N05: Psycholeptics
ATC N05 psycholeptics for modelers: dropout is informative.
Part of N: Nervous system.
Dropout is informative. Dropout probability rises with a high observed PANSS score, so the dropout hazard is modeled jointly with the score as a time-to-event process [1]. Ignoring it biases parameter estimates, though simulation put that bias relatively low; the model matters most for realistic trial simulation [2].
References
[1]
Pilla Reddy V, Kozielska M, Johnson M, Suleiman AA, Vermeulen A, Liu J, et al. Modelling and simulation of the Positive and Negative Syndrome Scale (PANSS) time course and dropout hazard in placebo arms of schizophrenia clinical trials. Clinical Pharmacokinetics 2012;51:261–75. https://doi.org/10.2165/11598460-000000000-00000.
[2]
Björnsson MA, Friberg LE, Simonsson USH. Performance of nonlinear mixed effects models in the presence of informative dropout. The AAPS Journal 2015;17:245–55. https://doi.org/10.1208/s12248-014-9700-x.