Neurosurgery Fellowships and the Residencies That Enfold Them: A Nationwide Correlational Analysis.

Background and objectives: Accredited neurosurgery fellowship training is available in 10 subspecialties and can sometimes be completed during the postgraduate year (PGY)-7 residency year. However, it is not clear whether there are sufficient residency graduates to fill the number of positions available, and residency curriculum structure to support enfolded training is evolving.

Methods: Detailed information about the 117 accredited neurosurgery residency programs and the 282 accredited neurosurgery fellowships was obtained from the Accreditation Council for Graduate Medical Education and Committee on Advanced Subspecialty Training, respectively. Information about residency chief year structure (PGY-6 vs PGY-7) was obtained electronically from each program. An analysis was performed to correlate residency and fellowship training characteristics at each program.

Results: The total number of neurosurgery fellowship positions available per year (352) is much higher than the total number of residency positions (237). Eighty-eight (75%) institutions with a neurosurgery residency offer at least 1 fellowship, and 51 of these have more fellowships than graduating residents. The resident complement at each program correlates with the number of fellowships offered (r2 = .56, P < .05), and the average institutional resident complement where fellowships are offered is greater than 2 per year. Thirty-eight residencies (32%) use a PGY-6 chief model (allowing for enfolded fellowships), and these programs offer significantly more fellowship programs on average than those using a traditional PGY-7 chief model (3.0 vs 2.1, P < .05). For most subspecialties, a minority of fellowships are offered in programs with a PGY-6 chief model.

Conclusion: The number of accredited neurosurgery subspecialty fellowship slots in the United States far exceeds the number of graduating neurosurgery residents. There is no standard for residency curriculum or enfolded fellowships, but smaller programs offer fewer opportunities for subspecialty training. There may be advantages to a uniform approach that standardizes subspecialty training across programs and matches fellowship availability to demand.