Bioequivalence and Bioavailability Forum

Hi Babe_Ruth,

❝ […] WNL (currently using v 6.3) …

Your version is four releases behind the current one (v8.1). High time to update.

❝ I've noticed that in the 0-24hr partial area calculation, there are differences between imputing BQL with 0 and setting it as no value.

As expected.

❝ When I set BQL to "no value," then it uses the rules stated in documentation: WNL rules for partial areas are stated here. Most notably: "If ... end time falls after the last numeric observation and λz is not estimable, the partial area will not be calculated." Requiring λz suggests that WNL does not default to another calculation method in case log-linear isn't available.

Correct (note that this post referred to v7.0 of 2016).

❝ However, when I set BQL to 0, it uses a linear-trapezoidal rule: (Clast + 0)*(T16 - Tlast)

Also correct.

❝ Nowhere in the documentation does it say that this was the plan.

See the last bullet point of the linked post:

• […] if […] there is an observation of zero that is used in computing the partial area, then the linear trapezoidal rule will override the log trapezoidal rule.

You will not find this in the documentation of v6.3; too lazy to check its behavior.

❝ In summary, when I set BQL to 0, calculation method for partial area changes and the values slightly differ. Is this intended?

As designed and explained by ElMaestro above.

❝ Is this normal practice?

Bad practice to force BQLs after t_max to zero. I have seen many “rules” (e.g., first BQL to BQL/√2 or BQL/2, keep subsequent ones at BQL, whatsoever…). IMHO, that’s all crap. AFAIK, Martin Wolfsegger and Alexander Bauer are working on a NCA-method dealing with terminal BQLs. In the meantime I suggest to keep BQLs as they are.