Temporal relationship modeling: DTP or DT immunizations and infantile spasms

The time relationship between DTP immunization and infantile spasms (IS) onset was examined using three models-association, temporal shift, and no-effect-and the case/control data from the National Childhood Encephalopathy Study (NCES). Infantile spasms cases classified as being previously abnormal (e.g. tuberous sclerosis complex patients) showed a no-effect relationship, whereas those classified as previously normal suggested a Jit to the temporal shift model, i.e. no increase in number-of cases but a shortening of time to onset of seizure. No data fit the association model. Analyses for vaccine complications should examine for temporal changes (i.e. temporal shift) in addition to increased risks. (C) 1997 Elsevier Science Ltd. All rights reserved.