Bioequivalence and Bioavailability Forum

~geometric mean of range [Bioanalytics]

posted by Helmut  – Vienna, Austria, 2014-06-18 18:07 (3997 d 04:47 ago) – Posting: # 13084
Views: 14,487

Hi Nobody,

❝ And the weighing is applied for heteroscedasticy, […] weighing increases accuracy of samples calculated from the calibration function, especially in the lower range.

Correct. Now think about the confidence bands of the regression: They are two hyperbolas. The confidence band is narrowest at x|y. Both with geometric spacing of calibrators and weighting we shift the means towards the lower end. Therefore, the accuracy close to the LLOQ increases (narrower CI). But there is no free lunch. Accuracy at the upper end decreases.

❝ So, where am I wrong?

In my example it might matter whether we look at x=16 or x=65.

—
Dif-tor heh smusma 🖖🏼 Довге життя Україна! 
Helmut Schütz


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Complete thread:

• determining the QC medium haydonat 2012-10-18 00:26 
  • QC medium: short answer Helmut 2012-10-18 16:14
    • QC medium: short answer ElMaestro 2012-10-18 16:51
  • QC medium: lengthy answer Helmut 2012-10-19 15:47
    • QC medium concentration in 2014 Debbie 2014-06-10 19:42
      • ~geometric mean of range Helmut 2014-06-17 14:30
        • ~geometric mean of range nobody 2014-06-17 14:49
          • ~geometric mean of range Helmut 2014-06-17 15:11
            • ~geometric mean of range nobody 2014-06-17 18:26
              • ~geometric mean of rangeHelmut 2014-06-18 16:07
                • compromise ElMaestro 2014-06-18 17:43
                  • compromise Ohlbe 2014-06-18 20:00
                    • compromise Helmut 2014-06-19 01:13
                      • compromise Ohlbe 2014-06-19 11:15
                • compromise nobody 2014-06-19 14:10