Just How Many People Have an FASD?
When talking about the number of people who have a Fetal Alcohol Spectrum Disorder (FASD), the statistic of 1 in 100 is commonly used. It is often followed by a caution that rates most likely are higher. It can also be confusing because when talking about Fetal Alcohol Syndrome (FAS), a diagnosis under the umbrella of FASD, the statistic is usually a number out of 1000.
Why is there uncertainty about the rate of FASD?
The rate that is found depends on:
- the type of study used to count people with an FASD
- the population that is looked at
Clinic-based studies are commonly used to look at the rate of FASD. These studies only look at children who have been referred to a clinic to be assessed by specialists. Many children who may have an FASD are not sent for an assessment and are not even considered as part of the count.
In-school studies
In-school studies are a recent method of looking at rates of FASD. In these studies, the specialists go to schools and examine all students of a particular age. These studies are representative of the local population and can be considered a good sample.
In-school studies are useful for two reasons:
- They examine all the children in a group, some of whom might never have been referred for an assessment.
- It is easier to diagnose school-age children.
It can be difficult to diagnose children from the ages of birth to 3, except in obvious cases such as when the child has facial features consistent with FAS. When looking at children in grade one, the tests used for a diagnosis in FASD can discover children who may never have been thought of as having the disability. Instead, they may have been seen as “bad children”.
Results from in-school studies
In 2001, Dr. Sterling Clarren led an in-school study of grade one students in two counties in Washington DC. He was looking at Fetal Alcohol Syndrome. At that time, it was believed the rate of FAS was .5 to 2 per 1,000. In one county, essentially all students were screened. He found that the rate of FAS was 3.1 per 1,000 which was much higher than earlier estimates. Out of the children found to have FAS, only one had been diagnosed before the study! In the second county, only 25% of children were screened and the results were inconclusive.
Dr. Philip May has done in-school studies in a variety of locations (South Africa, Italy, and the United States). As a result of his work, he concludes that the rates of FAS and FASD in the general population are higher than many experts state. He suggests that 2 to 7 children out of every 1,000 have FAS. For children with an FASD, he estimates that the rate may be as high as 2 to 5 out of every 100.
In a recent video hosted by NOFAS, Dr. May states that he sees 4 cases of partial FAS (pFAS - another diagnosis in the spectrum) for every 1 case of FAS. He also believes a large number of children have Alcohol Related Neurobehavioural Disorder (yet another diagnosis in the spectrum) compared to FAS and pFAS.
In conclusion
So…how many people have an FASD? At present, there are a variety of answers, and it is fair to say as many as 5 in 100 people have an FASD. No matter what statistic one chooses to use, FASD remains the most common developmental disability in Canada.
References
May, P. A., & Gossage, J. P. (2001). Estimating the Prevalence of Fetal Alcohol Syndrome: A Summary. Retrieved August 9, 2012, from http://pubs.niaaa.nih.gov/publications/arh25-3/159-167.htm.
May, P. A., Gossage, J. P., Kalberg, W. O., Robinson, L. K., Buckley, D., Manning, M., & Hoyme, H. E. (2009). Prevalence and epidemiologic characteristics of FASD from various research methods with an emphasis on recent in-school studies. Developmental Disabilities Research Reviews, 15, 176-192.
NOFAS. (n.d.). Dr. Philip May on FASD Prevalence Rates. Retrieved August 3, 2012, from http://www.youtube.com/watch?v=ZNSPVOzeRNc&feature=plcp
Sampson, P. D., Streissguth, A. P., Bookstern, F. L., Little, R. E., Clarren, S. K., Dehanne, P., Hanson, J. W., Graham, J. M. Jr.(1997). Incidence of FAS and prevalence of ARND. Teratology 56: 317-326.
Stoler, J. M., & Holmes, J. B. (2004). Recognition of facial features of fetal alcohol syndrome in the newborn. American Journal of Medical Genetics, 127C, 21-27.