BACKGROUND: For patients with Crohn's disease, age at onset is known to 
influence the clinical course of the illness.
AIMS: The aim of this study is to seek an association between age at onset of 
Crohn's disease and use of biologic agents for its treatment.
METHODS: We reviewed the medical records of 127 veteran patients with Crohn's 
disease treated at our hospital, and compared differences in age at disease 
onset between patients who had received biologics and those who had not.
RESULTS: The mean age of our patients was 54.9 ± 15.4 years, and 34% were 
currently receiving or had previously received treatment with a biologic agent. 
For those with biologic use, average age at time of diagnosis of Crohn's disease 
was 32.3 ± 12.2 years, compared with 43.7 ± 16.3 years for those who had not 
received biologics (P = 0.005). This relationship remained significant even 
after controlling for disease severity. The frequency of use of biologic agents 
varied inversely with age at diagnosis. For patients diagnosed before age 21 
years, 55.5% had used biologics, whereas no patient >70 years of age at time of 
diagnosis had used biologics. We found no significant correlation between 
biologic use and duration of disease, smoking or ethnicity. Perianal disease and 
concomitant arthritis were both significantly associated with use of biologics.
CONCLUSIONS: In our veteran patients with Crohn's disease, frequency of 
treatment with a biologic agent varied inversely with age at disease onset.