Validation studies from the Western Australian Congenital Malformations Registry.

A series of studies was undertaken in 1989 to validate the data held by the Western Australian Congenital Malformations Registry. Comparison with hospital discharge data identified 1585 children six years of age or younger with malformations discharged from hospitals in Western Australia in 1986, 226 of whom were not already recorded on the Congenital Malformations Register. When the records of a special register for cleft lip and palate were examined, all cases of facial cleft known to the special register were also recorded on the Malformations Register. Comparison of the Western Australian data for major groups of malformations with data from the South Australian Birth Defects Register raised the possibility of under ascertainment in Western Australia of cases of congenital heart disease. Multiple sources of ascertainment and evaluation of the ways in which such sources are tapped are important factors in striving for complete and accurate information on congenital malformations for research and public health purposes.