4F-01 - Sociodemographic and birth characteristics associated with initiation of recombinant growth hormone treatment in children: a nationwide study from 2010 to 2023

Background: Somatropin (recombinant growth hormone) is mainly used to offset growth deficiencies in children with a significant risk of short stature (growth hormone deficiency and other conditions such as small size for gestational age, chronic renal failure, Turner or Prader-Willi syndromes).

Objectives: To assess the association between selected sociodemographic and birth factors and somatropin initiation among children under 14 years of age.

Methods: A nationwide cohort study was conducted using the French National Health Data System. Children born from 2010 to 2016 were included from birth and followed until December 31, 2023 (study end) or somatropin prescription, whichever came first. The outcome measured was somatropin initiation. Explanatory variables assessed were sex, gestational age, birth weight, certain in utero exposures, birth rank, deprivation index, size of urban area and region of residence, birth quarter. Associations between somatropin initiation and explanatory variables were estimated by adjusted hazard ratios (aHR) and their 95% confidence intervals (95% CI) using Cox models.

Results: A total of 10 366 somatropin initiations were identified among 4 985 232 children included (incidence rate 0.2/1000 person-years). Factors associated with greater likelihood of somatropin initiation were prematurity (aHR 1.77 [1.66-1.88] for moderate to 6.82 [5.81-8.00] for extreme prematurity versus term birth), low weight for gestational age (aHR 3.13 [2.96-3.30] for low to 6.92 [6.58-7.29] for extremely low versus normal weight), in utero exposure to alcohol or psychotropic drugs (1.40 [1.17-1.68] and 1.18 [1.08-1.29] respectively), not being the first born (aHR 1.35 [1.30-1.41] for the second and 1.41 [1.30-1.54] after the second versus the first born), living in a urban area a with a population of 50 000 or more (aHR 1.25 [1.16-1.34] versus smaller areas) and later birth quarter (aHR increased from 1.07 [1.01-1.13] for children born in the second quarter to 1.21 [1.15-1.28] for those born in the fourth quarter versus those born in the first quarter of the same year). Most socioeconomically disadvantaged children had a lower likelihood of initiating somatropin (aHR 0.63 [0.59-0.67] for the most versus the least disadvantaged quintile). Sex, in utero exposure to tobacco or valproate were not significantly associated with somatropin prescription.

Conclusions: Prematurity, low birth weight, being more socially advantaged, not being the first-born sibling, in utero exposure to alcohol and psychotropics were associated with somatropin initiation in children. Within the same year of birth, younger children were more likely to be prescribed somatropin, which, to our knowledge had never been reported.