(277) Sociodemographic and birth characteristics associated with initiation of methylphenidate treatment in children: a nationwide study from 2015 to 2022

Publication Number: 936

Background: Methylphenidate (MPH) is a psychostimulant drug authorized in France for the treatment of attention deficit hyperactivity disorders and narcolepsy in children over the age of 6.

Objectives: To assess the association between selected sociodemographic and birth factors and MPH initiation among children aged 5 to 10 years.

Methods: A nationwide cohort study was conducted using the French National Health Data System. Children born from 2010 to 2016 were included on September 1 of their 5th year and followed until July 31 of their 10th year or until a first MPH prescription, loss to follow-up, death, or the end of the study period (ie, July 31, 2022). Children with congenital malformations or diseases of the nervous system, mental or behavioral disorders, or who used psychotropic drugs before inclusion were excluded. The outcome measured was first MPH prescription during follow-up. Explanatory variables assessed were sex, deprivation index, size of urban area and region of residence, gestational age, birth weight, and birth month. In France, children born in the same calendar year enter the same educational level. Associations between MPH initiation and explanatory variables were estimated by adjusted hazard ratios (aHR) and their 95% confidence intervals (95% CI) using Cox models.

Results: Among 4 769 837 children reaching age 5 years between 2015 and 2022 followed for a mean of 3.5 years (SD 1.5), 38 787 MPH initiations were identified (incidence rate 2.3/1000 person-years). Mean age at MPH initiation was 7.7 years (SD 1.2). Factors associated with an increased likelihood of MPH initiation were male sex (aHR 3.48, 95%CI 3.40-3.57), prematurity (aHR increased from 1.29 [1.24-1.34] for moderate to 3.39 [2.95-3,90] for extreme prematurity compared with term birth), low weight for gestational age (aHR increased from 1.26 [1.21-1.30] for low to 1.55 [1.48-1.62] for extremely low compared with normal weight) and later birth months (aHR increased from 1.07 [1.02-1.13] for children born in February to 1.54 [1.47-1.62] for those born in December compared with those born in January). Most socioeconomically disadvantaged children had a lower likelihood of MPH initiation (aHR 0.84 [0.81-0.87] for the least versus the most disadvantaged quintile), as did those living in a large urban area with a population of 200 000 or more (aHR 0.85 [0.83-0.88] versus smaller urban areas).

Conclusions: Male sex, prematurity, low birth weight, being more socially advantaged, residing in a medium-sized urban area were associated with MPH initiation in children. Younger children in the same grade were more likely to initiate MPH than older children. Health system seems to be used in part as a corrective factor to the educational system, which groups children of different ages and maturities in the same grade.