Function to calculate the number of sample points

[Sibojang9]

Hi Bill,

When we select the of Calculation Intervals, is there any function in PKNCA to calculate the number of points within the end specification? e.g. n=8 within 24 hours.

This would help to verify that intended sampling points are available to derive the PK parameters.

Thanks,

Sibo

[billdenney]

Yes, I've had the same question/need in the past. So there are two point counting parameters:

• count_conc which counts any non-missing concentrations (it does count BLQ and ALQ concentrations)
• count_conc_measured which counts any non-missing and non-BLQ/ALQ concentrations

For my work, the first is useful for QC checking that you're not missing (too many) samples. And, the second is useful for verification that a concentration interval is useful for more than cmax and tmax.

[Sibojang9]

Hi Bill, that is very helpful. Is there any cheat sheet or other documentation for all the interval parameters? This count_conc looks like a hidden gem.

[billdenney]

All parameters are defined here: https://humanpred.github.io/pknca/articles/v03-selection-of-calculation-intervals.html#parameters-available-for-calculation-in-an-interval

[Sibojang9]

Perfect. Thanks.