared with 62.3% ± 11%; p < 0.05). Among medical students, those with more hours of exposure to specific areas covered by the examination performed better in those areas than students who lacked additional experience. Medical students interested in a career in musculoskeletal medicine or surgery performed better than those with a different interest. If examinations are well prepared, students of equivalent ability who have more training and higher levels of interest score higher. The findings of this study support the validity statements for the examination.
Overall, the medical students in this study performed about as well in musculoskeletal medicine as North American medical students do in other areas of basic and clinical science covered by NBME examinations. An internal NBME study of performance on Step-3 musculoskeletal content conducted at the start of the Bone and Joint Decade demonstrated very similar findings. This is good news for faculty concerned with musculoskeletal education.
Physician assistant students performed less well on this examination. The performance difference is real, but lesser knowledge is only one of the potential explanations. Physician assistant students have fewer overall years of medical education and less exposure to United States Medical Licensing Examination (USMLE) review materials and may be less able than medical students in multiple choice examinations.
One should resist the temptation to make too much of this finding. Differential performance on multiple-choice examinations reflects different levels of knowledge, not overall competency. Clinical and communication skills, judgment, and professional behavior are equally important. Undergraduate examinations such as the USMLE Step-1 and Step-2 examinations and the NBME discipline-specific subject examinations are designed to measure an individual's readiness to enter supervised postgraduate training, not to begin unsupervised practice.
The medical students destined for specialization in orthopaedics, physical medicine, and rheumatology who participated in this experiment will complete five or more years of postgraduate training before they enter practice. During that period of time, their knowledge, technical skills, clinical judgment, and decision-making skills will grow with experience. Physician assistants may begin practice immediately on certification and licensure, but under supervision. The requirements for supervision vary among jurisdictions from direct oversight to availability by telephone or radio contact if necessary. One would hope that the level of responsibility accorded to physician assistants is appropriate to training and experience, but further study will be necessary to determine if, in similar circumstances, patient outcomes are the same for physicians and physician assistants.
In conclusion, competent clinical care combines knowledge, skill, judgment, and communication. Knowledge is necessary but insufficient alone. Although medical students had higher scores than physician assistant students on the NBME Musculoskeletal Subject Examination, it would be inappropriate to conclude from this study that one cohort or the other would be better prepared to provide clinical musculoskeletal care.