Attention-deficit hyperactivity disorder in Manitoba children: medical diagnosis and psychostimulant treatment rates.

OBJECTIVE: To describe physicians' diagnosis rates for attention-deficit hyperactivity disorder (ADHD) for children in the province of Manitoba and to describe the rate of psychostimulant medication use by these children.
METHODS: This descriptive study reviewed the computerized administrative records of physician visits and prescriptions dispensed to examine a population-based, cross-sectional cohort of children diagnosed with ADHD or prescribed stimulant medication, or both. We found 4787 children with a diagnosis of ADHD over a 24-month period or a prescription for stimulant medication over a 12-month period, or both. Rates were calculated by age, sex, region of residence, neighbourhood income level, and physician specialty.
RESULTS: Among Manitoba children, 1.52% received a medical diagnosis of ADHD and 0.89% received stimulant medication. Regionally, diagnosis rates for ADHD varied almost 4-fold, and over 8-fold for medications prescribed. Urban areas had higher rates than did rural areas, regardless of physician specialty. Diagnosis and prescription rates varied according to physician specialty, with the highest rates found among pediatricians. An income gradient was evident in rural areas, with rates of ADHD diagnosis and medication prescribed increasing with increased neighbourhood income level.
CONCLUSIONS: The pattern of regional variation found in this study suggests that the diagnosis and treatment of ADHD in Manitoba are influenced strongly by the practice styles of local physicians.