We thank Dr Morse and his colleagues for their comments regarding our publication entitled “Impact of robotic operative efficiency on profitability.” In clarification, the manuscript reports an analysis of the actual financial data for fiscal years 2010 and 2011 at our institution: “All associated costs, charges, assigned overhead, and total reimbursements were collected…Profitability was defined as a positive operating income. Operating income was defined as total revenue minus total operating costs (fixed and variable). Direct variable contribution margin was defined as payments minus direct variable costs (eg. instrumentation, operating room supplies, and labor).” As can be seen, the analyses were based on hard data rather than constructed as a decision analysis. The primary aim of this manuscript was to determine whether a large, coordinated, multidisciplinary academic robotics program was profitable. Secondary aims included understanding what factors affected the profitability. Based on the objectively defined endpoints described above, we found that the program as a whole was profitable for both fiscal years 2010 and 2011. When we reviewed each surgical service, we found 2 programs, which were only profitable in fiscal year 2011. Based on both bivariate analysis and Pearson correlation, it was demonstrated that operating income was directly associated with mean operating time. This association was neither implied nor assumed, but was directly demonstrated through several analyses. Our findings are logical, given that maximizing resource use (operating room staff, operating room use, surgeon, and anesthesiologist time) by performing more cases in a given time period will increase revenue over cost. They are indeed correct that our total costs and charges increased from fiscal year 2010 to fiscal year 2011, yet the assumption that “per-case cost went up” is not. As cost and reimbursement vary widely according to the diagnosis related group (Table 3), simply dividing the total charges by the number of cases performed in 1 year does not provide sufficient information regarding the profitability of an individual procedure. For these reasons, we performed a financial analysis for each subspecialty service, by procedure, during both fiscal years and then compared the factors that influenced profitability. This is how we determined the 3 important variables that were associated with profitability of the robotics program: mean case time, mean room time, and payor mix. Our results are in direct support of the observations made by Shah et al in a retrospective cohort analysis of methods of hysterectomy for patients with endometrial cancer, in which they found that “96.3% of the variation in operative cost between patients was predicted by operative time”. We reaffirm our conclusion that robotic operative efficiency is closely associated with overall profitability regardless of surgical specialty.

With regards to referencing the publication by Jonsdottir et al, we were not aware of the retraction regarding the findings for total hospital cost. In the published manuscript, the authors state, “…both the operative cost and total mean cost of robotic hysterectomy decreased significantly, potentially as a result of improved efficiency as our surgeons and ancillary staff gained familiarity with this mode of access. Although robotic hysterectomy often is thought to be the most costly mode from the hospital perspective, our calculated cost to society was lowest for robotic hysterectomy, ranging from $13,501 to $14,158.” However, because of “several errors [resulting] from a flaw in the study methodology” and the fact that “…total hospital cost was averaged out for all modes of access for hysterectomy, effectively rendering the analysis pertaining to total hospital cost meaningless”, the authors retracted their findings regarding robotic hysterectomy in a subsequent letter to the editors and instead concluded that robotic hysterectomy has the highest cost, although no adjusted analyses were published. Regardless, given the retraction of these results, we are happy to remove any reference to this publication in the future. We do not believe this alters our conclusions.

Finally, we thank Dr Morse and his colleagues for correctly identifying the citation issues for references for numbers 18 and 19. These should read as follows: 18. Sarlos D, Kots L, Stevanovic N, Schaer G. Robotic hysterectomy vs conventional laparoscopic hysterectomy: outcome and cost analyses of a matched case-control study. Eur J Obstet Gynecol Reprod Biol 2010;150:92-6. 19. Rowe CK, Pierce MW, Tecci KC, et al. A comparative direct cost analysis of pediatric urologic robot-assisted laparoscopic surgery versus open surgery: could robot-assisted surgery be less expensive? J Endourol 2012;26:871-7.

The profitability of robotics always generates a lively debate. Although there are clearly many factors at work, both financial and clinical, we were able to demonstrate that a large multidisciplinary academic robotics program can be profitable. We thank the authors for their contribution to this topic.