Table 5: Sensitivity analysis
Period of follow-up; strategy%Mean cost per patient
(95% CI),† $Cost difference (immediate treatment v. active surveillance) Mortality*Recurrence*Discount*Absolute,$Relative, %
Model integrating assumptions derived from Keegan et al. (23)
First year and 5-year follow-up
Active surveillance005 855 (5 780–5 930)6 41652.3
0055 474 (5 408–5 539)6 23753.3
Immediate treatment0012 271 (12 161–12 381)
00511 711 (11 625–11 798)
First year and 10-year follow-up
Active surveillance009 201 (9 069–9 334)5 84338.8
0057 673 (7 584–7 763)6 16544.6
Immediate treatment0015 044 (14 806–15 282)
00513 838 (13 679–13 997)
Model with discount rates of 3% and 10%
First year and 5-year follow-up
Active surveillance3.813.935 810 (5 701–5 920)7 49656.3
3.813.9105 134 (5 039–5 230)7 36758.9
Immediate treatment3.82.57313 306 (13 199–13 413)
3.82.571012 501 (12 417–12 586)
First year and 10-year follow-up
Active surveillance3.813.939 438 (9 246–9 629)7 60144.6
3.813.9107 357 (7 214–7 499)7 23949.6
Immediate treatment3.82.57317 039 (16 836–17 242)
3.82.571014 596 (14 461–14 731)
Model with 15 years of follow-up
Active surveillance3.8§; 8.16¶13.914 806 (14 480–15 132)8 06335.3
3.8§; 8.16¶13.9511 082 (10 853–11 311)7 01338.8
Immediate treatment3.8§; 8.16¶2.5722 869 (22 511–23 227)
3.8§; 8.16¶2.57518 095 (17 864–18 324)

Note: CI = confidence interval. *Yearly rate. †The 95% CI of the mean cost was obtained by the simulation of 1000 samples of equal sample size of 12 750 patients. ‡The assumptions are as follows: 1) 2 additional biopsies in the first 5-year period of follow-up; 2) rate of death and rate of recurrence, both set to 0; 3) probability of receiving each specific treatment assumed to be 0.4 for radical prostatectomy, 0.25 for intensity-modulated radiotherapy, 0.1 for intensity-modulated radiotherapy plus androgen deprivation therapy, 0.15 for brachytherapy and 0.1 for androgen deprivation therapy; and 4) probability of receiving delayed treatment of 7% per year, in the first 5 years of follow-up, and 4.5% per year in the following 5-year period. §Years 1 to 10.  ¶Years 11 to 15.