The use of medication against attention deficit/hyperactivity disorder in Denmark: a drug use study from a patient perspective.
OBJECTIVE
Our aim was to characterize utilization patterns for drugs used to treat attention deficit/hyperactivity disorder (ADHD) on the level of the individual patient among Danish users, focusing on treatment duration, doses used, and concurrent use of ADHD and non-ADHD drugs.


METHODS
Using the Danish Registry of Medicinal Product Statistics, we extracted data on 1,085,099 prescriptions for ADHD drugs issued to a total of 54,024 persons in the study period 1 January 1995 to 30 September 2011. For users in the final year of the study period, we further extracted 315,365 prescriptions for non-ADHD drugs. Drug utilization was characterized using descriptive statistics.


RESULTS
The mean duration of ADHD treatment was highest (3.6-4.2 years) for patients initiating therapy at a young age (age<13). Dropout rate after receiving only one prescription was highest among off-label users (age<6 and age >17). All age categories showed an increase in the average daily dosage of methylphenidate used from 2003 to 2010. Concomitant treatment with methylphenidate and atomoxetine was rare, as only 2 % of methylphenidate treatment overlapped with atomoxetine treatment. Nineteen percent of methylphenidate instant-release treatment overlapped with methylphenidate controlled-release treatment. Users of ADHD drugs across all age categories had an increased use of drugs related to the nervous system, especially antipsychotics [standardized morbidity rate (SMR), 6.4-19.5] and antiepileptics (SMR, 4.0-5.5).


CONCLUSIONS
We found certain traits that warrant further investigation: the apparent increase in average daily doses, the low adherence to treatment among off-label users, and the increased use of other psychotropic medication.
Clinical Pharmacology, Institute of Public Health, University of Southern Denmark, Winsløwparken 19, 2, 5000 Odense C, Denmark. apottegaard@health.sdu.dk
Anton
A
Pottegård
Bine Kjøller
BK
Bjerregaard
Dorte
D
Glintborg
Lisbeth Sandal
LS
Kortegaard
Jesper
J
Hallas
Søren Ilsøe
SI
Moreno
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000188:drug therapy* / Q000523:psychology; D000697:Central Nervous System Stimulants / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D003718:Denmark; D011307:Drug Prescriptions; D004359:Drug Therapy, Combination; D004363:Drug Utilization / Q000639:trends; D017723:Drug Utilization Review; D019983:Guideline Adherence; D006801:Humans; D053208:Kaplan-Meier Estimate; D055118:Medication Adherence; D008875:Middle Aged; D056687:Off-Label Use; D010352:Patient Dropouts; D017410:Practice Guidelines as Topic; D010818:Practice Patterns, Physicians' / Q000639:trends*; D012042:Registries; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
D000697:Central Nervous System Stimulants