Table 4.

Adjusted estimates of the costs attributable to robot-assisted laparoscopic prostatectomy (RALP): main model compared with extended model, which includes adjustment for tumour size and nodal involvement

Feature	Main model		Extended model
	Coefficient	p Value	Coefficient	p Value
Treatment
RALP (reference)
OP	−2459 (−3540 to −1377)	0.003	−2756 (−3965 to −1548)	0.003
LP	−3860 (−7160 to −559)	0.031	−3990 (−7073 to −906)	0.023
Age	14 (−43 to 71)	0.541	7 (−66 to 80)	0.815
Region
Central Denmark Region (reference)
Capital Region of Denmark	85 (−689 to 860)	0.775	881 (−833 to 2594)	0.227
Region of Southern Denmark	1907 (610 to 3204)	0.015	1882 (−13 to 3777)	0.051
North Denmark Region	241 (156 to 327)	0.001	404 (−288 to 1096)	0.181
Organisation type
Within-speciality (reference)
Robotic centre	1028 (460 to 1595)	0.007	978 (−181 to 2136)	0.079
Year of surgery
2006 (reference)
2007	376 (−264 to 1016)	0.178	304 (−253 to 861)	0.204
2008	1386 (−41 to 2813)	0.054	1222 (−51 to 2496)	0.056
2009	−688 (−1627 to 250)	0.111	−919 (−1870 to 32)	0.055
2010	910 (−540 to 2361)	0.156	668 (−734 to 2070)	0.257
2011	1244 (–226 to 2714)	0.079	971 (−552 to 2494)	0.151
2012	1423 (205 to 2641)	0.032	1371 (433 to 2309)	0.015
2013	3036 (1338 to 4734)	0.008	3058 (1591 to 4525)	0.004
Tumour size
T0-T2 (reference)
T3-T4			1172 (683 to 1660)	0.003
Missing data			1599 (−1270 to 4469)	0.197
Nodal involvement
N0 (reference)
N1-N3			−2676 (−5796 to 444)	0.076
Missing data			−1219 (−2102 to −335)	0.019
Constant	10 803 (7643 to 13964)	0.001	11 136 (7111 to 15 161)	0.002
n		4309		4309
R2		0.041		0.046
Root mean SE		10 232		10 213

Values are mean costs (2014, €) with 95% CI.

LP, laparoscopic prostatectomy; OP, open prostatectomy; RALP, robot-assisted laparoscopic prostatectomy.