Table 1.

Relative bias of model parameters using non linear mixed models taking into account left-censored (undetectable) values (corrected) or not (crude) with simulated data. N = 20 patients, 1000 simulations, 14% left-censored measures in average.

Parameter and true value		Crude estimate		Corrected estimate
		Estimates	Relative bias (%)	Estimates	Relative bias (%)
Fixed effects
V0	6.16 log10 IU/mL	6.09	-1.1	6.16	-0.021
δ	0.40 day-1	0.18	-55.2	0.40	+0.78
c	2.00 day-1	1.10	-44.8	2.03	+1.5
ε	0.80	0.93	+15.8	0.79	-1.3
Variances
${\sigma }_{{\gamma }_0}^2$	0.49	0.59	+20.3	0.46	-6.4
${\sigma }_{{\gamma }_1}^2$	2.69	2.18	-18.8	2.31	-13.9
${\sigma }_e^2$	0.04	0.09	+133.2	0.039	-2.4