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Sugihara et al. Mini-invasive Surg 2018;2:11 I http://dx.doi.org/10.20517/2574-1225.2018.14 Page 7 of 7

Ethics approval
The present study was approved by the Institutional Review Board and Ethics Committee of The University
of Tokyo (No. 3501).

Copyright
© The Author(s) 2018.

REFERENCES
1. Finks JF, Osborne NH, Birkmeyer JD. Trends in hospital volume and operative mortality for high-risk surgery. N Engl J Med
2011;364:2128-37.
2. Higashihara E, Baba S, Nakagawa K, Murai M, Go H, Takeda M, Takahashi K, Suzuki K, Fujita K, Ono Y, Ohshima S, Matsuda T,
Terachi T, Yoshida O. Learning curve and conversion to open surgery in cases of laparoscopic adrenalectomy and nephrectomy. J Urol
1998;159:650-3.
3. Hamada T, Yasunaga H, Nakai Y, Isayama H, Matsui H, Fushimi K, Koike K. No weekend effect on outcomes of severe acute
pancreatitis in Japan: data from the diagnosis procedure combination database. J Gastroenterol 2016;51:1063-72.
4. Sugihara T, Yasunaga H, Horiguchi H, Matsui H, Fujimura T, Nishimatsu H, Fukuhara H, Kume H, Changhong Y, Kattan MW, Fushimi
K, Homma Y. Robot-assisted versus other types of radical prostatectomy: population-based safety and cost comparison in Japan, 2012-
2013. Cancer Sci 2014;105:1421-6.
5. Ravi B, Jenkinson R, Austin PC, Croxford R, Wasserstein D, Escott B, Paterson JM, Kreder H, Hawker GA. Relation between surgeon
volume and risk of complications after total hip arthroplasty: propensity score matched cohort study. BMJ 2014;348:g3284.
6. Marrie RA, Dawson NV, Garland A. Quantile regression and restricted cubic splines are useful for exploring relationships between
continuous variables. J Clin Epidemiol 2009;62:511-7.e1.
7. Quan H, Sundararajan V, Halfon P, Fong A, Burnand B, Luthi JC, Saunders LD, Beck CA, Feasby TE, Ghali WA. Coding algorithms
for defining comorbidities in ICD-9-CM and ICD-10 administrative data. Med Care 2005;43:1130-9.
8. Sobin LH, Wittekind C. TNM Classification of Malignant Tumours, 6th edition. New York: Wiley; 2002.
9. Panageas KS, Schrag D, Riedel E, Bach PB, Begg CB. The effect of clustering of outcomes on the association of procedure volume and
surgical outcomes. Ann Intern Med 2003;139:658-65.
10. Rubin DB, Schenker N. Multiple imputation in health-care databases: an overview and some applications. Stat Med 1991;10:585-98.
11. Harrell FE Jr. rms: Regression Modeling Strategies. Available from: http://CRAN.R-project.org/package=rms [Last accessed on 4 May
2018].
12. The R Foundation. The R Project for Statistical Computing. Available from: http://www.R-project.org/ [Last accessed on 4 May 2018].
13. Pusic MV, Kessler D, Szyld D, Kalet A, Pecaric M, Boutis K. Experience curves as an organizing framework for deliberate practice in
emergency medicine learning. Acad Emerg Med 2012;19:1476-80.
14. Murre JM, Dros J. Replication and analysis of Ebbinghaus’ forgetting curve. PLoS One 2015;10:e0120644.
15. Hunter I, Ramanathan V, Balasubramanian P, Evans DA, Hardman JG, McCahon RA. Retention of laryngoscopy skills in medical
students: a randomised, cross-over study of the Macintosh, A.P. Advance(™), C-MAC(®) and Airtraq(®) laryngoscopes. Anaesthesia
2016;71:1191-7.
16. Atkinson RC, Shiffrin RM. Human memory: a proposed system and its control processes, vol 2. Psychology of learning and motivation.
New York: Academic Press; 1968.
17. Schneider CL, Cobb WS, Carbonell AM, Hill LK, Flanagan WF. A collaborative approach reduces the learning curve and improves
outcomes in laparoscopic nephrectomy. Surg Endosc 2011;25:182-5.
18. Shariff U, Kullar N, Haray PN, Dorudi S, Balasubramanian SP. Multimedia educational tools for cognitive surgical skill acquisition in
open and laparoscopic colorectal surgery: a randomized controlled trial. Colorectal Dis 2015;17:441-50.