In this study, the relationship between the age of MMR vaccination and autism is again examined using the same MADDSP data set used by DeStefano et al.
In the MADDSP, autistic "case" and non-autistic control children were selected from school districts in five counties.
Analyzing information from the MADDSP
and the Metropolitan Atlantic Congenital Defects Program, the researchers found that the risk of autism accompanied by mental retardation or other developmental disabilities was consistently higher for low-birth-weight and premature children than was the risk of autism alone.
Finally, DD prevalences were based on data from MADDSP
and might not be representative of national prevalences.
Medical data for children in MADDSP include pregnancy and birth history, data on congenital malformations, diagnostic information, and data on general medical conditions associated with the children's disability.
Thirteen children in MADDSP were identified as having possible metabolic disorders.
Cognitive test results from the MADDSP database were used to identify functional CNS impairment.
During 1981-1989, MACDP and MADDSP combined identified 92 children with possible FAS: MACDP uniquely identified 50 (54%) of these possible cases; MADDSP uniquely identified 31 (34%); and both registries identified 11 (12%).
For this period, MADDSP identified 413 children (283 in 1991, 288 in 1992, and 293 in 1993) who met the surveillance case definition for hearing impairment.
Because MADDSP focuses primarily on children with serious bilateral hearing impairment, these findings probably underestimate the actual magnitude of delayed diagnosis.
Editorial Note: This analysis of MADDSP data identified distinct causes for the four postnatally acquired developmental disabilities analyzed, most of which are preventable.
Hib vaccine was licensed for use in infants in the United States in 1990 and has been distributed widely (5); however, the 1991 MADDSP data include information about children born during 1981-1988 (before the vaccine became available).