Stata 15 help for pksumm

[R] pksumm -- Summarize pharmacokinetic data

Syntax

pksumm id time concentration [if] [in] [, options]

options Description ------------------------------------------------------------------------- Main trapezoid use trapezoidal rule to calculate AUC; default is cubic splines fit(#) use # points to estimate AUC; default is fit(3) notimechk do not check whether follow-up time for all subjects is the same nodots suppress the dots during calculation graph graph the distribution of statistic stat(statistic) graph the specified statistic; default is stat(auc)

Histogram, Density plots, Y axis, X axis, Titles, Legend, Overall histogram_options any option other than by() documented in [R] histogram -------------------------------------------------------------------------

statistic Description ------------------------------------------------------------------------- auc area under the concentration-time curve (AUC); the default aucline area under the concentration-time curve from 0 to infinity using a linear extension aucexp area under the concentration-time curve from 0 to infinity using an exponential extension auclog area under the log-concentration-time curve extended with a linear fit half half-life of the drug ke elimination rate cmax maximum concentration tmax time at last concentration tomc time of maximum concentration -------------------------------------------------------------------------

Menu

Statistics > Epidemiology and related > Other > Summarize pharmacokinetic data

Description

pksumm obtains summary measures based on the first four moments from the empirical distribution of each pharmacokinetic measurement and tests the null hypothesis that the distribution of that measurement is normally distributed.

pksumm is one of the pk commands. Please read pk before reading this entry.

Options

+------+ ----+ Main +-------------------------------------------------------------

trapezoid specifies that the trapezoidal rule be used to calculate the AUC. The default is cubic splines, which give better results for most situations. When the curve is irregular, the trapezoidal rule may give better results.

fit(#) specifies the number of points, counting back from the last time measurement, to use in fitting the extension to estimate the AUC. The default is fit(3), the last three points. This default should be viewed as a minimum; the appropriate number of points will depend on the data.

notimechk suppresses the check that the follow-up time for all subjects is the same. By default, pksumm expects the maximum follow-up time to be equal for all subjects.

nodots suppresses the progress dots during calculation. By default, a period is displayed for every call to calculate the pharmacokinetic measures.

graph requests a graph of the distribution of the statistic specified with stat().

stat(statistic) specifies the statistic that pksumm should graph. The default is stat(auc). If the graph option is not specified, this option is ignored.

+-------------------------------------------------------------------+ ----+ Histogram, Density plots, Y axis, X axis, Titles, Legend, Overall +

histogram_options are any of the options documented in [R] histogram, excluding by(). For pksumm, fraction is the default, not density.

Remarks

pksumm produces summary statistics for the distribution of nine common pharmacokinetic measurements. If there are more than eight subjects, pksumm also computes a test for normality on each measurement. The nine measurements summarized by pksumm are listed above and are described in Methods and formulas of [R] pkexamine.

Examples

Setup . webuse pksumm

Summary statistics for all pharmacokinetic measures . pksumm id time conc

Graph the distribution of the AUC . pksumm id time conc, graph bin(20)

Graph the distribution of the elimination rate . pksumm id time conc, stat(ke) graph bin(20)


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