Bioequivalence and Bioavailability Forum • The missing 72h

The missing 72h [NCA / SHAM]

posted by d_labes – Berlin, Germany, 2009-01-27 12:48 (6346 d 00:30 ago) – Posting: # 3137
Views: 41,306

Dear Helmut,

❝ ... I have such a procedure since decades (oh, I’m getting old) in my protocols ...

Don't lose heart! Getting old is not for sissies (Bette Davis) :-D

!

I have the vague suspicion that I have not explained my point precise enough.

So let me give an example (real data):


       time      Conc.

----------------------------------

 1     0.0        0.00

 2     0.5        0.00

 3     1.0        2.55

 4     2.0        9.79

 5     3.0       13.23

 6     4.0       14.43

 7     5.0       12.49

 8     6.0       12.78

 9     7.0       10.96

10     8.0       12.40

11    10.0       11.68

12    12.0       11.26        *

13    24.0        8.36        *

14    48.0        7.53        *

15    72.0        4.78 (missing)

----------------------------------

Half live for this curve with no missings is 53.6 h (using points 12-72 h).
AUC(0-72)=584.93 (linear trapezoidal rule for sake of simplicity).

If now the conc. value at 72h is missing unfortunately (vial broken or so), what to do?
AUC(0-48h) is 437.21, considerably lower than AUC(0-72), only 75%.

Option: Exclude subject
Option: Use AUC(0-48)
Option: Extrapolate to 72h (C(calc.)=5.69 using log-lin regression with * points) and calculate then AUC (result=595.85).

Looking forward to your opinion.
Other users also a position?

—
Regards,

Detlew

Complete thread:

Calculation of AUC0-72 Sasi 2008-06-10 10:44 [NCA / SHAM]
- Calculation of AUC0-72 Jaime_R 2008-06-10 12:18
  - Calculation of AUC0-72 Ohlbe 2008-06-10 17:28
    - Calculation of AUC0-72 Jaime_R 2008-06-10 18:45
      - Regulators truncated d_labes 2009-06-18 09:26
        
        Regulators truncated Ohlbe 2009-06-18 10:37
        Regulators truncated Helmut 2009-06-18 14:49
        
        Regulators truncated d_labes 2009-06-18 15:26
        
        Regulators truncated Helmut 2009-06-18 15:44
        
        Regulators truncated ElMaestro 2009-06-19 22:16
        
        Regulators truncated Helmut 2009-06-19 22:35
        
        Luke 23:34 ElMaestro 2009-06-18 14:50
    - Calculation of AUC0-72 d_labes 2008-09-05 15:00
      - Calculation of AUC0-72 Helmut 2009-01-26 16:24
        
        Calculation of AUC0-72 d_labes 2009-01-26 16:57
        
        Calculation of AUC0-72 Helmut 2009-01-26 17:20
        
        The missing 72hd_labes 2009-01-27 11:48
        
        The missing 72h Ohlbe 2009-01-28 00:00
        
        sensitivity analyses ? martin 2009-01-28 08:26
        Regulators ways are inscrutable d_labes 2009-01-28 09:54
        
        Regulators ways are inscrutable (at least the French) Ohlbe 2009-01-28 10:16
        
        The missing 72h ElMaestro 2009-01-28 14:32
        
        Page 3848 of 221 d_labes 2009-01-28 14:51
        
        Partial AUC calculation Astea 2017-03-11 20:14
        
        Partial AUC calculation mittyri 2017-03-16 19:46
- Calculation of AUC0-72 PharmCat 2022-12-21 20:49