The incidence of methylphenidate use by Canadian children: what is the impact of socioeconomic status and urban or rural residence?
OBJECTIVE
To examine socioeconomic, demographic, and behavioural factors that influence the incidence of methylphenidate use among children aged 4 to 13 years.


METHODS
A total of 11,316 children, aged 2 through 11 years, from Cycle 1 (1994-95) of the National Longitudinal Survey of Children and Youth were followed up 2 years later in Cycle 2 (1996-97). The outcome measure was methylphenidate use in Cycle 2. Individual-level explanatory variables included sex, age, socioeconomic status (SES), mother's age at birth of child, lone-parent family status, parental working status, and hyperactivity-impulsivity and inattention probabilities. Area-level explanatory variables included income and rural or urban residence. We used hierarchical linear modelling to examine individual- and area-level factors that predicted methylphenidate use.


RESULTS
The strongest predictors of methylphenidate use were behavioural: children with high hyperactive-impulsive and (or) inattention behaviours in 1994, compared with children low on these behaviours, were 4.5 to 6 times more likely to use methylphenidate 2 years later. SES remained a significant predictor of the incidence of methylphenidate use, even when other significant predictors were held constant, with lower SES being associated with higher use. Area-level income also predicted methylphenidate use.


CONCLUSIONS
Even when children with similar behavioural symptoms and demographic characteristics were compared, socioeconomic factors had a significant impact on incidence of methylphenidate use.
Brownell
Marni D
MD
Manitoba Centre for Health Policy, Winnipeg, Manitoba. marni_brownell@cpe.umanitoba.ca
Mayer
Teresa
T
Chateau
Daniel
D
D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy*; D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D004358:Drug Therapy / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000627:therapeutic use*; D012424:Rural Population; D012959:Socioeconomic Factors; D014505:Urban Population
D000697:Central Nervous System Stimulants; D008774:Methylphenidate