[Variability and tendencies in the consumption of methylphenidate in Spain. An estimation of the prevalence of attention deficit hyperactivity disorder].
BACKGROUND
Attention deficit hyperactivity disorder (ADHD) is one of the most frequently occurring behavioural disorders in childhood; its prevalence in Spain is estimated to be around 3-6%. Methylphenidate (MPH) is the only medication available on the Spanish market.


METHODS
The prevalence of ADHD was estimated by calculating the daily doses of MPH defined per 1000 inhabitants per day (Therapeutic group N06B A04), over the period 1992-2001, for each of the provinces in Spain. Figures for the number of prescriptions made out were obtained from the Spanish Ministry of Health and Consumer Affairs. The odds ratio and the 95% confidence interval were calculated, as was the linear tendency c2.


RESULTS
A minimum prevalence of ADHD was estimated to be 0.63 per 1000 inhabitants per day for the overall Spanish population. MPH use and consumption does, however, vary with a north-south slope, and higher prevalence in Catalonia than in Andalusia. Taken as a whole, the consumption of MPH has undergone a uniform 8% increase annually since 1992, with a rising variation in the OR from 0.19 up to the year 2001 (OR = 1), and every year it has been statistically significant (c 2 = 78.246; p < 0.05).


CONCLUSIONS
The consumption of MPH enables us to estimate the distribution of ADHD in Spain. The figures obtained do not yet allow us to offer an accurate estimate of the prevalence of the disease, despite the increase in consumption. Nevertheless, they do enable us to establish the variations that exist in medical practice regarding this disease.
Criado Alvarez
J J
JJ
Instituto de Ciencias de la Salud de Castilla La Mancha, Talavera de la Reina, Toledo, España. jjcriado@jccm.es
Romo Barrientos
C
C
D000293:Adolescent; D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy / Q000453:epidemiology*; D015415:Biomarkers; D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D002648:Child; D016000:Cluster Analysis; D004363:Drug Utilization / Q000706:statistics & numerical data / Q000639:trends; D005260:Female; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000627:therapeutic use*; D015995:Prevalence; D013030:Spain / Q000453:epidemiology
D015415:Biomarkers; D000697:Central Nervous System Stimulants; D008774:Methylphenidate