Attention Deficit Hyperactivity Disorder (ADHD)

Key DFM Personnel

Dennis J. Baumgardner, MD
Jonathan Weimer
Andrea Schreiber, MA.

Background

Attention deficit hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder of childhood. Previous studies have shown that male gender, low income, and family dysfunction increase incidence of ADHD, without apparent relationship to geographic region, socioeconomic status, or environmental factors. Formal community geographic systems analysis has not been done.

Purpose

A pilot study to determine if there is a non-random geographic distribution of ADHD in Milwaukee County.

Methods

Street addresses and demographic data of all children aged 5-17 receiving continuity care at three Family Medicine Clinics in Milwaukee, WI who did (N=80) or did not (N=1144) have ADHD were geocoded with Map Marker Plus and were mapped using ARC-GIS. CrimeStat III was used for spatial modeling, including mapping of ratio of case/control densities. Univariate analysis was done by Chi-Square test or Mann-Whitney U test, and multivariate analysis by binary logistic regression.

Results

In univariate analysis all non-white ethnicities were less frequently diagnosed with ADHD (all p values = 0.02). ADHD cases were 75% male (p=0.0001). In multivariate analysis, zip code of residence and gender were significant factors (p=0.000), but not race/ethnicity. ADHD cases were overrepresented in south and western suburban school districts, compared to Milwaukee, and particularly in a zip code adjacent to the major airport (ratio observed/expected cases=7).

Conclusion

Further studies are needed to determine if geographic distribution of ADHD patients can be partially explained by differential efficiency of referral for diagnosis by school districts and/or environmental factors such as noise corridors.