Issues in estimating the prevalence of fetal alcohol syndrome: examination of 2 counties in New York State.

OBJECTIVE Two demographically similar counties included in the New York Fetal Alcohol Syndrome Surveillance Network had very different prevalence rates. This study examined the components of the surveillance in an attempt to discover the reasons for this discrepancy. METHODS Erie County and Monroe County were the 2 most populous counties included in the New York Fetal Alcohol Syndrome Surveillance Network. Erie County includes Buffalo, the second largest city in New York State, and Monroe County includes Rochester, the third largest city. Multiple sources of ascertainment included birth defect surveillance systems, genetic clinics, and early intervention programs. The case definition was based on the Institute of Medicine criteria of an abnormality in each of the following 3 areas: facial features, central nervous system, and growth. RESULTS Children born in Erie County or Monroe County between 1995 and 1999 were included. The fetal alcohol syndrome prevalence rates in these 2 counties were 0.90 cases per 1000 births and 0.21 cases per 1000 births, respectively. The 2 counties were demographically similar and had similar rates of binge drinking among women of childbearing age. There was less participation in the surveillance system by sources in Monroe County. Erie County had a very active clinician with a specialized fetal alcohol syndrome clinic. CONCLUSIONS The participation of clinicians in one county, especially one with expertise in fetal alcohol syndrome, was the most likely explanation for the differences in prevalence rates between the counties.