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Interaction of Surgeon Volume and Nurse-to-Patient Ratio on Post-operative Outcomes of Medicare Beneficiaries Following Pancreaticoduodenectomy



We sought to assess the effect of nurse-to-patient ratio on outcomes with a focus on defining whether nurse-to-patient ratio altered outcomes relative to pancreaticoduodenectomy (PD) surgeon specific volume.


Medicare SAFs from 2013–2015 were used to identify patients who underwent PD. Nurse-to-patient ratio, PD specific surgeon volume were stratified. Association of factors associated with short term outcomes was evaluated.


Overall, 6668 patients (median age 73, IQR 68–77; 52.8% male) were identified. The median annual PD volume of surgeons in the highest volume tier was 24 (IQR 21–29), whereas surgeons in the lowest tier performed 2 PDs annually (IQR 1–3) (p < 0.001). Compared with hospitals that had the highest nurse-to-patient ratio tier, patients at hospitals with the lowest nurse-to-patient ratio tier were 26% more likely to have a complication (OR 1.26, 95% CI 1.02–1.55). Additionally, patients of surgeons in the lowest tier had 43% greater odds of suffering a complication compared to patients of surgeons in the highest tier (OR 1.43, 95% CI 1.11–1.84). However, patients who underwent a PD by a surgeon within the lowest tier had similar odds of a complication irrespective of nurse-to-patient ratio (OR 1.34, 95% CI 0.97–1.86).


Compared with patients who underwent an operation by a surgeon in highest PD volume tier, patients treated by surgeons in the lowest tier had higher odds of post-operative complications which was not mitigated by a higher nurse-to-patient ratio.

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Correspondence to Timothy M. Pawlik.

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Paredes, A.Z., Hyer, J.M., Tsilimigras, D.I. et al. Interaction of Surgeon Volume and Nurse-to-Patient Ratio on Post-operative Outcomes of Medicare Beneficiaries Following Pancreaticoduodenectomy. J Gastrointest Surg 24, 2551–2559 (2020).

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  • Surgeon volume
  • Nurse-to-patient ratio
  • Pancreaticoduodenectomy