Cerebral palsy and intrapartum careBMJ 1994; 309 doi: https://doi.org/10.1136/bmj.309.6963.1229 (Published 05 November 1994) Cite this as: BMJ 1994;309:1229
Wrong denominator used
- E Blair
EDITOR, - Geraldine Gaffney and colleagues calculated a significantly increased odds ratio for cerebral palsy and for perinatal death according to two definitions of suboptimal intrapartum care.1 Care was defined as suboptimal if there was failure to respond in specified ways to one of a large number of suboptimal conditions or if instrumental delivery met one of two descriptions. Therefore care was only at risk of being classified as suboptimal in the presence of one (or more) of those suboptimal conditions. In order to conclude that suboptimal care was or was not associated with an outcome, the proportion of cases and controls receiving suboptimal care who were at risk of suboptimal care must be compared.
Gaffney and colleagues did not say the number of cases …