Comparison of the 4-Digit Code, Canadian 2015, Australian 2016 and Hoyme 2016 fetal alcohol spectrum disorder...

As clinicians strive to achieve consensus worldwide on how best to diagnose fetal alcohol spectrum disorders (FASD), the most recent FASD diagnostic systems show convergence and divergence. Applying these systems to a single clinical population illustrates the contrasts between them, but validation studies are ultimately required to identify the best system.

The 4-Digit-Code, Hoyme 2016, Canadian 2015 and Australian 2016 FASD diagnostic systems were applied to 1,392 patient records evaluated for FASD at the University of Washington. The diagnostic criteria and tools, the prevalence and concordance of diagnostic outcomes, and validity measures were compared between the systems.

The proportion diagnosed with fetal alcohol syndrome (FAS) and FASD varied significantly (4-Digit-Code 2.1%, ≤79%; Hoyme 6.4%, 44%, Australian 1.8%, 29%; Canadian 1.8%, 16%). Eighty-two percent were diagnosed FASD by at least one system; only 11% by all four systems. Key factors contributing to discordance include: requiring high alcohol exposure; excluding growth deficiency; relaxing the facial criteria; requiring brain criteria that prevent diagnosis of infants/toddlers; and excluding moderate dysfunction from the spectrum. Primate research confirms moderate dysfunction (1-2 domains ≤-2 standard deviations) is the most prevalent outcome caused by PAE (FAS 5%, severe dysfunction 31%, moderate dysfunction 59%). Only the 4-Digit-Code replicated this diagnostic pattern.

The needs of individuals with FASD are best met when diagnostic systems provide accurate, validated diagnoses across the lifespan, the full spectrum of outcome, the full continuum of alcohol exposure; and utilize diagnostic nomenclature that accurately reflects the association between outcome and alcohol exposure.