Bioequivalence and Bioavailability Forum • Lin-up/log-down trapezoidal example

Lin-up/log-down trapezoidal example [NCA / SHAM]

posted by Helmut – Vienna, Austria, 2013-05-25 17:09 (4782 d 16:55 ago) – Posting: # 10656
Views: 24,599

Dear Yung-jin,

❝ […] is there any special consideration when using lin-up/log-down trapezoidal rule to calculate AUCs if there is more than one absorption peak?

I checked one study of bimodal release formulations. Imbalanced, n=15. I evaluated AUC_t based on the linear trapezoidal and the lin-up/log-down method. Then I introduced a failure of the centrifuge resulting in a complete loss of 12 h samples in the second period. Let’s see:

PE 90% CI %CV_intra %CV_inter complete, linear 99.89 95.23–104.78 7.38 33.75 complete, lin-up/log-down 99.78 95.10–104.69 7.42 33.40 incomplete, linear 100.08 95.64–104.72 7.00 33.84 incomplete, lin-up/log-down 99.93 95.37–104.72 7.23 33.39

With the linear trapezoidal results change whereas with the lin-up/log-down results are affected to a lesser degree. I didn’t check but expect to get identical results in a balanced case.

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Helmut Schütz

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Complete thread:

handling of missing data gracehung 2013-05-20 07:35 [NCA / SHAM]
- Lin-up/log-down trapezoidal avoids most trouble Helmut 2013-05-20 14:22
  - Lin-up/log-down trapezoidal avoids most trouble yjlee168 2013-05-22 08:25
    - Multiple peaks: fallback to linear trapezoidal Helmut 2013-05-22 20:25
      - Multiple peaks: fallback to linear trapezoidal yjlee168 2013-05-22 21:57
        
        No interpolation Helmut 2013-05-22 23:25
        
        No interpolation yjlee168 2013-05-23 11:43
        
        Spaghetti & other pasta Helmut 2013-05-23 15:15
        
        Spaghetti & other pasta yjlee168 2013-05-23 20:47
        
        Spaghetti & other pasta Helmut 2013-05-23 21:29
        
        Spaghetti & other pasta yjlee168 2013-05-23 22:46
        
        Spaghetti & other pasta Helmut 2013-05-24 01:24
        
        Spaghetti & other pasta yjlee168 2013-05-24 09:17
        
        No interpolation Ken Peh 2013-05-30 19:55
        
        Different algos! Helmut 2013-05-30 22:38
        
        Different algos! Ken Peh 2013-06-03 17:52
        
        Calculate what? Helmut 2013-06-03 18:11
    - Lin-up/log-down trapezoidal exampleHelmut 2013-05-25 15:09
      - Lin-up/log-down trapezoidal example yjlee168 2013-05-25 19:45
- handling of missing data Ohlbe 2013-05-20 21:45
  - Sorry Helmut 2013-05-21 13:53
    - Sorry gracehung 2013-05-23 01:06
      - Uncertain time point Helmut 2013-05-23 01:35