A transient state model for analysing ventilatory status in a randomized clinical trial.
We designed a randomized clinical trial to determine the efficacy of plasma exchange in Guillain-Barré syndrome, an acute neurological disease leading to paralysis in previously healthy subjects. Some patients require temporary mechanical ventilation during the course of the disease. Ventilatory status was analysed using a three-state model with a transient state defined by use of temporary mechanical ventilation, and the probability of being mechanically ventilated modelled as a function of time since randomization. The plot of this function reflects the effect of plasma exchange on ventilatory status showing that fewer plasma-exchanged patients than controls required ventilatory assistance and that the duration of assistance was shorter. Similar functions can be used in a more general framework when the response criterion includes a transient state.
Département de Biostatistique et Informatique Médicale, C.H.U. Lariboisière, Saint Louis, Paris, France.
J P
JP
Jais
C
C
Chastang
J C
JC
Raphael
D002986:Clinical Trials as Topic / Q000379:methods*; D003627:Data Interpretation, Statistical; D006801:Humans; D008962:Models, Theoretical; D010951:Plasma Exchange; D011129:Polyradiculoneuropathy / Q000503:physiopathology / Q000628:therapy; D011897:Random Allocation; D012119:Respiration; D012121:Respiration, Artificial