Franklin Dexter, Johannes Ledolter, Richard H. Epstein, Bradley J. Hindman

Supervision of anesthesia residents and nurse anesthetists is a major responsibility of faculty anesthesiologists. The quality of their supervision can be assessed quantitatively by the anesthesia residents and nurse anesthetists. Supervision scores are an independent measure of the contribution of the anesthesiologist to patient care. We evaluated the association between quality of supervision and level of specialization of anesthesiologists. We used two 6-month periods, one with no feedback to anesthesiologists of the residents' and nurse anesthetists' evaluations, and the other with feedback. Supervision scores provided by residents and nurse anesthetists were considered separately. Sample sizes among the 4 combinations ranged from n = 51 to n = 62 University of Iowa faculty. For each supervising anesthesiologist and 6-month period, we calculated the proportion of anesthetic cases attributable to each anesthesia Current Procedural Terminology code. The sum of the square of the proportions, a measurement of diversity, is known as the Herfindahl index. The inverse of this index represents the effective number of common procedures. The diversity (degree of specialization) of each faculty anesthesiologist was measured attributing each case to: (1) the anesthesiologist who supervised for the longest total period of time, (2) the anesthesiologist who started the case, or (3) the anesthesiologist who started the case, limited to cases started during "regular hours" (defined as nonholiday Monday to Friday, 07:00 AM to 02:59 PM). Inferential analysis was performed using bivariate-weighted least-squares regression. The point estimates of all 12 slopes were in the direction of greater specialization of practice of the evaluated faculty anesthesiologist being associated with significantly lower supervision scores. Among supervision scores provided by nurse anesthetists, the association was statistically significant for the third of the 6-month periods under the first and second ways of attributing the cases (uncorrected P < .0001). However, the slopes of the relationships were all small (eg, 0.109 ± 0.025 [SE] units on the 4-point supervision scale for a change of 10 common procedures). Among supervision scores provided by anesthesia residents, the association was statistically significant during the first period for all 3 ways of attributing the case (uncorrected P < .0001). However, again, the slopes were small (eg, 0.127 ± 0.027 units for a change of 10 common procedures). Greater clinical specialization of faculty anesthesiologists was not associated with meaningful improvements in quality of clinical supervision.