CA results

PKanalix automatically generates results after running the CA task. This page contains a description of all output tables and files.

Output tables

Compartmental analysis results are displayed in several tables in the “Results” tab, in the CA section at left.

Individual estimates

This table (shown above) contains results from the compartmental analysis for each individual: model parameter values, cost function values, and covariates (from the dataset). By default, the table shows 10 records (ids) per page. With the settings below the table, you can increase the number of records per page and navigate to subsequent pages.

Summary

This table contains summary statistics on compartmental analysis results. The complete description of parameters is here.

To better compare among groups, you can split or filter this table using covariates in a dataset. When you select split/filter, PKanalix automatically re-calculates the values according to the stratification settings and displays them. The following Feature of the week video explains how this feature works using the NCA individual estimates table as an example.

Cost

This table contains model comparison indices calculated for the CA model. It includes: total cost (the sum of individual costs from the INDIV. ESTIM. subtab), -2LL, AIC, and BIC, see here for details about the formulas. Information criteria allow one to statistically compare the fit obtained with different models. For these information criteria, the lower the value of the information criterion, the better the model fits. There is no absolute value of comparison; only the relative difference between two models is important.

Output Files

You can also find the compartmental analysis results in the project results folder in the directory “IndividualParameters > ca” . There are four text files:

summary.txt

Description: Human readable summary file.
Contents:

• Header: project file name, date and time of run, PKanalix version

• Table: Summary statistics of the individual cost function and individual model parameters

caIndividualParameters.txt

Description: Individual parameter estimates.
Contents:

• Identifier: subject name and occasion (if applicable). If one or more occasions are defined in the data, additional column(s) will be present specifying the occasions.

• Cost: value of the individual cost function

• parameterName: individual model parameter values estimated during the compartmental analysis.

• Covariates: continuous and categorical covariates values defined in the dataset.

caIndividualParametersSummary.txt

Description: Statistics summary of individual parameter estimates.
Contents:

• Identifier: subject name and occasion (if applicable). If one or more occasions are defined in the data, additional column(s) will be present specifying the occasions.

• Parameter: cost and model parameters

• Statistics: min, Q1, median, Q3, max, mean, SD, SE, CV, geoMean, geoSD, geoCV, harmMean

cost.txt

Description: Total cost and information criteria for the model.
Contents:

• Cost: Total cost (sum of individual costs)

• Log-likelihood estimation: -2LL, AIC, BIC