The AUClast is not calculated

[jeslo328]

Hi

The NCA calculation does not seem to generate AUClast for some IDs in my dataset. Though the similar has a different output through winnolin. Attached here is the example for 1 ID similar to what I have and its output. Also the code I'm using. Please guide me into what am I missing or doing wrong here. Thanks

#The data----
USID     DV	MDV TIME          AMT       	
1	     0	        0	0                 12403
1	     0.962	0	0.35
1	     0.7	0	0.7167
1	     0.444	0	1.6833
1	     0.303	0	3.1167
1	    0.0298	0	21.55


# The code ----
 o_conc <- PKNCAconc(data2_ncaCONC,DV~TIME|ID)
o_dose <- PKNCAdose(data2_ncaDOSE,AMT~TIME|ID)

data_NCA <- PKNCAdata(o_conc, o_dose,
                                    intervals=data.frame(start=0, # Change 1 
                                                         end=24,
                                                         cmax=T,
                                                         cmin=T,
                                                         cav=T,
                                                         tmax=T,
                                                         half.life=F,
                                                         aucall=TRUE,
                                                         auclast=TRUE,
                                                         aucinf.pred=T,
                                                         aucinf.obs=T))
results_NCA <- pk.nca(data_NCA)

#The Outcome----
0	24	1	auclast	NA	       NA
0	**24	1	aucall	NA	        NA**
0	24	1	cmax	0.962	NA
0	24	1	cmin	0.0298	NA
0	24	1	tmax	0.35	         NA
0	24	1	last	        21.55	NA
0	24	1	clast.obs	0.0298	NA
0	24	1	cav	        NA	        NA
0	24	1	lambda.z	        0.1316515	NA
0	24	1	r.squared	       0.9956067	NA
0	24	1	adj.r.squared	0.9912133	NA
0	24	1	lambda.z.time.first	1.6833	NA
0	24	1	lambda.z.n.points	3	         NA
0	24	1	clast.pred	                 0.0295851	NA
0	24	1	half.life	                 5.2650149	NA
0	24	1	span.ratio	3.7733416	NA
0	24	1	aucinf.obs	NA	NA
0	24	1	aucinf.pred	NA	NA

[billdenney]

Thanks for the example data and code. What value were you expecting?

[jeslo328]

PARAMCD AVAL
AE 3045
AUCIFO 2.60138522
AUCLST 2.55066093
CLO 3640.368189
CMAX 0.679
FE 32.15417107
Half-Life Lambda z (h) 3.805129697

[jeslo328]

PARAM PARAMCD
Amount Excreted Ae(0-3hr postdose) (kBq) AE
AUC Infinity Obs (hBq/uL) AUCIFO
AUC to Last Nonzero Conc (hBq/uL) AUCLST
Total CL Obs (mL/h) CLO
Max Conc (Bq/uL) CMAX
Fraction Excreted Fe(0-3hr postdose) (%) FE
Half-Life Lambda z (h) LAMZHL

Im expecting some values rather NC since there are data up to 21hours post dose

[jeslo328]

[billdenney]

My guess is that you did not have a time 0 concentration in your concentration data. This gets a result for me. (The numbers are different, but given that Cmax differs, I guess the input data is not identical.)

library(PKNCA)
#> 
#> Attaching package: 'PKNCA'
#> The following object is masked from 'package:stats':
#> 
#>     filter

#The data----
data2_ncaCONC <-
  data.frame(
    USID = 1,
    DV = c(0, 0.962, 0.7, 0.444, 0.303, 0.298),
    MDV = 0,
    TIME = c(0, 0.35, 0.7167, 1.6833, 3.1167, 21.55),
    AMT = c(12403, rep(0, 5))
  )

data2_ncaDOSE <- data2_ncaCONC[data2_ncaCONC$AMT > 0, ]

# The code ----
o_conc <- PKNCAconc(data2_ncaCONC,DV~TIME|USID)
o_dose <- PKNCAdose(data2_ncaDOSE,AMT~TIME|USID)

data_NCA <- PKNCAdata(o_conc, o_dose,
                      intervals=data.frame(start=0, # Change 1 
                                           end=24,
                                           cmax=T,
                                           cmin=T,
                                           cav=T,
                                           tmax=T,
                                           half.life=F,
                                           aucall=TRUE,
                                           auclast=TRUE,
                                           aucinf.pred=T,
                                           aucinf.obs=T))
results_NCA <- pk.nca(data_NCA)

as.data.frame(results_NCA)
#> # A tibble: 19 × 6
#>     USID start   end PPTESTCD            PPORRES exclude
#>    <dbl> <dbl> <dbl> <chr>                 <dbl> <chr>  
#>  1     1     0    24 auclast              7.08   <NA>   
#>  2     1     0    24 aucall               7.08   <NA>   
#>  3     1     0    24 cmax                 0.962  <NA>   
#>  4     1     0    24 cmin                 0      <NA>   
#>  5     1     0    24 tmax                 0.35   <NA>   
#>  6     1     0    24 tlast               21.6    <NA>   
#>  7     1     0    24 clast.obs            0.298  <NA>   
#>  8     1     0    24 cav                  0.295  <NA>   
#>  9     1     0    24 lambda.z             0.0246 <NA>   
#> 10     1     0    24 r.squared            0.368  <NA>   
#> 11     1     0    24 adj.r.squared        0.0522 <NA>   
#> 12     1     0    24 lambda.z.time.first  0.717  <NA>   
#> 13     1     0    24 lambda.z.time.last  21.6    <NA>   
#> 14     1     0    24 lambda.z.n.points    4      <NA>   
#> 15     1     0    24 clast.pred           0.284  <NA>   
#> 16     1     0    24 half.life           28.1    <NA>   
#> 17     1     0    24 span.ratio           0.741  <NA>   
#> 18     1     0    24 aucinf.obs          19.2    <NA>   
#> 19     1     0    24 aucinf.pred         18.6    <NA>

^{Created on 2025-07-21 with reprex v2.1.1}